TY - JOUR ID - 28527 TI - Effects of Different Dry Period Length on the Reproductive and Productive Performance of Holstein Cows During the Subsequent Lactation JO - Iranian Journal of animal Science JA - IJAS LA - en SN - 2008-4773 AU - amini, fatemeh AU - amanloo, hamid AU - zamiri, mohammad javad AU - eslamian, najme AD - Y1 - 2012 PY - 2012 VL - 43 IS - 2 SP - 183 EP - 191 KW - dry period KW - Energy balance KW - Holstein cow KW - reproductive performance DO - 10.22059/ijas.2012.28527 N2 - To evaluate the effects of different dry period lengths on milk yield, milk composition, reproductive performance and energy balance in dairy cows, 30 Holstein breeds (average 270 days pregnant) were made use of in a randomized complete block design. Cows were assigned to three treatments (60, 45 and 30 days of dry period) and two blocks as based on parity (either first lactation or multifarious cows). Milk production and composition as well as somatic cell counts of cows with 45 and 30 days of dry period were not significantly different from cows with 60 days of dry period (P>0.05). Body condition score changes after calving for 60, 45 and 30 days of dry period (1.06, 0.93 and 0.68, respectively) were significantly different. The smallest change in body condition score was observed for 30-day dry period ones, which also had a lower blood concentration of non-esterified fatty acids before calving (364.8 vs 394.9 and 390.9 µEq/l for 45- and 60-day dry periods). Mean days to first postpartum ovulation were 27.9, 27.8 and 22.7 days for dry periods of 60, 45 and 30 days, respectively (P UR - https://ijas.ut.ac.ir/article_28527.html L1 - https://ijas.ut.ac.ir/article_28527_dca2393ebbd006d20d6a91d62ad4594e.pdf ER -