A comparison of two methods for allocating concentrates to dairy cows according to yield

Abstract

SUMMARY: An experiment was carried out with 123 pairs of cows located at 11 centres and extending over 3 years, to compare the performance of cows fed at a fixed rate of starch equivalent per gallon with similar cows fed according to an experimental scale, in which the rate of feeding per gallon increased with increasing milk yield.Records of milk yields and concentrate consumption were made. Feeding according to the experimental scale produced significantly more milk during the first 14 weeks of the lactation. The increase in milk yield for 52 pairs observed over 28 weeks was not significant in either the first 14 or first 28 weeks.The economic response (lb. milk for each addition lb. starch equivalent for all pairs over 14 weeks was 1·42 and was very near the predicted value. A slightly larger response of 1·64 was obtained from the highest yielding cows. The response over 28 weeks (for 52 pairs only) was 1·30. Considerable variation in this response was found between seasons and between centres.These results are discussed in terms of the practical application of the feeding scales used and the responses obtained.