Performance 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 manufactured by PAMI were used to cut a 25-ha field of alfalfa (Medicago sativa) forage. The harvested forage was wilted and preserved as silage or hay. Maceration of alfalfa forage resulted in a lower crude protein concentration of fresh forage. Silage volatile fatty acid and ethanol concentration and hay and silage nutrient profiles were not affected by harvest methods. Thirty-four Holstein cows (602.9 ± 3.4 kg) in early lactation were used in a 14-wk lactation study. The cows were fed two dietary treatments in the form of a total mixed ration (TMR); one contained roller conditioner-harvested alfalfa silage and hay and the other contained macerator-harvested alfalfa silage and hay. Feed, weighbacks and milk were sampled daily. Daily dry matter intake (21.6 ± 0.5 kg) was not affected by harvest method. Daily milk yield (38.7 ± 0.3 kg) and milk composition were not affected by dietary treatment during the 14-wk lactation trial; however, cows fed the macerated forage as part of a TMR had a 0.23 kg greater daily body weight gain (P < 0.05). Dietary energy input and energy output (total energy in milk, maintenance and body weight change) were not affected by dietary treatment; however, energy contained in body weight change was greater (P < 0.05) in cows fed a TMR containing the macerated forage.