Danuta Borkowska, Ewa Januś, Robert Polski
1Sub-Department of Animal Keeping and Breeding, Faculty of Bioeconomy in Zamość, University of Life Sciences in Lublin, Szczebrzeska 102, 22-400 Zamość, Poland; 2 Department of Breeding and Conservation of Cattle Genetic Resources, Faculty of Biology, Animal Sciences and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland
Abstract. The aim of the study was to analyse the effect of the magnitude of losses in body condition after calving and the duration of the period of its decline on yield in 435 standard lactation periods in Polish Black-and-White Holstein-Friesian cows kept in five barns. The magnitude of losses in body condition after calving and the duration of the period of its decline were estimated on the basis of monthly body condition scores in the 5-point BCS scale, and data pertaining to productivity were obtained from the SYMLEK system. It was determined that the greater the mobilization at the start of lactation of fat accumulated by cows before parturition, the higher was the production of milk, fat, protein and dry matter. The decrease in body condition score was less strongly associated with the basic composition of the milk obtained in the standard lactation period. Longer duration of the negative energy balance was also associated with higher yield of milk, fat and dry matter and with higher content of fat in the milk. Increased length of the period of body condition decline was accompanied by a decrease in protein content in the milk.
Keywords: body condition of cows, calving, yield, negative energy balance
Accepted: 15 Sep 2016
Published online: 09 May 2017
Borkowska, D., Januś, E., Polski, R. (2016). Reduction in body condition of cows after calving and their lactation yield. Acta Sci. Pol. Zootechnica, 15(3), 43‒52. DOI:10.21005/asp/asp.2016.15.3.04