Mohamad ASADI; Amir Davar Foroozandeh Shahraki; Mehdi Bahrami-Yekdangi; davod Akbari; elham Kazemi-asfe
Abstract
The aim of this study two-hundred Holstein dairy cows were selected and used in 4 free stall barn in a completely randomized rotating design. Sixty cows (30 cows per pen) of selected animals with the same characteristics (DIM: 180 ±15, average milk production 49±5, lactation number 2.95) ...
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The aim of this study two-hundred Holstein dairy cows were selected and used in 4 free stall barn in a completely randomized rotating design. Sixty cows (30 cows per pen) of selected animals with the same characteristics (DIM: 180 ±15, average milk production 49±5, lactation number 2.95) were used for blood and milk sampling. Experimental treatments include control diet (diet 1) based on corn silage and experimental diet (diet 2) replacing 5% of corn silage with barley silage. The results showed that if barley silage is replaced at 5% level with corn silage so that other nutrients in the diet do not change significantly, it had no significant effect on milk production and composition, however, it significantly reduced (p <0.05) the feed intake in the experimental group that received barley silage. In addition, experimental treatments caused a significant increase in blood urea compared to the control group. Replacing barley silage at 5% level with corn silage also significantly increased the percentage of ruminal propionic acid, and had no significant effect on other ruminal parameters. Barely silage also increased the apparent digestibility of dry matter, protein and neutral and acidic detergent fiber. The results of this study showed that barley silage can be replaced with corn silage at the level of 5% without negatively affecting production performance.
Mahsa Hedayati Sichani; Amir Davar Forozandeh; Pirouz Shakeri
Abstract
The objective of this study was to determine the effects of different levels of mineral biochar (MB) on performance, nutrient digestibility, and some blood parameters of Holstein calves. Twenty-seven Holstein female weaned calves (67.66 ± 9.33 kg initial BW) were randomly assigned to one of three ...
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The objective of this study was to determine the effects of different levels of mineral biochar (MB) on performance, nutrient digestibility, and some blood parameters of Holstein calves. Twenty-seven Holstein female weaned calves (67.66 ± 9.33 kg initial BW) were randomly assigned to one of three experimental diets; contained 0%, 0.35% and 0.70% of mineral biochar in concentrate respectivelyDry matter intake (DMI) and body weight gain were recorded at the end of each week. Blood samples were collected on day 48 and nutrient digestibility was measured at the end of the experimental period (days 46 to 49). Results showed that mean of total body weight gain, final body weight and daily gain were not affected by different levels of MB in diets. There was no difference in average daily dry matter intake of calves consuming different experimental diets; while, feed conversion ratio (FCR) was lower (P = 0.02) in calves fed diets containing MB compared to control group and FCR decreased linearly (P = 0.02) as the level of MB increased in the diet. Apparent total tract digestibility of OM, CP and NDF increased (P < 0.01) with diets containing MB in comparison to control group. Also, blood urea nitrogen, total protein, triglycerides and VLDL were not different across experimental diets, but, calves fed 0.35% MB had lower (p<0.05) blood cholesterol than those fed other diet. It was concluded that using of MB had favorable effects on nutrient digestibility, FCR and blood cholesterol.
A. D. Foroozandeh; Pirouz Shakeri
Abstract
This trial was performed to determine the effects of alfalfa hay, sodium bicarbonate and their combination in the starter diet on performance, blood metabolites, digestibility of nutrients, fecal score and body structure in Holstein dairy calves. Individually housed calves (n=40, body weight=42.6±2.2 ...
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This trial was performed to determine the effects of alfalfa hay, sodium bicarbonate and their combination in the starter diet on performance, blood metabolites, digestibility of nutrients, fecal score and body structure in Holstein dairy calves. Individually housed calves (n=40, body weight=42.6±2.2 kg), 10 days after birth, were used in a completely randomized design (n=10 calves per treatment: 5 males and 5 females) and fed by one of the following four treatments: 1-Starter concentrate(Control), 2-Starter concentrate+15% alfalfa hay(SA) 3-Starter concentrate+1% sodium bicarbonate(SS) and 4-Starter concentrate+15% alfalfa hay+1% sodium bicarbonate (SAS) for 60 days. The calves had ad-libitum access to water and experimental starter diets and received 4 kg/d milk in the whole experimental period. The results showed that the calves used SAS diets had lowest final body weight (p<0.05) and average daily gain (P<0.02) than those fed other diets, while the dry matter intake was not affected by different diets. The calves fed SA diet had the lowest (p<0.05) feed efficiency and was lower than those fed SAS diet (p<0.05). The fecal score, blood metabolites and body structure were not affected by different diets. Calves fed SA diet had lower (P=0.02) digestibility of DM compared with those fed control diet, while the digestibility of OM, CP and NDF did not differ across treatments. In conclusion, the use of alfalfa hay up to 15% in starter diet can improve feed efficiency, but supplementation of starter diet with 1% sodium bicarbonate had no beneficial effect on growth performance of dairy calves.
