This research was conducted to determine the effects of pre-incubation warming on the hatchability of post-peak egg production broiler breeder eggs. An experiment with six trials was conducted with 7,920 freshly laid eggs from Ross 308 and 708 broiler breeders from 61-67-wks of age. For each trial, 1,320 eggs were used to determine if pre-incubation warming treatments of 0, 2, 4, and 6, or 0, 3, 6, and 9, or 0, 9, 12 and 15 hrs (at 37.6°C) could improve the hatchability of eggs stored (at 15.5°C) for three days. After a storage period of three days, the eggs were incubated for 21d. Unhatched eggs were broken to determine fertility, and if fertile, stage of embryonic death. Time of hatch was observed for pre-incubation warming treatments 0, 9, 12, and 15 hrs. Of the chicks that hatched, two trials were conducted, each using 192 randomly selected males to determine if the pre-incubation warming treatments affected initial weight, final weight, average daily gain, or feed conversion ratio. Statistical significance was assessed at P < 0.05. Pre-incubation warming of 6 hrs or less did not significantly affect fertile hatchability, total hatchability, embryonic morality or pips. However, pre-incubation warming of 15 hrs negatively affected early-dead mortality (11.6%) when compared to eggs that did not receive any pre-incubation warming (8.7%). Pips were significantly reduced in eggs that were treated for 9, 12 and 15 hrs (1.4, 1.3, and 0.3%, respectively) when compared to eggs that did not receive pre-incubation warming (2.4%). Average hatch time was shortened by pre-incubation warming of 9, 12, and 15 hrs with differences of 5, 7, and 12 hrs, respectively, compared to the eggs that were not pre-incubated. Average final weight, average daily gain, and feed conversion ratio were not significantly different at the end of an 18d trial period. The results of this study provide evidence that pre-incubation warming within a range of 2-15 hrs does not improve hatchability of post-peak broiler breeder eggs when stored for three days. The most significant finding is that eggs can be pre-warmed at incubation temperature for 15 hrs without negatively affecting hatchability.

Plasma leptin concentrations in obese adult horses have been shown to vary widely, and horses tend to fit into two groups: low leptin (<10 ng/mL) and hyperleptinemic (10 to 50 ng/mL). Observations over time revealed that the hyperleptinemic condition was consistent, possibly indicating a relatively permanent underlying cause. Based on these observations, three experimental approaches were used to further study equine obesity-related hyperleptinemia. The first experiment determined the prevalence of hyperleptinemia among postpartum, lactating mares, evaluated its consequence on their re-breeding success, and investigated correlations between leptin levels in lactating and non-lactating mares. Postpartum mares (n = 198) and non-foaling mares (n = 31) were categorized based on their leptin status: normoleptinemic or hyperleptinemic. Leptin in the lactating mares averaged 4.8 ng/mL, and 11 of the 198 (13%) displayed hyperleptinemia. Leptin in the non-lactating mares averaged 7.5 ng/mL, with 9 mares (29%) displaying hyperleptinemia. Of the 198 lactating mares bred, 81% became pregnant; there was no effect of leptin status on re-breeding success. To study one possible cause for hyperleptinemia in well-fed horses, a second experiment explored polymorphism(s) within exon 2 of the equine leptin gene. The DNA from five hyperleptinemic and five normal mares of high body condition was used to analyze exon 2 of the leptin gene for polymorphisms. Based on the 10 mares tested, there was no polymorphism in exon 2 of the equine leptin gene; therefore, polymorphism is not a likely explanation for the high vs. low leptin difference. The third experiment explored the possible effects of hyperleptinemia on the endocrine and immune systems. Endotoxin was given to mares and geldings to investigate the role and/or regulation of leptin in the pro-inflammatory cytokine response. Of the endpoints measured, only platelet count differed between normal and hyperleptinemic horses. Endotoxin infusion caused the expected pro-inflammatory cytokine and endocrine responses, but leptin status was not a significant factor for any endpoint. It is concluded that hyperleptinemia in mares is not associated with polymorphism in exon 2 of the leptin gene, does not affect re-breeding rates of foaling mares, and does not alter the endotoxin-induced responses of the endocrine and immune systems.

The ability to cryopreserve epididymal sperm from mature postmortem bucks has long been of interest to both wildlife conservationists and deer ranchers. Increased understanding of the cryobiology of epididymal sperm from a non domestic species, such as White-tail deer, could aid in development of future protocols to assist in the preservation of endangered species. In Experiment I, results showed that after cooling postmortem bull testes for 22 hours, no significant difference was noted between sperm parameters of epididymal sperm collected at room temperature or at a cool enviorment. In Experiment II, it was shown that White-tail deer sperm could be successfully cryopreserved using a bovine freezing protocol. Also, if immediate processing of epididymal sperm is not an option, testes can be held within the scrotum at 10°C to 15°C for up to 24 hours prior to processing the sperm for freezing. In Experiment III, post-thaw normal sperm morphology results show that glycerol should be considered over DMSO when freezing White-tail deer epididymal sperm. In Experiment IV, it was shown that White-tail deer epididymal sperm can be held in the presence of glycerol for up to 12 hours and still result in post-thaw motility values >30%. Also, when comparing exposure time of White-tail deer epididymal sperm to glycerol there was relatively no change in post-thaw membrane integrity from 0 hours to 24 hours. In the final experiment, the fawning rates of three different estrous synchronization protocols using timed artificial insemination were compared over two consecutive breeding seasons. The most preferred synchronization protocol was a 14 day CIDR with an eCG injection at the time of CIDR removal. A preliminary experiment was then conducted using the 14 day CIDR with eCG to synchronize and artificially inseminate six does with frozen-thawed epididymal sperm, resulting in five healthy fawns from three pregnancies.

The purpose of this research was to determine the influence of dietary Se on glutathione peroxidase (GPx)-1 and 3 activities and relative liver GPx mRNA levels in growing Holstein bull calves. Calves (n = 14) were started 28 d after birth on either a Se adequate (0.15 ppm Se) or deficient (0.01 ppm Se) diet consisting of 3 growth phases and maintained on the diet until 180 d of age. Blood samples were taken from each calf for determination of GPx-1 and GPx-3 activity. Three calves were euthanized at d 21 of age for determination of baseline liver GPx-1 mRNA level. Four calves from each treatment were euthanized at d 180 of age for determination of liver GPx-1 relative mRNA level. Feed intake and average daily gain were not affected by Se level. Mean liver Se concentration was higher (P < 0.05) for baseline calves and those fed the Se adequate diet than for calves fed the Se-deficient diet, but there was no difference between baseline calves and Se adequate calves with respect to liver Se concentration. The GPx-1 activity was greater for Se adequate than Se-deficient calves (P < 0.01) but not until d 84 of age. The GPx-3 activity was considerably more variable than that of GPx-1 with respect to the trend observed for activity by day, and the GPx-3 activity of the Se-deficient group was only less than that of the Se adequate group (P < 0.05) on d 180. N-fold differences were calculated for relative GPx-1 mRNA levels between treatments. There was a 50% decrease in GPx-1 mRNA for Se-deficient calves (P < 0.05) compared with the Se adequate calves. Regression analysis also was performed to determine the relationship between the various response variables. There was only a moderate relationship (r2 = 0.58) between GPx-1 mRNA transcript levels and GPx-1 activity at d 180, despite a correlation coefficient of 0.76. The relationship between GPx-1 mRNA transcript level and GPx-3 activity at d 180 was much stronger (r2 = 0.81), with a correlation coefficient of 0.90, which was unexpected, as GPx-3 is generally considered a short-term indicator of Se status and therefore a much more variable response. Erythrocyte GPx-1 activity was much more sensitive to Se in the diet and thus reflected the diet more closely than did GPx-3. However, GPx-3 activity was more highly correlated to GPx-1 transcript levels. These unexpected results suggest that another trial utilizing larger sample sizes and serial sampling of liver tissue with the sampling of plasma and erythrocytes may provide a clearer picture of the relationship between liver GPx-1 mRNA , tissue Se concentration, and GPx enzyme activities in neonatal and growing Holstein calves.

In recent years, the use of genetic markers has become more and more prevalent in beef breeding programs. This research focused on four previously identified single nucleotide polymorphisms in a leptin gene on chromosome 4 of beef cows. The SNP were E2FB, T945M, UA1, and UA2. Beef cows used in this research were maintained at the Louisiana State University AgCenter Central Research Station. Cows consisted of purebred Bos tauras and Bos indicus cattle as well as crossbreds. The objectives were to estimate genotypic and allelic frequencies for each SNP and to determine the influence of cow breed type, cow age, and SNP genotypes on cow calving rate and date of calving in 2006, cow plasma leptin concentration, body condition score, and pregnancy status in September of 2006, and cow weight change from April to September in 2006. Over all cows, each of the genetic markers showed polymorphism. Allelic frequency for T in these SNP was greater than 0.10. Within cow breed groups the trend for lower or higher frequencies of homozygous genotypes tended to be consistent. Genotypes TT in E2FB, TT in T945M, CC in UA1, and TT in UA2 had lower frequencies. Brahman cows were missing both CT and TT genotypes in UA2 and the UA2‐TT genotype was not present in Braford, Romosinuano F1 and Brahman F1 breed groups. Neither of the genetic marker genotypes influenced variation in plasma leptin level (P > 0.05). Several genetic markers had effects associated with cow traits that were of interest to this research. UA1 genotypes tended (P=0.07) to have an effect on calving rate. UA2 genotypes were associated (P<0.05) with calving date as well as weight loss. Cow breed group influenced (P < 0.05) calving rate, Julian calving date, weight change, and palpation status. Six year and older cows had a larger plasma leptin level and two year old cows had lower body condition scores than other ages of cows. These results indicate that after adjusting for cow breed group and cow age, genetic markers UA1 and UA2 appear to be associated with several reproductive and weight change traits of beef cows.

Increased fearfulness has been associated with adrenocortical activation. Maternal corticosterone (B) treatment increases egg yolk B, and elevated B in ovo enhances chick avoidance of humans. Quail selected for exaggerated (high stress, HS) as opposed to reduced (low stress, LS) plasma B response to stress are more fearful, and more B is found in the egg yolks of HS than LS hens. Therefore, the underlying fearfulness (tonic immobility, TI) and timidity (hole-in-the-wall box, HWB, emergence) responses were assessed in chicks hatched from eggs of LS and HS hens implanted with silastic tubes containing no B (CON) or B (B-IMPLANT) during egg formation. In chicks 14-15 d of age, the number of inductions (INDS) required to attain TI, the latency to first alert head movement (LATHEAD), and duration of TI were determined. In chicks 21-23 d of age, the latency until first vocalization (LATVOC), numbers of vocalizations (VOCS), proportions of chicks vocalizing (PVOCS), and the latencies to head (HE) and full body (FE) emergence from a HWB were determined. LS chicks required a lower number of INDS (P < 0.0005) and less time to achieve LATHEAD (P < 0.02) than did HS ones, although stress line, maternal B-treatment, and their interaction did not affect the duration of TI. During the acclimation period of the HWB tests, more (PVOCS; P < 0.0001) HS chicks vocalized sooner (LATVOC; P < 0.0001) and more often (VOCS; P < 0.0001) than did LS chicks; and, while maternal implant treatment did not affect LATVOC, progeny of B-implanted hens showed a tendency towards less (P < 0.07) VOCS than the CONs. A line*implantation treatment interaction (P < 0.02) was also found for VOCS. Post-hoc analyses of the interactive VOCS means showed that the HS-CON chicks vocalized more (P < 0.01) than the other three similarly less vocal groups. Chicks hatched from eggs of B-IMPLANT mothers also took longer to achieve both HE (P < 0.06) and FE (P < 0.05) from the HWB than did their CON counterparts. Stress line, implantation treatment and their interaction did not alter HE or FE responses. It was concluded that quail stress line genome may be affecting certain fear and alarm responses in chicks via the same or a different mechanism(s) that underlie(s) how maternal B increases in ovo B that in turn alters the fear behavior of progeny.

The purpose of this research was to determine if serum uric acid (SUA) could be used as an indicator of amino acid (AA) utilization in broilers and to determine the Lys requirement of broilers using SUA as a response variable. Treatments were replicated with at least 6 pens with at least 6 broilers per pen. Experiments (Exp.) were conducted from 0- to 14, 17, or 18- d posthatching in brooder batteries. Five experiments were conducted to determine if SUA and uric acid content of the excreta (UAE) could be used to determine AA adequacy of a diet. The results of these experiments indicate that after a 2 h fast, SUA can be used to determine the AA adequacy of a diet as well as UAE. Two experiments were conducted to determine the Lys requirement of female broilers from 0- to 17- d posthatching using growth performance and SUA as response variables. Using daily gain as the response, the Lys requirement of female broilers is 1.27% total Lys for diets formulated with the main source of Lys as SBM. Using gain:feed (GF) as a response variable, estimates of the Lys requirement are 1.30%, 1.42%, and 1.45% total Lys when supplemental Lys is the source of Lys. A final experiment was conducted to determine the effects of supplemental Lys and Met on SUA, serum urea N (SUN), and UAE concentrations. The results of this experiment indicate that supplemental Lys has no effect on SUA or SUN concentrations. The results of this research indicate that SUA concentrations can be used as an indicator of AA utilization in broilers fed AA adequate and deficient diets, but it is not a good response variable to estimate the Lys requirement of broilers.

Unstressed and stressed quail hens selected for exaggerated (HS, high stress) rather than reduced (LS, low stress) plasma corticosterone (B) response to brief restraint deposit more B into their eggs than do their LS hen counterparts. HS hens implanted with B also show reduced egg lay when compared to LS- and HS-control and LS-B-implanted hens. Herein, the effects of stress line on length of egg incubation (LEI) and chick body weight at emergence (BWTE) (Exp. 1) and the interactive influences of line with maternal B-treatment (sub-Q control, CON-, or B-implants) on LEI (Exp. 2) and on egg fertility (FERT), total (TOTHATCH) and fertile (FRTHATCH) egg hatchability, and the percentages of early (ED) and late (LD) dead embryos and pipped (PIP) eggs (Exp. 3) were determined. In Exps. 1 (P < 0.0003) and 2 (P < 0.0001), mean LEI was shorter for eggs laid by HS than LS hens, while chick BWTE was unaffected by line (Exp. 1). In Exp. 2, B-implanted hen eggs also hatched sooner (P < 0.0001) than did CON eggs and line*hen B-implant treatment affected (P < 0.05) the LEI as follows: LS-CON > LS-B > HS-CON > HS-B. In Exp. 3, FERT and TOTHATCH were dramatically reduced (P < 0.0001; both cases) in eggs of HS compared to LS hens and in eggs of B-implant compared to CON hens (P < 0.0001 and P < 0.0002, respectively). Line*implant treatment FERT and TOTHATCH means differed (P < 0.05) as follows: LS-B = LS-CON > HS-CON > HS-B and LS-CON = LS-B = HS-CON > HS-B, respectively. Although FRTHATCH and ED was unaffected by the main treatments, HS-B-implanted hen eggs had more (P < 0.05) EDs. LD embryo and PIP egg percentages were unaffected. The stress line*maternal B findings are important to avian geneticists as they further emphasize the benefits that selection for reduced adrenocortical responsiveness has on hen reproductive performance and they warn poultry producers that stress in the laying barn may abbreviate egg incubation periods and negatively affect egg FERT, TOTHATCH, and ED embryos, particularly in hens genetically predisposed towards high stress responses.

The objectives of this research were: 1) to compare the effect of source and level of inclusion of dried whey permeate (DWP) and a carbohydrate product (CHO) on growth performance of nursery pigs, 2) to evaluate the effect of a fortified nutrient pack (FNP) on growth performance and total tract nutrient digestibility in growing/finishing pigs, and 3) to compare chromic oxide (Cr2O3) and acid insoluble ash (AIA) as digestibility markers for total tract digestibility determination in growing/finishing pigs. Three experiments were conducted to compare the feeding value of DWP (80% lactose) and CHO (40% lactose, 30% sucrose, and 10% glucose) in diets for nursery pigs. Results from these experiments indicate that the inclusion of DWP and CHO improved ADG and ADFI compared with pigs fed a diet without lactose. However, the importance of including a highly digestible carbohydrate source in diets for nursery pigs is more evident as pigs are weaned lighter and younger. Two experiments were conducted to evaluate the effect of FNP (fumaric, malic, citric, phosphoric, and lactic acids, L-carnitine, chromium picolinate, inulin, d-pantothenic acid, and niacin) on growth performance and total tract nutrient digestibility in growing/finishing pigs. Results from these experiments indicate that the addition of 0.25 or 0.50% FNP to the diets did not improve ADG, ADFI, or G/F of growing/finishing pigs. Dry matter, CP, and GE digestibility were not improved (P > 0.1) with the addition of FNP in 50-kg pigs. However, the addition of 0.25% FNP to the diets of 85-kg pigs during the last 14 d of growth, improved CP and GE digestibility. Two experiments were conducted to compare Cr2O3 and AIA as digestibility markers for total tract digestibility determination in growing/finishing pigs fed ad libitum. Results from these experiments indicate that Cr2O3 and AIA offer a rapid and reliable technique for digestibility determination in growing/finishing pigs. However, AIA showed superior characteristics compared with Cr2O3 as its analyzed values are more consistent, produce less environmental impact, and is more cost effective.

The objectives of this study were to provide an overview of fluid milk quality in the U.S., determine if there is a correlation between rapid and traditional tests, determine if results from different analyses correlate with a sensory analysis and to determine any correlation between any of the analyses done in this study. Whole and 2% milks were received from 17 dairy processing plants located in the west, midwest, and southern regions of the U.S in duplicates. Samples were pasteurized at the processing plants by HTST method (161-175oF for 15-25 seconds). For standard plate counts at day 0 no significant differences were found. The mean value was 1.89 log CFU/ml. In day 14, significant differences were found. The mean was 7.58 log CFU/ml. No coliforms were found in any of the samples on either day 0 or day 14. Psychrotrophic counts had no significant differences for the traditional method. 5% of the samples showed psychrotrophic counts. For the rapid method no significant differences were found. The mean value was 0.63 log CFU/ml. 10% of the samples showed psychrotrophic counts. For heat-resistant spore-forming psychrotrophs no significant differences were found. 10% of the samples showed psychrotrophs. For aerobic spores no significant differences were found. The mean value was 1.94 log CFU/ml. HR-1 tests showed no significant differences. The mean was a pink coloration. HR-2 test results did result in significant differences at 48 and 60 hrs, with a mean of a pink color. HR-3 tests showed a mean of pink. Significant differences were found among samples. Fat% results had no significant difference for either milk samples. 2% samples had a mean of 2.08%. Whole milk samples had a mean of 3.43%. Protein content showed no significant differences. The mean was 3.15%. No significant differences were found for somatic cell counts. The mean value was 1.77 log SCC/ml. Regarding sensory evaluation, for day 0 no significant differences were found. The mean score was 7. Day 14 showed significant differences with a mean score of 4.39. Both test methods of psychrotrophic counts shared a high correlation coefficient but a t-test confirmed otherwise. We can conclude that the fluid milk quality in the U.S. needs to be improved.