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.
Sara Nadri; Ali Sadeghi-Sefidmazgi; Gholam Reza Ghorbani; Pouya Zamani
Volume 24, Issue 4 , December 2022, , Pages 383-393
Abstract
The aim of this study was to estimate the economic values for residual feed intake and some production and performance traits in Iranian Holstein dairy cow. For this purpose, trait by trait or multiple traits of bio-economic modeling along with production and economic data ...
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The aim of this study was to estimate the economic values for residual feed intake and some production and performance traits in Iranian Holstein dairy cow. For this purpose, trait by trait or multiple traits of bio-economic modeling along with production and economic data were used. These data were collected from seven large herds of dairy cows in 2020. The economic values of the residual feed intake was calculated in four different age groups. The diets of different groups were formulated using CNCPS software. Index economic weights (multiplication of the economic values by discounted genetic expressions, in Rial and one cow per year) on average at the level of the studied farms were estimated to be IRR 14280 per kg of milk yield; IRR 291060 per kg of fat yield; IRR 232260 per kg of protein yield; IRR - 790860 per kg of residual feed intake; IRR 702588 per month of longevity and IRR- 113820 per day of days open. The sensitivity analysis showed that the price of concentrate ingredients has a greater effect on the economic value of the residual feed intake than of forage ingredients. In the genetic- economic analysis, the milk production with a relative emphasis of 50 percent was the most important trait in the breeding of Iranian dairy cows, while the relative emphasis on feed efficiency was only about 5 percent. The results of this research provide valuable information for economic values of traits that can be used to complete the national selection index and cost-benefit analysis.
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.
Ali Kahyani; G. R. Ghorbani; M. Alikhani; E. Ghasemi; A. Sadeghi-Sefidmazgi; Sayyed Mahmoud Nasrollahi
Volume 20, Issue 3 , November 2018, , Pages 425-435
Abstract
The study was conducted to evaluate indigestible neutral detergent fiber (iNDF) and other related parameters of fiber digestibility of alfalfa hay, corn silage, wheat straw, beet pulp, and wheat bran of a dairy farm. Using two cannulated non-lactating Holstein cows and in situ method, undigested neutral ...
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The study was conducted to evaluate indigestible neutral detergent fiber (iNDF) and other related parameters of fiber digestibility of alfalfa hay, corn silage, wheat straw, beet pulp, and wheat bran of a dairy farm. Using two cannulated non-lactating Holstein cows and in situ method, undigested neutral detergent fiber (uNDF) after 288 h was measured as indicator of iNDF. Then with evaluating the kinetic of fiber digestibility in several time points, the rate and extent of NDF digestibility (NDFD) were measured according to newly-developed equations. The measured NDFD was used for estimation of total tract NDF digestibility (TTNDFD). Alfalfa hay had a greater amount of lignin as well as greater rate of NDF digestion than corn silage and wheat straw. Alfalfa hay and wheat straw, compared with corn silage, had a greater amount of uNDF and lower NDFD and TTNDFD. In spite of having relatively similar amount of NDF, the beet pulp and wheat bran had lower amounts of lignin and uNDF, while greater rate and extent of NDF digestibility as well as TTNDFD than forages. Overall, the considered fibrous feedstuffs showed a considerable variation in uNDF, NDFD, and TTNDFD that must be considered at the time of use.