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.
Safora Yousefinejad; Farshid Fatahnia; Mehdi Kazemi Bonchenari
Volume 23, Issue 2 , July 2021, , Pages 165-177
Abstract
The aim of this experiment was to investigate the effect of starter soybean oil (SO) and crude protein (CP) level on growth performance, plasma parameters and urinary purine derivatives (UPD) of dairy calves. Forty-eighth 3-old Holstein dairy calves with initial BW of 39.8 ± 2.4 kg were used in ...
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The aim of this experiment was to investigate the effect of starter soybean oil (SO) and crude protein (CP) level on growth performance, plasma parameters and urinary purine derivatives (UPD) of dairy calves. Forty-eighth 3-old Holstein dairy calves with initial BW of 39.8 ± 2.4 kg were used in a completely randomized design with 2 × 2 factorial arrangement. The experimental diets consisted of diet without SO and 19% CP, diet without SO and 22% CP, diet with 3% SO and 19% CP and diet with 3% SO and 22% CP. Feed intake, feces score, skeletal growth indices, plasma parameters, liver enzymes, urinary purine derivatives and microbial protein synthesis were measured. Growth performance, plasma parameters and UPD were not influenced by interaction effect of starter diet SO and CP level. Starter diet intake, average daily gain and feed efficiency were lower in calves fed SO than those fed diets without SO (P < 0.05). The fecal score and wither height of calves fed diets containing SO were higher and lower that those fed diets without SO, respectively (P < 0.05). Plasma concentrations of glucose, beta-hydroxy butyrate and total protein were lower in calves fed SO (P < 0.05). Addition of SO to the diets decreased urinary allantoin and total UPD concentrations (P ≤ 0.05). Microbial protein synthesis tended to be decreased in calves received diets containing SO compared to other groups (P=0.06). Plasma urea nitrogen concentration of calves increased by increasing dietary CP level (P < 0.05). According to this results, growth performance of Holstein dairy calves is not affected by interaction of SO and CP level in starter diet
vahid piri; farokh kafilzadeh
Volume 22, Issue 3 , September 2020, , Pages 379-389
Abstract
This study was conducted to evaluate the effects of treating ground barley grain with lactic acid (LA) in starter diets on feed intake, average daily gain, feed efficiency, nutrient digestibility, skeletal growth, and blood metabolites of pre-weaneddairy calves. Thirty male Holstein calves with average ...
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This study was conducted to evaluate the effects of treating ground barley grain with lactic acid (LA) in starter diets on feed intake, average daily gain, feed efficiency, nutrient digestibility, skeletal growth, and blood metabolites of pre-weaneddairy calves. Thirty male Holstein calves with average initial body weight of 45.06±2.25 were randomly allocated to one of the 3 treatments. Starter containing 41% ground barley grain from day 4 to 65 of birth. Experimental treatments include: 1) diet containing treated barley in tap water (No LA), 2) diet containing treated barley in 0.5% LA solution, and 3) diet containing treated barley with 1% LA solution. Feed intake was recorded daily. Body weight and skeletal growth measures were recorded on day 4, day 35, and day 56. Calves blood samples were collected on day 4, 35, and 65. Total tract dry matter digestibility and feed efficiency were greater in calves fed diet containing lactic acid treated barley (p < /em> ≤0.05). No effects on dry matter intake, average daily gain, and blood metabolites was observed. At day 35 of the experiment the withers height and body length were greater in calves received LA-treated barely (p < /em> ≤0.05). It seems that treating barley grain with lactic acid decreased starch digestion in the rumen and increased starch flow to the small intestine; accordingly, feed efficiency was improved. Using higher levels of lactic acid may have a positive effect on calf performance.