Particle size reduction of alfalfa silage did not alter nutritional quality of high forage diets for dairy cattle.
Twelve multiparous, lactating Holsteins were fed an energy adequate diet (50% wilted alfalfa silage) and two isonitrogenous diets containing 80% of the same silage. The two 80% alfalfa diets were identical in all respects except that for one diet 38% of the alfalfa silage was rechopped after fermentation to reduce the particle length from 5.63 to 3.12 mm. Feeding the 80% alfalfa diets decreased milk production due to limitation of digestible energy intake. Under conditions of energy restriction, reduction of particle size of alfalfa silage after fermentation did not result in any changes in feed intake, feed digestibility, or milk production. The results do not preclude the possibility of some changes for intake or digestibility with more extensive reductions in particle length of alfalfa silage. However, because the extent of forage particle size reduction is limited by nutritional and economic constraints, the results of this study indicate that there is no practical advantage to reducing the particle size of fermented alfalfa beyond that required for adequate fermentation.
Armentano
L E
LE
Department of Dairy Science, University of Wisconsin, Madison 53706.
Pastore
S C
SC
Hoffman
P C
PC
D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004063:Digestion; D005260:Female; D007774:Lactation; D000455:Medicago sativa; D009753:Nutritive Value; D010316:Particle Size; D011247:Pregnancy; D012820:Silage