Fateme Ahmadi; hamid Amanlou; Tahere Amirabadi Farahani; Najme Eslamian Farsuni
Volume 24, Issue 4 , December 2022, , Pages 415-425
Abstract
The aim of the present study was to evaluate the effect of supplementing close-up diets of Holstein dairy cows with rumen undegradable protein (RUP) on milk yield, calf birth weight and colostrum composition during the hot season. Eighty-eight multiparous Holstein dairy cows were enrolled in the study ...
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The aim of the present study was to evaluate the effect of supplementing close-up diets of Holstein dairy cows with rumen undegradable protein (RUP) on milk yield, calf birth weight and colostrum composition during the hot season. Eighty-eight multiparous Holstein dairy cows were enrolled in the study 30 d before expected calving and assigned to 1 of 2 treatments groups: low crude protein (14.3% CP with 4.0% RUP based on DM) and high crude protein (17.1% CP with 6.0% RUP based on DM). Diets were fed for ad libitum intake during the close-up and fresh period. After calving, all cows received the same diet from calving to 21 days of milk. Milk production of all cows was recorded daily from the day of calving to 21 days after calving. The milk samples of each cow were collected twice a week to measure milk composition. The evaluation of body condition score (BCS) was performed at -30, -3, 0, and 21 d relative to calving. The production of milk and the amount of milk protein and lactose were greater and milk fat content was lower in cows fed high protein diet than cows fed low protein diet (P<0.05). The BCS changes were not different between cows of two treatments in pre- and post-partum periods. According to the results, feeding a diet containing high RUP content to close-up cows during the hot season increases milk yield and decreases milk fat percentage in fresh cows.
Maryam Nosrati
Volume 19, Issue 1 , May 2017, , Pages 47-58
Abstract
The aim of this study was to compare copy number variation (CNV) in some Italian sheep breeds with Holstein cows. Blood samples were collected form 580 Holstein bulls and 360 different Italian sheep breeds and then DNA was extracted. The SNPs genotypes across the genome were determined by ovine and bovine ...
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The aim of this study was to compare copy number variation (CNV) in some Italian sheep breeds with Holstein cows. Blood samples were collected form 580 Holstein bulls and 360 different Italian sheep breeds and then DNA was extracted. The SNPs genotypes across the genome were determined by ovine and bovine 50K BeadChip in both species. By PennCNV, the 904 CNV with mean and median size of 154.7 kb and 103.7 kb in sheep and 744 CNV with mean and median of 213.7 kb and 124.5 kb in Holstein were detected, respectively. A total length of this variation were 8.5 Mb in sheep and was 80 Mb in cattle. After merging similar regions, the 35 and 141 non- unique copy number variation regions (CNVR) were detected in sheep and cows, respectively which 20% of sheep’s CNVRs overlapped with cattle’s CNVRs. In addition to, these regions in Sheep genome were partially or completely overlapped with 40 RefGen & 62 QTL in cattle and 110 RefGen in Human. CNVRs distribution in both species was more in subtelomeric and pericentromeric regions. According to these results, it could be possible to use bovine CNVRs which were closely linked to genes for characterizing functional genes and QTLs in sheep, however more studies are need in this regards.
Moustafa Hajilou; Hamid Reza Mirzaei Alamouti; Mehdi Ganjkhanlou; Hamid Amanlou
Volume 17, Issue 2 , October 2015, , Pages 347-358
Abstract
Four ruminally-cannulated Holstein cows were used in a 4 × 4 Latin square changeover design within periods of 21 days to evaluate effects of feeding frequency of different sources of rumen degradable nitrogen on total tract digestibility of nutrients, feeding behaviors, rumen and blood metabolites ...
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Four ruminally-cannulated Holstein cows were used in a 4 × 4 Latin square changeover design within periods of 21 days to evaluate effects of feeding frequency of different sources of rumen degradable nitrogen on total tract digestibility of nutrients, feeding behaviors, rumen and blood metabolites of Holstein cows. Treatments were: 1) control diet which was as total mixed ration (TMR) offered once daily in the morning (08:00), 2) control diet in which a part of its soybean was offered at 19:00, 3) control diet in which a part of its urea was offered at 19:00 and 4) control diet in which a part of its fish meal was offered at 19:00. Rumination time increased in cows fed twice daily with protein sources (P<0.05). Total tract digestibility of dry matter and organic matter were higher in cows received urea at the evening time. Total tract digestibility of neutral detergent fiber increased with feeding all sources of protein at the evening time (P<0.05). Molar proportion of volatile fatty acids, rumen pH and rumen ammonia concentration were not affected by feeding time of protein sources. The results indicated that increasing delivery of rumen degradable nitrogen sources improved dry matter and fiber digestibility and chewing activity of non-lactating Holstein dairy cows.