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Biomedical subjects

W E Marsh

Publications and source records attributed to W E Marsh.

26 records · Page 2Linked to original sources
PubMed1994

Multiple manifestations of season on reproductive performance of commercial swine.

Seasonal variation of reproductive performance of female swine was analyzed by use of a data base that included farrowing records from 42 commercial swine herds. Farrowing rates of sows bred during December or January were higher (P < 0.001) than those bred in July or August (79.2 vs 74.1%). The percentage of sows with irregular (prolonged) return-to-estrus intervals after mating in December or January (2.63%) was lower (P < 0.01) than those mated in July or August (4.65%). Sows mated in November through January had greater total number of pigs born per litter (11.66 vs 11.19 pigs per litter), more pigs born alive per litter (10.39 vs 9.84 pigs per litter), and greater litter birth weights (15.20 vs 14.28 kg) than sows mated in June through August (P < 0.001). Adjusted 21-day litter weights were lower (P < 0.001) for litters from sows farrowing in July or August (52.04 kg) than sows farrowing in all other months (55.13 kg) except June and September. Sows that had their litters weaned in June through August had longer (P < 0.001) weaning-to-estrus intervals (7.95 days) than sows that had their litters weaned in November through January (6.84 days). The effects of season varied across parties. Primiparous sows had the greatest seasonal variability in weaning-to-estrus interval, whereas multiparous sows had the greatest seasonal variability in total number of pigs born per litter and pigs born alive per litter.

Animals↗
PubMed1994

Influence of a gonadotropin-releasing hormone agonist on circulating concentrations of luteinizing hormone and testosterone and tissue concentrations of compounds associated with boar taint.

Twenty-four Yorkshire boars and six barrows approximately 8 mo of age were used to evaluate the effects of a GnRH agonist (GnRH-A) on circulating concentrations of LH and testosterone (T), concentrations of skatole in fat, and concentrations of 16-androstene steroids in fat and salivary glands. Pigs were assigned to five groups of six pigs each: L200, boars injected with 200 micrograms of GnRH-A/kg BW; L50, boars injected with 50 micrograms of GnRH-A/kg BW; Boar, boars treated with vehicle; Castrate, males castrated on the same day that Groups 1 to 3 received injections; and Barrow, males castrated as neonates. Pigs in L200, L50, and Boar were only given one injection. Blood samples were taken twice daily from d -2 to 28 for determinations of T and LH concentrations and at 15-min intervals for 6 h on d -1, 1, 7, 14, 21, and 28 for characterization of pulsatile LH release. Pigs were slaughtered on d 30, and samples of backfat and salivary glands were collected for quantification of skatole and 16-androstene steroid concentrations. The LH concentrations increased immediately following GnRH-A injection in L200 and L50 (P < .001) and then declined to pretreatment values by approximately 29 h after treatment. Serum T concentrations in L200 and L50 increased after GnRH-A treatment (P < .0001) and then decreased to less than pretreatment concentrations by d 5 in L200 (P < .001) and by d 8 in L50 (P < .01). Concentrations of 16-androstene steroids in fat were less (P < .05) in L200 and Barrow than in Boar.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1994

Pregnancy attrition associated with pregnancy testing by rectal palpation.

The objective of this study was to estimate the effect on calving risk of interval from AI date until scheduled date of pregnancy examination. First AI (n = 7105) from 65 dairy herds in the United States and Canada were followed for 294 d to determine whether cows calved. Calving was modeled as a function of the number of days in the interval, herd, season, and breeding at PGF2 alpha-induced estrus by multivariate logistic regression. The main effects of herd and AI following PGF2 alpha-induced estrus were significantly associated with calving rate from first AI. The main effects of interval and season were not significantly associated with calving.

Abortion, Veterinary↗
PubMed1993

Prevalence and severity of lameness in lactating dairy cows in a sample of Minnesota and Wisconsin herds.

An epidemiologic study investigating the prevalence of lameness in lactating dairy cows was performed in 17 dairy herds in Minnesota and Wisconsin. The mean herd size was 50 cows. Cows from 14 herds were housed in stanchions or tie stalls, and cows from 3 herds in free stalls or dry lot. During visits to each farm in the summer and subsequent spring, 2 investigators simultaneously but independently evaluated the ambulation of lactating cows by use of a standardized scoring system. The lameness scoring system was reliable at the 2 visits, with 92.7 and 91.3% agreement between the 2 observers and kappa coefficients of 0.60. The prevalence of lameness detected by the investigators ("clinical" lameness) was 13.7% (117/853) in summer and 16.7% (134/801) in spring in lactating dairy cows. These prevalences were 2.5 times higher than those estimated by the herd managers. Parity was significantly (P < or = 0.03) associated with lameness, with higher prevalence of clinical lameness found in cows of higher parity.

Animals↗
PubMed1992

Breeding and gestation facilities for swine. Matching biology to facility design.

The rate-limiting phase of commercial swine production is breeding. The design of the breeding/gestation facilities influences the capacity of the producer to efficiently manage the breeding stock around the time of service and during the postservice period. Thus, breeding design potentially affects total born litter size and farrowing rates. In general, with original construction and facility renovation, the three principal activities of the breeding/gestation phase of production, (1) boar exposure/estrus detection, (2) breeding, and (3) gestation and pregnancy detection, should be independently considered.

Animal Husbandry↗
PubMed1992

Financial evaluation and decision making in the swine breeding herd.

As the swine industry continues to evolve and develop a greater business orientation--one that demands justification of costs, benefits, and risk-exposure--the veterinarian will be confronted with the need to develop an economic basis to supplement the biologic. The profession should view such a challenge as an opportunity to broaden its role in serving the businesses that make up the industry. However, to be effective in such an expanded role requires that the veterinarian develop a good working knowledge of risk and risk management as well as the role played by economic evaluation techniques used in financial evaluation in the risk management process. Several potential advantages exist for the veterinarian who determines to expand his or her risk management role by using financial evaluation in the course of day-to-day practice routine: Additional service or consulting income may be generated through evaluating alternatives through decision analysis. Client confidence may be strengthened in the veterinarian and in the recommendations made. The costs of consulting services and health products for the client may be viewed as income-generators instead of being viewed solely as expenses. Referrals of additional progressive clients may be generated by satisfied current clients. The veterinarian may achieve personal satisfaction through substantiating his or her recommendation beyond clinical or experimental judgment. With the capability of using financial evaluation techniques in the evaluation and justification of recommendations comes significant responsibility. Reliance upon financial evaluation techniques as a more objective approach in the management of risk for clients carries with it an inherently greater degree of trust. Such trust must be deserved. The universal adage "garbage in, garbage out" applies directly to financial evaluation. Financial evaluation techniques have the potential to provide the decision-maker with objective and accurate analysis, improving the probability of choosing an optimal course of action for the business. However, the objectivity and accuracy achievable is highly dependent upon the quality and quantity of information used in the analysis. Veterinarians must be cognizant of the increased responsibility demand placed on those using financial evaluation techniques to direct the course of action for their clients. Financial evaluation tools are available to decision-makers that may improve the objectivity of the decision-making process, providing for a greater degree of confidence in the expected outcome. Stated another way, these tools can reduce the number of surprises a decision-maker encounters as a result of the decisions made.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Husbandry↗
PubMed1991

Factors associated with the seroprevalence of pseudorabies virus in breeding swine from quarantined herds.

Strategies for the elimination of pseudorabies virus (PRV) from swine herds include test and removal, offspring segregation, and depopulation/repopulation. The prevalence of PRV in a herd is a major factor in selection of the most appropriate strategy. The purpose of the study reported here was to describe the prevalence of PRV in adult swine in PRV quarantined herds in Minnesota, and to determine herd factors associated with the seroprevalence. Questionnaires describing the health history of the herd, management practices, and design of the swine facilities were obtained from the owners of 142 quarantined herds. Blood was collected from 29 finishing pigs over the age of 4 months, up to 29 adult females, and all herd boars. Factors considered to be significant in a bivariate analysis were combined in a stepwise multiple logistic regression analysis. The prevalence of PRV-seropositive adults in each herd was bimodally distributed among the 142 herds. In 42 (30%) of the herds, none of the females tested was seropositive, which represented the lower mode. At least 90% of the adults tested were seropositive in 30 (21%) of the herds and represented the higher mode. The odds of the breeding swine of a given herd having a PRV seroprevalence of greater than or equal to 20% as compared with having a seroprevalence of less than 20% was 1.654 times higher per 50 adults in the herd, 13.550 times higher if the finishing pigs were seropositive, 2.378 times higher if sows were housed inside during gestation, and 1.481 times lower per number of years since the imposition of quarantine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗