کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10982457 | 1108097 | 2010 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Net flux of nutrients across splanchnic tissues of lactating dairy cows as influenced by dietary supplements of biotin and vitamin B121
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Biotin and vitamin B12 are coenzymes in reactions that are essential to propionate metabolism in dairy cows. The objective of the present studies was to determine whether an increased dietary supply of these vitamins would change the net flux of nutrients through the rumen, the portal-drained viscera (PDV), the total splanchnic tissues (TSP), and the liver. Four lactating cows equipped with ultrasonic flow probes around the right ruminal artery and the portal vein and catheters in the right ruminal vein, the portal vein, one hepatic vein, and one mesenteric artery were fed 12 times per day a mixed ration at 95% of ad libitum dry matter intake. Daily supplements of 500Â mg of vitamin B12Â +Â 20Â mg of biotin or no vitamin supplement (study 1) or 500Â mg of vitamin B12 alone or with 20Â mg of biotin (study 2) were fed according to a crossover design with two 4-wk periods in each study. On the last day of each period, blood flow was recorded and blood samples were collected every 30Â min for 4Â h. In study 1, biotin and vitamin B12 given together increased milk production and milk protein yields compared with the control diet. The supplement increased appearance of the 2 vitamins across the PDV and TSP. It also reduced the net portal appearance of ammonia and total volatile fatty acids across the PDV. In study 2, compared with the 2 vitamins together, vitamin B12 alone increased glucose flux across PDV and TSP as well as its arterial concentration and PDV flux of ammonia. With the diet used in the present experiment, the major effects of the vitamin supplements seem to be mediated through changes in ruminal fermentation and gastrointestinal tract metabolism rather than by effects on hepatic metabolism.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 93, Issue 4, April 2010, Pages 1644-1654
Journal: Journal of Dairy Science - Volume 93, Issue 4, April 2010, Pages 1644-1654
نویسندگان
C.L. Girard, A. Desrochers,