Low live weight gain of cattle in the wet season of tropical areas was identified as a major limitation to achieving annual growth rates from tropical pasture systems sufficient to meet new market specifications of young animals of high carcass weight. Both protein and energy are limiting nutrients for growth. Net transfer of feed protein to the intestines is often not complete, and losses occu...

Metabolizable protein (MP) supply and amino acid balance in the intestine were manipulated through selection of highly digestible rumen-undegradable protein (RUP) sources and protected methionine (Met) supplementation. Four ruminallycannulated, multiparous Holstein cows averaging 193±13 days in milk were used in a 4×4 Latin square design to assess N utilization and milk production responses to ...

Abstract Sustainability use of expensive protein source in a dairy ration requires formulation based on rumen degradable and undegradable ratio (RDUP). It improves the efficiency microbial synthesis less feed residue to environment. Providing green sources such as leucaena (Leucaena leucocephala) is also an alternative. This study aimed evaluate effect RDUP with addition vitro fermentability di...

Five steers (491 ± 21 kg BW) were used in an incomplete 5 × 4 Latin square with four 24-d periods to determine the influence of supplemental nonprotein N (NPN) source and supplementation frequency (SF) on nutrient intake and site of digestion in steers consuming low-quality grass straw (4% CP). Treatments (TRT) included an unsupplemented control and a ureaor biuret-containing supplement placed ...

Particle size alterations during neutral detergent fiber (NDF) determination and in situ rumen incubation were analyzed by dry sieving and image analysis to evaluate the in situ procedure for estimation of NDF degradation parameters and indigestible NDF concentration in terms of particle size. Early-cut and late-cut grass silages, corn silage, alfalfa silage, rapeseed meal, and dried distillers...

The rumen typically operates as an energy-limited, nitrogen-excess system, but diets can be so low in degradable crude protein that microbial growth is limited by N. Ruminal bacteria respond differently to N sources and N-limitation. Cellulolytic ruminal bacteria need ammonia as an N source, have little capacity to utilize amino-N, are unable to ferment fiber when ammonia is depleted, and do no...

Several methods were used for the evaluation of feed protein for rumen degradability and intestinal digestibility of rumen undegraded protein (RUP). The aim of this work was to explore the possibility of using the Cornell method of predicting the fraction RUP. An in situ method was adopted for estimation of degradability parameters (a, b, c) and effective degradable crude protein (EDCP), and fi...

Particle size alterations during neutral detergent fiber (NDF) determination and in situ rumen incubation were analyzed by dry sieving and image analysis to evaluate the in situ procedure for estimation of NDF degradation parameters and indigestible NDF concentration in terms of particle size. Early-cut and late-cut grass silages, corn silage, alfalfa silage, rapeseed meal, and dried distillers...

The aim of this study was to evaluate the effects of substituting soybean meal for urea on milk protein fractions (casein, whey protein and non-protein nitrogen) of dairy cows in three dietary levels. Nine mid-lactation Holstein cows were used in a 3× 3 Latin square arrangement, composed of 3 treatments, 3 periods of 21 days each, and 3 squares. The treatments consisted of three different diets...