this study was conducted to evaluate production response of early lactating cows to rumen protected fats. twelve (nine multiparous and three primiparous) holstein cows (26±4 d in milk) were empolyed in a replicated 3×3 latin square design of 21-d periods. each period consisted of 14 days of adaptation and 7 days of sampling. cows received diets containing either one of two types of protected fa...

Feed efficiency has a major influence on the unit cost of beef cattle production. Gibb and McAllister (1999) have reported that a 5% improvement in feed efficiency has an economic impact four times greater than a 5% improvement in average daily gain. In addition, the cost of feed is second only to fixed costs in importance to the profitability of commercial beef operations (Basarab, 1999). The ...

Most breeding programs have focused on improving economically relevant output traits such as growth, carcass quality and fertility to enhance the economic viability of beef production systems. Generally absent from current breeding programs in the U.S. are avenues for exploiting genetic variation in feed efficiency, even though reductions in feed inputs would substantially improve profitability...

OBJECTIVE The feed intake (FI) and feed efficiency are economically important traits in ducks. To obtain insight into this economically important trait, we designed an experiment based on the residual feed intake (RFI) and feed conversion ratio (FCR) of a random population Pekin duck. METHODS Two thousand and twenty pedigreed random population Pekin ducks were established from 90 males mated ...

We examined effects of feeding chicks differing levels of macronutrients on performance during the first 7 d posthatch in this study. Four experiments were conducted using male Ross x Ross broiler chicks. The first experiment examined, in a 3 x 3 factorial design, the effect of feeding fat at 3, 7, and 11% and protein at 18, 23, and 28%. With increasing protein and fat levels feed intake and BW...

Feed efficiency is an economically important trait that is likely influenced by complex molecular mechanisms. We utilized the NRC Beef Cattle Model to predict feed intake based on observed gain (and gain based on observed intake), where the NRC model also accounts for breed type, sex and season. The difference between this NRC-predicted feed intake and observed intake is termed model predicted ...

in this study, the effects of culban seed (vicia peregrine l.) on live body weight, feed intake, feed efficiency, egg production, egg quality characteristics, egg yolk fatty acid profiles and yolk cholesterol content in laying hens were investigated. the experiment consists of seven treatment groups with ten replications containing one laying hen in each and for 32 weeks old seventy laying hen ...