Duarte Diaz

Interests

Research

Mycotoxins, Dairy, Nutrition, Comparative Nutrition, Animal Nutrition, International Agriculture, Toxicology, Food Safety

Teaching

Diary, Animal Nutrition, International Agriculture (livestock)

Courses

Scholarly Contributions

Chapters

• Diaz, D. E. (2008). A review on the use of mycotoxin sequestering agents in agricultural livestock production. In The Mycotoxin Blue Book. American Chemical Society. doi:10.1021/BK-2008-1001.CH007
• Jouany, J. P., & Diaz, D. E. (2005). Effects of Mycotoxins in Ruminants. In The Mycotoxin Blue Book. Nottingham University Press.
• Santin, E., & Diaz, D. E. (2005). Mould growth and mycotoxin production.. In The Mycotoxin Blue Book. Nottingham University Press.
• Smith, T. K., Diaz, G., Swamy, H. V., & Diaz, D. E. (2005). Current concepts in mycotoxicoses in swine.. In The Mycotoxin Blue Book. Nottingham University Press.
• Surai, P. F., Dvorska, J. E., & Diaz, D. E. (2005). Effects of mycotoxins on antioxidant status and immunity.. In The Mycotoxin Blue Book. Nottingham University Press.

Journals/Publications

• Wagoner, R., Benally, K., Cabrera, D., Lopez, G., Lopez-Galvez, N., & Diaz, D. (2024). Prevalence of e.coli O157:H7, Salmonella, and Cryptosporidium Among Arizona Dairy Workers Using Post-Work Swabbing. Journal of Agricultural Safety and Health, 30(1). doi:10.13031/jash.15680
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  The dairy industry in Arizona, like many other agricultural industries in the United States, is dependent on the labor that migrant farm workers provide. Infections caused by zoonotic pathogens are commonly underreported or misdiagnosed, and possibly more so in migratory workers that face cultural, structural, legal, financial, and geographic barriers to health services. The objectives of this project were to: assess the demographics of Arizona dairy workers, determine the exposure potential of Arizona dairy workers to zoonotic organisms, and inform best management practices. A questionnaire including demographics, work tasks, and household characteristics was administered. Swab samples were collected from the shoulders, knees, and foreheads of employees at two dairy operations at the end of the work shift. The swabs were cultured for E.coli O157:H7 and Salmonella. Molecular DNA isolated from Salmonella and Cryptosporidium was quantified using droplet-digital Polymerase Chain Reaction (ddPCR). Twenty dairy workers were recruited, and 60 samples were collected. The majority of workers were male, preferred to speak Spanish, and identified as Latino/Hispanic (68.8%, 93.8%, and 93.8%, respectively). E. coli O157:H7 was detected in 13% of cultured knee and forehead samples. Salmonella spp. gene copies were detected on 60.0% of samples collected from forehead skin samples; 40.0% of shoulder clothing samples; and 15% of knee clothing samples, as measured via ddPCR. The positive cultural and molecular samples indicate the need for improved post-workday sanitation practices at farms. This study provides surveillance of a largely invisible population, including insights that can be used to create site-specific health and safety protocols for the dairy industry, inform risk assessment models, and foster preventive practices in the dairy industry.
• Diaz, D., Reith, R., Sieck, R., Grijalva, P., Diaz, D., Schmidt, T., Yates, D., & Pettersen, J. (2021). Zilpaterol Hydrochloride and Heat Stress Each Alter the Cattle Adipose Transcriptome and Predicted to Alter Molecular Pathways After 21 Days. Journal of Animal Science, 99, 17-18.
• Garcia, S., Beard, J., Diaz, D. E., Schmidt, T. B., Yates, D. T., Petersen, J. L., Webster, C., Grijalva, P., & Rios, A. (2022). 12 Growth Performance, Physiology, and Carcass Merit of Supplementing Brahman Steers with Zilpaterol Hydrochloride Under Heat Stress Conditions. Journal of Animal Science, 100(Supplement_4), 6-7. doi:10.1093/jas/skac313.008
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  Abstract Supplementation with a β- adrenergic agonist (β-AA) for 21 days in Brahman steers under heat stress conditions (HS) was evaluated with respect to feedlot performance and carcass merit. Twenty-four Brahman steers (kg = 338 ± 39) were housed in two controlled environment chambers with one of two environmental (ENV) conditions 1) heat stress (HS; THI = 73 to 85) and 2) thermoneutral (TN; THI = 68) with either Zilpaterol hydrochloride (ZL) or soymeal supplementation (CN) using a randomly assigned in a 2 x 2 factorial design (n=6/group). Daily data were collected for dry matter intake, water intake, respiratory rate (RR), and rectal temperature (RT). At the end of 21 d period, total weight gain was used to calculate average daily gain (ADG) and gain to feed. Blood samples were collected from the jugular vein on days -7, 3, 10, and 21 for cortisol analysis, and biological impedance analysis (BIA) was determined on days 3, 10, and 21 on each animal. Steers were harvested at 544 kg on average post supplementation/environment conditions, and carcass merit was determined. There were no differences (P > 0.05) in feedlot performance. Brahmans exposed to heat stress had greater RR during the heat stress periods of the experiment, regardless of supplementation. Environment and day interactions (P < 0.04) were observed for RT, HS steers had a greater RT on d 8 but similar RT on d 15 and 19. Stressed steers with ZL had higher RT (P < 0.05) than TN/CN steers on d 11. There was no interaction (P > 0.05) between environmental conditions and CN and ZH supplementation for cortisol concentrations. Regardless of environmental treatment or supplementation, no difference (P > 0.05) was associated with BIA characteristics. There were no differences (P > 0.05) for hot carcass weight, cold carcass weight, USDA yield grade, 12th rib loin eye area, marbling score, KPH percentage, and 12th rib fat thickness between groups. Twelfth-rib loin eye area lean color from HS/CN had higher lightness (L*) (P < 0.05) than TN/CN steers. HS/CN steers present a similar (L*) to ZL in TN and HS conditions. Redness-greenness (a*) was greater (P = 0.01) in carcasses from HS steers with or without ZL than TN/ZL but similar to TN/CN. Steers exposed to HS and CN had a higher (P = 0.02) change of 12th rib lean color from yellow to blue (b*) than TN steers with CN and ZL. Supplementation with β-AA did not negatively impact growth, carcass performance, or carcass merit in heat-stressed steers.
• Reith, R. R., Sieck, R. L., Grijalva, P. C., Swanson, R. M., Fuller, A. M., Diaz, D. E., Schmidt, T. B., Yates, D. T., & Petersen, J. L. (2022). Transcriptome analyses indicate that heat stress-induced inflammation in white adipose tissue and oxidative stress in skeletal muscle is partially moderated by zilpaterol supplementation in beef cattle. Journal of animal science.
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  Heat stress (HS) triggers oxidative stress, systemic inflammation, and disrupts growth efficiency of livestock. β-adrenergic agonists supplemented to ruminant livestock improve growth performance, increase skeletal muscle mass and decrease carcass fat. The objective of this study was to understand the independent and interacting effects of HS and zilpaterol hydrochloride (ZH) supplementation on the transcriptome of subcutaneous white adipose tissue and the longissimus dorsi muscle in steers. Twenty-four Red Angus-based steers were assigned to thermoneutral (TN; Temperature Humidity Index (THI)=68) or HS (THI=73-85) conditions and were not supplemented or supplemented with ZH (8.33 mg/kg/day) for 21 d in a 2x2 factorial. Steers in the TN condition were pair-fed to the average daily feed intake of HS steers. RNA was isolated from adipose tissue and skeletal muscle samples collected via biopsy on 3, 10, and 21 d and sequenced using 3' Tag-Seq to an achieved average depth of 3.6 million reads/sample. Transcripts, mapped to ARS-UCD1.2, were quantified. Differential expression (DE) analyses were performed in DESeq2 with a significance threshold for false discovery rate of 0.05. In adipose, 4 loci (MISP3, APOL6, SLC25A4, S100A12) were DE due to ZH on d 3, and 2 (RRAD, ALB) were DE due to the interaction of HS and ZH on d 10 (Padj
• Diaz, D. E., Reith, R. R., Sieck, R. L., Grijalva, P. C., Schmidt, T. B., Yates, D. T., & Petersen, J. L. (2021). 131 Zilpaterol Hydrochloride and Heat Stress Each Alter the Cattle Adipose Transcriptome and Predicted to Alter Molecular Pathways After 21 Days. Journal of Animal Science, 99(Supplement_1), 17-18. doi:10.1093/jas/skab054.031
• Ottman, M. J., Diaz, D., Sheedy, M. D., & Ward, R. (2016). Effect of Amount of Irrigation Water Applied on Forage Sorghum Yield and Quality at Maricopa, AZ, 2015.. College of Agriculture and Life Sciences, University of Arizona.
• Ottman, M. J., Diaz, D., Sheedy, M. D., & Ward, R. (2016). Forage Sorghum Hybrid Yield and Quality at Maricopa, AZ, 2015. College of Agriculture and Life Sciences, University of Arizona.
• Ottman, M. J., Diaz, D., Sheedy, M. D., & Ward, R. (2016). Irrigation Interval Effect on Yield and Quality of Forage Sorghum at Maricopa, AZ, 2015. College of Agriculture and Life Sciences, University of Arizona.
• Ottman, M. J., Diaz, D., Sheedy, M. D., & Ward, R. (2016). Nitrogen Fertilizer Rate Effect on Forage Sorghum Yield, Quality, and Tissue Nitrogen Concentrations at Maricopa, AZ, 2015. College of Agriculture and Life Sciences, University of Arizona.
• Ottman, M. J., Diaz, D., Sheedy, M. D., & Ward, R. (2016). Row Spacing Effect on Forage Sorghum Yield and Quality at Maricopa, AZ, 2015. College of Agriculture and Life Sciences, University of Arizona.
• Reith, R., Sieck, R., Grijalva, P., Swanson, R., Diaz, D., Schmidt, T., Yates, D., & Petersen, J. (2021). Supplementing zilpaterol hydrochloride to heat-stressed beef cattle for 21 d alters the adipose transcriptome and is predicted to alter stress response pathways. Translational Animal Science, 56-60. doi:http://doi.org/10.1093/tas/txabl158
• Sieck, R., Reith, R., Fuller, A., Grijalva, P., Treffer, L., Swanson, R., Ponte, M., Khalimonchuk, O., Diaz, D., Schmidt, T., Yates, D., & Petersen, J. (2021). Beta-adrenergic agonists and heat stress impact skeletal muscle gene expression and mitochondrial function in beef cattle. Translational Animal Science, 99, 17-18.
• Allen, S. C., Russo, K., Compart, D. M., Diaz, D., & Ward, S. H. (2020). Dose response reduction of aflatoxin M1 in milk of Holstein cows administered an aluminosilicate clay adsorbent. The Bovine Practitioner, 54(1), 1-8. doi:https://doi.org/10.21423/bovine-vol54no1p1-8
• Matthew, V. P., Robert, C., Yao, X., Compart, D., Kay, R., Renquist, B. J., Leticia, C., & Diaz, D. (2020). Evaluation of Mid-Lactation Holstein Cows During Heat Stress in Response to a Dietary Feed Additive. Dairy and Vet Sci J., 14(5), 116-125. doi:DOI: 10.19080/JDVS.2020.14.555900
• Diaz, D. (2019). Mycotoxins and mycotoxicosis. Feedstuffs reference issue and & nutrition guide, 52-60.
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  Feedstuffs Yearly Reference Guide. Feedstuff is the most important popular press agricultural magazine with global readership with 71.5k total weekly impressions, 10,000 eNews subscribers, and 12.5k Audited Subscribers (https://marketing.farmprogress.com/brands/livestock/feedstuffs/)
• Compart, D., Collier, R., Wright, A., Renquist, B. J., Xiao, Y., Diaz, D., & Vander Poel, M. (2018). Environmental chamber heat stress responses and adaptations in crossbred Hereford steers. Translational Animal Science (TAS), Supplement 1, S185-S188.
• Diaz, D., Vander, P. M., Xiao, Y., Renquist, B., Wright, A., Collier, R., & Compart, D. (2018). Environmental chamber heat stress responses and adaptations in crossbred Hereford steers. Translational Animal Science, 2(suppl_1), S185--S188.
• Diaz, D., Whitlow, L., & Hagler, W. (2018). Mycotoxins and Mycotoxicosis. Feedstuffs Magazine Feed Mill Tech Guide, 9-23.
• Diaz, D., Whitlow, L., & Hagler, W. (2017). Mycotoxins and Mycotoxicosis. Feedstuff Feed and Mill Technology Guidebook, 9-23.
• Ward, R. W., Sheedy, M. D., Diaz, D. E., & Ottman, M. J. (2017). Effect of Amount of Irrigation Water Applied on Forage Sorghum Yield and Quality at Maricopa, AZ, 2015.. College of Agriculture and Life Sciences, University of Arizona.
• Ward, R. W., Sheedy, M. D., Diaz, D. E., & Ottman, M. J. (2017). Irrigation Interval Effect on Yield and Quality of Forage Sorghum at Maricopa, AZ, 2015. College of Agriculture and Life Sciences, University of Arizona.
• Diaz, D., Whitlow, L. W., & Hagle, W. M. (2016). Mycotoxins & Mycotoxicosis. Feedstuffs: The Feed & Mill Technology Guidebook.
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  This review is part of a special issue published by Feedstuffs magazine titled "The Feed & Mill Technology Guidebook".
• Rottinghaus, G. E., Oliver, W. T., Miles, J. R., Harrell, R. J., Dibner, J. J., & Diaz, D. E. (2012). Zearalenone enhances reproductive tract development, but does not alter skeletal muscle signaling in prepubertal gilts !. Animal Feed Science and Technology, 174(1), 79-85. doi:10.1016/j.anifeedsci.2012.02.012
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  Abstract Zearalenone is a potent mycotoxin that has estrogenic properties. In vitro results indicate that zearalenone metabolites down-regulate proteins associated with protein synthesis (protein kinase B, Akt) and cellular proliferation (extracellular signal-regulated kinase, ERK). The objectives of this study were to determine the effect of zearalenone on (1) growth performance and signaling for protein synthesis, and (2) reproductive tract development. At 28 d of age, gilts were randomly assigned to consume a commercial basal diet (C) or C+1.5 mg/kg zearalenone ( n  = 10) for 4 wk, at which time gilts were euthanized, urine collected, and tissue collected. No differences were observed in average daily gain, average daily feed intake, or gain:feed (P>0.28). Reproductive tract weight (2.4-fold) and uterine endometrial gland development (50%) were increased in zearalenone fed gilts (P 0.28), but gilts consuming zearalenone had 2.0- and 3.5-fold higher abundance of ER-β mRNA and protein, respectively (P 0.36). Zearalenone had no effect on growth performance or skeletal muscle signaling in prepubertal gilts, but zearalenone increased reproductive tract size and glandular development, possibly due, in part, to altering the expression of ER-β.
• Zanton, G. I., Richards, J. D., Nemec, L. M., Gressley, T. F., Diaz, D. E., & Atwell, C. A. (2012). Immune responses in lactating Holstein cows supplemented with Cu, Mn, and Zn as sulfates or methionine hydroxy analogue chelates.. Journal of dairy science, 95(8), 4568-77. doi:10.3168/jds.2012-5404
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  The aim of this study was to compare effects of inorganic sulfate versus chelated forms of supplemental Cu, Mn, and Zn on milk production, plasma and milk mineral concentrations, neutrophil activity, and antibody titer response to a model vaccination. Holstein cows (n=25) were assigned in 2 cohorts based on calving date to a 12-wk randomized complete block design study. The first cohort consisted of 17 cows that had greater days in milk (DIM; mean of 77 DIM at the start of the trial) than the second cohort of 8 cows (32 DIM at the start of the trial). Diets were formulated to supplement 100% of National Research Council requirements of Cu, Mn, and Zn by either inorganic trace minerals (ITM) in sulfate forms or chelated trace minerals (CTM) supplied as metal methionine hydroxy analog chelates, without accounting for trace mineral contribution from other dietary ingredients. Intake and milk production were recorded daily. Milk composition was measured weekly, and milk Cu, Mn, and Zn were determined at wk 0 and 8. Plasma Cu and Zn concentrations and neutrophil activity were measured at wk 0, 4, 8, and 12. Neutrophil activity was measured by in vitro assays of chemotaxis, phagocytosis, and reactive oxygen species production. A rabies vaccination was administered at wk 8, and vaccine titer response at wk 12 was measured by both rapid fluorescent focus inhibition test and ELISA. Analyzed dietary Cu was 21 and 23mg/kg, Mn was 42 and 46mg/kg, and Zn was 73 and 94mg/kg for the ITM and CTM diets, respectively. No effect of treatment was observed on milk production, milk composition, or plasma minerals. Dry matter intake was reduced for CTM compared with ITM cows, but this was largely explained by differences in body weight between treatments. Milk Cu concentration was greater for CTM than ITM cows, but this effect was limited to the earlier DIM cohort of cows and was most pronounced for multiparous compared with primiparous cows. Measures of neutrophil function were unaffected by treatment except for an enhancement in neutrophil phagocytosis with the CTM treatment found for the later DIM cohort of cows only. Rabies antibody titer in CTM cows was 2.8 fold that of ITM cows as measured by ELISA, with a trend for the rapid fluorescent focus inhibition test. Supplementation of Cu, Mn, and Zn as chelated sources may enhance immune response of early lactation dairy cows compared with cows supplemented with inorganic sources.
• Meldrum, J. B., Harrell, R., Harper, A. F., Estienne, M. J., & Diaz, D. E. (2010). Assessment of a hydrated sodium calcium aluminosilicate agent and antioxidant blend for mitigation of aflatoxin-induced physiological alterations in pigs. Journal of Swine Health and Production, 18(6), 282-289.
• Eun, J., ZoBell, D., Dschaak, C., Diaz, D., & Tricarico, J. (2009). Effects of Supplementing a Fibrolytic Feed Enzyme on the Growth Performance and Carcass Characteristics of Beef Steers. Professional Animal Scientist, 25(3). doi:10.15232/S1080-7446(15)30729-4
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  The objective of this study was to determine the growth performance of growing and finishing beef steers when fed with a fibrolytic feed enzyme (FFE) in a completely randomized design. This experiment was conducted during growing and finishing periods using 60 group-penned Angus crossbred steers randomly assigned to treatments: control (no enzyme), low enzyme, and high enzyme. For the enzyme treatments, the FFE was added to the control diet at a dose of 1 or 2 g enzyme/kg DM TMR for the low-enzyme or high-enzyme treatment, respectively. Supplementing the growing diet with FFE did not affect DMI, regardless of dose rate. Body weight gain was not affected by FFE supplementation. Supplementation with FFE did not affect ADG and G:F. The overall growth performance during the finishing period was not influenced by the FFE, as was seen in the growing period. However, supplementation with FFE reduced 12thrib fat thickness (P < 0.01) and tended to decrease the marbling score (P = 0.14) across both enzyme doses. Supplementing the beef growing and finishing diets with FFE at 1 and 2 g/kg DM TMR did not affect growth performance and had minor effects on the carcass characteristics of beef steers.
• Piva, G., Moschini, M., Masoero, F., Gallo, A., & Diaz, D. E. (2009). Effects of the procedure of inclusion of a sequestering agent in the total mixed ration on proportional aflatoxin M1 excretion into milk of lactating dairy cows. Animal Feed Science and Technology, 150(1), 34-45. doi:10.1016/j.anifeedsci.2008.07.009
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  Abstract The objectives were to determine changes of aflatoxin M1 (AFM1) concentration and proportional excretion in milk of lactating cows when adding a commercial sequestering agent (SA) to a total mixed ration (TMR) contaminated with aflatoxin B1 (AFB1) from different feeds and how these changes were affected by different ways of adding the SA to the TMR. Two experiments were completed using eight cows each and the same TMR which had a common forage base of corn silage, alfalfa and grass hays (300, 250 and 50 g/kg dry matter, respectively) to which AFB1-contaminated feeds were added. The AFB1 ingestion period was 9 days followed by a 5 day clearance period. In experiment 1, cows were randomly assigned to one of the two diets in a completely randomized design and fed a control diet made of forages plus AFB1-contaminated corn meal plus a pelleted protein/mineral/vitamin premix (Pmx) or the CC-SA diet of forages plus AFB1-contaminated corn meal with SA plus the pellet Pmx. In experiment 2, cows were randomly assigned to one of four diets in a replicated 4×4 Latin square design. Diets were CC-SA (forages plus AFB1-contaminated corn meal with SA plus a pellet Pmx), Pellet-SA (forages plus an AFB1-contaminated complete concentrate with SA as a pellet), Meal-SA (forages plus AFB1-contaminated complete concentrate with SA as a meal) and PMX-SA (forages plus AFB1-contaminated corn meal plus a pellet Pmx with SA). Milk samples were collected at days 0, 3, 5, 7, 9, 11 and 14 of each period and analyzed for AFM1 content and the proportion AFB1 excretion in milk was calculated. In experiment 1, milk AFM1 concentration and proportional excretion were reduced (47% and 44%, respectively; P P P
• Whitlow, L. W., Huntington, G. B., Hopkins, H., Hopkins, B. A., Hill, S. R., Diaz, D. E., Davidson, S., Brownie, C., Brown, T. T., & Bolt, S. M. (2009). The addition of cottonseed hulls to the starter and supplementation of live yeast or mannanoligosaccharide in the milk for young calves.. Journal of dairy science, 92(2), 790-8. doi:10.3168/jds.2008-1320
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  The objectives of this study were to investigate the effects of the addition of cottonseed hulls (CSH) to the starter and the supplementation of live yeast product (YST) or mannanoligosaccharide product (MOS) to milk, on growth, intake, rumen development, and health parameters in young calves. Holstein (n = 116) and Jersey (n = 46) bull (n = 74) and heifer (n = 88) calves were assigned randomly within sex at birth to treatments. All calves were fed 3.8 L of colostrum daily for the first 2 d. Holstein calves were fed 3.8 L of whole milk, and Jersey calves were fed 2.8 L of whole milk through weaning at 42 d. Calves continued on trial through 63 d. Six treatments were arranged as a 2 x 3 factorial. Calves received either a corn-soybean meal-based starter (21% crude protein and 6% acid detergent fiber; -CSH) or a blend of 85% corn-soybean meal-based starter and 15% CSH (18% crude protein and 14% acid detergent fiber; +CSH) ad libitum. In addition, calves received whole milk with either no supplement (NONE) or supplemented with 3 g/d of mannanoligosaccharide product (MOS) or 4 g/d of live yeast product (YST) through weaning at 42 d. Twelve Holstein steers [n = 6 (per starter type); n = 4 (per supplement type)] were euthanized for collection and examination of rumen tissue samples. Dry matter intake (DMI) was greater for Holstein calves fed +CSH (0.90 kg/d) than -CSH (0.76 kg/d). Final body weight at 63 d of Holstein calves fed +CSH (75.8 kg) was greater than that of those fed -CSH (71.0 kg). Average daily gain (ADG) was greater for Holstein calves fed +CSH (0.58 kg/d) than -CSH (0.52 kg/d). However, Holstein calves fed -CSH had a greater feed efficiency (FE; 0.71 kg of ADG/kg of DMI) than those fed +CSH (0.65 kg of ADG/kg of DMI). Also, Holstein calves fed +CSH had narrower rumen papillae (0.32 mm) compared with those fed -CSH (0.41 mm). There were no significant effects of CSH on DMI, ADG, or FE in Jersey calves. There were no significant effects of YST or MOS on DMI, ADG, FE, or rumen papillae measures in Holstein calves. Jersey calves fed YST or MOS had greater final body weight at 63 d (51.2 kg and 51.0 kg, respectively) than calves fed NONE (47.5 kg). However, there were no significant effects of YST or MOS on DMI, ADG, or FE in Jersey calves.
• Moschini, M., Masoero, F., Gallo, A., & Diaz, D. E. (2007). In vivo release of aflatoxin B1 bound to different sequestering agents in dairy cows. Italian Journal of Animal Science, 6(sup1), 315-317. doi:10.4081/ijas.2007.1s.315
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  Nine lactating dairy cows, producing 31.08±5.00 kg of milk/cow/day and fed with a Total Mixed Ration (TMR) with an intake of 22.3±0.8 Kg s.s./cow, were used to investigate the resistance of the AFs-SA complex in the rumen and in the gastro-intestinal tract. Two commercial sequestering agents Atox® and Mycosorb® were used. The AFB1 was also mixed to a rumen fluid (R-SA). AFB1 sequestered by Atox®, Mycosorb® and by R-SA were then fed to cows before the morning meal. Milk samples were collected for 6 consecutive milkings and analyzed for AFM1 content. The in vitro binding capacity of the two SA were 94.2% for Atox®, 84.3% for Mycosorb® and 71.86% for the R-SA. Both Atox® and Mycosorb® released some of the sequestered AFB1 determining an increase of the AFM1 in milk as soon as in the 1st milking from oral drenching (4.23±7.33; 23.60±8.23 and 46.06±39.84 ppt for Atox®, Mycosorb® and R-SA respectively). The AFM1 (ng/cow) in milk at the 4th milking was lower (66.04, 661.77 and 1613.04; P
• Moschini, M., Masoero, F., Gallo, A., & Diaz, D. E. (2007). Mucosal absorption of aflatoxin B1 in lactating dairy cows. Italian Journal of Animal Science, 6(sup1), 324-326. doi:10.4081/ijas.2007.1s.324
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  The objective of this experiment was to monitor plasma levels of aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1) in lactating dairy cows fed afltaoxin contaminated corn. Seven lactating Holstein cows were given a bolus of a naturally contaminated corn meal assuring an intake of 4.9mg AFB1, 1.01 mg AFB2, 10.63 mg AFG1 and 0.89 mg AFG2. Vitamin A, at 1,000,000 IU, was also added as a biomarker of intestinal absorption. Blood samples were collected at 0, 15, 30, 60, 120, 180, 270 and 360 min after bolus. Plasma was analyzed by HPLC for AFB1, AFB2, AFG1, AFG2 and AFM1 concentrations. Within the considered time points, the peak plasma AFB1 concentration was obtained as soon as 15 minutes from drenching. The plasma AFM1 concentration was considerable as early as the first collection (15 minutes) and peaked at 270 minutes indicating both a rapid absorption of AFB1 through the rumen wall and metabolization into AFM1 in liver. The plasma palmitate level suggests the intestinal contribution to the aflatoxin plasma level after 120 min.
• Piva, G., Moschini, M., Masoero, F., Gallo, A., & Diaz, D. E. (2007). Carryover of aflatoxin from feed to milk in dairy cows with low or high somatic cell counts.. Animal : an international journal of animal bioscience, 1(9), 1344-50. doi:10.1017/s1751731107000663
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  Aflatoxin M1 (AFM1) residues in milk are regulated in many parts of the world and can cost dairy farmers significantly due to lost milk sales. Additionally, due to the carcinogenicity of this compound contaminated milk can be a major public health concern. Thirty-four lactating dairy cows were utilised to investigate the relationship between somatic cell counts (SCC), milk yield and conversion of dietary aflatoxin B1 (AFB1) into milk AFM1 (carryover (CO)). The AFM1 in milk increased as soon as the first milking after animal ingestion with a pattern of increment up to the observed plateau (between 7th and 12th days of AFB1 ingestion). There was a significant (P < 0.01) effect of the milk yield whereas no effect could be attributed to the SCC levels or to the milk yield × SCC interaction. Similarly, the main effect of milk yield was also observed (P < 0.01) on the total amount of AFM1 excreted during the ingestion period. Although the plasma concentration of gamma-glutamyl transferase was significantly affected by aflatoxin administration, levels of this liver enzyme were within the normal range for lactating dairy cows. The current data suggest that milk yield is the major factor affecting the total excretion of AFM1 and that SCC as an indicator of mammary gland permeability was not related to an increase in AFM1 CO.
• Piva, G., Moschini, M., Morlacchini, M., Masoero, F., Fusconi, G., & Diaz, D. E. (2006). Pea seeds (Pisum sativum), faba beans (Vicia faba var. minor) and lupin seeds (Lupinus albus var. multitalia) as protein sources in broiler diets: effect of extrusion on growth performance. Italian Journal of Animal Science, 5(1), 43-54. doi:10.4081/ijas.2006.43
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  The effect of extrusion of pea seeds (Pisum sativum) (PS), faba bean (Vicia faba, variety minor) (FB) and lupin seeds (Lupinus albus, variety multitalia) (LS) on broiler performance were evaluated. Four hundred sixty two 1d-old Ross male chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens per treatment/22 birds per pen). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The bulk of the base diet (control diet) was corn (48.8%, 53.7% and 57%), solvent-extracted soy- bean meal (42.8%, 37.3% and 33.4%), corn oil (4.4%, 5.2% and 6.3%), plus synthetic amino acids, minerals, trace minerals and vitamins, respectively for the 1-10d-old, 11-28d-old and 29 to 42d-old growing periods. The amounts of PS, FB and LS used on an as fed basis were: PS and extruded PS (EPS): 353 (1-10d-old), 356 (11-28d-old) and 350 (29- 42d-old) g/kg; FB and extruded FB (EFB): 479 (1-10d-old), 497 (11-28d-old) and 500 (29-42d old) g/kg; LS and extrud- ed LS (ELS): 360 (1-10d-old) and 300 (11-42d-old) g/kg. High levels of pea (350 g/kg) and faba bean (500 g/kg) did not show negative effects on body weight gain (BWG) and bird feed intake compared to control. Lupin at the 300 g/kg level reduced (P< 0.05) the BWG during the finishing period (22 to 42 d), however the effect disappeared over the whole experimental period (1-42 d) compared to the control group. The ELS group had a lower (P< 0.01) feed intake com- pared to the control group and to the LS group. The feed conversion rate (FCR) was similar among groups for the whole experimental period; however during the grower period the FCR was higher (P< 0.05) for the PS, FB and EFB groups com- pared to the control group. Birds consuming the PS diet had a reduced (P< 0.05) eviscerated carcass yield compared to the control group. The breast meat percent yield was higher (P< 0.01) for birds consuming the FB and EFB diets compared to the control group. There were no statistical differences in percent yield of the leg quarters and in blood parameters.
• Casadei, G., Pagliuca, G., Solfrizzo, M., Riley, R. T., Piva, A., Pagliuca, G., Galvano, F., Diaz, D. E., Casadei, G., & Cabassi, E. (2005). Activated carbon does not prevent the toxicity of culture material containing fumonisin B1 when fed to weanling piglets.. Journal of animal science, 83(8), 1939-47. doi:10.2527/2005.8381939x
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  Fumonisins are mycotoxins found primarily in corn and corn products that are produced by Fusarium verticillioides, F. proliferatum, and several other Fusarium species. The toxicity of fumonisin B1 (FB) from culture material with and without activated carbon was evaluated using weanling piglets. Fifty-six weanling pigs were assigned to one of four treatments diets based on BW. The treatment diets were 1) control = corn-soybean basal diet with < 2 ppm FB; 2) AC = control + activated carbon at 1% of the diet, as fed; 3) FB = control + culture material (formulated to contain 30 ppm FB, as-fed basis); and 4) AC + FB = control + activated carbon at 1% of the diet as fed + culture material (formulated to contain 30 ppm FB). A total of four replicates of four pigs per pen for the control and AC treatments and three piglets per pen for the FB and AC + FB treatments were used. Feed and water were offered ad libitum for the duration of the 42-d experiment. Compared with pigs fed the control or AC diets, pigs receiving the two FB-contaminated diets (FB or AC + FB) had lower G:F (P < 0.01), higher serum enzyme activities of gamma-glutamyltransferase and glutamic oxaloacetic transaminase (P < 0.05), and higher concentrations of cholesterol, free sphinganine, sphingosine-1-phosphate, and sphinganine 1-phosphate (P < 0.05). Although animals consuming FB diets showed no signs of respiratory distress, all pigs consuming either the FB or the AC + FB diets had marked pulmonary edema. Lesions were observed in the lungs, heart, and liver of pigs fed the FB or AC + FB diets, and treatment-associated changes also were seen in the pancreas, intestines, spleen, and lymph nodes. No lesions were observed in the brain. In liver, lung, heart, pancreas, spleen, intestines, and lymph nodes, the histopathological effects observed were more severe in the AC + FB group, suggesting that the AC treatment worsened the toxic effects of FB. Additionally, immunological measurements of macrophage function (CD14) were affected (P < 0.05) by the consumption of the FB diets. The consumption of FB diets containing 30 ppm fumonisin B1 from cultured material significantly affected performance, biochemical measurements, and organ pathology in weanling pigs. The addition of activated carbon at the rate of 1% to the diet was not effective in protecting against the detrimental effects of fumonisin consumption.
• Prandini, A., Piva, G., Moschini, M., Morlacchini, M., & Diaz, D. E. (2005). Raw and extruded pea (Pisum sativum), faba bean (Vicia faba var. minor) and lupin (Lupinus albus var. multitalia) as alternative protein sources in broiler diets. Italian Journal of Animal Science, 4(sup2), 519-519. doi:10.4081/ijas.2005.2s.519
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  AbstractResearch on vegetable-based protein sources has grown as a result of the European Union ban on the inclusion of meat and bone meal in diets of agricultural livestock. This together with recent concern over genetically modified soybeans, the protein source of choice for monogastric diets, has sparked research into the identification of some alternative protein sources. The objective of this study was to evaluate the effect of raw or extruded pea (RP and EP), faba beans (RFb and EFb) or lupin (RL and EL) in partial substitution of soybean meal and other starch sources in broiler diets. A total of 462-d-old male Ross chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens/treatment). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The amount of alternative proteins used as fed basis and for 1-10 d-old and 11-42 d-old growing periods were: RP and EP: 350 g/kg for all diets; RFb...
• Whitlow, L. W., Huntington, G. B., Hopkins, H., Hopkins, B. A., Hill, S. R., Diaz, D. E., Davidson, S., Brownie, C., Brown, T. T., & Bolt, S. M. (2005). Technical note: technique for dissection and analysis of the rumen in young calves.. Journal of dairy science, 88(1), 324-6. doi:10.3168/jds.s0022-0302(05)72691-6
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  This paper discusses a technique used to evaluate rumen development in young calves, including removal, dissection, and analysis of tissue. The method allowed for examination of the different sacs of the rumen (dorsal, ventral, cranial, and caudal) using scanning electron microscopy to measure papillae denseness and histology slides to measure papillae length and width. Computer software was used to produce accurate measurements of papillae. The rumens of young calves were dissected, and samples were taken from the cranial, caudal, ventral, and dorsal sections. Calves were part of a nutrition research study, and dietary treatments did have an effect on development measurements such as length, width, and papillae denseness.
• Prandini, A., Piva, G., Diaz, D. E., & Conti, F. (2004). Levels of conjugated linoleic acid (CLA) in ewe milk and Pecorino cheese: effect of season, feed and cheese aging. Progress in Nutrition, 6.
• Whitlow, L. W., Jr, W. M., Jones, F. T., Hopkins, H., Hopkins, B. A., Hagler, W. M., Eve, J. A., Diaz, D. E., Blackwelder, J. T., & Anderson, K. L. (2004). Aflatoxin binders II: reduction of aflatoxin M1 in milk by sequestering agents of cows consuming aflatoxin in feed.. Mycopathologia, 157(2), 233-41. doi:10.1023/b:myco.0000020587.93872.59
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  Sequestering agents bind dietary aflatoxin B1 (AFB1) and reduce absorption from an animal's gastrointestinal tract. As a result, they protect an animal from the toxic effects of AFB1 and reduce transfer of the metabolite, aflatoxin M1 (AFM1), into milk. Three experiments, using late-lactation Holstein cows fed AFB1-contaminated feed, were conducted to evaluate several potential sequestering agents for their abilities to prevent or reduce the transmission of AFM1 into milk. Six agents previously tested in our laboratory for AFB1 binding in vitro were evaluated in these experiments. These were: SA-20, an activated carbon (AC-A); Astra-Ben-20, a sodium bentonite (AB-20); MTB-100, an esterified glucomannan (MTB-100); Red Crown, a calcium bentonite (RC); Flow Guard, a sodium bentonite (FG); and Mycrosorb, a sodium bentonite (MS). Five of the six sequestering agents significantly (P < 0.01) reduced AFM1 contamination of milk (AB-20, 61%; FG, 65%; MS, 50%; MTB-100, 59%; and RC, 31%); whereas, AC-A, activated carbon, had no effect on AFM1 transmission at 0.25% of feed. By the first milking (1 day after cows consumed contaminated feed), AFM1 appeared in milk, then reached maximum levels after three days, and was absent from milk within four days after AFB1 was removed from the feed. Sodium bentonites at 1.2% of feed showed good potential as AFB1 binders; MTB-100, a yeast cell wall product, was equally effective at 0.05% in feed. Potential AFB1 binding agents should be evaluated experimentally to demonstrate efficacy. Our data show that sequestering agents can reduce AFM1 in milk of cows fed AFB1-contaminated feed.
• Whitlow, L. W., Hopkins, H., Hopkins, B. A., Fellner, V., Diaz, D. E., Davidson, S., Brownie, C., & Bolt, S. M. (2003). Effects of amounts and degradability of dietary protein on lactation, nitrogen utilization, and excretion in early lactation Holstein cows.. Journal of dairy science, 86(5), 1681-9. doi:10.3168/jds.s0022-0302(03)73754-0
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  Five treatment diets varying in crude protein (CP) and rumen undegradable protein (RUP) were calculated to supply a postruminal lysine to methionine ratio of about 3:1. Diets were fed as a total mixed ration to 65 Holstein cows that were either primiparous (n = 28) or multiparous (n = 37) from 21 to 120 d in milk to determine effects on lactation and nitrogen utilization. Crude protein % and calculated RUP (% of CP) of diets [on a dry matter (DM) basis] were: 1) 19.4, 40 (HPMU), 2) 16.5, 34 (LPLU), 3) 16.8, 40 (LPMU), 4) 16.8, 46 (LPHU), 5) 17.2, 43 (LPHU + UREA), which is the result of adding 0.4% of the diet DM as urea to LPHU. The corn silage-based treatment diets contained an average of 24% acid detergent fiber and 1.6 Mcal/kg net energy of lactation. Milk urea nitrogen (MUN) concentrations and body weights (BW) were used to calculate predicted amounts of urinary nitrogen (N) using the relationship: urinary N (g/d) = 0.0259 x BW (kg) x MUN (mg/dl). Cows fed HPMU had greater CP and RUP intakes, which resulted in higher concentrations of plasma urea nitrogen, rumen ammonia, MUN, and predicted urinary N. Milk yield, fat yield, fat percent, protein yield, and protein percent were not significantly different among treatments. Parity primarily affected parameters that were related to body size and not measurements of N utilization. The interaction of treatment and parity was not significant for any measurements taken. In this study, cows fed LPHU had significantly lower MUN and predicted urinary N without limiting production. These results demonstrate the potential to optimize milk production while minimizing N excretion in lactating dairy cattle.
• Whitlow, L. W., Hopkins, H., Hopkins, B. A., Hagler, W. M., & Diaz, D. E. (2002). Aflatoxin binders I: in vitro binding assay for aflatoxin B1 by several potential sequestering agents.. Mycopathologia, 156(3), 223-6. doi:10.1023/a:1023388321713
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  Nine potential proprietary sequestering agents consisting of 4 activated charcoals, 3 sodium bentonites, a calcium bentonite, and an esterified glucomannan were compared in a novel in vitro assay for aflatoxin B1 (AFB1) binding. Agents were evaluated in 10% methanol prepared as 1% stirred suspensions at pH 3, 7, 10 and pH-unadjusted, with or without AFB1 at 5 microg/ml. All nine agents bound more than 95% of the 5 microg of AFB1 in solution, regardless of pH. The sodium bentonites bound 98, 95, and 98% of the AFB1. The four activated charcoals bound over 99%, the calcium bentonite bound 98%, and the esterified glucomannan bound 97% of the AFB1 in solution. The results suggested that the sequestering agents tested here had sufficient potential to bind AFB1 at pH values commonly found in the gastrointestinal tracts of ruminants and other animals.
• Lewbart, G. A., Hurty, C. A., Diaz, D. E., & Campbell, J. L. (2001). Chemical Analysis of Six Commercial Adult Iguana, Iguana iguana, Diets. Journal of herpetological medicine and surgery, 11(3), 23-26. doi:10.5818/1529-9651.11.3.23
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  ABSTRACT Reptile keeping is one of the most rapidly expanding areas in the pet industry. In response to this trend, several pet food companies have formulated specialized diets and supplements that cater to the unique nutritional needs of different reptile species. Since nutrition is a key variable of captive reptile husbandry, we investigated the nutrient composition of six commercially available adult iguana, Iguana iguana, feeds that are intended for use as principle diets. We compared the results of our analyses to the nutrient information provided on packaging labels and to available information on the suggested nutrient recommendations for iguanas. Crude protein contents ranged from 13.21% dry matter (DM) to 27.15% DM with two of the six diets containing a lower protein than indicated on the label. Crude fat content ranged from 1.46 ± 0.44% DM to 10.25 ± 0.05% DM with three of the six diets having fat contents below the amount stated on labels. The acid detergent fiber (ADF) content, a measure of in...
• Whitlow, L. W., Noftsger, S. M., Hopkins, H., Hopkins, B. A., Diaz, D. E., & Brownie, C. (2000). Effect of whole and expanded-expelled cottonseed on milk yield and blood gossypol.. Journal of dairy science, 83(11), 2539-47. doi:10.3168/jds.s0022-0302(00)75146-0
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  Thirty-two primiparous and 12 multiparous Holstein cows were randomly assigned at calving to treatments to determine the effects of type and amount of cottonseed product on plasma gossypol, milk production, and composition, and conjugated linoleic acid concentration in milk fat. Rations consisted of corn silage, corn grain, soybean meal, and cottonseed hulls, and contained on average 16.8% crude protein and 25.3% acid detergent fiber on a dry matter basis. On a dry matter basis, diets contained one of the following: 1) 14% whole cottonseed; 2) 14% expanded-expelled cottonseed; 3) 21% expanded-expelled cottonseed; or 4) 28% expanded-expelled cottonseed. Cows remained on treatment from 30 through 120 d in milk. Dry matter intakes were not significantly different, but intakes of crude protein, acid detergent fiber, and fat were higher for multiparous cows fed whole cottonseed. Multiparous cows fed whole cottonseed had higher yields of milk, fat-corrected milk, crude protein, fat and solids-not-fat than those fed any level of expanded-expelled cottonseed. Concentrations of milk fat, protein, and SNF were not affected by treatment. Although there were treatment differences in fat intake, there were no production differences in primiparous cows. Milk production efficiency (fat-corrected milk/dry matter intake) was not affected by treatment for either multiparous or primiparous cows. Cows fed 14% whole or 14% expanded-expelled cottonseed had similar levels of total plasma gossypol and plasma levels of the negative isomer of gossypol. Increasing the level of expanded-expelled cottonseed in the diet increased both total plasma gossypol and the negative isomer. In this experiment, multiparous but not primiparous cows fed whole cottonseed produced more milk than those fed expanded-expelled cottonseed at 14 to 28% of the diet dry matter, however, feed efficiencies were similar for all treatments.
• Harrison, L. D., Diaz, D. E., Dennis, P. M., Degernes, L. A., & Crosier, M. L. (1999). Autologous, Homologous, and Heterologous Red Blood Cell Transfusions in Cockatiels (Nymphicus hollandicus). Journal of Avian Medicine and Surgery, 13(1), 2-9.
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  The use of heterologous blood transfusions in birds is controversial. The purpose of this study was to determine the survival of fluorescent-labeled red blood cells (RBCs) after single and multiple transfusions in compatible cross-matched groups of birds. Twenty cockatiels (Nym- phicus hollandicus) were equally divided into four transfusion groups: an autologous or control group (transfusion to same bird); a homologous group (cockatiel to cockatiel), a heterologous group of two species in the same taxonomic family (blue-fronted Amazon parrot (Amazona aestiva) to cockatiel), and a heterologous group of two species in different orders (pigeon (Columba livia) to cockatiel). Donor blood (1 ml) was centrifuged and the plasma discarded. The washed RBCs were stained with a fluorescent dye and transfused into recipient cockatiels. Three RBC transfusions using the same donor-recipient pairs were administered at 0, 7, and 9 weeks, and then serial blood samples were analyzed by using flow cytometry to measure fluorescent-labeled RBCs remaining in circulation over time. The fluorescent-labeled RBC half-life was significantly longer in the autologous and ho- mologous groups (range, 10.5 to 16.8 days) than in the two heterologous groups (range, 0.1 to 2.6 days) after all three transfusions (P < .001 for all comparisons). No difference was found in half-life of RBCs between the two heterologous groups after any of the transfusions or between the autologous and homologous groups after transfusions 1 and 2. After transfusion 3, the half-life was longer in the autologous group than in the homologous group (P < .001). We conclude that fluorescent-labeled RBC survival is comparable after autologous and homologous avian transfusions; however, heterol- ogous transfusions result in significantly shorter half-life of transfused RBCs, regardless of taxonomic relatedness. Therefore, heterologous transfusions in birds may not be efficacious.
• Smith, D. W., Ross, C. E., Newton, H. M., Harrison, L. D., Diaz, D. E., & Degernes, L. A. (1999). Autologous, homologous, and heterologous red blood cell transfusions in conures of the genus Aratinga. Journal of Avian Medicine and Surgery, 13(1), 10-14.
• Whitlow, L. W., Hopkins, H., Hopkins, B. A., Diaz, D. E., Brownie, C. F., & Blackwelder, J. T. (1998). Milk production and plasma gossypol of cows fed cottonseed and oilseed meals with or without rumen-undegradable protein.. Journal of dairy science, 81(11), 2934-41. doi:10.3168/jds.s0022-0302(98)75855-2
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  Twenty-four multiparous Holstein cows were randomly assigned at calving to treatment diets using a modified split-plot design to determine the effects of protein source on milk production and composition. The treatment diets consisted of an 80:20 combination of corn and alfalfa silages and whole cottonseed at 12% of the dietary dry matter (DM). The treatment diets were formulated to contain 17% crude protein (CP) and 20% acid detergent fiber on a DM basis. One of the following sources of supplemental CP was included in each treatment diet: 1) cottonseed meal, 2) cottonseed meal plus a rumen-undegradable protein (RUP) supplement, 3) soybean meal, and 4) soybean meal plus an RUP supplement. Cows were fed the initial treatment diet for 6 wk and then were switched to the other oilseed meal source but continued to receive the same amount of RUP during the second period of the study. Milk production and composition were not affected by treatment diet. Cows fed treatment diets without RUP supplementation consumed more DM and thus more CP. Supplementation with RUP resulted in greater milk production efficiency per unit of DM consumed. Cows fed treatment diets containing cottonseed meal had higher plasma gossypol concentrations than did cows fed treatment diets containing soybean meal. Plasma gossypol concentrations for all cows in each group were below the recommended upper limit that is considered to be safe. Data suggest that cottonseed meal in the diet can be substituted for soybean meal, resulting in similar milk production and composition.

Proceedings Publications

• Diaz, D. (2024, January). Mycotoxins: A critical component of any feed quality program.. In Pacific Northwest Animal Nutrition Conference.
• Diaz, D. (2024, September). Impact of heat stress on lifetime performance of sheep (ovine).. In Feedworks Conference.
• Diaz, D. (2024, September). Mycotoxins - what you don't know should. In Feedworks Conference.
• Diaz, D. (2019, April). Prevention, Assessment, and Mitigation of Mycotoxicosis in Dairy Cattle. In Proceedings for the Tri-state Nutirtion Conference, 27-36.
• Diaz, D. (2019, February). Video Technology for Large Dairy Operations: from Management to Precision Agriculture. In Western Dairy Management Conference.
• Diaz, D., Knight, C. W., Wright, A. D., & Greene, E. A. (2018, September). Shade use by horses in the arid southwest. In 14th International Society for Equitation Science Conference.
• Ottman, M. J., Ottman, M. J., Diaz, D. E., Sheedy, M. D., Ward, R. W., Ward, R. W., & Diaz, D. E. (2017). Forage Sorghum Hybrid Yield and Quality at Maricopa, AZ, 2015. In College of Agriculture, University of Arizona (Tucson, AZ).
• Diaz, D. (2016, April). Efecto de tricocenos en la producción avícola y estrategias de control. In ANECA (Asociacion Nacional de Especialistas en Ciencias Avicolas).
• Diaz, D. (2016, February). A Multidisciplinary Approach to Prevention, Assessment, and Mitigation of Mycotoxicosis in the Dairy Industry. In Southwest Nutrition Conference.
• Diaz, D. (2016, October). Nutritional Toxicology in the Dairy Industry: Feed quality and Mycotoxins. In World Nutrition Forum, 267-276.

Presentations

• Diaz, D. (2024, August). Forage Quality for the Dairy, Beef, & Equine Clients. Alfalfa & Forage Tent Talks. Buckeye, AZ, USA: University of Arizona Cooperative Extension.
• Diaz, D. (2024, August). Forage Quality for the Dairy, Beef, & Equine Clients. Annual Forage Tent Talks. Mesa, AZ, USA: University of Arizona Cooperative Extension.
• Diaz, D. (2024, January). Mycotoxins: A critical component of any feed quality program. Pacific Northwest Conference. Boise, ID, USA.
• Diaz, D. (2024, June). The Silage Ecosystem: Negative Consequences of Improper Silage Fermentation. Silage for Beef Conference. Mead, NE, USA.
• Diaz, D. (2024, May). Forage Water Efficiency: Survey Evaluation in Maricopa and Pinal Counties. Annual UA Alfalfa & Forage Workshop. Maricopa, AZ, USA: University of Arizona Cooperative Extension.
• Diaz, D. (2024, September). Impact of heat stress on lifetime performance of sheep (ovine).. Feedworks Conference. Sunshine Coast, QLD, Australia.
• Diaz, D. (2024, September). Mycotoxins – what you don’t know but should. Feedworks Conference. Sunshine Coast, QLD, Australia.
• Rios, A., Fuentevilla, E., Limesand, S. W., & Diaz, D. (2024, July). Tracking growth performance and insulin response on fourth-month-old maternal heat-stressed lambs.. ASAS-CSAS-WSASAS Annual Meeting, Calgary, AB, Canada.. Calgary, CA.
• Diaz, D. (2021, Fall). Invited Presentation: Monitorizacion y control de micotoxinas a lo largo de la cadena de fabricacion de piensos. Latinamerican Poultry Nutrition Conference. Miami USA: LPN Agrinews.
• Diaz, D. (2020, December). Abordaje de un proceso de micotoxicosis en ganado de leche. Congreso Nacional Lechero Costa Rica. Costa Rica (Changed to virtual conference): Camara Nacional de Productores de Leche de Costa Rica.
• Diaz, D. (2020, December). Micotoxins and Ruminants. Society of Feed Technology UK. Edinburg UK (Cancelled and held virtually): Society of Feed Technology.
• Diaz, D. (2020, June). Micotoxicosis: Interacciones en la cadena de produccion. Sanfer Animal Health Annual Symposium (Keynote Speaker). Guadalajara Mexico (Moved to virtual conference): SanFer animal health.
• Diaz, D. (2020, May). Mycotoxin Mitigation: Linking Feed Quality and Dairy Cow Performance. Alltech One Experience (Virtual). Lexington KY, USA (Cancelled and moved to virtual): Alltech.
• Diaz, D. (2020, September). New Studies and Trends in Understanding the Role of Mycotoxins in Feed Production. Phibro Academy Virtual Conference (Global). Virtual (Globally): Phibro Animal Health.
• Diaz, D. (2020, September). Nuevos estudios y tendencias para comprender el papel de las micotoxinas en la producion de alimentos para animales. Phibro Academy (Virtual). Virtual (Global): Phibro Animal Health.
• Diaz, D. (2019, April). Practically evaluating and utilizing mycotoxin solutions on modern dairies. Alltech Dairy Nutritionist Meeting. San Diego: Alltech Biotechnology.
• Diaz, D. (2019, April). Prevention, Assessment, and Mitigation of Mycotoxicosis in Dairy Cattle. Tri-State Nutrition Conference. Fort Wayne Indiana: Tri-State Nutrition Conference.
• Diaz, D. (2019, April). Resumen de estudios sobre el impacto de las micotoxinas en el ganado lechero: Interacciones entre hongos, animales y el medio ambiente. Wisium - Technical meetings. Aguascalientes, Torreon Mexico: Wisium Nutrition.
• Diaz, D. (2019, February 19). Careers in the livestock industry. Pre-veterinary medicine club. Tucson Arizona: University of Arizona Pre-Vet Club.
• Diaz, D. (2019, Febuary). Camera placement to protect your dairy - Video tecvhnology as a precision Ag. Tool. Western Dairy Management Conference. Reno, Nevada.
• Diaz, D. (2019, July). Dairy Forage Initiative. Dairy Forage Initiative. Avondale Arizona: Cooperative Extension.
• Diaz, D. (2019, July). Update on the Arizona Dairy Forage Initiative. Dairy Forage Initiative. Casa Grande, Arizona: Cooperative Extension.
• Diaz, D. (2019, June). AF36 for Aflatoxin Control in Cotton. What is the Value to Dairy Production?. Cotton “Tent Talks”. Goodyear Arizona: Cooperative Extension.
• Diaz, D. (2019, June). Bridging the Gap Between Dairy Producers and Alfalfa Growers. 2019 Alfalfa and Forage “Tent Talk”. Buckeye Arizona: Cooperative Extension.
• Diaz, D. (2019, June). Nutritional intervention for the mitigation of heat stress in beef and dairy cattle. W3173-NC1029 Year in review meeting. Bozeman Montana.
• Diaz, D. (2019, June). Ruminants—Are they as resilient to mycotoxicosis as we think?. American Dairy Science Association Annual Meeting. Cincinnati, Ohio: American Dairy Science Association.
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  Invited presentation during a special symposium - Ruminant nutrition: MYCOTOXINS—RECOGNIZING THEIR PRESENCE AND DEALING WITH THEM IN RUMINANT NUTRITION
• Diaz, D. (2019, March). Heat stress abatement through nutritional supplementation internventions. PMI - Land O'Lakes webinar. Online - webinar: PMI - Land O'Lakes.
• Diaz, D. (2019, November). Como impactan las micotoxinas en el desepeño productivo de las vacas, la inocuidad en la leche y el comercio. INTA - Special conference. Rafaela and Cordoba, Argentina: Instituto Nacional de Tecnologia Agropecuaria.
• Diaz, D. (2019, November). How dairy systems are adapting to increasing heat. Climate Adaptation and Food Systems Lunch and Network-Building Event. University of Arizona: Center for Climate Adaptation Science and Solutions.
• Diaz, D. (2019, Spring). Heat Stress Effects and Mitigation Strategies for Cattle in the Southwestern U.S.. Range Livestock Nutrition Workshop. Wilcox, Prescott, Holbrook Arizona: Cooperative Extension University of Arizona.
• Diaz, D., Vander Poel, M., Collier, R., Camacho, L., Xiao, Y., Compart, D., & Russo, K. (2019, June). Evaluating heat stress response in lactating Holstein cows with supplementation of a feed additive during mid lactation.. American Dairy Science Association Annual Meeting. Cincinnati Ohio: American Dairy Science Association.
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  Graduate Student presentation
• Diaz, D. (2018, February). Low lignin alfalfa: Understanding the value to dairy producers. Alfalfa University. Ogden, UT: High Plains Journal.
• Diaz, D. (2018, February). Low lignin alfalfa: Where we are in the Dairy Industry. Tulare Farm Show. Tulare, CA: Aflorex Seeds.
• Diaz, D. (2018, January). Dairy Forage Production and Needs in Arizona. Southwest Indian Agricultural Association. Laughlin, NV: SWIIA.
• Diaz, D. (2018, June). Environmental chamber heat stress responses and adaptations in crossbred Hereford steers. ASAS Western Section Annual Meeting. Bend, OR: American Society of Animal Scientist.
• Diaz, D. (2018, June). Practical Considerations for Feeding Cows Under Heat Stress. American Dairy Science Association Annual Meeting. Knoxville, TN: ADSA.
• Diaz, D. (2018, October). Low Lignin Alfalfa: Dairy Applications. ARPAS Northeast Chapter Annual Meeting. Harrisburg, PA: American Registry of Professional Animal Scientists.
• Diaz, D. (2018, October). Mold, Plant, Animal and Climate Interactions in Mycotoxin Exposure. Penn State Dairy Cattle Nutrition Workshop. Harrisburg, PA: Penn State University Cooperative Extension.
• Diaz, D., Compart, D., Collier, R. J., Wright, A., Renquist, B. J., Xiao, Y., & Vander Poel, M. (2018, April). Evaluation of the efficacy of a feed supplement (BeefAbate) in attenuating the effects of heat stress on growing steers. Plains Nutrition Council. San Antonio, TX: Plains Nutrition Council.
• Diaz, D., Knight, C. W., Wright, A. D., Greene, E. A., Diaz, D., Knight, C. W., Wright, A. D., & Greene, E. A. (2018, September). Shade use by horses in the arid southwest. 14th International Society for Equitation Science Conference. Rome, Italy: International Society for Equitation Science.
• Diaz, D., Vander Poel, M., Xiao, Y., Renquist, B. J., Wright, A., Collier, R. J., & Compart, D. (2018, Summer). Environmental chamber heat stress responses and adaptations in crossbred Hereford steers. American Society of Animal Science Western Section. Bend, OR: American Society of Animal Science.
• Diaz, D. (2017, February). Forage Quality and Aflatoxin Control. 38th Annual Southeastern Arizona Ad Day & Trade Show. Wilcox, Arizona: CES University of Arizona.
• Diaz, D. (2017, February). Forage Quality and Aflatoxin Control. 38th Annual Southeastern Arizona Ad Day & Trade Show. Willcox, Arizona.
• Diaz, D. (2017, February). Mycotoxin Production in Grains. What's Under the Tarp: 2017 Emerging Mycotoxin Issues and Strategies. Online: Neogen Webinar Series.
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  Online webinar - youtube records
• Diaz, D. (2017, February). Role of Antioxidants during Mycotoxicosis and Heat Stress. Southwest Nutrition Conference - pre-conference seminar. Tempe, Arizona.
• Diaz, D. (2017, January). Forage quality and its impact on milk quality. Field Crops "Clinics". Casa Grande: Cooperative Extension.
• Diaz, D. (2017, January). Forage quality and its impact on milk quality. Field Crops "Clinics". Maricopa: Cooperative Extension.
• Diaz, D. (2017, January). Forage quality and its impact on milk quality. Field Crops "Clinics". Pima: Cooperative Extension.
• Diaz, D. (2017, July). Applied Mycotoxicology in Production Agriculture: A Broad Look at a Specialized Field. Sociedad Latinoamericana de Micotoxicologia (SLAM). Puebla, Mexico: SLAM.
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  Keynote speaker - Latinoamerican Micotoxicology Society
• Diaz, D. (2017, July). Low lignin alfalfa: what is the value to dairy producers. Cooperative Extension Workshop. Alfalfa and forage "tent talks". Buckeye Arizona: CES University of Arizona.
• Diaz, D. (2017, March). Sample Collection and Sampling Protocols and Analysis of Forages for Dairy Rations. The 3rd Alfalfa & Forage Crops Workshop. Maricopa Arizona: CES University of Arizona.
• Diaz, D. (2017, May). Mycotoxin Effects: Making Sense of Complex Biological Interactions. California Animal Nutrition Conference (CANC). Fresno, California: CANC.
• Diaz, D. (2017, October). Micotoxicosis en el campo: Interacciones entre hongos, plantas, animales, y el medio ambiente. (Mycotoxicosis in the Field: Mold, Plant, Animal and Environment Interactions). Asociación Mexicana de Especialistas en Nutrición Animal. Puerto Vallarta, Mexico: AMENA.
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  Mexican Association of Animal Nutritionists annual meeting - invited talk.
• Diaz, D. (2016, April). Efecto de tricocenos en la producción avícola y estrategias de control. ANECA (Asociacion Nacional de Especialistas en Ciencias Avicolas). Ixtapa Mexico: ANECA.
• Diaz, D. (2016, February). A Multidisciplinary Approach to Prevention, Assessment, and Mitigation of Mycotoxicosis in the Dairy Industry. Southwest Nutrition Conference.
• Diaz, D. (2016, June). Mycotoxins and Mycotoxicosis in the Dairy Industry. Nutriad Dairy Seminars. Jerome & Burley Idaho: Nutriad.
• Diaz, D. (2016, June). The use of Bio-competitive Products for Aflatoxin Management. New Technologies for Arizona Field Crops Workshop. Maricopa Arizona: CALS Cooperative Extension.
• Diaz, D. (2016, March). Mold and Plant Interaction in Aflatoxin Contamination. The 2nd Arizona Alfalfa & Forage Crops Workshop. Maricopa AZ: CALS Cooperative Extension.
• Diaz, D. (2016, March). University of Arizona Dairy Extension Programs. Arizona Agricultural Experience. Tempe AZ: Pinal 40.
• Diaz, D. (2016, October). Nutritional Toxicology in the Dairy Industry: Feed Quality and Mycotoxins. World Nutrition Forum. Vancouver Canada.
• Diaz, D. (2016, October). Pre and Post Harvest Mycotoxin Prevention Programs. University of Hawaii Manoa Seminar for Department of Human Nutrition, Food and Animal Sciences. Manoa Hawaii: University of Hawaii Manoa.
• Diaz, D. (2016, September). Dairy Extension Programs at the University of Arizona. Greenly County Extension Advisory Board Meeting. Duncan Arizona: Greenly Country Cooperative Extension.
  More info

  Tour of Lunt Dairy and a gave a presentation to the board about the state of the dairy industry in Arizona and our extension programs.

Poster Presentations

• Fuentevilla, E., Rios, A., Limesand, S. W., & Diaz, D. (2024). Gestational heat stress and its impact on placental weight, colostrum production, and milk production on Columbia-Rambouillet ewes. ASAS. Calgary, CA: ASAS.
• Ottman, M. J., Norton, E. R., Mostafa, A. M., Andrade Sanchez, P., Grijalva, P., Diaz, D., & Evancho, B. E. (2020, October). Agronomic Assessment of Corn Silage Forage Production in Buckeye, and Casa Grande Arizona: Part of the Arizona Dairy Forage Initiative. Arizona Cooperative Extension 2020 Virtual Conference. Virtual: Arizona Cooperative Extension.
• Diaz, D. (2019, June). Evaluating skeletal muscle and mammary tissue energy expenditure during heat stress for lactating Holstein cows. ASAS Western Section Annual Meeting. Boise, Idaho.
• Diaz, D., Abrell, L. M., Ellsworth, P. C., Hall, G., & Pier, N. (2019, August). Blister Beetles of Arizona. University of Arizona Cooperative Extension Annual Conference. Tucson Arizona: Cooperative Extension - University of Arizona.
• Diaz, D., Andrade Sanchez, P., Mostafa, A. M., Evancho, B. E., Ottman, M. J., & Norton, R. (2019, April). Arizona Extension Dairy Forage Initiative: Agronomic Assessment of Common Forage Commodities in the State of Arizona. 2019 ALVSCE Poster Forum. Tucson Arizona.
• Ottman, M. J., Diaz, D., Norton, R., Andrade Sanchez, P., Evancho, B. E., Mostafa, A. M., Mostafa, A. M., Evancho, B. E., Norton, R., Andrade Sanchez, P., Diaz, D., & Ottman, M. J. (2019, August). Evaluation of agronomic needs to improve our extension educational programs to dairy forage growers in the state.. 2019 Arizona Cooperative Extension Conference. Tucson Arizona: University of Arizona Cooperative Extension.
• Diaz, D., & Vander Poel, M. (2018, April). Evaluation of the efficacy of a feed supplement (BeefAbate) in attenuating the effects of heat stress on growing steers.. Plains Nutrition Council Annual Meeting. San Antonio: PNC.
• Diaz, D., Greene, E. A., & Wright, A. D. (2016, October). Statewide survey asa tool for identifying dairy-related cooperative extension program priorities for the state of Arizona. NACAA Western Region Conference. Kailua-Kona Hawaii: NACAA.

Others

• Diaz, D. (2024, April). Dairy Cattle Disease: Highly Pathogenic Avian Influenza (HPAI).. University of Arizona A.L.I.R.T. BOLO. https://extension.arizona.edu/publication/dairy-cattle-disease-highly-pathogenic-avian-influenza-hpai
• Wulf, D. M., Diaz, D., Garcia, S. R., Garcia, S. R., Diaz, D., & Wulf, D. M. (2020, May). How to Butcher a Pig (On Farm Pig Harvest Procedures). YouTube. https://www.youtube.com/watch?v=ojctijm2Tgo
  More info

  Due to COVID shut downs at several pork processing plants, there was much demand for science-based procedures for on-farm pig harvest. This video was produced and published with the support of the National Pork Board.