Milk Production of Dairy Cows Fed Grass-Clover Silage Pulp

Abstract

Silage pulp (SP) is a byproduct from biorefinary of silage that can be used as forage source for ruminants. However, there is a lack of information regarding the complete replacement of dietary silage for SP on performance of dairy cows. The purpose of this study was to evaluate the complete substitution of dietary grass-clover silage for SP on milk production of dairy cows. Grass-clover mixture was harvested, wilted, and ensiled in bunker silos. The silage was screw pressed in a biorefinery for solid (SP) and liquid (protein-rich juice) separation. Seventy-two lactating cows were used in a completely randomized block design, receiving either the original silage- or SP-based diets. The SP-based diet had lower concentrations of water-soluble carbohydrates and crude protein but greater fibre concentration compared to the silage-based diet. Milk yield and energy corrected milk were generally greater for cows receiving the silage-based diet compared to the SP-based diet. Cows receiving the silage-based diet had a greater yields of milk protein and milk fat, and tended to have a greater yield of milk lactose than cows receiving the SP-based diet. Milk composition, body condition score and body weight were not affected by diets. The complete substitution of silage for SP reduced the lactation performance of dairy cows over time.

Keywords

• biorefinery
• fibre
• forage
• press cake
• ruminant
• screw press