The differentiation potential of adult stem cells (ASC) has long been thought to be limited to cell lineages present in the organ from which they are derived; however, several studies have challenged this notion by demonstrating that some ASC exhibit a remarkably high degree of plasticity. Unlike terminally differentiated somatic cells, the less differentiated state of ASC can assume the functional phenotypes and expression profiles of cells unique to other tissues. The expansive repertoire of differentiation potential exhibited by ASC suggests these cells possess characteristics similar to pluripotent cells, including epigenomic regulatory pattern. Therefore, ASC may be better equipped for complete epigenetic reprogramming than terminally differentiated cells. The objective of Experiment 1 was to analyze bovine adipose-derived adult stem cells (ADAS) and fetal fibroblast (BFF) cells for the presence of the pluripotency-associated genes, Oct-4, Nanog, and Sox-2. Because the endogenous expression of these genes is believed to contribute to reprogramming efficiency, Experiment 2 sought to increase Oct-4, Nanog and Sox-2 expression levels in BFF cells through exposure to ADAS cell extracts. Transcripts for all three pluripotency-associated genes were detected in all BFF and ADAS cell samples at every passage analyzed; however, expression was quite low and highly variable between cell lines and passage numbers. Nevertheless, these findings support the notion that these cells are less differentiated than other somatic cells. This less differentiated state appears to sufficient for at least the partial reprogramming of BFF cells using ADAS cell extracts in a cell extract-based nuclear reprogramming system.

Streptococcus salivarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus are dairy cultures widely used in the dairy industry. Low sonication intensity condition is a non-destructive technique that uses sound waves to cause cavitation in aqueous solutions and may improve the permeability of membranes, speed up the transfer of substrates and promote cellular growth and propagation. The objective of this study was to determine the effect of low sonication intensities at different temperatures on acid tolerance, bile tolerance, protease activity and growth of the two dairy cultures. The cultures were freshly thawed and suspended in 0.1% peptone water and 18 ml of sample was sonicated using horn (diameter 13 mm) set at a maximum acoustic power output of 750 W, frequency 24 kHz. The treatments were four sonication intensities of 8.07, 14.68, 19.83 and 23.55 Watts/cm2 randomized at three different temperatures (4, 22 and 40°C) of inoculated peptone water before sonication. The energy input (1500 Joules) was kept constant in all treatments. Control samples did not receive any sonication treatment. Growth and bile tolerance of samples were determined hourly for 12 hours of incubation. Acid tolerance was determined for Streptococcus thermophilus every 5 minutes for 20 minutes of incubation and for Lactobacillus bulgaricus every minute for 5 minutes of incubation. Protease activity was determined at 0, 12 and 24 hours of incubation. The experimental design was a completely randomized design (CRD). Three replications were conducted for each experimental condition. Data were analyzed using Proc Mixed Model of Statistical Analysis System (SAS®). Differences of least square means were used to determine significant differences at P<0.05 for main effects (low sonication intensity, time and temperature) two way interaction effect (low sonication intensity * temperature and low sonication intensity * time) and three way interaction effects (low sonication intensity * time * temperature). Low sonication conditions include a) low sonication intensities, b) temperatures and c) times, all three of which played a role in influencing the desirable attributes of both microorganisms. Of all the low sonication intensities studied, 14.68 watts /cm2 had the best overall influence at certain time points for Streptococcus thermophilus improving its acid tolerance, bile tolerance and growth at 4°C, growth at 22°C, bile tolerance and growth at 40°C and improving the Lactobacillus bulgaricus bile tolerance and growth at 4°C, its acid tolerance and protease activity at 40°C. Low sonication intensity of 19.83 Watts/cm2 had the overall best influence at certain time points for acid tolerance of both microorganisms at 22°C. Low sonication intensity of 23.55 Watts/cm2 had the overall best influence at certain time points for protease activity of Streptococcus thermophilus at 40°C and Lactobacillus bulgaricus at 22°C. Some low sonication conditions improved certain characteristics of culture bacteria.

Equine embryo cryopreservation is unsuccessful in larger, more easily collected, day-7 embryos. It is imperative that methods to successfully cryopreserve large equine embryos or develop reliable methods to determine embryo size before collection. Therefore the objectives for this study were to quantify the amount of tritiated glycerol that would permeate various sizes of equine embryos and to determine if circulating progesterone concentration was correlated with in utero embryo size. Mean embryo diameter (± SEM) across treatments (1.4M and 3.4M tritiated glycerol) was 696.5µm ± 108.6µm and 925.9 µm ± 214.1µm, respectively and were not different (P=0.44). The percent permeation for 1.4M and 3.4M glycerol were not different (P=0.68). Embryos <400 µm in the 1.4M glycerol treatment group had higher (P=0.002) permeation than embryos >400 µm, 8.32% ± 3.85% and 0.35% ± 0.11%, respectively. Length of time, 60 or 120 minutes, did not affect amount of glycerol uptaken (P=0.26. Serum progesterone concentrations on day 7 post-ovulation were higher (P=0.009) for mares who produced two viable embryos from double ovulation (24.17±2.82ng/ml) compared with mares from which a single embryo (14.04±0.99ng/ml) was collected and control mares (13.53±1.80ng/ml). No differences (P=0.91) were detected in serum progesterone concentration on day 7 post-ovulation between mares from which a single embryo (14.04±0.99ng/ml) was collected and control mares (13.53±1.80ng/ml). Mares producing embryos >400µm tended to have higher (P=0.08) circulating progesterone concentrations than mares producing embryos <400µm. Serum progesterone concentrations day 7 post-ovulation in mares producing embryos >400µm and <400µm were not different (P=0.61 and P=0.68, respectively) than control mares. Single embryos <1000µm in diameter were correlated with circulating progesterone concentration day 7 post-ovulation (r=0.46, P=0.006). There was no significant correlation between embryo diameter, corpus luteum diameter, and serum progesterone concentration day 7 post-ovulation.This is the first study to quantify the amount of glycerol permeating into equine blastocysts and suggests that the capsule may be a barrier to cryoprotectant permeability. Maternal progesterone concentrations day 7 post-ovulation could be utilized in predicting embryo stage and size prior to collection for cryopreservation and in diagnosis of twin pregnancies as a result of double ovulation.

Seven experiments were performed to assess the use of glucose responses to insulin injections as a means of estimating insulin sensitivity in horses; to compare the insulin sensitivities of normal horses vs. those displaying hyperleptinemia; and to put this method into practical application. Experiment 3.1 examined dose-responses in mares of potentially different insulin sensitivities. Recombinant human insulin was injected at doses of 8, 20, 50, and 125 mU/kg BW, as needed, to estimate the dose of insulin causing a 50% decrease in glucose concentrations (ED50). Five mares each of low leptin concentrations (LL) and low BCS, LL and high BCS, and high leptin concentrations and high BCS, were studied. The ED50 was similar for LL mares, regardless of BCS, and was lower (P < 0.01) than for mares with high leptin concentrations. It was concluded that a dose of 50 mU/kg BW of recombinant human insulin could be used safely to start the dose-response curve; lower or higher doses could then be used to estimate ED50. Experiment 3.2 assessed the repeatability of the estimates for ED50 obtained in Exp. 3.1. Estimates obtained were highly correlated (R2 = 0.822) with those obtained in Exp. 3.1, with an average within-mare CV of 8.9%. The next five experiments studied the effects of 1) prior administration of epinephrine, 2) overnight feed deprivation versus hay or pasture consumption, 3) 10-d acclimatization to hay in a dry lot versus pasture grazing, 4) cinnamon extract supplementation, and 5) fish oil supplementation on insulin sensitivity. Epinephrine stimulated blood glucose (P < 0.05) and prevented the insulin-induced decrease in blood glucose in both sensitive and insensitive mares. Overnight feed deprivation decreased (P < 0.06) insulin sensitivity relative to overnight ad libitum access to hay, and both regimens resulted in reduced insulin sensitivity relative to overnight pasture availability. Ten days of hay consumption in a dry lot reduced (P < 0.05) insulin sensitivity in insensitive mares relative to pasture grazing. Supplementation with cinnamon extract or fish oil had no effect on insulin sensitivity of mares with known low insulin sensitivity under the conditions of these experiments.

Forty-two female Holstein calves were assigned to one of three treatments at d 2 of age to study the effects of adding resistant starch (RS) to the milk replacer on health and performance. Treatments were control (0g RS), 4g RS, or 8g RS mixed into the reconstituted milk replacer. Calves were housed in individual calf hutches and fed milk replacer once daily until d 42 of age. Water and an 18% crude protein calf starter were offered ad libitum beginning d 3 throughout the duration of the 56 d trial. Calves remained in their hutches until d 56 of age to determine immediate postweaning performance. Body weights (BW) were measured at birth and d 7, 14, 28, 42, and 56 d of age. Wither height (WH), hip height (HH), and hip width (HW) were measured on d 7, 14, 28, 42, and 56 d of age. Feed intake, body temperatures, and fecal scores were recorded once daily through d 56. On d 14, 28, 42, and 56, fecal samples were collected for analysis of pH and short chain fatty acids (SCFA), and blood was collected for analysis of plasma urea nitrogen (PUN) and total protein (TP). The PUN and TP were within normal ranges suggesting that there were no major metabolic problems. There was no effect (P>0.05) of treatment on BW, HH, HW, WH, or body temperatures. There was a treatment by week interaction (P<0.01) and a week effect (P<0.01) for grain intake, with all calves increasing intake throughout the duration of the study. There was a treatment by week interaction (P<0.01) for fecal scores. All calves had lower (P<0.01) fecal scores at the end of the study compared to the beginning. Fecal pH increased as calves aged (P<0.01). There was a treatment by week interaction (P<0.05) for propionate concentration in the feces. Propionate concentrations decreased (P<0.01) until weaning at week 6 for all treatments while calves consuming 4g RS had higher (P<0.05) concentrations compared to those consuming 8g RS over the entire trial. Acetate, butyrate, and total SCFA concentrations all decreased (P<0.01) for all calves until weaning at week 6. Incorporation of RS in the milk replacer of calves did show changes in fecal SCFA at 2 and 4 weeks of age. However, incorporation of RS in milk replacer had no overall treatment effects on health and performance of neonatal dairy calves.

Sheep production is an important socioeconomic activity for the small producers and it can represent their primary income source. Gastrointestinal parasites have become the principal limiting factor for this industry around the world, especially because of the anthelmintic resistance phenomenon that has been increasing worldwide. The negligent use of anthelmintics has been reported as the main factor in the development of resistance. Among the parasites that infect sheep, H. contortus is considered the most harmful and also the parasite responsible for the fastest development of nematode resistance in small ruminants. Due to the economic impact this parasite may bring upon producers, the search for alternative methods of control has become a necessity. The use of condensed tannin containing forages and copper oxide wired particles have been shown to produce promising results. Studies have shown that both of these control methods can reduce fecal egg counts, worm fecundity, egg hatchability and larvae development of H. contortus. The general objective of this research was to evaluate the effect of inorganic copper and condensed tannins on fecal egg counts of naturally infected animals and consisted of three trials. No significant differences were observed in the trials using condensed tannins as the main effect in parasite control (p>0.05). It was possible to observe that the number of H. contortus larvae decreased in the treated group, but the differences were not significant (p>0.05). A significant difference in fecal egg counts in the inorganic copper trial was observed (p<0.05). The copper oxide group yielded the greater reduction throughout the study (p<0.001). Copper sulfate was able to reduce fecal egg counts but there was no difference between this group and the control group, which did not receive any treatment (p>0.05). The use of condensed tannins did not show reductions in parasite load, but its use should not be discarded especially in areas where the use of anthelmintics is no longer possible. Inorganic copper has been shown to reduce GIN infection and its concomitant use with other control methods may represent a useful tool in controlling parasites.

The objectives of this research were to determine whether delaying the feeding of a diet with reduced crude protein, supplemented with L-Lysine, for several days post-hatching, would result in improved growth performance of broiler chicks and determine an optimal time to feed such a diet to the chick. All experiments were conducted in brooder batteries from 0- to 14- or 18- days (d) post-hatching. Treatments contained a minimum of 6 replicate pens with at least 6 broilers per pen. Two experiments were conducted to determine whether delaying the feeding of a corn-soybean meal (SBM) diet with reduced CP for either the first 5 or 10 days post-hatching would result in improved growth performance of broilers. The results of these experiments show that even when the diets are not deficient in amino acids (AA), feed efficiency is negatively affected by switching birds to a low CP diet several days after post-hatching; effects on daily gain are minimal until the diet becomes deficient in AA. Two experiments were conducted to determine the optimal time to feed a diet with reduced CP, supplemented with L-Lysine, to the chick. The results of these experiments indicate that as long as the diets are not deficient in AA, overall growth performance during the starter phase is not negatively affected for broilers switched from diets with reduced CP to one with an adequate level, at day 5 or day 10 post-hatching, or those fed the reduced CP diets continuously.

Excess protein in dairy cattle diets unnecessarily increases the cost of production and may contribute to environmental pollution. The objective of this research was to evaluate the effect of feeding dairy cows with two levels of dietary protein on animal performance and manure characteristics. Two experiments were carried out with 24 lactating dairy cows each. Experiment 1 was corn silage based and had a control TMR (HP1) estimated to contain 16.5% CP with SBM and treatment TMR (LP1; 13.5% CP) using DDGS and rumen protected Lys and Met. Experiment 2 was ryegrass haylage based and had a control TMR (HP2) with 15.5% CP with Met and a treatment TMR (LP2) with 13.5% CP with Lys and Met. Experiments were analyzed as a crossover design using the MIXED procedure of SAS with pen as the experimental unit. Experiment 1 had no significant difference between treatments in DMI (21.0 for HP1 and 20.4 kg/cow/d for LP1; P=0.46) and milk yield (20.7 for HP1 and 20.5 kg/cow/d for LP1; P=0.91). Percentage of milk components averaged 4.21, 3.72, 4.54, and 9.15, respectively for fat, protein, lactose, and solids non-fat (P>0.60). Milk urea nitrogen (MUN) decreased (P<0.01) from 17.2 with HP1 to 9.93 mg/dL with LP1. Manure pH was significantly higher for HP1 than LP1 (7.87 and 7.53 respectively, P<0.05). Experiment 2 had no significant difference in cow performance (DMI: 21.4 for HP2 and 20.9 kg/cow/d for LP2; P=0.51; milk yield: 26.4 for HP and 24.4 kg/cow/d for LP2; P=0.19; percentage of milk components averaged 3.48, 3.29 and 4.71, respectively for fat, protein and lactose; P>0.30; MUN decreased (P<0.01) from 9.85 with HP2 to 6.40 mg/dL with LP2). Manure pH was significantly higher for HP2 than LP2 (7.50 for HP and 7.13 for LP, P=0.05). There was no difference in volatilized N between HP2 and LP2. This experiment suggests that performance of late-lactation dairy cows can be maintained with low-protein DDG based diets supplemented with Lys and Met.

Two experiments assessed the potential of altrenogest, an artificial progestogen, and deslorelin acetate, a gonadotropin-releasing hormone (GnRH) agonist, for suppressing estrus and ovulation in cyclic mares. In the first experiment, mares were administered a luteolytic dose of prostaglandin-F2á on d 6 of diestrus, and were then treated with 1 of 3 formulations of altrenogest in slow-release vehicle (6 mares/group): 1) Biorelease altrenogest LA150 (225 mg total as a 1.5 mL injection); 2) Biorelease altrenogest LA225 (225 mg total as a 1.0 mL injection); or 3) Biorelease altrenogest LA225 (450 mg total as a 2.0 mL injection). Six control mares received vehicle. Compared to control mares (10.0 days), time to ovulation was greater (P < 0.01) for all mares receiving altrenogest (17.5 days overall); there was no difference (P > 0.5) among groups receiving altrenogest. Control mares (6 out of 6) first displayed estrus an average of 4.5 days after prostaglandin-F2á injection; of the 18 mares receiving altrenogest, 11 displayed first estrus at an average of 13.5 days (P < 0.02 relative to controls) and there was no difference (P > 0.19) among groups. It was concluded that the 3 formulations of altrenogest were equally effective in delaying estrus and ovulation in cyclic mares. It is suggested that a 10-day injection interval could be used to keep mares out of heat for extended periods of time. The second experiment was similar to the first, except that there were 2 groups: 1) control mares that received a vehicle injection and 2) mares that received an i.m. injection of 1.5 g of deslorelin acetate in biodegradable microparticles. Administration of deslorelin did not affect (P > 0.1) the day of first onset of estrus or the day of ovulation. There was a tendency (P = 0.08) for deslorelin treated mares (3 out of 7 vs. 0 out of 6 controls) to not show estrus at the expected time, even though they experienced luteolysis and ovulation. It was concluded that injection of 1.5 g of deslorelin acetate was not an effective method for suppressing estrus and ovulation in cyclic mares.

Four experiments were conducted in an effort to develop a method, based on prolactin secretion, for assessing the efficacy and duration of activity of dopaminergic agonists for the treatment of pituitary pars intermedia dysfunction (PPID) in horses. In the first experiment, prolactin response to a low dose of the dopamine antagonist, sulpiride, was generally repeatable in estrogen-primed geldings in winter over 8 every-other-day challenges. It was concluded that estrogen-primed, sulpiride-challenged geldings in winter could serve as a model for the study of potential dopaminergic drugs for the treatment of PPID in horses. The second experiment was performed in the summer with mares, and again tested the repeatability of the prolactin responses over a 30-day period. The responses in mares were generally repeatable, and there was no effect due to stage of the estrous cycle. It was concluded that mares could serve as a model for the study of potential dopaminergic drugs as well as geldings, and stage of the estrous cycle did not have to be taken into account. In the third experiment, two formulations of the dopamine agonist, pergolide, were tested (oral administration versus injection) against a single formulation of cabergoline (injected) and control injections (vehicle) for their efficacy to reduce unstimulated plasma prolactin concentrations in geldings. Oral pergolide reduced prolactin concentrations for a few hours, whereas injected pergolide suppressed prolactin concentrations for 24 hours. Cabergoline suppressed prolactin concentrations for up to 5.5 days. It was concluded that the injectable formulations had potential for further study as possible treatments for PPID in horses. The last experiment tested the efficacy of daily pergolide injection versus a single injection of cabergoline, for suppressing the prolactin secretion induced by low dose sulpiride injections in mares. Daily injection of pergolide suppressed prolactin responses as long as the injections were given, plus another 2 days. The single cabergoline injection suppressed prolactin responses for a minimum of 10 days. Based on these results, cabergoline in slow-release vehicle seems to provide an excellent possibility for administering dopaminergic activity to horses with PPID. Whether these results are directly applicable to PPID horses needs to be determined.