Effets des facteurs alimentaires sur la synthèse ruminale de vitamines B chez la vache laitière
|Advisor:||Chouinard, Yvan; Girard, Christiane|
|Abstract:||B-vitamins are synthesized by rumen microflora but knowledge on factors affecting this synthesis is very scarce. Two studies were conducted to determine the effects of dietary factors such as family forage or forage-to-concentrate ratio on B-vitamin ruminal syntheses. In study 1, eight Holstein cows were fed with diets containing either alfalfa or orchardgrass silages as sole forage. In study 2, fourteen Holstein cows were fed low-forage (44.8% forage) or high-forage (64.1% forage) diets. Apparent ruminal synthesis of thiamin, riboflavin, niacin and vitamin B6 were greater with orchardgrass silage than with alfalfa silage. Using a low-forage diet increased ruminal syntheses of thiamin, riboflavin and niacin, reduced vitamin B6 degradation, but decreased ruminal synthesis of vitamin B12. These studies are a step towards identification of diets that may require B-vitamin supplementation to optimize milk production of dairy cows.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||19 April 2018|
|Collection:||Thèses et mémoires|
All documents in CorpusUL are protected by Copyright Act of Canada.