A bioeconomic computer model was constructed to simulate biological and economic inputs and outputs for life cycle swine production. Parameters and relationships used in model were developed and verified by comparison with experimental results in the literature. The bioeconomic model was constructed by several modules such as growth and development, pregnancy, lactation, and replacement gilt et...

Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and ...

INDIVIDUAL SELECTION BASED ON FEMALE PERFORMANCE ONLY WAS CONDUCTED IN FOUR LINES OF MICE: L(+) for increased litter size, W(+) for increased 6-week body weight, L(-)W(+) for a selection index aimed at decreasing litter size and increasing 6-week body weight and L(+)W(-) for a selection index aimed at increasing litter size and decreasing 6-week body weight. A fifth line (K) served as an unsele...

Rearing animals in small litters induces a permanent increase in body weight and body fat. To determine whether changes in sympathoadrenal activity contribute to this effect, litter size was adjusted the day after birth and maintained until weaning at 21 days. Sympathetic nervous system (SNS) activity was measured in adult animals using [(3)H]norepinephrine ([(3)H]NE) turnover in peripheral tis...

Increasing size and concentration of production is a long-established and continuing trend in the poultry producing industry. The size of poultry litter produced in this industry shows a sustained and increasing trend too. Daily fresh litter/manure output per is about 30 kg/100 birds. For example, the size of Delmarva broiler farms is average 50,000 heads, and the daily poultry litter productio...