Plasma nitrogen isotopic fractionation and feed efficiency in growing beef heifers
نویسندگان
چکیده
منابع مشابه
Plasma nitrogen isotopic fractionation and feed efficiency in growing beef heifers.
Fractionation of N isotopes occurs in many metabolic reactions which causes tissue proteins to become enriched in ¹⁵N while urea (urine) is depleted in ¹⁵N relative to the diet. We investigated ¹⁵N enrichment of whole plasma and its relationship with feed conversion efficiency (FCE) in growing beef heifers (n 84) offered 2 kg/d of concentrates with grass silage ad libitum. Heifers were on avera...
متن کاملGrowth Performance and Feed Conversion Efficiency of Crossbred Heifers
Theexperiment was conducted to investigate the growth performance and feed conversion efficiency of crossbred heifer at different age level in Government Dairy Farm in Bogra, Bangladesh. Twelve female crossbred heifers were equally distributed (n=3) into four groups [Group A: (7±2 months), B: (12±2 months), C: (15±2 months) and D: (20±2 months)] according to age and fed concentrate mix, rice st...
متن کاملVariation in Feed Efficiency of Growing Heifers and Implications for Intensified Cow-Calf Production
Global demand for food has been projected to increase 70% by 2050 in order to support a growing population that is becoming more urbanized and affluent. As disposable incomes increase in developing countries, people will elect to include more animal-protein foods in their diet. This rising demand for animal protein will require a concomitant increase in the supply of cereal grains as well as pr...
متن کاملDefining Feed Efficiency in Beef Cattle
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...
متن کاملTechnical note: Nitrogen isotopic fractionation can be used to predict nitrogen-use efficiency in dairy cows fed temperate pasture.
The objective of this study was to investigate the relationship between nitrogen isotopic fractionation (δ(15)N) and nitrogen-use efficiency (milk nitrogen/nitrogen intake; NUE) in pasture-fed dairy cows supplemented with increasing levels of urea to mimic high rumen degradable protein pastures in spring. Fifteen cows were randomly assigned to freshly cut pasture and either supplemented with 0,...
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ژورنال
عنوان ژورنال: British Journal of Nutrition
سال: 2014
ISSN: 0007-1145,1475-2662
DOI: 10.1017/s0007114513004078