Effects of gonadotrophin releasing hormone on reproductive performance of dairy cows with retained placenta.

The effects of gonadotrophin releasing hormone (GnRH) on the reproductive performance of dairy cows with retained placenta were studied. Three hundred and seventy-eight cows diagnosed as having retained placenta received intramuscular injections of either 2 mL sterile water or 200 micrograms of GnRH in 2 mL sterile water between day 8 and day 14 postpartum. Rectal palpation was performed at the time of treatment and ten to 20 days after treatment in order to determine the rate of uterine involution. Thereafter, monthly rectal examinations were carried out until insemination. Pregnancy diagnosis was made by rectal palpation at 40 days or more after breeding. Using the entire experimental population, there were no significant differences between GnRH-treated and control cows for the rate of uterine involution, the occurrence of reproductive problems, the interval from parturition to first observed estrus, the interval from parturition to first insemination, the interval from parturition to conception, the number of services per conception, the total number of services per cow regardless of conception and the incidence of culling for infertility. When the data for herds in which breeding began earlier in the postpartum period (herds having a mean less than or equal to 80 days from parturition to first service for retained placenta cows) were considered, the GnRH treatment resulted in a significantly shorter (p less than or equal to 0.01) calving to conception interval as compared to control cows. Also, there was a significant reduction (p less than or equal to 0.05) in the total number of services per cow regardless of conception and a significant reduction in the interval from parturition to first service.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Effect of Retained Placenta and Metritis Complex on Reproductive Performance in Dairy Cattle — A Case Control Study

A study of the computer stored records of 293 dairy cows and 652 calvings reveals the effects of retained placenta and metritis complex on reproductive performance. The overall incidence rate of retained placenta was 11.2%. Retained placenta was 4.6 times more likely to occur following twin births than following single births. Most cases of retained placenta occurred during the fall. Forty-five percent of that seasonal increase was explained by an increased number of calvings. Metritis complex was diagnosed following 54.8% of retained placenta cases. Retained placenta alone did not significantly impair reproductive performance. Metritis complex, in the presence or absence of retained placenta, caused a significant (P相似文献   

Effects of proportion of pigs removed from a group and subsequent floor space on growth performance of finishing pigs

The effects of the proportion of pigs removed from an established group and subsequent floor space on growth performance during the final 19 d of the finishing period were evaluated using 28 pens of mixed-sex crossbred pigs (mean initial BW = 113.4 +/- 0.57 kg; n = 1,456; approximately 52 pigs per pen). A randomized block design was used with four pig-removal treatments: 1) 0% of pigs removed [Control], 2) approximately 25% of pigs removed, 3) approximately 50% of pigs removed, and 4) approximately 50% of pigs removed and floor and feeder spaces/pig decreased to equal those of Control. A block consisted of four pens with the same number of pigs and sex ratio per pen and with similar initial BW. Pens within blocks were randomly allocated to treatment, and the heaviest animals were removed from Treatments 2, 3, and 4 at the start of the study. Group size and floor space/pig for Treatments 1, 2, 3, and 4 were 52 and 0.65 m(2), 39 and 0.87 m(2), 26 and 1.30 m(2), and 26 and 0.65 m(2), respectively. Each pen contained a six-place feeder that provided 212 cm of total trough space; however, only three-places were accessible to pigs on Treatment 4. Compared with Controls, removing 25 or 50% of pigs resulted in increased (P < 0.001) ADG by 20.6 and 21.0%, ADFI by 10.8 and 7.9%, and G:F by 7.7 and 14.3%, respectively. Average daily gain by pigs on Treatment 4 (50% removal rate and decreased floor and feeder spaces) was greater (P < 0.05) than that of the Controls, but lower (P < 0.05) than that of Treatment 3 pigs (50% removal rate, no adjustment in floor or feeder spaces). No differences were observed among treatments for either morbidity or mortality. These results indicate that removing 25 or 50% of the heaviest pigs from groups of finishing pigs increased growth rate of the remaining pigs, and that the improved performance was only partly due to increased floor and feeder spaces.     

Effect of grape polyphenols on oxidative stress in canine lens epithelial cells

OBJECTIVE: To evaluate whether the effects of oxidative stress could be attenuated in cultures of canine lens epithelial cells (LECs) by incubation with grape seed proanthocyanidin extract (GSE), resveratrol (RES), or a combination of both (GSE+RES). SAMPLE POPULATION: Primary cultures of canine LECs. PROCEDURES: LECs were exposed to 100MM tertiary butyl-hydroperoxide (TBHP) with or without GSE, RES, or GSE+RES. The dichlorofluorescein assay was used to detect production of reactive oxygen species (ROS), and immunoblot analysis was used to evaluate the expression of stress-induced cell-signaling markers (ie, the mitogen-activated protein kinase [MAPK] and phosphoinositide-3 kinase [PI3K] pathways). RESULTS: GSE and GSE+RES significantly reduced ROS production after a 30-minute exposure to TBHP. Only GSE significantly reduced ROS production after a 120-minute exposure to TBHP. Incubation with GSE reduced TBHP-induced activity of the MAPK and PI3K pathways. CONCLUSIONS AND CLINICAL RELEVANCE: GSE inhibited key components associated with cataractogenesis, ROS production, and stress-induced cell signaling. On the basis of the data reported here, there is strong evidence that GSE could potentially protect LECs from the damaging effects of oxidative stress.     

Cattle‐associated risk factors for human tuberculosis in rural livestock‐keeping communities,Uganda

Tuberculosis (TB) is a leading infectious cause of human death worldwide. In cattle, TB infection results in productivity losses, trade barriers and zoonotic transmission via milk, meat or direct contact. We conducted a cross‐sectional study in rural communities in Uganda between 2014 and 2016 to evaluate the association between tuberculosis skin test (TST) positivity in humans and cattle‐associated risk factors: household herd positivity and raw milk consumption. Human and cattle TSTs were performed in communities followed by a survey of household practices. TST data were available on 493 humans, 184 (37.3%) with positive results, and 1,441 cattle, 50 (3.5%) with positive results. We fit separate log binomial generalized estimating equation models for the herd positivity‐human TST positivity association, stratified on sex; and for the raw milk consumption‐human TST positivity association, stratified on frequency of milk consumption. Having at least one TST‐positive bovid in the household's herd was significantly associated with lower risk of TB among men (prevalence ratio [PR] 0.66, 95% CI 0.49, 0.87) but was not significantly associated with TB among women (PR 1.21, 95% CI 0.76, 1.95). This apparent protective effect was contrary to our a priori hypothesis of higher exposure effect among men, the primary caretakers of cattle. This finding may be the result of residual confounding by socioeconomic status; wealthier individuals may be less likely to be TB positive, but more likely to have TST‐positive herds by virtue of larger herd sizes, ability to purchase new and possibly infected stock, and propensity to keep more TB‐susceptible European breeds. For raw milk consumption, effect estimates were close to one and not statistically significant. Thus, in settings where bovine TB prevalence is low, such as Uganda, cattle‐associated zoonotic transmission may be rare, and cattle‐associated risk factors may not be important drivers of human TB burden.     

A comparison of liquid and lyophilized egg yolk plasma to low density lipoproteins for freezing of canine spermatozoa

The current study aimed to explore the potential usefulness of liquid or lyophilized egg yolk plasma (EYP) as a substitute for low‐density lipoproteins (LDL) for cryopreservation of canine spermatozoa. In the first experiment, a total of 20 ejaculates harvested from six Beagles were frozen in extenders containing 6% LDL (control) or liquid or lyophilized EYP at one of three concentrations (20%, 40% or 60%). Motility parameters were assessed 10 min after thawing using computer‐assisted sperm analysis. For both liquid and lyophilized EYP, the 40% concentration yielded motility similar (p > 0.05) to that observed with the control extender. In the second experiment, 12 ejaculates collected from the same six dogs were frozen in 6% LDL (Control), 40% liquid EYP or 40% lyophilized EYP extenders. Spermatozoal membrane integrity (hypo‐osmotic swelling test [HOSt] and SYBR14/propidium iodide [PI] staining), acrosome integrity (FITC‐Pisum sativum agglutinin staining) and DNA integrity (acridine orange staining) characteristics were evaluated 10 min after thawing. Both liquid and lyophilized 40% EYP‐based extenders successfully preserved all assessed integrity parameters as efficiently as the control. Results of this study suggest that lyophilized EYP is a viable alternative to LDL in freezing extenders for dog semen.     

Genomic signatures predict migration and spawning failure in wild Canadian salmon

Long-term population viability of Fraser River sockeye salmon (Oncorhynchus nerka) is threatened by unusually high levels of mortality as they swim to their spawning areas before they spawn. Functional genomic studies on biopsied gill tissue from tagged wild adults that were tracked through ocean and river environments revealed physiological profiles predictive of successful migration and spawning. We identified a common genomic profile that was correlated with survival in each study. In ocean-tagged fish, a mortality-related genomic signature was associated with a 13.5-fold greater chance of dying en route. In river-tagged fish, the same genomic signature was associated with a 50% increase in mortality before reaching the spawning grounds in one of three stocks tested. At the spawning grounds, the same signature was associated with 3.7-fold greater odds of dying without spawning. Functional analysis raises the possibility that the mortality-related signature reflects a viral infection.