Body development of Simmental bull dams

Abstract

Body development and production capacity in dairy production are in relation. However, body development, i.e. exterior of cows doesn’t define its functionality which is manifested in production of milk. Therefore, the capacity of cow to produce milk can only be determined more precisely by direct measuring of the production. Visual evaluation of body development and way to recognize the characteristics of dairy cows are initial parameters of milk traits, partially also longevity, as well as reproductive traits of the head of cattle, which is important from many aspects of the economical efficiency in dairy production. Exterior measures taken when cows were selected to be included in herd of bull dams, and which are also subject of this research, are following: height of withers, carcass length, breast depth, breast girth, body weight. For all investigated traits basic variation-statistical parameters were calculated: arithmetic mean value, standard deviation, coefficients of variation, standard error, variation interval. Average values of exterior measures obtained in this research were following: height to withers 136.29 cm, carcass length 165.50 cm, breast depth 72.97 cm, breast girth 200.07 cm, body weight 686.27 kg. Based on presented data it can be concluded that traits of body development of Simmental bull dams are above the average values determined for controlled population, which further justifies our conclusion that bull dams are "top" heads of cattle of the main herd.

Veće i krupnije krave pri jednakim naslednim i drugim uslovima obično daju više mleka od manjih krava. Količina mleka međutim ne povećava se u direktnoj srazmeri sa telesnom masom. Uzrok tome leži u činjenici da celo telo ne učestvuje direktno u proizvodnji mleka već samo organi preko kojih se vrše funkcije varenja, respiracije, izlučivanja i sekrecije. Prilikom odabira krava u kategoriju bikovskih majki sva grla moraju biti eksterijerno izmerena i linearno ocenjena. Eksterijerne mere koje su uzete prilikom odabira krava, a koje su ispitivane u ovom istraživanju su: visina grebena, dužina trupa, dubina grudi, obim grudi, telesna masa. Za sve ispitivane osobine izračunati su osnovni varijaciono-statistički parametri: aritmetička sredina, standardna devijacija, koeficijenti varijacije, standardna greška, interval varijacije. Prosečne vrednosti eksterijernih mera dobijene u ovom istraživanju su sledeće: visina grebena 136.29 cm, dužina trupa 165.50 cm, dubina grudi 72.97 cm, obim grudi 200.07 cm, telesna masa 686.27 kg.