view:27788 Last Update: 2024-3-30
Hosseini, S. H., Mirzaei-Alamouti, H., Vazirigohar, M., Mahjoubi, E., Rezamand, P.
Effects of whole milk feeding rate and straw level of starter feed on performance, rumen fermentation, blood metabolites, structural growth, and feeding behavior of Holstein calves اثر میزان شیر کامل خورانده شده و سطح کاه بر عملکرد، تخمیر شکمبه، متابولیت های خون، رشد اسکلتی، و رفتار خوراک خوردن گوساله های هلشتاین
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Sixty Holstein female calves [41 ± 3.6 kg of body weight (BW)] at 4 d of age were housed individually and allocated to 1 of 6 treatments in a complete randomized design with a 2 × 3 factorial arrangement of treatments to examine effects of whole milk (WM) feeding rate and wheat straw (WS) content of starter feed (SF) on calves' performance. Thus, 6 treatments were evaluated: usually 4 L/d of WM (4L) along with a SF without WS (CON; 4L-CON), 4L along with a SF containing 75 g/kg of DM WS (75S; 4L-75S), 4L along with a SF containing 150 g/kg of DM WS (150S; 4L-150S), usually 8 L/d of WM (8L) along with a CON (8L-CON), 8L along with a 75S (8L-75S), and 8L along with a 150S (8L-150S). Calves in 8L were gradually (in 2 steps) offered WM and both 4L and 8L calves were gradually (in 1 and 2 steps, respectively) weaned at 56 d of age. Calves had ad libitum access to water and SF containing ground concentrate and no or desired amount of chopped WS as total mixed ration during the trial (from 4 to 70 d of age). Overall, milk feeding rate had no effect on solid feed intake. Calves on 8L had greater (P < 0.05) BW than calves on 4L from the third week until the end of study, however, 4L-75S calves showed similar BW with calves in 8L groups. Final body length, heart girth, and hip width were greater (P < 0.05) in 8L compared with 4L calves. Incremental increases in the WS content of SF increased (P < 0.05) post-weaning intake and average daily gain (ADG), and improved (P < 0.01) pre- and post-weaning rumen pH and total time of ruminating, all in a linear manner. Feeding 4L-75S resulted in numerical greater overall ADG (620, 519, and 553 g/d; respectively) and final BW (82.9, 77.6, and 79.8 kg; respectively) rather than 4L-CON or 4L-150S. Feeding 8L-150S increased numerically overall ADG (668, 621, and 596 g/d; respectively) and final BW (88.2, 84.4, and 82.8 kg; respectively) in calves compared with 8L-75S or 8L-CON. In conclusion, offering usually 8 L/d of WM increased growth performance of calves throughout the study, without altering SF consumption, and increases in the WS content of SF increased intake and ADG of calves after weaning. |