Effect of replacing rolled wheat with a moist food co-product on the yield and composition of milk from Holstein Friesian dairy cows fed a grass silage based diet

Abstract

AbstractThis study compared the effect of feeding AmyPlus, a moist feed, as opposed to rolled wheat on the yield and composition of milk from dairy cows consuming grass silage based total mixed ration (TMR). Seventy-two Holstein-Friesian cows were distributed into AmyPlus (Treatment) and Wheat (Control) groups and loose housed on straw in an open shed. Each kg Wheat based concentrate contained 345g rolled wheat, 230g rapeseed meal, 115g sugarbeet pulp, 115g Molaferm 20, 115g soybean meal, 56g barley straw and 24g vitamin-minerals. In contrast, each kg AmyPlus based concentrate contained 501g AmyPlus (480g DM /kg), 105g rapeseed meal, 126g sugarbeet pulp, 126g Molaferm 20, 84g soybean meal, 41g barley straw and 17g vitamin-minerals. Here, AmyPlus was loaded directly into the mixer wagon to prepare fresh AmyPlus based TMR with a silage to concentrate ratio of 68:32. Each TMR was fed once daily to the corresponding group of cows also receiving 2kg of Distillers’ grains per cow in the parlour during milking. Daily milk yield and composition was recorded from November 1999 to February 2000. The overall daily Dry matter intake (DMI) of each TMR per cow remained uniform (20.19 vs 20.15 kg for Treatment and Control group respectively) across both groups. Daily milk yield and total cell counts per cow did not vary significantly (P>0.05) between groups during various months. While, milk fat and protein contents were greater in Treatment than Control group during each month, the differences were significant (P<0.05) only during November and December for fat and in January for protein. On average, the Treatment group tended to show a non-significant increase (P>0.05) in daily milk yield per cow by 0.144 kg than the Control group. The fat (46.2 vs 43.7) and protein (34.5 vs 33.5) contents in g /kg milk were also increased significantly (P<0.001) in Treatment compared with Control group. Total cell counts did not vary significantly (P>0.05) and remained within the acceptable limits. The cows consuming AmyPlus maintained their health as indicated by their intake, production, cell counts and general appearance. It would appear that AmyPlus can replace rolled wheat in TMR. However, it may be necessary to evaluate the storage, economic and environmental implications of using such moist co-products in silage based dairy rations.