کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10973641 1108017 2016 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Performance and nitrogen use efficiency in mid-lactation dairy cows fed timothy cut in the afternoon or morning
ترجمه فارسی عنوان
عملکرد و بهره وری استفاده از نیتروژن در گاوهای شیرخوار به مدت طولانی بعد از ظهر و یا صبحانه تاتیوتیک خورده می شود
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
چکیده انگلیسی
Shifting cutting from morning to afternoon has been shown to increase the concentration of nonstructural carbohydrates in forages. We hypothesized that, compared with a total mixed ration containing timothy baleage and silage cut in the morning (a.m.-cut TIM), a total mixed ration containing timothy baleage and silage cut in the afternoon (p.m.-cut TIM) would improve animal performance and N use efficiency in mid-lactation Holstein cows due to enhanced supply of ruminal fermentable energy. The objective of this study was to compare the effects of p.m.- versus a.m.-cut TIM on milk yield, concentrations and yields of milk components, ruminal metabolism, and plasma concentrations of AA in mid-lactation Holstein cows. Ten (6 ruminally cannulated) primiparous cows averaging 139 ± 13 d in milk and 550 ± 56 kg of body weight, and 6 (2 ruminally cannulated) multiparous cows averaging 128 ± 11 d in milk and 632 ± 57 kg of body weight at the beginning of the experiment, were used in a crossover design. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. The concentration of nonstructural carbohydrates (water-soluble carbohydrates plus starch) was numerically greater in the p.m.- versus the a.m.-cut TIM and averaged 13.2 ± 1.06% and 12.2 ± 1.13%, respectively. Treatment × parity effects were observed for milk urea N, feed efficiency, and milk N efficiency, whereas parity effects were observed for nutrient intake, milk yield, and plasma concentration of several essential and nonessential AA. Intakes of dry matter (19.3 versus 18.6 kg/d) and nonstructural carbohydrates (2.56 versus 2.31 kg/d), and yields of 4% fat-corrected milk (23.1 versus 22.2 kg/d), energy-corrected milk (25.0 versus 24.1 kg/d), milk fat (0.91 versus 0.88 kg/d), and milk protein (0.77 versus 0.73 kg/d) were all greatest with feeding p.m.-cut TIM. Milk yield (23.5 versus 22.7 kg/d) tended to increase in cows fed p.m.-cut TIM. The ruminal fermentation profiles and plasma concentrations of AA were mostly unaffected by treatments. However, ruminal valerate (1.01 versus 1.17 mol/100 mol) and plasma Gly (172 versus 188 µM) were lowest with feeding p.m.-cut TIM. Overall, feeding mid-lactation dairy cows a total mixed ration that consisted of p.m.-cut timothy baleage and silage significantly increased dry matter intake and yields of milk, milk fat, and milk protein.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 99, Issue 7, July 2016, Pages 5445-5460
نویسندگان
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