The low survival rates of nuclear transfer fetuses and neonates in goats and cattle have been linked to placental abnormalities. A series of studies was designed to investigate the possibility of supplementing nuclear transfer embryos with electrofused embryos to generate placental tissue in goats and cattle. The initial study was designed to determine if the breeding season of goats could be extended with hCG treatment. Progesterone concentrations in treated does increased but pregnancy rates were unaffected. In the second study, goat embryos were electrofused and combined with nuclear transfer embryos at the 8-cell stage to produce the first offspring as a result of electrofused embryo complementation in goats. The remainder of the studies focused on electrofused embryos in cattle. The method of electrofusion was studied and it was determined that fusion efficiency and developmental rates after two fusogenic pulses were not different from fusion efficiency and developmental rates after a single pulse. The latter study also showed that the time of cleavage following in vitro fertilization affected the cleavage and blastocyst rates of embryos after electrofusion. In the next study, electrofused embryos were aggregated with nuclear transfer embryos at the 8-cell stage. Aggregate embryos developed to the blastocyst stage at the same rate as electrofused and nuclear transfer control embryos. The final study was a series of experiments conducted to characterize the nuclear status of electrofused embryos. In the first and second experiments of the series, embryos were stained following electrofusion and it was found that more embryos were tetraploid and fewer were binucleate when embryos were electrofused later after cleavage. The third and fourth experiments in this series examined the stage of the cell cycle prior to electrofusion. These experiments indicated that the embryos electrofused at 30 hours post-insemination were in the G2 phase of the cell cycle. It was concluded that the stage of the cell cycle would be an important factor in the production of tetraploid embryos via electrofusion and this should be the basis of future research in this area.

This research was conducted to determine the effects of feeding different P levels with and without phytase supplementation on broiler growth performance, bone breaking strength (BBS), and P excretion. An experiment with 4 trials was conducted with 7,840 Ross x Ross straight run broilers. For each trial, 1,960 broilers were allotted on d 0 to 4 treatments with 7 replications per treatment with 70 broilers per replication. The broilers were fed a 4 period feeding program consisting of starter (0 to 14 d), grower (14 to 32 d), finisher (32 to 41 d), and withdrawal (41 to 50 d) periods. For each trial, the same pen was used continuously for each treatment/replication combination, and the litter was not removed between trials. Broilers were fed a control diet (0.43, 0.40, 0.36, or 0.32% nonphytate P (nPP) in the starter, grower, finisher, and withdrawal periods, respectively), a low Ca and P (LCaP) diet with a 0.05% reduction in nPP in each period, and these two diets supplemented with 600 phytase units/kg (nPP was reduced by 0.094% in diets with phytase). Diet did not affect (P > 0.10) broiler performance in the starter or withdrawal periods. Generally, both phytase addition and the LCaP diet decreased some aspects of growth performance during the grower and finisher periods. There was no main effect of phytase on BBS, but BBS was decreased in the broilers fed the LCaP diet with phytase addition (nPP x Phy, P < 0.01) in the grower period, and BBS was decreased in finisher (P < 0.02) and withdrawal (P < 0.01) periods for broilers fed the LCaP diet. Total P (TP), soluble P (SP), and reactive soluble P (RSP) were decreased (P < 0.04) in the litter of broilers fed the LCaP diets. Total P was decreased (P < 0.01) in the litter of broilers fed phytase, but SP and RSP were not affected (P > 0.10) by phytase. These data indicate that phytase supplementation at 600 phytase units/kg reduces growth in some periods, has no effect on BBS, and that phytase reduces TP but not SP or RSP in the litter.

Rapid growth of warm-season grasses such as bermudagrass (Cynodon dactylon) and bahiagrass (Paspalum notatum) is associated with a decline in their nutritional value. This study was initiated to provide production and composition data with different cultivars of bermudagrass (common, Russell, Jiggs) and bahiagrass (Tifton-9, Pensacola, Argentina). Dry matter (DM), ash, crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) composition and production were evaluated every two weeks for a ten-week period on six different cultivars. Also, Russell bermudagrass was evaluated in a second trial very similar to the first trial for composition and production but was started at three different harvest times. Bermudagrass cultivars had higher DM (P < 0.05) than bahiagrass at all stages of maturity except for d 14. Dry matter production was less than 2000 kg/ha at the 14-d harvest for all of the cultivars. Jiggs produced more DM (P < 0.05) than the other grasses at 42-d harvest. Ash (%) decreased at a constant rate from day 14 until day 70. There was no significant difference (P > 0.05) among the three bermudagrasses and Argentina bahiagrass CP (%) at the 14-d harvest. Russell produced the least amount (P < 0.05) of CP at d 14, while Argentina produced the most CP. Russell, common, and Pensacola CP production (kg/ha) were similar (P > 0.05) and each were higher than Tifton-9 and Argentina after 42 days of growth. Bahiagrass NDF (%) was similar (P > 0.05) across the three cultivars at each of the different harvest times except for the 42-day harvest where Argentina had higher NDF levels (P < 0.05) than either Tifton-9 or Pensacola. The bahiagrass cultivars were similar (P > 0.05) in NDF production at 42 days. Jiggs produced more (P < 0.05) NDF than the other grasses at 56 and 70-d of growth. Common had the least amount of ADF at 56 and 70-d harvest (P < 0.05). ADF production was the highest (P < 0.05) in Jiggs from d 28 to d 70 of growth. Russell early- and mid-season harvest had greater (P < 0.05) DM (%) and production than in the late season. Crude protein was the highest (P < 0.05) in both the early and mid season harvested Russell. The late season harvested Russell produced the least amount (P < 0.05) of DM and the least amount (P < 0.05) of CP. It was predicted that the late season harvested Russell would maintain DM and CP production at a constant rate for a longer period of time. This means that it would allow a producer a wider range of time to make hay or even graze this forage at that time of the year.

Eighty-six primiparous or multiparous sows and their pigs were used to evaluate the effects of changing dietary cation-anion difference (DCAD) in late gestation and in lactation on sow productivity. Twenty sows were used in Exp. 1, and the dietary treatments consisted of a positive control (PC) corn-soybean meal (C-SBM) diet with four levels of DCAD (140, 99, 75, and 45 mEq/kg). These DCAD’s were achieved by four levels of SoyChlor (SC) additive (0, 1.5, 2.5, and 3.5%). In Exp. 2, 66 sows were used and the dietary treatments consisted of the diets providing DCAD of 140 and 45 mEq/kg. The diets were fed from d 107 of gestation to weaning in Exp. 1 and from d 111 of gestation to weaning in Exp. 2. Sows were allotted based on parity and their farrowing date. Experiment 1 was a preliminary experiment to determine the level of DCAD that reduced urinary pH. Reducing DCAD did not affect sow reproductive responses. Urinary pH was linearly decreased (P < 0.001) as DCAD decreased in the diet. Reducing DCAD tended to linearly increase (P = 0.15) plasma Ca concentrations. In Exp. 2, reducing DCAD from 140 to 45 mEq/kg reduced ADFI from d 111 of gestation to d 1 postfarrowing (P < 0.02), but ADFI was not affected by DCAD during any other period. Reducing DCAD did not affect reproductive performance of the sows nor litter response variables or plasma Ca. Decreasing DCAD in the diet decreased urinary pH (P < 0.001). Twenty-seven sows fed the PC diet and 21 sows fed the reduced DCAD diet during the previous lactation were evaluated during their subsequent farrowing. Sows that were fed the reduced DCAD diet had increased total number of pigs born (P < 0.08) and pigs born alive (P < 0.02) in the subsequent farrowing. Changing DCAD had little affect on sow and litter response variables in the current lactation, but it decreased urine pH (P < 0.001), and increased total number of pigs born (P < 0.08) and pigs born alive (P < 0.02) in the subsequent farrowing.

Three experiments were conducted to determine the effects of the chromium propionate (CrProp) in swine and poultry diets. Two broiler experiments, each utilizing 1,460 Ross X Ross broilers, were conducted to evaluate the effects of 0, 200, 400, or 800 ppb CrProp on growth performance and carcass traits in 0 to 42 and 0 to 49 d-old broilers. In Exp. 1, 400 ppb Cr decreased (P < 0.10) ADG and G:F in the grower phase, but mortality was reduced (P < 0.10) in broilers fed 200 ppb or 800 ppb Cr. In the finisher phase, G:F was increased (P < 0.10) in broilers fed all dietary levels of Cr, and mortality was reduced (P < 0.10) in broilers fed 200 and 400 ppb Cr. Chromium did not affect the overall growth data or carcass traits. In Exp. 2, CrProp did not affect growth performance. The results indicated that Cr as CrProp improved G:F in the later phases of growth and reduced mortality in Exp. 1 but not in Exp. 2. In Exp. 3, 108 crossbred Yorkshire gilts were used to examine the effects of 0 or 200 ppb CrProp on iodine value, fatty acid profile of fat, growth, carcass traits, and pork quality from gilts fed tallow or choice white grease (CWG). Chromium decreased (P < 0.03) 10th rib back fat and increased (P < 0.02) percent muscle. Gain:feed was increased (P < 0.003) and ADFI decreased by fat addition. Fat increased hot carcass weight (P < 0.07) and dressing percent (P < 0.02). Average back fat, 9th rib CL, and total loss were decreased (P = 0.02 to 0.04) by tallow. Belly width was increased (P < 0.08) by tallow, but belly bending on both the teatline and scribe side were increased (P = 0.004 to 0.01) by CWG. Iodine values on belly and loin samples were increased (P < 0.001) by CWG. Overall, Cr affected BF and percent muscle and the inclusion of tallow decreased (P = 0.03 to 0.09) belly and loin iodine value further than CWG or no added fat.

Two experiments studied the effects of pretreatment with estradiol benzoate before treatment with a dopamine antagonist on prolactin secretion and reproductive traits in mares during 1) the seasonal anovulatory period and 2) the normal breeding season. Experiment 1 was performed in winter with 17 mares selected for low follicular activity. Nine mares received estradiol benzoate injections every other day for a total of 10 injections; 8 mares received similar injections of vehicle. Ten days after onset of injections, all mares were placed on a daily injections of sulpiride (250 mg) for 45 d or until ovulation. Plasma prolactin concentrations were higher (P < 0.001) in mares receiving estradiol than in control mares for all assessments from d 12 through 36. Mean day of ovulation was 73.6 d for control mares and 29.0 for estradiol-treated mares (P = 0.016). It was concluded that estradiol treatment greatly enhanced prolactin secretion in response to sulpiride in seasonally anovulatory mares and hastened the date of first ovulation by an average of 45 d. Experiment 2 was designed to assess the efficacy of a single injection preparation of another dopamine antagonist, domperidone, for increasing prolactin secretion in cyclic mares in the summer. The experimental design and procedures used in Experiment 1 were repeated, except that a single shot of 3 g of domperidone was administered on d 11 rather than 45 d of sulpiride injections. Day 0 was the first day of estrus for each mare. Prolactin concentrations were higher (P < 0.05) in mares receiving estradiol than in control mares from d 12 through 25 and after a thyrotropin releasing hormone injection on d 21. It was concluded that estradiol enhanced the prolactin response to a single injection of 3 g of domperidone in cyclic mares in the summer in a manner similar to the estradiol enhancement of prolactin secretion in response to daily sulpiride injections in anovulatory mares in winter. Thus, the single injection of domperidone could possibly replace the daily sulpiride injections used in Experiment 1 to induce ovulation in seasonally anovulatory mares; this needs to be tested in future experiments.

Biological resource banking is becoming important for endangered species conservation. A series of experiments were conducted to address issues concerning collection and utilization of biomaterials from Gulf Coast Native (GCN) sheep (model species) (Ovis aries) and Eland antelope (Taurotragus oryx). In the first experiment, two ejaculates were collected 10 minutes apart from each of five rams three times a week for three weeks to maximize output and minimize handling time. Semen volume, concentration and total number of spermatozoa were significantly greater in first ejaculates, whereas pre-cooled, cooled and post-thaw motility, as well as sperm survival, were greater in second ejaculates. The second experiment was designed to develop a practical method for freezing skin biopsies for tissue culture. Cell survival was enhanced by an equilibration time of at least 15 minutes in biological media (containing blood or serum) as compared to non-biological medium (containing PVP). Then, the possibility of using semen and cooled milk as sources of somatic cells (SC) for in vitro culture was evaluated. Fresh, cooled and cryopreserved semen from rams and fresh eland semen was cultured and although SC plated, proliferation was low. From milk, cell attachment was observed in 92% of the samples, whereas only 38% proliferated in culture. Therefore, the ensuing experiment was focused on increasing in vitro proliferation of semen-derived SC by developing (1) a Percoll gradient technique to separate SC from spermatozoa before culture and (2) a method for co-culture of isolated SC with inactivated mouse fibroblasts. Proliferation was significantly increased by co-culture, but contact between the semen-derived SC and feeder cells was not necessary. Finally, intergeneric nuclear transfer (igNT) of semen-derived eland epithelial cells into bovine cytoplasts showed that these cells could direct early embryonic development up to the 8-cell stage. Determination of BrdU-incorporation and evaluation of nuclear status revealed that initial remodeling of the eland nucleus was similar to that of bovine NT embryos within the first 16 hours post-activation; however, after 84 hours, only 13% of interspecies embryos had cycling nuclei in their blastomeres. Future improvements in the technology should eventually allow cloned offspring to be produced from semen-derived somatic cells.

Haemonchus contortus is one of the most threatening parasites to small ruminant production. Control has traditionally relied on the use of anthelmintics. Control has waned because the worm population has developed resistance to most of the currently available anthelmintics and alternative control measures are needed. Current consumer pressure is to reduce the use of chemicals in agricultural products, thus pushing control methods to more natural and acceptable approaches. One such approach is the feeding of condensed tannin containing forages either as fresh forage or dried products (hay, meal, pellets, etc). This study was conducted to determine the effect of a ground meal form of sericea lespedeza (SL), a forage plant high in condensed tannins, on H. contortus infection in sheep. Twenty-eight mixed sex lambs with essentially zero fecal egg count (FEC) were randomly allocated to 4 treatment groups (7 animals each). Two groups received a bolus of 5000 H. contortus infective larvae (L3) once and the infection was allowed to mature over five weeks (existing infection). The remaining two groups received trickle infections of 500 H. contortus L3 three times a week for three weeks (establishing infection). SL meal was fed over a five week period to one of the existing and one of the establishing infection groups while the other groups were fed bermudagrass hay. All groups were fed bermudagrass hay for an additional two weeks and then necropsied. FEC was significantly reduced in the existing infection SL fed group over the 5 week feeding period. Similarly, FEC was lower in the establishing infection SL fed group, but the difference was not significant. After SL feeding was terminated, FEC increased in both existing and establishing infection groups which indicated an effect on female worm fecundity. At necropsy, there were fewer worms in both SL fed groups, but the differences were not significant. This trend of fewer worm numbers suggested that there may have been an effect on reducing infection level also. These results indicate that SL meal had more of an effect on reducing FEC of existing female worm infections than establishing infections of H. contortus.

The objective of this research was to evaluate color and tenderness in chilled or frozen pork loin chops after antioxidant dipping and modified atmosphere packaging. Loin chops were dipped in 0.3 M calcium chloride, 2.0 % sodium ascorbate, 0.2 M calcium ascorbate, or 0.3 M calcium ascorbate. Non-dipped chops served as controls. Chops were packaged in high oxygen (80% O2 / 20% CO2) or no oxygen (80% N2 / 20% CO2) and stored chilled (4° C) for 7 days or frozen (-18° C) for 21 days. After storage, chops were displayed under continuous fluorescent lighting for 3 or 6 days. Instrumental color evaluations indicated that Longissimus dorsi (LD) L* values (lightness) were not significantly different between treatment combinations. However, chops dipped in 0.2 M or 0.3 M calcium ascorbate, stored frozen, packaged in high oxygen, and displayed for 3 days had higher final LD a* (redness) and b* (yellowness) values than other treatment combinations. Sodium or calcium ascorbate increased a* and b* values in vertebrae bone. Chops frozen for 21 days, dipped in 0.2 M or 0.3 calcium ascorbate, packaged in high oxygen, and displayed for 3 days had higher vertebrae a* and b* values than other treatment combinations. This combination of factors indicates that high oxygen atmospheres along with ascorbate and freezing will help keep the hemoglobin iron in a reduced state. In addition, chops dipped in 0.2 M calcium ascorbate, packaged in high oxygen, frozen for 21 days, and displayed for 3 days had lower percent drip loss, percent cook loss, and shear force values than other treatment combinations. Based on the results of our experiment, dipping pork loin chops in 0.2 M calcium ascorbate, packaging in high oxygen, freezing for 21 days, and displaying for 3 days will enhance color and tenderness.

The objective of this study was to use fluorescent in situ hybridization (FISH) to determine if a skew in the sex ratio was present at the level of the bovine round spermatid. Paraffin embedded bovine testicular tissue obtained from biopsies were used to perform FISH, and the seminiferous tubules were examined. Our findings show that the skew does exist within the round spermatids. Analysis of variance on X- and Y-chromosome bearing round spermatids as affected by sex, slide, picture set, and tubule was performed. Sex showed that the variation in round spermatid sex ratio differed between slides (P = 0.0001). The interaction of sex by slide were indicated to be non-significant (P = 0.0815). Sex within tubule nested in slide showed a significant deviation in sex ratio (P = 0.0122). Picture set showed no significant difference in counts, confirming that the counts were consistent (P = 0.2096). A closer look at the data also showed a 10 to 30% variation in the number of seminiferous tubules with a significant skew per slide. Most the skew was toward the Y-chromosome, but a significant skew toward the X-chromosome was also seen. This skew toward the X-chromosome showed that the skew could be counteracted or reversed. Meiotic drives have been shown to exist in other species. Meiotic drives are alleles with the ability to increase their probability of being transmitted to the next generation. Although we cannot prove that a meiotic drive exists in bovine, our findings agree with the meiotic drive principle. These drives push the sex ratio of the population in one direction. Modifiers attached to these drives can counteract or reverse the effect of the meiotic drive. Environmental factors such as crowding, brought on by intense group housing could also have an effect on the expression of these drives. Further investigation is necessary to completely understand these skews in sex ratio and what factors may affect it.