Abstract

The effect of barley-based (BBD) or co-based diets (CBD), or their equal blend (BCBD) on dry matter (DM) intake, feeding and chewing behavior, and production performance of lactating dairy cows was evaluated. Nine multiparous Holstein cows (75.6 ± 11.0 d in milk) were used in a triplicate 3 × 3 Latin square design with 21-d periods. Forage-to-concentrate ratio (40:60), forage neutral detergent fiber (20% of DM), total neutral detergent fiber (>29% of DM), and geometric mean particle size (4.3 mm) were similar among treatments. Meal pattes, including meal size and intermeal interval, were not affected by the dietary treatments and DM intake (25.6 kg/d) was not different among treatments. Ether extract intake increased linearly with increasing amount of the co grain in the diets. Due to similar feed intake, actual milk (48.6 kg/d), 4% fat-corrected milk (36.8 kg/d), and fat- and protein-corrected milk (38.1 kg/d) yields were not affected by treatments. Average milk protein percentage and yield were 2.83% and 1.37 kg/d, respectively, and were not different across treatments. Milk fat percentage increased linearly with increasing amount of co grain in the diets and was greater in CBD relative to BCBD but not BBD (2.31, 2.28, and 2.57%, for BBD, BCBD, and CBD, respectively). However, milk fat yield tended to show a linear increase as the amount of co grain included in the diets increased. Results indicated that changing diet fermentability by replacing barley grain for co grain in oil-supplemented diets did not influence feeding pattes and thereby no changes in feed intake and milk yield occurred

Abstractخلاصه

equalشبیه،یکسان

blendآمیخته گری کردن

chewingجویدن

lactatingشیرده

multiparousچندشکم زا

productionتولید و پرورش

performanceعملکرد

Forageعلوفه

extractعصاره

Latin squareطرح مربع لاتین

detergentمواد شوینده

actualواقعی

concentrateچسباندن

percentageبرحسب درصد

treatmentsتیمارها

correctedاصلاح شده

BBD=Barley Based Diet=جیره غذایی بر اساس جو

co-based diets (CBD)=جیره غذایی بر اساس ذرت

BCBD=Barley and co Based Diet=جیره غذایی بر اساس ذرت و جو

relativeخویشاوندی

intakeمصرفی

fermentabilityقابل تخمیر

mealکنجاله،پودر