HamidReza Dadkhah; GholmReza Ghorbani; Farzad Hashemzadeh; Abbas Rajaeerad
Volume 25, Issue 1 , April 2023, , Pages 13-24
Abstract
The objective of this study was to evaluate the effect of feeding two oral Ca boluses at calving and 12 h later on feed intake, milk yield, body weight (BW) changes, blood calcium and some reproductive parameters of high producing dairy cows during summer season. Twenty-four Holstein cows with average ...
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The objective of this study was to evaluate the effect of feeding two oral Ca boluses at calving and 12 h later on feed intake, milk yield, body weight (BW) changes, blood calcium and some reproductive parameters of high producing dairy cows during summer season. Twenty-four Holstein cows with average parity of 2.8 ± 0.8 were selected and randomly assigned to one of two treatments including control or the group receiving slow-release oral Ca bolus at calving and 12 h post-calving. Row milk yield was greater in cows receiving Ca boluses compared to control treatments during 21 days of lactation (P = 0.02). The milk fat (P = 0.01) and solid non-fat percentage (P = 0.05) were greater in cows that received calcium bolus compared to control treatment. In addition, energy-corrected and fat-corrected milk yields increased in cows received Ca bolus (P = 0.03). Plasma glucose and serum calcium concentration as well as BW change were not affected by experimental treatments. The pregnancy per artificial insemination, days to first insemination and open days were not significantly different between the experimental treatments (P >0.05). The results showed that using oral calcium bolus at calving and 12 hours after calving improved milk production and composition, but had no effect on serum Ca, BW change during first 21 days of lactation, and reproduction parameters.
Abbas Rajaeerad; Gholam Reza Ghorbani; Mohammad Khorvash; Ali Sadeghi-Sefidmazgi; Amir Hossein Mahdavi; Masoud Boroumand Jazi; Mirja Rosmarie Wilkens
Volume 23, Issue 1 , March 2021, , Pages 21-33
Abstract
The effects of different levels of mild metabolic acidosis by anionic diet on the performance of transition dairy cows were investegieted in 12 cows from 3 weeks (wk) before calving. One wk before calving, cows assigned to two groups according to urine pH (UpH) to recommended level (R UpH=6.2 ...
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The effects of different levels of mild metabolic acidosis by anionic diet on the performance of transition dairy cows were investegieted in 12 cows from 3 weeks (wk) before calving. One wk before calving, cows assigned to two groups according to urine pH (UpH) to recommended level (R UpH=6.2 to 7) and less than 6.3 (low UpH). The average prepartum urine pH was 6.7 and 5.8 for R UpH and low UpH groups, respectively (P<0.01). The prepartum serum concentration of Ca was not affected by the experimental groups, but significantly increased in the low UpH group within 2 h after calving. A trend was observed for higher serum concentration of phosphorus in the low UpH cows before calving. Although no significant difference was observed in prepartum DMI, but postpartum DMI and milk production were higher during wk 1 after calving in low UpH group (P<0.05). Total concentrations of protein and globulin were decreased on the day before calving in low UpH group. Also, after calving the concentrations of BUN, total protein, globulin, and milk protein were lower in this group of cows (P<0.05). Therefore, the induction of higher levels of metabolic acidosis in comparison to the recommended level before calving, can improve serum concentration of Ca and performance of transition cows.