Browsing by Author "Washburn, Kevin E"
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Item IMPACTS OF COMMINGLING CATTLE FROM DIFFERENT SOURCES ON THEIR PHYSIOLOGICAL, HEALTH, AND PERFORMANCE RESPONSES DURING FEEDLOT RECEIVING(2021-04-28) Wiegand, Jacob B.; Cooke, Reinaldo F; Gouvêa, Vinicius N; Pohler, Ky G; Daigle, Courtney L; Washburn, Kevin EThis experiment compared physiological, health, and performance responses of beef heifers assigned to different commingling schemes (1, 2, or 4 sources/pen) during a 56-d feedlot receiving period. Ninety-six recently weaned Angus-influenced heifers were obtained from an auction facility. Heifers originated from 4 cow-calf ranches and were reared in the same herd within each ranch since birth. Heifers were loaded into 2 livestock trailers at the auction yard (2 sources/trailer; d -2), arranged in 2 sections of each trailer according to source, and transported for 10 h to stimulate the stress of a long-haul. Heifers were not mixed with cohorts from other sources prior to and at the auction yard. Upon arrival (d -2), shrunk body weight (BW) was recorded and heifers were maintained in 4 paddocks by source with ad libitum access to a complete starter feed and water for 36 h. On d 0, heifers were ranked by source and shrunk BW and allocated to 1 of 24 drylot pens (4 heifers/pen) containing: 1) heifers from a single source (1SRC, n = 8), 2) heifers from 2 sources (2SRC, n = 8), or 3) heifers from 4 sources (4SRC, n = 8). From d 0 to 55, heifers had free-choice access to the complete starter feed and water. Heifers were assessed daily for symptoms of bovine respiratory disease (BRD), and feed intake was recorded from each pen daily. Blood samples were collected on d 0, 6, 13, 27, 41, and 55, and shrunk BW (after 16 h of water and feed withdrawal) was recorded on d 56 for average daily gain (ADG). No treatment differences were noted (P ≥ 0.56) for heifer ADG (mean ± SE = 0.853 ± 0.043 kg/d), final shrunk BW, feed intake, and feed efficiency. No treatment differences were noted (P ≥ 0.27) for plasma concentrations of cortisol and haptoglobin, and serum concentrations of antibodies against BRD viruses and Mannheimia haemolytica. No treatment differences were noted (P ≥ 0.17) for incidence of BRD (mean ± SE = 59.3 ± 5.0 %) or mortality. The proportion of heifers diagnosed with BRD that required three antimicrobial treatments to regain health increased linearly (P = 0.03) according to the number of sources (0.0, 12.3, and 20.8% of 1SRC, 2SRC, and 4SRC heifers, respectively; SEM = 7.0). Hence, commingling heifers from different sources did not impact performance, physiological responses, and BRD incidence during a 56-d receiving period, although recurrence of BRD after the second antimicrobial treatment increased according to commingling level.Item Impacts of Gestational and Early-Life Nutrition on Productive and Health Responses of Beef Cattle(2020-10-30) Schubach, Kelsey Margaret; Cooke, Reinaldo F; Cardoso, Rodolfo C; Pohler, Ky G; Smith, Stephen B; Washburn, Kevin ENutritional management during gestation as well as postnatally is critical to optimize efficiency and profitability of cow-calf systems. Two experiments were performed to evaluate the effects of trace mineral supplementation during gestation and supplementation with calcium salts of soybean oil (CSSO) to nursing beef steers on performance and physiological responses. In experiment one, the impact of inorganic or organic Co, Cu, Mn, and Zn supplementation to beef cows during gestation were evaluated on parameters associated with offspring performance and physiological responses. One hundred and ninety non lactating pregnant beef cows were assigned to the experiment at 117 ± 2.2 days of gestation (d 0) and received diets containing either 1) sulfate sources of Cu, Co, Mn, and Zn (INR), or 2) organic complexed source of Cu, Co, Mn, and Zn (AAC). No treatment differences were detected (P ≥ 0.19) for calf body weight at birth or at weaning. Heifers born to INR cows had delayed puberty attainment (treatment ×day interaction; P < 0.01), whereas no treatment differences were detected (P ≥ 0.24) for carcass traits when male offspring were reared as feeder cattle. In experiment two, the impacts of supplementing CSSO at 2 months of age via creep-feeding and/or postweaning via preconditioning were evaluated on parameters associated carcass quality and development. Steers receiving CSSO at 2 mo of age had greater (P ≤ 0.01) mRNA expression of genes associated with lipid metabolism in the longissimus muscle later in life, although this did not translate into improved carcass characteristics. Outcomes of these experiments may be used to develop nutritional strategies to enhance reproductive efficiency in female offspring and upregulate genes associated with lipogenesis during the finishing period. Research is still warranted to examine the effects of such supplementation during these periods of developmental plasticity on cattle productivity.Item Management of Feedlot Cattle Under Stressful Conditions(2023-06-20) Colombo, Eduardo Antonio; Cooke, Reinaldo F; Tedeschi, Luis O; Gouvea, Vinicius N; Washburn, Kevin EFour experiments were conducted to evaluate the (1) effects of an immunomodulatory feed ingredient (Omnigen-AF®) on body temperature, physiological and productive responses in heat-stressed finishing cattle, (2) effects of magnesium oxide supplement on ruminal, physiological, and productive parameters of finishing cattle consuming a corn-based diet, (3) effects of a synbiotic product, (i.e., a combination of yeast-derived product (prebiotic) and Bacillus subtilis (probiotic)), to replace or fed in conjunction with traditional feed-grade antimicrobials on performance, physiological and health parameters of receiving cattle during a 45-day feedlot receiving period, and (4) evaluate the impacts of administering a bovine appeasing substance at feedlot entry on respiratory disease incidence, physiological responses, feed intake, feed efficiency and body weight gain of feedlot cattle. In experiment 1, a treatment x day interaction (P < 0.01) was noted for vaginal temperature where animals consuming Omnigen-AF comparing with control had reduced vaginal temperature, which resulted in reduced (P < 0.04) mRNA expression of HSP70 and HSP72 towards the end of the study. In experiment 2, magnesium oxide supplementation linearly increased (P = 0.03) ruminal pH and linearly reduced (P < 0.01) hair concentration of cortisol at the end of the study (treatment x day; P = 0.02). In experiment 3, a reduced (P < 0.03) proportion of steers consuming the synbiotic supplement required a second antimicrobial treatment upon bovine respiratory disease diagnosis. Morbidity and mortality rates were also reduced (P = 0.02) for animals consuming the synbiotic supplement. In experiment 4, body weight gain and feed efficiency were improved (P < 0.05) for animals that received the appeasing substance comparing with control cohorts. Administering appeasing substance upon feedlot arrival also reduced (P = 0.05) plasma cortisol concentration and reduced the amount of antimicrobial treatments to heal upon respiratory disease incidence comparing with steers from control group. Collectively, these studies investigated and confirmed novel nutritional and management strategies to enhance the performance of feedlot cattle experiencing stressful conditions, mainly by improving their physiological and health conditions.Item Management of Feedlot Cattle Under Stressful Conditions(2023-06-20) Colombo, Eduardo Antonio; Cooke, Reinaldo F; Tedeschi, Luis O; Gouvea, Vinicius N; Washburn, Kevin EFour experiments were conducted to evaluate the (1) effects of an immunomodulatory feed ingredient (Omnigen-AF®) on body temperature, physiological and productive responses in heat-stressed finishing cattle, (2) effects of magnesium oxide supplement on ruminal, physiological, and productive parameters of finishing cattle consuming a corn-based diet, (3) effects of a synbiotic product, (i.e., a combination of yeast-derived product (prebiotic) and Bacillus subtilis (probiotic)), to replace or fed in conjunction with traditional feed-grade antimicrobials on performance, physiological and health parameters of receiving cattle during a 45-day feedlot receiving period, and (4) evaluate the impacts of administering a bovine appeasing substance at feedlot entry on respiratory disease incidence, physiological responses, feed intake, feed efficiency and body weight gain of feedlot cattle. In experiment 1, a treatment x day interaction (P < 0.01) was noted for vaginal temperature where animals consuming Omnigen-AF comparing with control had reduced vaginal temperature, which resulted in reduced (P < 0.04) mRNA expression of HSP70 and HSP72 towards the end of the study. In experiment 2, magnesium oxide supplementation linearly increased (P = 0.03) ruminal pH and linearly reduced (P < 0.01) hair concentration of cortisol at the end of the study (treatment x day; P = 0.02). In experiment 3, a reduced (P < 0.03) proportion of steers consuming the synbiotic supplement required a second antimicrobial treatment upon bovine respiratory disease diagnosis. Morbidity and mortality rates were also reduced (P = 0.02) for animals consuming the synbiotic supplement. In experiment 4, body weight gain and feed efficiency were improved (P < 0.05) for animals that received the appeasing substance comparing with control cohorts. Administering appeasing substance upon feedlot arrival also reduced (P = 0.05) plasma cortisol concentration and reduced the amount of antimicrobial treatments to heal upon respiratory disease incidence comparing with steers from control group. Collectively, these studies investigated and confirmed novel nutritional and management strategies to enhance the performance of feedlot cattle experiencing stressful conditions, mainly by improving their physiological and health conditions.Item Refining Productivity of Bovine IVF Embryo Transfer with Recipient Selection(2023-04-25) Staples, Alyx J.; Pohler, Ky G; Cooke, Reinaldo F; Washburn, Kevin EReproductive efficiency is a critical component of a successful cattle operation. Embryo transfer (ET) is a reproductive technology that cattlemen around the world use, to capitalize on elite females by using common females as a recipient. This reproductive technology has become increasingly common in both the dairy and seedstock sectors. Costs associated with ET deters other producers from utilizing ET technology. By improving ET pregnancy rates, costs decline. A lowered cost and enhanced ET pregnancy rate will appeal to more producers resulting in broader application. It is noteworthy that a small surge in ET pregnancy rate yields thousands of additional dollars for cattle producers. This study addressed factors that potentially contribute to reduced pregnancy rates in recipient cattle. There were five factors assessed in this study: 1) days following recipient estrus (DSE), 2) embryo quality grade, 3) embryo stage, 4) embryo state, and 5) matching embryo stage to recipient estrus. Data from 435 transfers was included in this study. Two factors were identified significantly (P < .01) decreasing pregnancy rates in recipients: days following recipient estrus and embryo state. The state of the embryo exhibits a sizable (40.6% and 18.8%) difference in pregnancy rates. By addressing how many days followed a recipient estrus and the embryo state before transfer can potentially boost pregnancy rates.Item Reproductive Strategies for Increasing Fertility in Beef Cattle(2023-08-14) Oliveira Filho, Ramiro Vander; Pohler, Ky G; Lamb, Graham C; Cardoso, Rodolfo C; Washburn, Kevin EThe present research efforts focused on identifying different strategies to increase reproductive efficiency in beef cattle. Reproductive efficiency of beef females has a direct impact on the profitability of beef cattle operations. Therefore, the use of reproductive technologies coupled with appropriate reproductive management has a tremendous impact on beef cattle production. Three experiments were performed to evaluate the effects of a different estrus synchronization approach, use of heterospermic sex-sorted semen and evaluation of the influence of estrus activity and reproductive tract size and position scores on fertility of beef cows. In experiment one, extended length of progesterone exposure for 12 days with additional PGF injection in the middle of the protocol, increased follicular diameter and decreased circulating concentrations of progesterone at CIDR removal in Brahman cows; however not difference in estrus response, ovulation time and pregnancy rates was observed when compared to the Bos indicus PG 5 – Day + CIDR protocol. In experiment two, increased dosage of sex sorted SuperConventional heterospermic semen did not improve pregnancy rates of cows submitted to TAI, therefore, lower semen dosage could be used for Super Conventional semen production, optimizing the collection process. The restricted use of Super Conventional semen for cows that have activated estrus detection patch at TAI and use of conventional semen for cows that do not express signs of estrus can be used as an alternative management approach to achieve higher conception rates and higher percentage of calves with the desired sex while ensuring that cows failing to express estrus the best chance of becoming pregnant early in the breeding season. In experiment three, pregnancy rate at day 30 following FTAI were directly affected by estrus expression and size and position of the reproductive tract (SPS). Pregnancy rates were greatest in cows with smaller reproductive tracts and expressed estrus by AI. Thus, from a management perspective, it may be beneficial to incorporate both an estrus detection system and assign reproductive tract SPS at breeding to make individual breeding decisions.Item Supplementation of Omega-6 Fatty Acids in Cow-calf Operations(2021-12-08) Poggi Brandão, Alice; Cooke, Reinaldo F; Dunlap, Kathrin A; Pohler, Ky G; Lamb, Graham C; Washburn, Kevin EFour experiments were conducted to evaluate: (1) effects of calcium salts of soybean oil (CSSO) supplementation to Bos taurus beef cows post-AI on conception rates and (2) on pregnancy establishment factors; (3) effects of CSSO supplementation to late gestating beef cows on the performance of the offspring; (4) the viability of utilizing low-moisture molasses-based blocks (LMB) as a delivery method for CSSO. In Exp. 1, 1,771 cows were divided into groups, and inseminated on d 0. After AI, groups received CSSO (n = 11), or prilled saturated fat (CON; n = 11) from d 0 to 21. Cows receiving CSSO had greater (P = 0.01) pregnancy rates. In Exp. 2, 90 cows housed in 18 pens were assigned to the same treatments and timed AI program from Exp. 1. On d 15, selected cows were assigned to conceptus collection. On d 20 blood was sampled for RNA extraction. CSSO supplementation increased (P = 0.05) mRNA expression of IFNT by the conceptus, and blood mRNA expression of ISGs. In Exp. 3, cows were assigned to receive: CSSO (n = 52) or CON (n = 52) during late gestation. CSSO cattle had greater (P ≤ 0.02) colostrum and plasma IgG; greater (P ≤ 0.05) expression of adipogenic and myogenic genes; required fewer microbial treatments for BRD (P = 0.05) and had greater LM area compared to CON cohorts. In Exp. 4, 36 cows (n = 9 pens) were assigned to receive: 1) NOSUPP; 2) LMB, 24.7% CSSO; 3) CONC, hand-fed, 24.7% CSSO. Plasma concentrations of linoleic acid, ω-6 PUFA, and total FA were greater (P < 0.01) in CONC and LMB vs. NOSUPP cows. Collectively, these results present CSSO supplementation as a strategy to improve reproductive success in Bos taurus beef cows and productive performance of offspring born from supplemented dams. These results are associated to effects of linoleic acid and its ω-6 derivates. Additionally, the use of LMB seems to be a valid delivery method for CSSO supplementation, and consequently ω-6 FA, to beef cows.