Twenty-five crossbred gilts were used in an experiment to determine the tryptophan (Trp) requirement for reproduction. L-tryptophan was added to a fortified corn-gelatin diet to attain the five Trp levels of .64, 1.04, 1.44, 1.84 and 2.24 g per day. These diets were fed at 2 kg daily during pregnancy I and 1.82 kg daily during pregnancies II and III. During each 3-week lactation, all animals we...

the objective of this study was to evaluate the effects of supplementation of different level protein diets with rumen protected methionine and lysine on performance and ruminal parameters in holstein dairy cows when in their early lactation. twenty one dairy cows in their early lactations were assigned to three treatments in a randomized block design experiment of a 35-d duration period. diets...

monthly and seasonal concentrations of milk protein and urea and their relationships were investigated in 614 milk samples from 61 industrial holstein dairy herds in urmia, iran. milk samples were prepared monthly interval up to 12 months. the amount of 10 ml milk was prepared from each dairy herd when they were delivering to the milk factory. milk protein and urea concentration was evaluated b...

Twenty-five Landrace • Yorkshire sows (second through seventh parity) were randomly assigned to five dietary treatments in an experiment designed to estimate the isoleucine requirement of the sow during the first 3 weeks of lactation. The basal diet (.20% isoleucine), composed of oat groats, corn sugar, wood cellulose, soybean oil, vitamins, minerals, indispensable amino acids and L-glutamic ac...

The objective was to evaluate the effect of beta-lactoglobulin (beta-lg) polymorphism and seasonality on milk composition (fat, lactose, total solids, milk urea nitrogen, total protein, true protein, casein and somatic cell counts) of Holstein and Girolando cows. Milk and blood samples from 278 Holsteins cows and 156 Girolando cows were taken during two dry seasons and two rainy seasons, for mi...