Bovine adipose-derived stem cells (ADS), a form of adult stem cells, are somatic cells that have similar characteristics of embryonic stem (ES) cells. Bovine ADS cells possess multipotent capabilities and have been found to express pluripotency genes associated with ES cells. The unique properties of ADS cells make them a desirable source for reprogramming experiments. The goal of reprogramming experiments is to transform somatic cells from a differentiated state to a pluripotent state. When somatic cells reprogram, there are certain epigenetic changes or modifications that must occur in order to successfully reprogram the nucleus. Epigenetic modifications will change the chromatin configuration without changing the DNA sequence. Somatic cells can be exposed to small molecules that may be able to reduce the chances of having incomplete chromatin modification. Two epigenetic modifying factors are a DNA methyltranferase inhibitor, zebularine (Zeb), and a histone deacetylase inhibitor, valproic acid (VPA). By inducing gene expression with the epigenetic modifiers, the cells may be stimulated to reprogram more efficiently than cells with lower gene expression. In the first experiment, three bovine ADS cell lines were treated with VPA or Zeb to observe the changes in expression levels of Oct4, Sox2, and Nanog (pluripotency-associated genes). The cells were treated for a period of 5, 7,10, or 14 days. VPA led to the highest increase of the pluripotency genes; however, both treatments may have produced a partial reprogramming. This partial reprogramming may result in the bovine ADS cells reaching complete pluripotency when combined with a reprogramming technique. In the second experiment, three bovine ADS cell lines were treated with VPA or Zeb for five days then followed with transduction using lentivirus. Oct4, Sox2, and Nanog were increased the highest when using epigenetic modifiers. Statistical differences for expression of the pluripotency-associated genes were found for cells treated with zebularine. While it was thought that viral transduction in combination with epigenetic modifiers would produce higher expression levels of the pluripotency-associated genes, this was not found to be true in this experiment.

Research has found conflicting results on animal performance and carcass traits associated with the use of forage as the primary feed source for finishing cattle. Consumer interest in forage-fed products has grown and little research has been done comparing performance of forage-fed animals and beef finished on different forages. Spring weaned calves (n=54; 257 ± 2.5 kg; 3/8 Gelbvieh, 3/8 Red Angus, and 1/4 Brahman) were used in the evaluation of three forage systems (S1, S2, and S3) on a 100% forage diet in two consecutive years (June 2009 and 2010). Steers were divided into 9 groups based on initial body weight (d0) and randomly assigned to replicates within system (3 replicates per system). Pastures were rotationally stocked at 1.01 ha/steer. Steers in S1 grazed bermudagrass (45% of area) during summer, and ryegrass (35% of area) and ryegrass sod-seeded into bermudagrass paddocks (20% of area) in winter. Steers in S2 grazed bermudagrass (45% of area) during summer, dallisgrass/clover mix (20% of area) during fall and spring, and ryegrass/cereal rye/clover mix (35% of area) during winter. Those in S3 had access to bermudagrass (20% of area) and sorghum-sudan hybrid/forage soybean during summer (7.5% of area each), dallisgrass/clover mix (20% of area) during fall and spring, and ryegrass/cereal rye/clover mix (45% of area) during winter. Excess forage was cut for hay and fed within system when necessary. Average daily gain (ADG) for summer, winter and for the whole study were not different (P > 0.05) between systems. Animals in Y2 (0.5 kg/d) gained more (P > 0.05) than those in Y1 during summer (0.21 kg/d), but ADG in Y1 (1.5 kg/d) was greater (P > 0.05) than in Y2 (1.3 kg/d) during winter. No significant differences (P > 0.05, Table 3.12) were found in final weights, LM area, KPH, YG, lean color and marbling. Dressing percentage and hot carcass weight were greater (P < 0.05) for S3 than those for S1 and S2 was intermediate. Backfat and PYG was affected by YxS interaction (P < 0.05). Cooking loss and Warner-Bratzler shear force were greater (P < 0.01) for Y1 than for Y2.

There has been thorough documentation to support the role of dopamine in the control of prolactin production and secretion in various mammalian species, including the horse. However, there is evidence that other factors are involved in prolactin secretion. Seven experiments were conducted to assess factors that potentially might affect prolactin secretion in the horse. The first two experiments were conducted (separately) to test whether arginine vasopressin (AVP) or vasoactive intestinal polypeptide (VIP) affected prolactin secretion. In each experiment, AVP or VIP was administered intravenously and blood samples were collected to determine the effect on prolactin secretion. Neither peptide produced any alteration in plasma prolactin concentrations compared to simultaneous saline-injected controls (P > 0.1). Five subsequent experiments were conducted to assess the effects of various drugs on prolactin secretion in response to acute exercise. Pre-exercise treatments included dexamethasone (a glucocorticoid analog, administered 15 h before exercise), naloxone (an opiod antagonist, administered 2 min before exercise), cabergoline (a dopaminergic agonist, administered 15 h before exercise), flunixin meglumine (a prostaglandin inhibitor, administered 15 min before exercise), and sulpiride (a dopamine antagonist that causes the release of prolactin, administered 1.5 h before exercise). In all experiments, exercise induced an immediate increase (P < 0.05) in plasma prolactin concentrations in control horses. Pretreatment with dexamethasone, naloxone, or flunixin meglumine did not alter (P > 0.1) plasma prolactin concentrations relative to saline-treated controls. Pretreatment with cabergoline completely obliterated (P < 0.01) the exercise induced rise in prolactin concentrations. Pretreatment with sulpiride caused an immediate increase (P < 0.001) in prolactin concentrations relative to controls, but resulted in no change in prolactin response to exercise 90 min later relative to controls. It is concluded that the only drug that had a significant effect on prolactin secretion was the dopaminergic agonist cabergoline. Direct administration of AVP or VIP, or perturbations of the adrenal cortical axis, the opioid system, or the prostaglandin system, had no effect on prolactin secretion as has been reported previously for other species.

Eighteen neonatal Holstein bull calves (38.85 ± 4.71 kg) were assigned to one of two treatments at birth to determine the effect of feeding time on growth, nutrient intake, metabolic hormone secretion, and energy metabolism. Regularly fed calves (n = 9) were fed MR daily at 0630 h, and irregularly fed calves (n = 9) at 1030, 0800, 0630, 0830, 0530, 0930, and 0730 Monday through Sunday. Body weights were measured weekly from birth to 9 weeks. Water intake, fecal scores, and starter intake were measured daily. Serial blood collections were conducted at 2, 4, 6, and 8 weeks for ghrelin and GH concentrations. Blood sample collection began one hour prior to regular feeding time (0530 h) and ended one hour post regular feeding time (0730 h), at time points 0, 15, 30, 45, 50, 55, 60, 65, 70, 75, 90, 105, and 120 minutes. An IVGTT was performed at weeks 3, 6, and 9 to assess glucose metabolism. Water intake increased (P < 0.05) in irregularly fed calves at weeks 1 and 3. A treatment by week interaction and a main effect of week were observed for ghrelin concentrations (P < 0.05), and regularly fed calves exhibited increased ghrelin concentrations at week 4 (P < 0.10). Plasma ghrelin concentrations increased with age until weaning at week 6 then decreased at week 8. An increase in GH concentrations were observed at time points t= 75 (P < 0.05), 90 (P < 0.10), and 120 (P < 0.10) min. A treatment by week interaction and a main effect of week were observed for GH concentrations (P < 0.0001). Regularly fed calves had higher GH concentrations at weeks 2 and 4 (P < 0.05). No differences were observed (P > 0.10) for glucose concentrations. Peak insulin concentrations (P < 0.05) and AUC for insulin (P < 0.10) increased as calves aged, indicating that calves become less sensitive to insulin as they develop. Results indicated that feeding time does not have an overall effect on growth, feed intake, and glucose metabolism, but does affect growth hormone concentrations.

Six insulin sensitive and six insensitive mares were used in a replicated 3 x 3 Latin square design to determine the pituitary hormonal responses (compared to vehicle) to sulpiride and thyrotropin-releasing hormone (TRH), two compounds commonly used to diagnose pituitary pars intermedia dysfunction (PPID) in horses. Mares were classified as insulin sensitive or insensitive by their previous glucose responses to direct injection of human recombinant insulin. Treatment days were February 25 and March 10 and 24, 2012. Treatments were sulpiride (racemic mixture, 0.01 mg/kg BW), TRH (0.002 mg/kg BW), and vehicle (saline, 0.01 mL/kg BW) administered intravenously. Blood samples were collected via jugular catheters at -10, 0, 5, 10, 20, 30, 45, 60, 90, 120 min relative to treatment injection. Plasma ACTH concentrations were variable and were not affected by treatment or insulin sensitivity category. Plasma melanocyte stimulating hormone (MSH) concentrations responded (P < 0.01) to both sulpiride and TRH injection, and were greater (P < 0.05) in insulin insensitive mares than in sensitive mares. Plasma prolactin concentrations responded (P < 0.01) to both sulpiride and TRH injection, and the response was greater (P < 0.05) for sulpiride; there was no effect of insulin sensitivity. Plasma thyroid stimulating hormone (TSH) concentrations responded (P < 0.01) to TRH injection only, and were higher (P < 0.05) in insulin sensitive mares in almost all time periods. Plasma LH and FSH concentrations varied with time (P < 0.05), particularly in the first week of the experiment, but were not affected by treatment or insulin sensitivity category. Plasma GH concentrations were affected (P < 0.05) only by day of treatment. The greater MSH responses to sulpiride and TRH in insulin insensitive mares were similar to, but not as exaggerated as, those observed by others for PPID horses. Also, the reduced TSH concentrations in insulin insensitive mares are consistent with the previous observation of elevated plasma triiodothyronine concentrations in hyperleptinemic horses (later shown to be insulin insensitive as well).

Gastrointestinal nematodes (GIN) are parasites of major concern for domestic and exotic ruminant species around the world. In the past, zoological facilities used anthelmintics as their primary control method. Challenges in accurate dosing and administration of anthelmintics to exotic hoofstock contributed to the development of resistant nematode populations in zoological settings. The historic dependency on anthelmintics to control GIN populations is no longer an option. Biological alternatives are urgently needed, in both exotic and domestic ruminants, in the war against resistance. One such alternative is the use of the nematophagous fungus, Duddingtonia flagrans. Three independent studies were conducted: A nine day study in the spring of 2010, a nine day study in the spring of 2011, and a 12 week study in the summer of 2011. The first study evaluated the efficacy of D. flagrans chlamydospores, as a suspension mixed into feed, in reducing infective GIN in feces at a dose of 500,000 chlamydospores per kg/BW administered for 4 consecutive days to giraffe and antelope. The second and third studies evaluated the efficacy of a powdered mixture containing D. flagrans chlamydospores incorporated into feed in reducing infective GIN in feces at a dose of 30,000 chlamydospores per kg/BW administered for 4 consecutive days and 8 weeks, respectively, in giraffe, antelope, and gerenuk (study 3 only). For studies 1 and 2, fecal samples were collected daily to monitor fecal egg count and percent reduction of infective larvae (L3) in fecal cultures. For study 3, samples were collected on a weekly basis. Results from all 3 studies indicated that D. flagrans was effective in reducing L3 in the feces during the period of feeding, The results from these studies demonstrated that the use of D. flagrans in exotic artiodactylids infected with GIN could be a long term prophylactic tool to reduce forage infectivity. Used in conjunction with other control methods, D. flagrans could be part of the future of GIN parasite control in zoological facilities.

The objective of this study is to evaluate the association of single nucleotide polymorphisms with growth, performance, and carcass quality and composition characteristics in a population of cattle consisting of multigenerational Angus sired calves and modern characteristic Charolais sired calves. A total of 132 calves were evaluated. Due to a limited sample population statistical difference was set at p ˂ 0.05 and statistical trends were set at p ˂ 0.1. Mean birth weights were significantly higher for Charolais sired calves as compared to Angus sired calves. Significant differences were observed between the two breed types for mean weaning weights with Angus sired calves having heavier weaning weights as compared to Charolais sired calves. Charolais sired animals had significantly larger rib eye areas as compared to the Angus sired animals. A significant difference was observed between the two groups for back fat thickness with the Angus sired animals having a larger amount than the Charolais sired animals. Angus sired animals had significantly higher marbling scores as compared to the Charolais sired animals. Eleven SNP on CAPN3 and two SNP on CAST were found to be associated with at least one of the traits observed. Two of these SNP were significantly associated with weaning weight. Three of these SNP were significantly associated with hip height. One SNP was significantly associated with average daily gain. Three of these SNP were significantly associated with hot carcass weight. One of the SNP was significantly associated with marbling score. One was significantly associated with rib eye area and two of these SNP were significantly associated with back fat thickness.

Four experiments were performed to study the effects of the gonadotropin releasing hormone (GnRH) analog, deslorelin acetate (Ovuplant), on endocrine and reproductive characteristics in mares. The first experiment tested whether anecdotal field reports of Ovuplant causing extended interovulatory intervals would be detectable under controlled, experimental conditions. The use of Ovuplant to hasten ovulation in 13 mares, compared to 12 controls, increased (P < 0.05) the interovulatory interval by 6.2 d and suppressed (P < 0.05) plasma concentrations of both luteinizing hormone (LH) and follicle stimulating hormone (FSH) for approximately 11 d. Two mares receiving Ovuplant did not return to estrus within 30 d. In the second experiment, 10 control mares and 10 mares induced to ovulate with Ovuplant were administered GnRH (50 μg) on d 1, 4, 7, and 10 after ovulation. Again, treated mares had a longer (4.4 d, P < 0.05) interovulatory interval and suppressed LH and FSH concentrations in daily plasma samples. The gonadotropin response to GnRH was lower (P < 0.05) in the deslorelin mares on d 1, 4, and 7, indicating a lack of pituitary responsiveness. In the third experiment, 9 stallions and 12 steroid-treated geldings were used to determine if males were potential models for studying the deslorelin-induced gonadotropin suppression. In both cases, treatment with Ovuplant caused an initial rise in both gonadotropins followed by suppression for about 14 d. In the last experiment, 21 mares were used to determine if multiple doses of deslorelin would cause complete ovarian shutdown. Mares received either sham injections, three Ovuplant implants on the first day, or one implant per day for 3 d (n = 7 per group). Treatment with multiple deslorelin implants increased (P < 0.05) the interovulatory interval by 14.8 d and suppressed LH and FSH concentrations for approximately 25 d, however no mares exhibited complete ovarian shutdown. In conclusion, deslorelin acetate implants in horses in the form of Ovuplant induce short-term increases in LH and FSH secretion followed by long-term suppression of these concentrations and an insensitivity of the pituitary to GnRH. In a small percentage of mares, long-term ovarian shutdown is a possibility.

This research was conducted to estimate the true digestible Trp (dTrp) requirements in nursery, growing, and late finishing pigs and the effects of supplemental Trp on physiology, behavior, and meat quality. Five experiments were conducted to estimate the dTrp requirement in nursery pigs. Using broken-line regression analysis, dTrp requirements were 0.21, 0.20, and 0.18% for Phase I (5.2 to 7.3 kg), II (6.3 to 10.2 kg), and III (10.3 to 15.7) nursery pigs. In addition, four experiments were conducted to estimate the dTrp requirements in growing and finishing pigs. Using broken-line regression analysis, the dTrp requirement of pigs weighing 30.9, 51.3, and 74.6 to 104.5 kg was 0.167, 0.134, and 0.102%, respectively. An experiment also was conducted to determine the ratio of Trp:Lys and Thr:Lys in diets for nursery pigs (7.1 to 15.6 kg BW). The treatments were arranged in a 3 x 3 factorial with three ratios of true digestible Thr:Lys (0.55, 0.60, or 0.65) and three ratios of true digestible Trp:Lys (0.145, 0.170, or 0.195). Overall, optimal performance was in pigs fed the true digestible Trp:Lys ratio of 0.195 at Thr:Lys ratios 0.60 and 0.65. These results indicate that dietary levels of Trp above 0.19% may be needed to maximize growth performance in diets containing wheat and barley. Four experiments were conducted to determine the effects of supplemental Trp on meat quality and plasma and salivary cortisol and plasma lactate in growing pigs. Pigs fed the diet with supplemental Trp had lower (P < 0.01) mean plasma cortisol and lactate (P < 0.07) concentration than pigs fed the basal diet. Meat quality effects varied, but overall, results indicated that Trp had no positive effect on meat quality. Lastly, a study was conducted to evaluate the effects of Trp on growth, behavior, intestinal morphology, and brain and plasma metabolites subsequent to weaning and mixing. Cortisol was decreased (P < 0.07) after mixing in pigs fed Trp. Brain metabolites also were increased (P < 0.09) by Trp. Tryptophan supplementation has varied effects on growth performance, behavior, physiology, and meat quality in pigs.

Six experiments were conducted to determine the interactive effects of Eimeria acervulina (E. acervulina) infection and phytase, and the effects of phytase in nutritionally adequate diets and in diets deficient in Ca and available P (aP). Corn-soybean meal (C-SBM) diets were used. In Exp 1, treatments were: 1) C-SBM, 1.0% Ca and 0.45% aP; 2) C-SBM, 0.80% Ca and 0.25% aP; 3) Diet 1 + 600 FTU phytase/kg; 4) Diet 2 + 600 FTU phytase/kg; 5 to 8) Diets 1 to 4 but infected with coccidiosis. Weight gain (ADG), feed intake (ADFI), and gain:feed were reduced (P < 0.01) by the coccidial infection and the reduction in Ca and aP. Phytase increased (P < 0.02) ADG and ADFI, regardless of the Ca and aP content of the diet or the presence of coccidiosis. Gain:feed was increased by phytase but only in uninfected chicks (phytase x coccidiosis interaction, P < 0.02). Phytase increased (P < 0.02) bone ash percentage but only in diets deficient in Ca and aP (P < 0.01). Experiments 2 and 3 included only treatments 1 to 4 of Exp 1. The reduction in Ca and aP reduced (P < 0.01) ADG, ADFI, and gain:feed. Phytase addition increased (P < 0.02) ADG and ADFI in diets deficient in Ca and aP and in the nutritionally adequate diets. Experiments 4, 5, and 6 were conducted to determine the effects of phytase on intestinal transit time in broilers. Diets were: 1) C-SBM, 0.9% Ca and 0.35% aP; 2) C-SBM, 0.80% Ca and 0.25% aP + 600 FTU phytase/kg. Transit time on Day 1, but not on Day 7, was faster (P < 0.03) in chicks fed phytase. These data indicate that phytase is effective in the presence of a coccidial infection, but it may not be as effective as in uninfected chicks. Futhermore, phytase increases growth in diets deficient in Ca and aP and in diets formulated to be adequate in all nutrients. This increase in growth may be due to a faster transit time of feed through the digestive tract, resulting in a greater feed intake and gain.