Effects of supplementation of energy or ruminally undegraded protein to lactating cows fed alfalfa hay or silage.
نویسندگان
چکیده
Alfalfa was harvested as silage or hay and fed in two 12-wk trials with a 4 x 4 Latin square design that used 12 (trial 1) or 24 (trial 2) multiparous lactating cows (4 ruminally cannulated cows per trial). Diets contained (dry matter basis) 75 or 50% alfalfa plus 24 of 40% high moisture corn (trial 1) or 50% alfalfa, 44 or 41% high moisture corn, with (3%) or without fish meal (trial 2). Experiments were conducted to evaluate the responses of cows fed alfalfa hay or alfalfa silage diets to an increase in protein supply from microbial protein synthesis (trial 1) or from the supplementation of ruminally undegraded protein (RUP) (trial 2). In trial 1, the increase in high moisture corn in the diet increased both milk protein and microbial crude protein yields (estimated from the excretion of purine derivatives) to a greater extent for the cows fed the alfalfa silage diets (170 and 337 g/d, respectively) than for the cows fed the alfalfa hay diets (100 and 100 g/d, respectively). In trial 2, RUP supplementation (as fish meal) increased milk protein yield 100 g/d for cows fed alfalfa silage diets and 20 g/d for cows fed alfalfa hay diets. These results indicated that protein status was poorer and, thus, more responsive to absorbable protein from microbial protein (trial 1) or RUP (trial 2) for cows that consumed alfalfa conserved as silage versus those that consumed alfalfa conserved as hay.
منابع مشابه
Effect of yeast culture supplementation of alfalfa silage or alfalfa hay fed to lactating dairy cows
متن کامل
اثر نسبتهای مختلف علوفه خشک یونجه و ذرت سیلو شده با دیواره سلولی و تعادل کاتیون - آنیون برابر، بر تغذیه و تولید گاوهای شیرده
To determine the best ratios of alfalfa hay to corn silage with similar dietary NDF, cation-anion balance, energy and protein content in the lactating dairy cows, eight mid-lactating Holstein dairy cows with average body weight of 570 kg, and milk yield of 22 kg/d with 3.5% fat, were assigned to each of four experimental diets with alfalfa hay to corn silage ratios of 100:0, 67:33, 33:67 and 0:...
متن کاملاثر نسبتهای مختلف علوفه خشک یونجه و ذرت سیلو شده با دیواره سلولی و تعادل کاتیون - آنیون برابر، بر تغذیه و تولید گاوهای شیرده
To determine the best ratios of alfalfa hay to corn silage with similar dietary NDF, cation-anion balance, energy and protein content in the lactating dairy cows, eight mid-lactating Holstein dairy cows with average body weight of 570 kg, and milk yield of 22 kg/d with 3.5% fat, were assigned to each of four experimental diets with alfalfa hay to corn silage ratios of 100:0, 67:33, 33:67 and 0:...
متن کاملEffects of Fat Supplementation and Chop Length on Milk Composition and Ruminal Fermentation of Cows Fed Diets Containing Alfalfa Silage
The aim of this study was to evaluate the effect of fat supplementation for enhancing milk conjugated linoleic acid (CLA) in early lactation without affecting ruminal fermentation. 24 Holstein dairy cows were assigned to a completely randomized design employing a 2 × 4 factorial arrangement. Factors were particle size (15 and 25 mm) and two different sources of alfalfa supplemented with and wit...
متن کاملPerformance of lactating dairy cows fed macerated forage conserved as silage and hay
Suwarno, Wittenberg, K. M., Ingalls, J. R. and McCaughey, W. P. 2000. Performance of lactating dairy cows fed macerated forage conserved as silage and hay. Can. J. Anim. Sci. 80: 123–129. The effect of forage maceration at harvest on silage characteristics and its effect on lactation performance of Holstein cows were determined. Either a roller conditioner or a prototype forage macerator manufa...
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ورودعنوان ژورنال:
- Journal of dairy science
دوره 80 8 شماره
صفحات -
تاریخ انتشار 1997