+publisher:"University of Arizona" +contributor:("Duff, Glenn C.")

University of Arizona

1. Allen, Jamison. Use of a portable near-infrared spectrophotometer to predict nutrient composition of feces from feedlot Holstein cattle and its applicability for on-site research and industry use .

Degree: 2011, University of Arizona

URL: http://hdl.handle.net/10150/145464

► Two studies were performed to investigate the ability of a portable near-infrared spectrophotometer (NIRS) for on-site analysis of nutrient components in feces from cattle. In… (more)

▼ Two studies were performed to investigate the ability of a portable near-infrared spectrophotometer (NIRS) for on-site analysis of nutrient components in feces from cattle. In trial 1 of study 1, growing dairy steers were fed diets containing either 86 or 90% concentrate. Regression values from a calibration set of 56 samples were promising for CP, DM, and NDF, but not for ADF or starch. In trial 2 of study 1, finishing dairy steers were fed diets containing either thick (512 g/L) or thin (460 g/L) steam-flaked corn. Regression values from a calibration set of 126 samples were poor for all nutrients. Both studies showed statistically valid NIRS calibrations, but further validation was required to make regression values acceptable (R² > 0.80) for all fecal nutrient components. In study 2, NIRS analysis was employed on novel research. Young dairy bull calves were fed diets containing either whole or steam-flaked corn from pre-weaning until 8 weeks post-weaning when the first animal was heavy enough for inclusion into a commercial feedlot. Again, although statistically valid, regression values from a calibration set of 220 samples were promising for CP and ADF, but not predictive for DM, NDF, ash, and starch. Growth performance parameters were similar between diets, with starch digestibilities diverging after weaning and changing to a Holstein starter diet. These 2 studies show that commercial and research application of a portable NIRS for on-site analysis of the nutrient composition of feces from young, growing, and finishing dairy steers statistically possible but requires further validation research. Also, results from the second study imply that there is no advantage in feeding steam-flaked corn to dairy calves from pre-weaning to 8 weeks post-weaning or until reaching feedlot weight. However, starch digestibility begins to improve for steam-flaked corn to whole corn once the animal has been weaned. Advisors/Committee Members: Duff, Glenn C (advisor), Limesand, Sean W (committeemember), Guerriero, Vincent (committeemember), Marchello, Elaine V (committeemember), Cuneo, S. Peder (committeemember).

Subjects/Keywords: digestion; feces; feedlot; Holstein; NIRS; nutrient

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APA (6^th Edition):

Allen, J. (2011). Use of a portable near-infrared spectrophotometer to predict nutrient composition of feces from feedlot Holstein cattle and its applicability for on-site research and industry use . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/145464

Chicago Manual of Style (16^th Edition):

Allen, Jamison. “Use of a portable near-infrared spectrophotometer to predict nutrient composition of feces from feedlot Holstein cattle and its applicability for on-site research and industry use .” 2011. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/145464.

MLA Handbook (7^th Edition):

Allen, Jamison. “Use of a portable near-infrared spectrophotometer to predict nutrient composition of feces from feedlot Holstein cattle and its applicability for on-site research and industry use .” 2011. Web. 07 Mar 2021.

Vancouver:

Allen J. Use of a portable near-infrared spectrophotometer to predict nutrient composition of feces from feedlot Holstein cattle and its applicability for on-site research and industry use . [Internet] [Doctoral dissertation]. University of Arizona; 2011. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/145464.

Council of Science Editors:

Allen J. Use of a portable near-infrared spectrophotometer to predict nutrient composition of feces from feedlot Holstein cattle and its applicability for on-site research and industry use . [Doctoral Dissertation]. University of Arizona; 2011. Available from: http://hdl.handle.net/10150/145464

University of Arizona

2. McMurphy, Casey Paul. Effects of Humic/Fulvic Acid on Rumen Fermentation in Holstein Steers .

Degree: 2007, University of Arizona

URL: http://hdl.handle.net/10150/193335

► Six ruminally fistulated steers (average BW 317 kg) were used in a 5 X 5 + 1 Latin Square design to determine effects of humic/fulvic… (more)

Subjects/Keywords: Humates; Feed additives; serum urea nitrogen; rumen ammonia nitrogen; volatile fatty acids

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APA (6^th Edition):

McMurphy, C. P. (2007). Effects of Humic/Fulvic Acid on Rumen Fermentation in Holstein Steers . (Masters Thesis). University of Arizona. Retrieved from http://hdl.handle.net/10150/193335

Chicago Manual of Style (16^th Edition):

McMurphy, Casey Paul. “Effects of Humic/Fulvic Acid on Rumen Fermentation in Holstein Steers .” 2007. Masters Thesis, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/193335.

MLA Handbook (7^th Edition):

McMurphy, Casey Paul. “Effects of Humic/Fulvic Acid on Rumen Fermentation in Holstein Steers .” 2007. Web. 07 Mar 2021.

Vancouver:

McMurphy CP. Effects of Humic/Fulvic Acid on Rumen Fermentation in Holstein Steers . [Internet] [Masters thesis]. University of Arizona; 2007. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/193335.

Council of Science Editors:

McMurphy CP. Effects of Humic/Fulvic Acid on Rumen Fermentation in Holstein Steers . [Masters Thesis]. University of Arizona; 2007. Available from: http://hdl.handle.net/10150/193335

University of Arizona

3. Dick, Karianne. The Effects of Direct-Fed Microbials on Performance and Digestive Tract Morphology of Neo-Natal/Transition Hostein Bull Calves .

Degree: 2006, University of Arizona

URL: http://hdl.handle.net/10150/193345

► Calf diarrhea or scours is one of the most significant and costly problems dairy producers face on a daily basis. A study was designed and… (more)

Subjects/Keywords: direct-fed microbials; calves; digestive tract morphology; performance

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APA (6^th Edition):

Dick, K. (2006). The Effects of Direct-Fed Microbials on Performance and Digestive Tract Morphology of Neo-Natal/Transition Hostein Bull Calves . (Masters Thesis). University of Arizona. Retrieved from http://hdl.handle.net/10150/193345

Chicago Manual of Style (16^th Edition):

Dick, Karianne. “The Effects of Direct-Fed Microbials on Performance and Digestive Tract Morphology of Neo-Natal/Transition Hostein Bull Calves .” 2006. Masters Thesis, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/193345.

MLA Handbook (7^th Edition):

Dick, Karianne. “The Effects of Direct-Fed Microbials on Performance and Digestive Tract Morphology of Neo-Natal/Transition Hostein Bull Calves .” 2006. Web. 07 Mar 2021.

Vancouver:

Dick K. The Effects of Direct-Fed Microbials on Performance and Digestive Tract Morphology of Neo-Natal/Transition Hostein Bull Calves . [Internet] [Masters thesis]. University of Arizona; 2006. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/193345.

Council of Science Editors:

Dick K. The Effects of Direct-Fed Microbials on Performance and Digestive Tract Morphology of Neo-Natal/Transition Hostein Bull Calves . [Masters Thesis]. University of Arizona; 2006. Available from: http://hdl.handle.net/10150/193345

University of Arizona

4. Whitney, Travis Raymond. Effects of weaning programs on metabolic profiles and hepatic IGF-1 mRNA of first-calf heifers and mature cows, and effects of diet for early-weaned steers on response to an infectious bovine herpesvirus-1 challenge .

Degree: 2004, University of Arizona

URL: http://hdl.handle.net/10150/280572

► Effects of weaning on metabolic profiles and hepatic IGF-1 mRNA of beef dams (Trial 1), and diet effects for early-weaned (EW) steers on response to… (more)

▼ Effects of weaning on metabolic profiles and hepatic IGF-1 mRNA of beef dams (Trial 1), and diet effects for early-weaned (EW) steers on response to an infectious bovine herpesvirus-1 (BHV-1) challenge (Trial 2) were investigated. Trial 1 treatments were arranged in a 2 x 2 factorial and included 14 heifers and 14 cows assigned randomly to one of two treatment regimens: EW (average age of 114 ± 13 d) or normal-weaned (NW, average age of 197 d). Heifers with calves EW experienced a greater increase (parity x weaning; P = 0.02) in BW over heifers with calves NW, but no change in BW due to weaning was observed for cows (P > 0.71). Early weaning (vs. NW) increased (P < 0.05) body condition (BC) and change in BC of all dams. No parity x weaning or parity x weaning x d interactions (P > 0.14) were observed for serum IGF-1, NEFA, or urea nitrogen (SUN). A parity x d interaction (P < 0.05) for hepatic IGF-1 mRNA, serum IGF-1, and SUN was observed, but no differences (P > 0.10) were detected between heifers and cows within d. For Trial 2, backgrounding treatments included a bermudagrass hay diet (CTRL); bermudagrass hay plus soybean meal (SBM) fed at 0.175% of BW (as-fed); bermudagrass hay plus SBM at 0.35% of BW; or a 70% concentrate (CONC) diet. During the receiving phase, all steers were fed CONC and intranasally challenged with BHV-1. Treatment x d interactions (P < 0.01) were observed for serum NEFA, total protein, SUN, glucose, immunoglobulin G (IgG), insulin, and rectal temperature. Three d after the BHV-1 challenge, IgG was greater (P < 0.05) for forage-fed steers vs. CONC. Three and 4 d after the challenge, rectal temperature was greater (P < 0.01) for protein supplemented steers vs. CTRL. Therefore, EW can increase BW and BC of first-calf heifers and decrease SUN in first-calf heifers and mature cows, and a higher quality diet fed to EW steers during a backgrounding phase enhances ADG and G:F, and increases febrile response (measured by rectal temperature) to an infectious BHV-1 respiratory challenge. Advisors/Committee Members: Duff, Glenn C (advisor).

Subjects/Keywords: Agriculture, Animal Culture and Nutrition.; Agriculture, Range Management.

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APA (6^th Edition):

Whitney, T. R. (2004). Effects of weaning programs on metabolic profiles and hepatic IGF-1 mRNA of first-calf heifers and mature cows, and effects of diet for early-weaned steers on response to an infectious bovine herpesvirus-1 challenge . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/280572

Chicago Manual of Style (16^th Edition):

Whitney, Travis Raymond. “Effects of weaning programs on metabolic profiles and hepatic IGF-1 mRNA of first-calf heifers and mature cows, and effects of diet for early-weaned steers on response to an infectious bovine herpesvirus-1 challenge .” 2004. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/280572.

MLA Handbook (7^th Edition):

Whitney, Travis Raymond. “Effects of weaning programs on metabolic profiles and hepatic IGF-1 mRNA of first-calf heifers and mature cows, and effects of diet for early-weaned steers on response to an infectious bovine herpesvirus-1 challenge .” 2004. Web. 07 Mar 2021.

Vancouver:

Whitney TR. Effects of weaning programs on metabolic profiles and hepatic IGF-1 mRNA of first-calf heifers and mature cows, and effects of diet for early-weaned steers on response to an infectious bovine herpesvirus-1 challenge . [Internet] [Doctoral dissertation]. University of Arizona; 2004. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/280572.

Council of Science Editors:

Whitney TR. Effects of weaning programs on metabolic profiles and hepatic IGF-1 mRNA of first-calf heifers and mature cows, and effects of diet for early-weaned steers on response to an infectious bovine herpesvirus-1 challenge . [Doctoral Dissertation]. University of Arizona; 2004. Available from: http://hdl.handle.net/10150/280572

University of Arizona

5. Bailey, Clayton R. Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle .

Degree: 2006, University of Arizona

URL: http://hdl.handle.net/10150/193620

► Two trials were conducted to evaluate the effects of gender on optimal CP concentrations (TRIAL 1) and gender and anabolic implants on the somatotropic axis… (more)

Subjects/Keywords: Crude Protein; Beef Cattle; Somatotropic Axis; Anabolic Implants; Gene Expression

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APA (6^th Edition):

Bailey, C. R. (2006). Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/193620

Chicago Manual of Style (16^th Edition):

Bailey, Clayton R. “Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle .” 2006. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/193620.

MLA Handbook (7^th Edition):

Bailey, Clayton R. “Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle .” 2006. Web. 07 Mar 2021.

Vancouver:

Bailey CR. Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle . [Internet] [Doctoral dissertation]. University of Arizona; 2006. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/193620.

Council of Science Editors:

Bailey CR. Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle . [Doctoral Dissertation]. University of Arizona; 2006. Available from: http://hdl.handle.net/10150/193620

University of Arizona

6. Moore, Chel Earl. CONTROLLED MILK FAT DEPRESSION AS A MANAGEMENT TOOL TO IMPROVE ENERGY BALANCE IN LACTATING DAIRY CATTLE .

Degree: 2005, University of Arizona

URL: http://hdl.handle.net/10150/194107

► Research conducted for this dissertation had three goals; 1) determine if CLA can induce milk fat depression immediately postpartum, 2) determine if CLA can alter… (more)

▼ Research conducted for this dissertation had three goals; 1) determine if CLA can induce milk fat depression immediately postpartum, 2) determine if CLA can alter energy availability, 3) determine the mechanism behind the mammary gland's decreased sensitivity to CLA immediately postpartum. The first study provides strong evidence indicating CLA can decrease milk fat synthesis immediately postpartum, but the dose required is approximately 3x greater than in established lactation. This trial also provided evidence that CLA can alter energy status, as CLA decreased days to EBAL nadir by nearly 5 days. This is relevant as recovery of EBAL from its lowest point provides an important signal for initiating ovarian activity and days to nadir is highly correlated with days to first ovulation. Study two was designed to determine if CLA induced milk fat depression could improve energy status during heat stress. Rumen-inert CLA reduced milk fat synthesis, and was able to improve energy availability, but did not increase milk yield or yield of other milk components. Although production was unchanged in this study, the study did provide further evidence that rumen-inert CLA can alter energy availability. Study three utilized intravenous infusion of CLA in cows in mid and early lactation to determine the mechanism for the mammary gland's decreased sensitivity in early lactation. It is postulated that increased fatty acid oxidation and subsequent enhanced levels of circulating NEFA present during the transition period competitively prevent adequate CLA uptake by the mammary gland. In the current study, trans-10, cis-12 CLA concentration in milk was not different between early and established lactation, while milk fat yield was drastically reduced on d 4 and 5 of trans-10, cis-12 CLA infusion in mid lactation cows, but unaltered in early lactation. Further, NEFA levels were nearly 3 fold higher in early lactation than in mid lactation, providing further evidence that increased circulating NEFAs in early lactation are unlikely to be the source of the mammary gland's decreased sensitivity during this time. Do to the variation in gene expression observed in this trial, we were unable to make any definitive conclusions as to the sensitivity of the expression of genes involved in milk lipid synthesis to CLA in early vs. mid lactation. Advisors/Committee Members: Baumgard, Lance H. (committeemember), Collier, Robert J. (committeemember), Duff, Glenn C. (committeemember).

Subjects/Keywords: Dairy; Milk Fat Depression; Conjugated Linoleic Acid

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APA (6^th Edition):

Moore, C. E. (2005). CONTROLLED MILK FAT DEPRESSION AS A MANAGEMENT TOOL TO IMPROVE ENERGY BALANCE IN LACTATING DAIRY CATTLE . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/194107

Chicago Manual of Style (16^th Edition):

Moore, Chel Earl. “CONTROLLED MILK FAT DEPRESSION AS A MANAGEMENT TOOL TO IMPROVE ENERGY BALANCE IN LACTATING DAIRY CATTLE .” 2005. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/194107.

MLA Handbook (7^th Edition):

Moore, Chel Earl. “CONTROLLED MILK FAT DEPRESSION AS A MANAGEMENT TOOL TO IMPROVE ENERGY BALANCE IN LACTATING DAIRY CATTLE .” 2005. Web. 07 Mar 2021.

Vancouver:

Moore CE. CONTROLLED MILK FAT DEPRESSION AS A MANAGEMENT TOOL TO IMPROVE ENERGY BALANCE IN LACTATING DAIRY CATTLE . [Internet] [Doctoral dissertation]. University of Arizona; 2005. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/194107.

Council of Science Editors:

Moore CE. CONTROLLED MILK FAT DEPRESSION AS A MANAGEMENT TOOL TO IMPROVE ENERGY BALANCE IN LACTATING DAIRY CATTLE . [Doctoral Dissertation]. University of Arizona; 2005. Available from: http://hdl.handle.net/10150/194107

University of Arizona

7. Sanders, Sara Ray. Effects of Heat Stress on Energetic Metabolism in Rats .

Degree: 2010, University of Arizona

URL: http://hdl.handle.net/10150/194613

► Studies conducted for this dissertation utilized a rodent model exposed to single or multiple short duration heat loads in an effort to: 1) elucidate the… (more)

▼ Studies conducted for this dissertation utilized a rodent model exposed to single or multiple short duration heat loads in an effort to: 1) elucidate the changes in energy metabolism occurring at the tissue and whole-body level in response to hyperthermia, 2) characterize specific aspects of glucose utilization and hepatic glucose production following a heat load and 3) determine if aspects of mitochondrial function and/or dysfunction might play a role in the metabolic changes that occur in response to heat stress. Study 1 was conducted to determine if rodents exposed to heat stress shared similarities using a bovine heat stress model. Specifically, we were interested in identifying changes in blood metabolites and hormones, as well as gene expression and protein abundance of enzymes associated with energy metabolism in skeletal muscle (type I and type II), liver and adipose tissue. Previous bovine data indicates glucose may be preferentially utilized during heat stress, suggesting alterations in energy metabolism. This study provided evidence that tissue-specific changes occur in response to a heat load and that full glucose oxidation might be reduced, specifically in skeletal muscle where abundance of PDK4 mRNA was increased. Within skeletal muscle, glucose transporters (GLUTs 1 and 4) also tended to be increased in rats exposed to a heat load. Increases in skeletal muscle AMPK-α and PGC-1α as well as increased expression of energy substrate transporters suggests heat stress may impose a cellular energy deficit and/or increased energy demands which subsequently leads to changes in energy metabolism. Few changes were noted in either hepatic or adipose tissue in response to acute heat stress in this pilot study. Study aim of Chapter 3 was to further characterize the effects of heat stress on energy metabolism at the tissue and whole-body level in rats exposed to either 1 or 2 bouts of heat. Rats exposed to a 6 h heat load tended to have higher plasma glucose but reduced insulin levels, compared to thermal neutral controls, suggesting decreased glucose uptake or increased hepatic glucose output. Additionally, although heat stress likely increases whole-body energy demand, plasma NEFA levels were blunted in the early hours following onset of heat, suggesting increased adipocyte insulin sensitivity. Gene expression of enzymes associated with oxidative energy metabolism were increased in the TA (which is comprised primarily of glycolytic muscle fibers) following 2 bouts and in liver following a single bout of heat, while expression of oxidative enzymes were decreased within the soleus (a primarily oxidative muscle type). AMPK mRNA was increased following a single bout of heat in hepatic tissue and after 2 bouts of heat in type I skeletal muscle. AMPK mRNA abundance remained the same following 1 bout but was reduced following 2 bouts of heat within type II skeletal muscle. In the TA, phosphorylated AMPK protein abundance was reduced by HS. Abundance of PGC-1α mRNA was increased in types I and II skeletal muscle but was… Advisors/Committee Members: Baumgard, Lance H. (committeemember), Rhoads, Michelle L. (committeemember), Limesand, Sean W. (committeemember), Duff, Glenn C. (committeemember).

Subjects/Keywords: AMPK; Energy metabolism; Heat stress; Oxidative stress; Rodents

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APA (6^th Edition):

Sanders, S. R. (2010). Effects of Heat Stress on Energetic Metabolism in Rats . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/194613

Chicago Manual of Style (16^th Edition):

Sanders, Sara Ray. “Effects of Heat Stress on Energetic Metabolism in Rats .” 2010. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/194613.

MLA Handbook (7^th Edition):

Sanders, Sara Ray. “Effects of Heat Stress on Energetic Metabolism in Rats .” 2010. Web. 07 Mar 2021.

Vancouver:

Sanders SR. Effects of Heat Stress on Energetic Metabolism in Rats . [Internet] [Doctoral dissertation]. University of Arizona; 2010. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/194613.

Council of Science Editors:

Sanders SR. Effects of Heat Stress on Energetic Metabolism in Rats . [Doctoral Dissertation]. University of Arizona; 2010. Available from: http://hdl.handle.net/10150/194613

University of Arizona

8. Ibrahim, Rita M. Effect of Two Breeds and Two Dietary Concentrate Levels on Feedlot Performance, Carcass Merit, Tenderness parameters and fatty Acid Profiles .

Degree: 2007, University of Arizona

URL: http://hdl.handle.net/10150/196131

► The objectives of this study were to investigate the different characteristics of the newly introduced breed, Waguli (Wagyu x Tuli) when comparing it with the… (more)

▼ The objectives of this study were to investigate the different characteristics of the newly introduced breed, Waguli (Wagyu x Tuli) when comparing it with the Brahman breed. Twenty-four animals were used. Six steers of each breed were fed 94% concentrate diet (94C) and the other six were fed 86% concentrate diet (86C). Eight steers, two from each group, each were harvested at 128 days, 142 days, and 156 days on feed. Feedlot performance data indicated that Waguli steers were highly efficient (P < 0.05) and gained more than Brahman steers on a daily basis (P < 0.05). Carcass characteristic data showed that Waguli steers have larger ribeye area with more 12th rib fat thickness, marbling score and higher quality grade (P < 0.05). It is well known that Wagyu is a highly marbled and tender Japanese breed. It was found that the reason for the Waguli tenderness and low shear force values to be the low level of calpastatin activity (P < 0.05), the inhibitor of the postmortem proteolytic enzyme-calpain. While the toughness of the Brahman meat was due to the high level of calpastatin activity. The calpain activity did not differ between the two breeds. Shear force values agreed with the calpain and calpastatin activities data, in which the Waguli steaks showed less shear force values at day 7 and 10 postmortem than the Brahman steaks (P < 0.05). However, at day 14 postmortem there was no difference in shear force values between the two breeds (P < 0.05). Fatty acid data analysis indicated that Waguli steers had a profile with less saturated fatty acids (SFA) and more unsaturated fatty acids (UFA) content than those in Brahman steers fat. Looking at the ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA), it is observed that Waguli steers had a greater ratio than Brahman steers. In conclusion, Waguli steers produce tender meat with good marbling ability, which likely to satisfy the consumers demand. In addition, they have a desirable average daily gain and feed efficiency with high polyunsaturated fatty acids comparatively with Brahman steers. Advisors/Committee Members: Marchello, John A. (committeemember), Goll, Darrell E. (committeemember), Duff, Glenn C. (committeemember), Baumgard, L. H. (committeemember), Marchello, E. V. (committeemember).

Subjects/Keywords: Waguli; Brahman; tenderness; carcass merit; fatty acids

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APA (6^th Edition):

Ibrahim, R. M. (2007). Effect of Two Breeds and Two Dietary Concentrate Levels on Feedlot Performance, Carcass Merit, Tenderness parameters and fatty Acid Profiles . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/196131

Chicago Manual of Style (16^th Edition):

Ibrahim, Rita M. “Effect of Two Breeds and Two Dietary Concentrate Levels on Feedlot Performance, Carcass Merit, Tenderness parameters and fatty Acid Profiles .” 2007. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/196131.

MLA Handbook (7^th Edition):

Ibrahim, Rita M. “Effect of Two Breeds and Two Dietary Concentrate Levels on Feedlot Performance, Carcass Merit, Tenderness parameters and fatty Acid Profiles .” 2007. Web. 07 Mar 2021.

Vancouver:

Ibrahim RM. Effect of Two Breeds and Two Dietary Concentrate Levels on Feedlot Performance, Carcass Merit, Tenderness parameters and fatty Acid Profiles . [Internet] [Doctoral dissertation]. University of Arizona; 2007. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/196131.

Council of Science Editors:

Ibrahim RM. Effect of Two Breeds and Two Dietary Concentrate Levels on Feedlot Performance, Carcass Merit, Tenderness parameters and fatty Acid Profiles . [Doctoral Dissertation]. University of Arizona; 2007. Available from: http://hdl.handle.net/10150/196131

University of Arizona

9. Zimbelman, Rosemarie Burgos. Management Strategies to Reduce Effects of Thermal Stress on Lactating Dairy Cattle .

Degree: 2008, University of Arizona

URL: http://hdl.handle.net/10150/195322

► Two strategies to reduce impact of heat stress on high producing dairy cows were examined. The first was to recalculate the temperature-humidity index (THI) using… (more)

▼ Two strategies to reduce impact of heat stress on high producing dairy cows were examined. The first was to recalculate the temperature-humidity index (THI) using high producing dairy cows under diurnal summer conditions. This re-evaluation confirmed that current THI values underestimate the severity of heat stress levels. Therefore, cooling of dairy cattle during warm summer months should begin at a THI of 68. Previously, a THI equal to or greater than 72 has been used to define onset of heat stress. This study demonstrated that a THI greater than or equal to 68 is sufficient to increase body heat storage, respiration rate, skin evaporative heat loss, declines in feed intake and milk yield. A second objective involved three studies carried out to evaluate use of niacin in dairy cow rations to improve evaporative heat loss and resistance to heat stress. Niacin is known to cause intense vasodilation in human and lab species. We hypothesized that increasing vasodilation would improve evaporative heat loss in dairy cows. In the first niacin study, supplementation of lactating dairy cows with an encapsulated rumen by-pass form of niacin (NIASHURE™; Balchem Corporation, New Hampton, NY) at a dose of 12 g/d proved effective in alleviating some affects of heat stress during mild thermal stress. We hypothesized that encapsulated niacin would induce vasodilation effects documented in humans and lab animals increasing evaporative heat loss. Past research demonstrated that the possible mechanism for vasodilation affects seen by niacin were most likely due to prostaglandin D secretions. Niacin may act through increased prostaglandin D and E production and secretion by Langerhans cells which then act upon vascular endothelial prostaglandin D receptors to increase vasodilation. No studies have evaluated impact of encapsulated niacin on milk yield and composition during periods of thermal stress under commercial dairy conditions. The objective of the last study was to examine the effects of encapsulated niacin during heat stress on milk production and composition as well as core body temperatures under commercial conditions. Advisors/Committee Members: Collier, Robert J (advisor), Baumgard, Lance H (committeemember), Duff, Glenn C (committeemember), Bilby, Todd R (committeemember), Foster, Billye (committeemember).

Subjects/Keywords: Heat stress; niacin; temperature humidity index; THI

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APA (6^th Edition):

Zimbelman, R. B. (2008). Management Strategies to Reduce Effects of Thermal Stress on Lactating Dairy Cattle . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/195322

Chicago Manual of Style (16^th Edition):

Zimbelman, Rosemarie Burgos. “Management Strategies to Reduce Effects of Thermal Stress on Lactating Dairy Cattle .” 2008. Doctoral Dissertation, University of Arizona. Accessed March 07, 2021. http://hdl.handle.net/10150/195322.

MLA Handbook (7^th Edition):

Zimbelman, Rosemarie Burgos. “Management Strategies to Reduce Effects of Thermal Stress on Lactating Dairy Cattle .” 2008. Web. 07 Mar 2021.

Vancouver:

Zimbelman RB. Management Strategies to Reduce Effects of Thermal Stress on Lactating Dairy Cattle . [Internet] [Doctoral dissertation]. University of Arizona; 2008. [cited 2021 Mar 07]. Available from: http://hdl.handle.net/10150/195322.

Council of Science Editors:

Zimbelman RB. Management Strategies to Reduce Effects of Thermal Stress on Lactating Dairy Cattle . [Doctoral Dissertation]. University of Arizona; 2008. Available from: http://hdl.handle.net/10150/195322

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And / Or
		in

Open Access Theses and Dissertations