Popis: |
Five experiments compared silages, by-product roughages, and added sodium bicarbonate. Thirty-four cows were fed diets containing 1) 30% cottonseed hulls, 2) corn silage to supply 25% of dry matter intake from nongrain portion, 3) alkali-treated sugarcane bagasse silage, or 4) sugarcane silage both to supply 25% of dry matter intake. Only dry matter intake differed for diets 1 and 2 which excelled 3 and 4 for daily dry matter intake, milk yield, and protein percent. With 36 cows, sugarcane silage, enzyme-treated sugarcane silage, nongrain portion of corn silage, and pelleted cottonseed hulls with sodium bicarbonate (0 or 1%) and an enzyme product from Aspergillus oryzae (0 or 56.7 g/day) were compared. Milk yield was decreased and fat percent increased by silage compared with pelleted cottonseed hulls. Bicarbonate increased milk fat percent and fat-corrected milk in silage-containing rations. For the effect of sodium bicarbonate in early lactation, 36 cows were in a continuous feeding trial of corn silage, cottonseed hulls, or steam pressure-treated sugarcane bagasse, with sodium bicarbonate (0 or 170 g/cow per day). Lactation curves for feed intake, milk yield, and milk fat percent showed no effects of sodium bicarbonate. Cottonseed hull diets excelled corn silage diets. For the same cows and diets plus additional forms of steam pressure-treated bagasse (pelleted and wetter), bicarbonate was detrimental to feed intake and milk yield in pelleted bagasse diets but tended to be beneficial to milk yield in corn silage. Four groups of cows (152 cows/group) receiving 0 or 150g sodium bicarbonate in a corn silage-based ration for 30 days did not differ in a field study. |