Recent advances in our understanding of feed efficiency in livestock have moved the focus of much of the scientific community, possessing an interest in this important aspect of animal production, to a trait known as residual feed intake (RFI). This approach to understanding feed efficiency was first proposed as having potential for use in beef cattle by Koch et al. (1963), but is now being ext...

A review is presented of the genetic and physiological aspects of growth, body composition and feed efficiency in mice. The genetic parameters considered are: nature and extent of within and between-line genetic variation for body weight and growth rate; direct and correlated responses to selection for body weight, weight gain, feed intake and feed efficiency; direct genetic effects of the offs...

Feed efficiency, as defined by the fraction of feed energy captured in products, has more than doubled for the US dairy industry in the past 100 years. This increased feed efficiency resulted from increased milk production per cow achieved through genetics, nutrition, and management with the desired goal being greater profitability. With increased milk production per cow, more feed is consumed ...

eighteen female, neonatal brown swiss calves (39.5±1.2kg) were randomly divided into three treatment groups to investigate the effect of physical processing of diet on weaning age and some blood metabolites. treatments were included: mash starter (m), pelleted starter (p) and heterogen of mixture moisturized, rolled barley and corn. (h). diets were formulated to be isonitrogenous. there were no...

Despite substantial advances in milk production efficiency of dairy cattle over the last 50 years, rising feed costs remain a significant threat to producer profitability. There also is a greater emphasis being placed on reducing the negative impacts of dairy production on the environment; thus means to lower greenhouse gas (GHG) emissions and nutrient losses to the environment associated with ...

Divergent selection for heat loss was applied to lines of mice for 15 generations (G) in 3 replicates. Selection resumed at G42 and continued through G51 across all replicates. At the end of G51, differences in heat loss and feed intake per unit of BW were approximately 56 and 34%, respectively, between high heat loss (MH) and low heat loss (ML) lines, as a percentage of the control line (MC) m...

Previous studies have determined that stress causes decreases in feed intake and efficiency in livestock, but the effect of repeated transport on these parameters has not been well studied. This study determined how repeated transport affected calf post-transport behavior, feed intake, ADG, and feed conversion. Thirty-six 4-mo-old Holstein steer calves were housed in groups of 6 with each group...

The aim of the study was to investigate the effects of a standardized mixture of a commercial blend of phytogenic feed additives containing 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum on utilization of dietary energy and performance in broiler chickens. Four experimental diets were offered to the birds from 7 to 21 d of age. These included 2 basal control diets based on either wheat or mai...