کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10980258 1108069 2012 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enteric methane emissions and lactational performance of Holstein cows fed different concentrations of coconut oil
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Enteric methane emissions and lactational performance of Holstein cows fed different concentrations of coconut oil
چکیده انگلیسی
To determine if dietary medium-chain fatty acids (FA; C8 to C14) may mitigate enteric methane emissions, 24 cows were blocked by body size (n = 2) and randomly assigned to 1 sequence of dietary treatments. Diets were fed for 35 d each in 2 consecutive periods. Diets differed in concentrations of coconut oil (CNO; ∼75% medium-chain FA): 0.0 (control) or 1.3, 2.7, or 3.3% CNO, dry matter basis. The control diet contained 50% forage (74% from corn silage), 16.5% crude protein (60% from rumen-degradable protein), 34% neutral detergent fiber (NDF; 71% from forage), and 28% starch, dry matter basis. Data and sample collections were from d 29 to 35 in environmentally controlled rooms to measure methane (CH4) production. Methane emitted was computed from the difference in concentrations of inlet and outlet air and flux as measured 8 times per day. Control cows emitted 464 g of CH4/d, consumed 22.9 kg of DM/d, and produced 34.8 kg of solids-corrected milk/d and 1.3 kg of milk fat/d. Treatment with 1.3, 2.7, or 3.3% dietary CNO reduced CH4 (449, 291, and 253 g/d, respectively), but concomitantly depressed dry matter intake (21.4, 17.9, and 16.2 kg/d, respectively), solids-corrected milk yield (36.3, 28.4, and 26.8 kg/d, respectively), and milk fat yield (1.4, 0.9, and 0.9 kg/d, respectively). The amount of NDF digested in the total tract decreased with increased dietary CNO concentrations; thus, CH4 emitted per unit of NDF digested rose from 118 to 128, 153, and 166 g/kg across CNO treatments. Dietary CNO did not significantly affect apparent digestibility of CP but increased apparent starch digestibility from 92 to 95%. No FA C10 or shorter were detected in feces, and apparent digestibility decreased with increasing FA chain length. Coconut oil concentrations of 2.7 or 3.3% decreased yields of milk FA C14. The highest milk fat concentration (3.69%; 1.3% CNO) was due to the greatest yields of C12 to C16 milk FA. Milk FA concentrations of C18:2 trans-10,cis-12 were related to increased dietary CNO concentrations and presumably to depressed ruminal NDF digestion. Moderate dietary CNO concentrations (e.g., 1.3%) may benefit lactational performance; however, CNO concentrations greater than or equal to 2.7% depressed dry matter intake, milk yield, milk fat yield, and NDF utilization. If mitigation of enteric CH4 emissions is due to decreased digestion of dietary NDF, then this will lessen a major advantage of ruminants compared with nonruminants in food-production systems. Thus, CNO has limited use for enteric CH4 mitigation in lactating dairy cows.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 95, Issue 5, May 2012, Pages 2602-2615
نویسندگان
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