In addition to dose-response studies, modeling of N utilization, depending on intake of the first limiting amino acid in the diet, is one of the tools for assessing amino acid requirements in growing animals. Based on a verified nonlinear N-utilization model and following the principles of the diet dilution technique, N-balance experiments were conducted to estimate the Thr requirement of fast-...

abstract bottom rack intake is one of the most appropriate structures for diverting water in steep rivers. the problems of corrosion, deformity and clogging of the bottom racks in long term, inspires a new system of bottom intake in which a filled trench of porous media is replaced by the bottom racks. diversion of a specified amount of discharge through the porous media when void space in the ...

An experiment was conducted to evaluate the impact of different rationale on performance certain attributes Vencov, Hubbard and Croiler breeds. The average feed intake, body weight, weight gain, conversion efficiency, gain at slaughter dressing evaluated. intake were 2.18, 2.02 2.03 kg/bird, in treatments (Ist, IInd IIIrd) it 1.89, 1.76 2.57 kg/bird breeds (Vencov, Croilers) respectively. 1.07,...

Broiler chicks were fed on chemically-defined crystalline amino acid diets containing graded levels of L-threonine (Thr) during the period 10-20 d post-hatching. Doses of Thr represented 5,10,15,40, 55, 70 and 95 % of its ideal level for maximal weight gain and feed efficiency. Other amino acids were maintained at minimized excess levels that were 15 % (of ideal) above the various doses of Thr....

Mixed model analysis of data from 32 studies (122 diets) was used to evaluate the precision and accuracy of the omasal sampling technique for quantifying ruminal-N metabolism and to assess the relationships between nonammonia-N flow at the omasal canal and milk protein yield. Data were derived from experiments in cattle fed North American diets (n=36) based on alfalfa silage, corn silage, and c...

Providing feed is a major input cost in beef production, hence improvements in the efficiency of feed utilisation will reduce the cost of production. Residual feed intake (RFI) is a measure of feed efficiency, and is defined as the difference between an animal's actual feed intake and its expected feed intake based on its size and growth. It is independent of the level of production, and the lo...

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 ...

Broiler chicks were fed on chemically-defined crystalline amino acid diets containing graded levels of L-threonine (Thr) during the period 10-20 d post-hatching. Doses of Thr represented 5, 10, 15, 40, 55, 70 and 95% of its ideal level for maximal weight gain and feed efficiency. Other amino acids were maintained at minimized excess levels that were 15% (of ideal) above the various doses of Thr...

Recent improvement in technologies for measuring individual feed intake has made possible the collection of data suitable for breed-wide genetic evaluation. The goals of this research were to estimate genetic parameters for components of feed efficiency and develop a prototype system for conducting a genetic evaluation of Angus cattle for feed intake. Weaning weight (WWT), postweaning BW gain (...

Both feed efficiency and sow production are economically important traits in pig breeding. One challenge in a maternal line such as Norwegian Landrace is to breed for highly feed efficient fattening pigs and, at the same time, produce sows with high daily feed intake to maintain their BCS in multiple parities. The aim of this study was to estimate genetic correlations among novel feed efficienc...