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.
Mehdi Mirzaei; Ali Sadeghi Sefid Mazaki; Mohammad Khorvash; Gholam Reza Ghorbani; Pirouz Shakeri
Volume 18, Issue 2 , June 2016, , Pages 225-234
Abstract
This study was carried out to assess the effects of alfalfa hay level and replacing corn grain by other grains in starter on daily feed intake, average daily gain (ADG) and feed efficiency (FE) of pre and post-weaning dairy calves during the pre and post-weaning periods. For this purpose, a database ...
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This study was carried out to assess the effects of alfalfa hay level and replacing corn grain by other grains in starter on daily feed intake, average daily gain (ADG) and feed efficiency (FE) of pre and post-weaning dairy calves during the pre and post-weaning periods. For this purpose, a database Meta-analysis used in the present study. Statistical analyses were performed using PROC MIXED in SAS software. Starter intake and ADG were not affected by alfalfa hay feeding level during the pre-weaning period. However, alfalfa hay feeding tended to increase starter intake during the post-weaning and entire periods (P = 0.07 and P = 0.09, respectively). Further, ADG increased during the post-weaning and entire periods with alfalfa hay supplementation. Starter intake and ADG quadratically affected by the level of alfalfa hay supplementation. At pre-weaning period, feed efficiency tended to decrease (P = 0.06) with alfalfa hay supplementation, but was not different with control group during the post-weaning and entire periods. In addition, partial replacement of corn with other grains increased (P < 0.01) starter intake of dairy calves, but feed efficiency decreased (P < 0.01). Based upon the findings of the present research, alfalfa hay supplementation up to 7.5 % of the total diet could improve starter intake and ADG in dairy calves at post-weaning period. Further, it is possible to replace corn with other grains, up to 50 %, without any negative effect on neonatal dairy calves performance.