Variation in the complete diet composition given during the winter period to an autumn-calving herd

Abstract

SUMMARYAutumn-calving cows on a complete diet system were given a similar amount of concentrates over two winter periods in the years 1980–1 and 1981–2. Two feed allocation systems were examined: step (different diets given at different stages of lactation) and uniform (one single diet given over all the winter period).The yield of fat-corrected milk (FCM) was similar (P > 0·05) in both systems with 5·32 and 5·37 t/cow for the step and uniform system respectively in the 1st year and 4·75 and 4·35 t/cow in the 2nd year.There is an indication that adult cows or cows with a higher potential for yield can respond to the higher energy concentration diet given in early lactation but with the main effect on milk, not in FCM yield.No effect of diet distribution was found on overall weight gain but cows given the uniform system lost less weight in early lactation and this may lead to better conception for cows in such a system.

Grouping and complete diet composition in relation to parity and potential yield in dairy cows

“…Results of our studies (Kroll & Owen, 1986) and many others have shown a greater yield persistency if one fixed diet is given (Johnson, 1977;Spahr, 1977;Broster, 1980) and also does not show any effect of diet distribution on milk yield and mainly FCM yield.…”

Allocation of feed based on individual dairy cow live weight changes

“…However, several experiments were found where a specific time relative to parturition or milk yield were used to assess the time for reducing ration energy concentration (e.g. Smith et al, 1978;Cassel et al, 1984;Kroll et al, 1986). Results from these experiments indicate, that the positive effect of high energy rations in early lactation was counterbalanced by reduced milk yield persistency when ration energy concentration was reduced.…”