Variation in protein metabolism accompanies genetic selection for a wide range of traits including growth of lean tissue, wool and possibly residual feed intake. This variation is observed at the level of protein and amino acid kinetics in response to nutrient supply in major tissues. There are associated effects on cellular development, endocrine secretion, hormonal action at the tissue level,...

To assess the genetic potential for selection of increased feed efficiency in rainbow trout (Oncorhynchus mykiss), we estimated the heritabilities and correlations for BW, daily weight gain (DG), and daily feed intake (DFI). Body weight was recorded 5 times, and DG and DFI 3 times during a feeding trial lasting 22 mo. To test the hypothesis that phenotypic and genetic parameters were influenced...

Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body's homeostasis. L-ascorbic acid (L-AA) has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production...

For more than half a century, progeny testing has been the foundation of genetic selection programs in dairy cattle (Robertson and Rendel, 1950). Several factors make progeny testing especially advantageous in dairy cattle, most notably widespread use of artificial insemination (AI) with frozen semen and the fact that nearly all traits of economic importance, including milk production, milk com...

in the past decade, a global demand for products from organic agriculture has increased rapidly. milk quality is of major interest for all parties. therefore, the objective of this study was to compare cow performance and product quality in conventional and organic system. twenty holstein dairy cows were allotted to one of 2 diet groups, which including: a conventional diet (con), and an organi...