The relationship between the amount of concentrate offering in and frequency of visit to an automatic milking unit by cows kept in a free cow traffic barn

Abstract

The objective of this study was to describe the effect of herd size, the quality of mixed ration fed in the barn trough, and the amount of concentrate in the automatic milking unit (AM unit) on the frequency of the visit and milking of cows. Eighteen automatic milking system (AMS) herds were used in the study, with the average herd size per AM unit ranging from 24 to 61 lactating cows. All of the herds were kept in a free cow traffic barn. The frequencies of visiting and milking, as well as milk yield and the amount of concentrate offering in the AM units were automatically recorded by AM unit. The average frequencies of visit to an AM unit ranged from 2.9 to 5.9 times per day. The average number of milking times was from 2.3 to 3.6 per day. There was a significant (P<0.05) relationship between the frequency of visiting (y) and milking (x). The frequency of visiting an AM unit was changed quadratically with the herd size. The significant (P<0.05) equation was given; y=-6.6/x+4.5, r=0.738. Maximum estimated number of visit to AM unit was 4.7 visit/day at about 41 cows. After the two herds were removed because of the high nutritional formulation of the partly mixed ration for the cows, a quadratic equation (y=-2.07x+0.28x²+7.36, R=0.753) was given to describe the relationship between the amount of concentrate offered (x) and the frequency of visits to an AM unit (y). This equation showed that the amount of concentrate offering in AM unit facilitated cow’s visit to AM unit over 3.7 kg/day.