نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری، گروه علوم دامی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران، کرج
2 استاد، گروه علوم دامی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران، کرج
3 دانشیار، گروه علوم دامی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران، کرج
4 استاد، بخش شیمی پلیمر، دانشکده شیمی، دانشگاه تهران، تهران
5 دانشیار، گروه مامایی و بیماری های تولیدمثل دام، دانشکده دامپزشکی، دانشگاه تهران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Increasing glucose supply in the small intestine may be effective in improving the physiological status of dairy cows, and it is hypothesized that glucose supply in the small intestine increases whole body glucose supply and then improves the liver function of dairy cows during the early lactation. The aim of the present experiment is to produce a Rumen-Protected Glucose product and evaluation its effects on milk production and dry matter intake of fresh Holstein dairy cows.
Materials and methods: In this study, the matrix and true encapsulation method was used to produce Rumen-Protected Glucose. Hydrogenated fat was used as the matrix for matrix encapsulation. For the true encapsulation coating method, the dextrose powder was first converted into 1-3 mm granules and then completely coated. In order to evaluate the rumen degradability of encapsulated glucose, three cows with ruminal cannula were used. In order to investigate the effects of produced Rumen-Protected Glucose, 16 fresh cows were used in a completely randomized design with two treatments and 8 cows in each treat. The diets of both treatments were exactly the same, except that the cows in Rumen-Protected Glucose treat received 600 g of Rumen-Protected Glucose daily as top dresesd, and the cows in control treat received the same amount of coating material and dextrose. Rumen-Protected Glucose was fed from day 4 to 30 after calving. The cows were kept in individual boxes and milk production and dry matter intake were recorded daily.
Results: Matrix encapsulation failed to adequately protect glucose from rumen degradation. Using the true encapsulation method, a Rumen-Protected Glucose source with suitable degradation resistance (approximately 50% passing) and high intestinal digestibility (95% intestinal digestion) with a ratio of 70% active ingredient and 30% coating material was produced. Feeding 600 g of Rumen-Protected Glucose had no significant effect on dry matter intake (17.76 kg/day in Rumen-Protected Glucose treatment and 17.43 kg/day in control treatment; P>0.48) and milk production (33.58 kg/day in Rumen-Protected Glucose treatment and 33.95 kg/day in control treatment; P> 0.78). The effect of time on milk production was significant in both treatments (P < 0.005). However, the effect of time on dry matter consumption was not significant (P>0.31). Milk fat was increased in cows received Rumen-Protected Glucose (4.94% in Rumen-Protected Glucose treatment and 4.29% in control treatment, P< 0.033).
Conclusion: A source of Rumen-Protected Glucose with suitable degradation resistance (about 50% passing) and high intestinal digestibility (95% intestinal digestion) was produced. Feedig of Rumen-Protected Glucose to fresh dairy cows improved their glycogenic status and reduced nutrient transfer for milk production.
کلیدواژه‌ها [English]
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