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.

Although superfetation has been reported in cattle and other species, there is considerable skepticism as to its existence due to the lack of clear evidence in these reports. Other explanations such as embryonic diapause or differential growth of twins have been suggested as more accurate descriptions of the cases reported as superfetation. The hypothesis of this study is that if a viable pregnancy can ensure maternal recognition in cattle, an asynchronous embryo can develop in a more chronologically advanced uterine environment. The objective was to produce superfetation by (1) ovulation induction and artificial insemination (AI) of pregnant cows and (2) transfer of 7-day embryos to cows with more advanced pregnancies. An attempt to produce superfetation by induction of ovulation in mated cattle with human chorionic gonadotropin (hCG) followed by AI was unsuccessful. Ovulation was induced in pregnant cows on day 7 but could not be induced >23 days of pregnancy. Subsequently, it was shown that uterine stage bovine embryos (7-day) could develop when transferred to recipients on day 14 of pregnancy, but not on day 28, day 60, or day 90 of pregnancy. Twins (7 days asynchronous) were produced in a recipient that received two 7-day embryos 14-days post-estrus. Although the younger twin was a heifer and her co-twin was a bull, the heifer was not a freemartin. FSH and hCG treatment 7 days prior to embryo transfer (ET) did not increase the rate of superfetation in 14-day or 25-day mated recipients. The nonsurgical ET technique may have caused pregnancy loss in recipients receiving embryos >25 days post-estrus. Two sets of asynchronous twins were produced by transfer of 7-day embryos to 14-day pregnant recipients. An additional experiment was undertaken to determine if asynchronous embryos could develop following maternal recognition in pregnant cows yet prior to invasion of the contralateral uterine horn by the primary conceptus. Asynchronous twins were produced following transfer of 7-day embryos to a 13-day pregnant recipient but not in 19-day pregnant recipients. Asynchronous twin pregnancies (superfetation) were therefore consistently produced in this series of experiments by transfer of embryos to recipients up to 16 days of pregnancy.

The objectives of the first experiment were to ascertain if there were any differences between two mouse areola and adipose tissue cell lines. These cell lines differed only in the presence or absence of the hypoxanthine phosphoribosyl transferase (HPRT) gene. It was found that the cell lines were similar for all parameters. The objectives of the second experiment were to determine if the HPRT gene had an effect on the development of preimplantation mouse embryo. To test this transgenic mouse lines were created. The embryo sex and genotype ratio, the embryo diameter, and the embryo developmental patterns, using a Collin-Ryan Embryo Development (C-RED) score, were determined. The sex and genotype ratios differed from the expected 1:1. The experiment concluded that HPRT is effecting embryo development and sex ratios The objectives of the third experiment were to determine if there is an effect of sex and HPRT on the cell number of mouse blastocysts. It was found that there was not an effect of sex, but that HPRT independent of sex was effecting the cell number of mouse blastocysts. The objectives of the fourth experiments were to determine if the HPRT gene in co-culture would have an effect on the development and cell number of mouse blastocysts. The blastocysts co-cultured with cells containing the HPRT gene had significantly greater number of blastomeres. This experiment concluded that HPRT in co-culture can alter the cell number of mouse blastomeres. The objective of the fifth experiment was to determine if the same results that were seen with the HPRT gene in co-culture on mouse embryos could be found with bovine embryos. There was significantly more blastocyst from co-culture with the cells containing the HPRT gene. There was not a difference in cell number of the bovine blastocyst. The sixth experiment determined the effect of HPRT inhibitors and an inducer on bovine embryo development and sex ratios. It was found that the embryos developed with the inducer in the medium did not have altered sex ratios. The results of these experiments demonstrate that HPRT is effecting mammalian embryo development.

The objective of the first experiment was to determine the effects of storage at 22aC vs. 4aC on the motility and percentage of membrane-intact sperm (%MIS) of epididymal mouse sperm. Testicles were allocated into 22aC or 4aC treatment groups and stored for 24 or 48 hours. Additional testicles were allocated into the 4aC treatment for storage for 72 or 96 hours. Sperm was collected and analyzed at each time point. Storage at 22aC lowered motility and %MIS (P<0.05) when compared with control sperm and 4aC sperm at both the 24 and 48 hours. Motility and %MIS of 4aC sperm did not decrease when compared with the control until after 72 hours of storage. The second experiment evaluated the effects of 22aC vs. 4aC storage for 24 and 48 hours on epididymal dog sperm. Motility and %MIS of the 22aC sperm was lower than that of the 4aC sperm and the control (P<0.05) at 24 and 48 hours. Motility of the 4aC sperm was lower than the control at 24 and 48 hours (P<0.05), however %MIS was not lower than the control until 48 hours. The third experiment tested the effect of cryopreservation on epididymal dog sperm. Sperm was frozen immediately (A), after 48 hours at 4aC in liquid (B) or after 48 hours at 4aC of the whole testicle (C). Both pre-freeze (PF) and post-thaw (PT) motility and %MIS of B and C were lower than A (P<0.05). PT values were lower than PF values in all treatments (P<0.05). PT motility of B was lower than C (0 vs. 35.0¡Ó3.6%). Storage at 4aC allows collection of motile epididymal mouse and dog sperm for several days after death. Dog testicles can be refrigerated for 2 days and epididymal sperm frozen with PT motility and %MIS of 35 and 62%.

The objectives of this study were the description of changes in genetic diversity in a colony of dog guides since its founding, and the investigation of the genetics of longevity in that population. Two breeds of dog, German Shepherds (GS) and Labrador Retrievers (LR), were evaluated. There were rapid increases in average pairwise relationship in both breeds, although the average was approximately one-third higher in the GS population than in the LR population. A similar trend was observed for average inbreeding. In the current generation, relationship and inbreeding for all animals averaged 25.3% and 26.2% in GS and 15.5% and 22.0% in LR, respectively. Effective founder numbers initially decreased in GS until generation 3, and then increased steadily. There was a constant increase in effective founder number in LR after founding. A similar pattern was seen for effective ancestor number as well. Founder genome equivalents were initially higher in the GS but decreased over time in both breeds. New breeding stock should be imported in order to reduce the levels of inbreeding and relationship in this colony. Data on longevity for 1,403 GS and 1,816 LR dogs who worked as guides were used to estimate genetic parameters for working life. Two measures of working life were considered: working life to 18 months post-graduation (EWL) and working life beyond 18 months post-graduation (LWL). Survival analysis was used to estiamte the sire component of variance and estimated breedinb values (EBVs). Linearized heritability estimates were small: 0.032 and 0.045 for EWL and 0.016 and 0.032 for LWL in GS and LR, respectively. Genetic trend was estimated by regression of EBVs on year. No trend was observed for either trait in either breed, suggesting that historical selection criteria were not effective in improving working life. An antagonistic relationship may exist between aptitude for guide work and risk of culling for temperament.

In this study, I evaluated the cryopreservation by pellet freezing of spermatozoa from individual dogs. In Experiment I, spermatozoa from 15 pairs of epididymides were suspended in glycerol, frozen as pellets of 10, 50, 100, or 200 μl volumes, and thawed by dilution with TALP (Tyrode's solution plus albumin, lactate, pyruvate). In Experiment II, spermatozoa from 16 pairs of epididymides were suspended in glycerol, dimethyl sulfoxide, or ethylene glycol, frozen as 100 μl pellets, and thawed by dilution with TALP, canine capacitation medium (CCM), or 3% sodium citrate solution. In Experiment III, spermatozoa from 15 pairs of epididymides were suspended in glycerol, frozen as 100 μl pellets, and thawed by dilution with CCM. In Experiment IV, ejaculated spermatozoa from each of three dogs and epididymal spermatozoa from each of four other dogs were suspended in glycerol and were frozen and thawed as in Experiment III. Survival was determined by microscopic evaluation of motility and of membrane integrity. In Experiments III and IV, survival was also assayed by measuring the zona-binding capacity of the spermatozoa. Survival of frozen-thawed samples was significantly lower than unfrozen samples. Sperm survival after freezing depended significantly on the pellet volume, reflecting the effect of cooling rate as a function of pellet volume. Thawing solutions and CPAs also significantly affected post-thaw sperm survival. The highest post-thaw survival was obtained with a pellet volume of 100 μl and with the CPA-thawing solution combinations of glycerol-CCM and glycerol-TALP. The number of membrane-intact spermatozoa bound to each oocyte was significantly higher for unfrozen samples than for frozen-thawed samples. Ejaculated spermatozoa exhibited survival and zona-binding capacity similar to that of epididymal spermatozoa, and there was little variation in the survival of ejaculated spermatozoa from an individual dog. There were significant differences in post-thaw sperm survival and zona-binding capacity among individual dogs. These results complement previous studies showing male-to-male differences in freezing susceptibility of canine spermatozoa.