Animal and poultry management
Pirouz Shakeri; nader asadzadeh; Sayyed Mahmoud Nasrollahi; Mahdi Nikbakhti; Amirali Shakeri
Abstract
The objective of this study was to compare feedlot performance between crossbred male Simmental×Holstein (S×H) and purebred Holstein (H) calves over a 6-month in hot and humid conditions of Iran. For this purpose, 17 male calves (181.4±42.30 kg BW) including 10 H and 7 S×H male ...
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The objective of this study was to compare feedlot performance between crossbred male Simmental×Holstein (S×H) and purebred Holstein (H) calves over a 6-month in hot and humid conditions of Iran. For this purpose, 17 male calves (181.4±42.30 kg BW) including 10 H and 7 S×H male were assigned to one of the two treatments in the national research and development cattle station of Gawdasht in the suburbs of Babol. The calves were kept individually in the cages (3×3 m) and were fed two times daily in equal portions at 8:00 and 16:00 with total mixed ration. The results showed that in the 6-month fattening period, there was no difference in the average dry matter intake of S×H calves and H calves, however, the average daily gain of S×H calves was 1.508 kg/d and higher (P=0.02) than H calves (1.190 kg/d). Feed conversion ratio in S×H calves (6.25) was better (P=0.02) than H calves (7.73). All of measured nutrients digestibility were higher in H calves than S×H calves (P=0.02). Also, there was no difference in the concentration of blood parameters of urea, urea nitrogen, triglyceride, total protein and serum albumin between S×H and H calves. It was concluded that in a fattening period of 6 months, S×H calves had 26.7% more weight gain, and 19.2% better feed conversion ratio compared to H calves with the same feed intake. Therefore, cross-breeding can be a successful strategy to improve beef production via produce commercial calves.
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.
