Influence of the breed and lactation period on the concentration of urea in the cow milk
2008
Dzhurbinev, D. | Mikhajlova, M. | Girginov, D. | Ivanova, I. | Dimova, N.
The experiment was carried out with cows of Bulgarian Brown cattle BBC and Bulgarian Black and White cattle BBWC. Only animals after the first lactation and those at their first or second part of lactation were included in the experiment. The experiment lasted for eight consecutive test days in a continuation of eight months, and the first phase included cows with a lactation period up to the 120th day and the second phase – from the 120th to the 260th day of the lactation. The animals of both breeds were reared at the same conditions and were fed with equal rations depending on the stage of lactation. The urea was determined by the urea method in the milk samples at the morning milking. From the study the following conclusions could be drawn: The concentration of urea in the milk increased (P0.05) with the stage of lactation for both breeds. Independent of the lactation stage, the BBC cows were with higher - P0.05 urea concentration compared to the BBWC.
显示更多 [+] 显示较少 [-]