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Ninety-nine multiparous Brahman-influenced (1/4 to 3/8 Brahman) cows were managed to achieve low (BCS = 4.3 ± 0.1; n = 50) or moderate (BCS = 6.1 ± 0.1; n = 49) body condition (BC) to determine the influence of bovine somatotropin (bST) on estrous characteristics, reproductive performance, and concentrations of serum GH and plasma NEFA. Beginning 32 d postpartum, cows within each BC were assigned randomly to treatment with or without bST. Non-bST-treated cows received no treatment, and treated cows were administered bST (Posilac, 500 mg s.c.) on d -35, -21, and -7 before initiation of the breeding season. On d -7, all cows received an intravaginal, controlled internal drug-releasing (CIDR) device. On d 0 (initiation of the 70-d breeding season), the CIDR were removed and cows received prostaglandin F₂α (PGF₂α). Blood samples were collected from the median caudal vein of the cows at each bST treatment and at d -28 and 0. Estrous behavior was monitored by radiotelemetry during the first 30 d of the breeding season. Growth hormone was increased (P < 0.05) in low and moderate BC cows treated with bST. The percentage of cows detected in estrus during the first 30 d of the breeding season was decreased (P = 0.05) for low BC (64%) compared with moderate BC (82%) cows. The interval to first estrus tended (P = 0.07) to be shorter in low BC-bST-treated cows (3.7 ± 1.9 d) than in moderate BC-bST-treated cows (9.6 ± 1.8 d). During the first 30 d of the breeding season, cows in low BC had a decreased (P = 0.02) number of mounts received and increased (P = 0.001) quiescence between mounts compared with cows in moderate BC. The number of mounts received was reduced (P = 0.04) in bST-treated cows. More (P = 0.02) cows treated with bST became pregnant during the first 3 d of the breeding season compared with non-bST-treated cows. The cumulative first-service conception rate tended (P = 0.07) to be greater for bST-low BC cows than non-bST-treated cows in low or moderate BC. On d 0, NEFA were greater (P < 0.05) in bST-treated vs. non-bST-treated cows. Low BC and bST reduced the intensity of behavioral estrus in postpartum Brahman-influenced cows. However, bST increased the first-service conception rate during the first 30 d of breeding and pregnancy rates during the first 3 d of breeding in postpartum Brahman-influenced cows.

An abstract of the study by Acharya et al evaluating the effects of ram semen extender and extender supplementation on computer assisted sperm analysis (CASA) parameters which were positively correlated with progressive motility, is discussed. Semen collected from 5 rams was distributed across treatment combinations consisting of either TRIS citrate or milk. Also noted that based on CASA parameters measured, milk is superior to TRIS based extender for ram chilled semen storage.

Abstract A study evaluated the effects of ram semen extender and extender supplementation on computer assisted sperm analysis (CASA) parameters positively correlated with progressive motility. Semen collected from 5 rams was distributed across treatment combinations consisting of either TRIS citrate (T) or milk (M) extender supplemented with 5 or 20% (v/v) egg yolk (EY) ± 1% ethylene glycol (EG) and ± 20 μL penicillamine, 10 μL hypotaurine and 2 μL epinephrine (PHE). Semen from each ram was distributed across treatment combinations, diluted to a final concentration of 300 million sperm/mL, cooled slowly to 4°C, and evaluated daily for 3 d, using CASA. Multivariate analysis indicated that progressive motility was positively correlated with straight line velocity (VSL; r = 0.715; P < 0.01), as well as departure of the average (STR; r = 0.706; P < 0.01) and actual (LIN; r = 0.773; P < 0.01) sperm path from a straight line. Repeated measure data were analyzed using the mixed model for main effects of extender, supplements, and their interactions on VSL, STR and LIN. Regardless of extender supplementation, VSL, STR and LIN were greater in M than T extender (P < 0.01). Addition of EG to extender reduced (P = 0.02) VSL, but had no effect (P > 0.05) on STR or LIN. An interaction occurred where EG increased LIN of sperm stored in T but decreased LIN in M extender (P < 0.01). Addition of PHE increased (P = 0.01) VSL, STR and LIN. The percent EY in extender had no effect (P > 0.05) on VSL, STR or LIN. Based on CASA parameters measured, milk is superior to TRIS based extender for ram chilled semen storage. Addition of PHE improved the sperm motility parameters while the EY percentage had no effect. Further study is needed to correlate CASA parameters with pregnancy rate.

Multiparous beef (1/4 to 3/8 Bos indicus; n = 99) cows were managed to achieve low (BCS = 4.3 ± 0.1; n = 50) or moderate (BCS = 6.1 ± 0.1; n = 49) body condition (BC) to determine the influence of bovine (b) ST on the number of follicles, diameter of largest follicle, and serum concentrations of IGF-I, triiodothyronine (T3), thyroxine (T4), and prolactin. Beginning 32 d postpartum, cows within each BC were assigned randomly to treatment with or without bST. Non-bST-treated cows received no treatment, and treated cows were administered bST (Posilac, 500 mg, s.c.) on d 32, 46, and 60 postpartum. On d 60, all cows received a controlled internal drug-releasing (CIDR) device for 7 d and PGF^sub 2α^ at CIDR removal (CIDR-PGF^sub 2α^). Blood samples (7 mL) were collected at each bST treatment and d 39 and 67 postpartum. Ultrasound was performed 1 d after CIDR-PGF^sub 2α^ to determine the number of small (2 to 9 mm) and large (≥10 mm) follicles and the diameter of largest follicle. Cows treated with bST in low BC had increased (P < 0.05) IGF-I vs. low-BC non-bST-treated cows on d 39, 46, 60, and 67 postpartum. Prolactin and T3 were greater (P < 0.05) in moderate-BC than in low-BC cows on all sample dates. Thyroxine was greater (P < 0.001) in moderate-BC cows on d 46, 60, and 67 compared with low-BC cows. On d 67, bST-treated cows had greater (P < 0.05) T4 compared with non-bST-treated cows. Diameter of the largest follicle 1 d after CIDR-PGF^sub 2α^ was greater (P < 0.01) in anestrous cows treated with bST than for non-bST-treated anestrous cows. Diameter of the largest follicle was correlated with concentrations of IGF-I (r ≥ 0.18; P ≤ 0.08), T3 (r ≥ 0.17; P ≤ 0.10), and prolactin (r ≥ 0.20; P ≤ 0.06). Treatment with bST increased IGF-I in low-BC cows, and IGF-I was correlated with the diameter of the largest follicle 1 d after CIDR-PGF^sub 2α^. Undernutrition of cattle may be communicated to the hypothalamic-pituitary-ovarian axis via metabolic hormones including IGF-I, thyroid hormones, or prolactin. [PUBLICATION ABSTRACT]

Sixteen (mean age = 1.1 ± 0.1 yr; mean BW = 478 ± 34 kg) Brahrnan-influenced bulls were used to determine the influence of fescue type on sperm characteristics and serum concentrations of pro-lactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing sperm characteristics and randomly assigned to graze toxic endophyte-infected (El; 4 bulls/pasture; 2 pastures) or novel endophyte-infected (NE; 4 bulls/pasture; 2 pastures) tall fescue for 121 d. Semen was collected by electroejaculation, and SC was measured and blood samples collected monthly. Sperm were evaluated for motility and morphology with an integrated visual optical system. Overall mean concentration of prolactin was decreased more (P < 0.01) in El bulls than NE bulls from May to August. Scrotal circumference was not affected by fescue type (P 0.58); overall SC averaged 36.7 + 2.3 cm. Percentage of live sperm was not different (P = 0.24) between NE bulls (80%) than El bulls (67%) in July and August. Bulls grazing NE fescue had more (P < 0.06) motile sperm than El bulls in July and August. Percentages of progressive (57 vs. 38%, NE and El, respectively; P < 0.06) and rapid (67 vs. 46%, NE and El, respectively; P = 0.04) sperm were greater from bulls grazing NE than El bulls in July and August. Average velocity of the smoothed sperm path and progressive velocity in a straight line from the beginning to the end of the sperm track were slower (P < 0.09) in El bulls than NE bulls and were slower (P = 0.04) in August compared with July. Mean width of head oscillation as the sperm swims was less (P < 0.06) in August than July. Concentrations of cortisol and testosterone were not (P > 0.10) influenced by fescue type. Semen from bulls grazing El had reduced motility and morphology than bulls grazing NE. Detrimental effects of toxic fescue may not be mediated by cortisol, testosterone, or both. Semen quality of bulls grazing toxic El tall fescue was decreased with increased maximum ambient temperatures. [PUBLICATION ABSTRACT]

Future cockpits are going to require new onboard technologies (e.g., Cockpit Display of Traffic Information, CDTI) in order to accommodate the responsibilities likely to be delegated to pilots under NextGen. The current study investigated the effects of multiple levels of force feedback on operator performance in a task designed to approximate a CDTI environment. Participants were presented with two different types of force feedback (gravitational and spring force feedback), each with multiple levels of gain. Approach Time, Time Inside Target and Overall Movement Time were recorded. Results demonstrated that the two highest levels of gravitational force significantly reduced Overall Movement Times and Approach Times relative to the lowest level of gravitational force. The two highest levels of gravitational force, however, resulted in largely similar performance and were found to be comparable to performance with a computer mouse. Spring force level only had a main effect on Time Inside Target.

Individual ewes vary in reproductive performance parameters, such as age at first lambing, twinning rate, and ability to breed during off-season. Previous studies indicate that anti-mullerian hormone (AMH) in circulation reflects the total pool of follicles within the ovaries, and is positively correlated with fertility. In this study, retrospective analysis was used to determine if AMH could serve as an indicator of ewe fecundity. Serum samples were collected from 152 Katahdin ewes ranging from 0.5 to 7 yr of age, their pregnancy and lambing rate recorded, and estimated breeding values obtained from the National Sheep Improvement Program. Anti-mullerian hormone was analyzed using an equine and ovine AMH enzyme-linked immunosorbent assay (ELISA) kit. Continuous variables were analyzed by ANOVA and categorical data by chi-squared, using JMP⌖(SAS institute) software. Serum AMH ranged from 0.04 to 0.39 ng/mL, with mean of 0.17 ng/mL. Mean serum AMH was similar (P = 0.37) across all ewe age groups (< 1, 1 to 2, 2 to 3, and > 4 yr). The distribution of AMH concentrations was divided into quartiles (AMH Q1 through Q4, with the Q1 lowest and Q4 the highest). There was no relationship (fall; P = 0.65; summer; P = 0.11) between AMH quartile and mean number of lambs born (NLB) from fall and summer breeding. No correlation (P = 0.39) was found between individual estimated breeding value for NLB and serum AMH concentration. A significant correlation (P < 0.01; r = 0.411) existed between mean NLB per individual ewe during summer (0.79) and fall (1.44). Overall pregnancy rate was higher (P < 0.01) for fall (79%) than summer (48%) breeding. It was noted that 25/68 (36.8%) of ewes < 2 yr of age fell into the lowest AMH quartile (Q1) as compared with 13/84 (15.5%) for older ewes. Similarity of AMH among different ewe age groups and a lower percentage of older ewes in AMH Q1 could reflect particular selection criteria.