Fertility and milk yield of cows in Bohinj area

Abstract

In 1996 on 17 family farms in Bohinj area data on 193 lactations were analysed. Diferent cattle breeds were reared on farms: Simmental (51.4%), Black-and-White (31.3%), Brown (2.5%), Pinzgau (2.5%) and unknown breeds (12.3%). Milk yield and fertility traits were analysed for 156 cows. Thirty-seven cows were culled for different reasons. The average milk yield in the lactation was 5590 ± 1988 kg and in standard lactation 5178 ± 1687 kg, and milk yield per feeding day was 14.2 ± 4.8 kg. Calving to conception interval lasted on average 113.8 ± 62.3 days. Calving interval was 400.2 ± 69.1 days. Conception rate was on average 65.2%. Calving interval, parity and breeder significant by affected on milk yield per feeding day (FD). The highest milk yield per FD was achieved with calving intervals between 341 and 365 days. Prolonged calving interval increased the average milk yield in standard lactation. Calving to conception interval was significantly correlated (P< 0.0001) with all fertility traits, milk yield in lactation, and milk yield in standard lactation. Number of inseminations was correlated with milk per FD (r = -0.1769, P< 0.0271). Distribution analyses of diferent fertility traits showed that low heat detection rate (62.1%) folowed by prolonged insemination to conception interval was a major problem that caused the prolongation of calving interval on analised farms. On four farms, where heat detection rate was 100%, calving to conception interval lasted 83 days and first insemination to conception interval 21 days on average.