title: Influence of various amounts of fumaric acid on performance and parameters of the acid-base balance of growing bulls fed with grass or maize silage.
abstract: The aim of the present study was to determine the effects of the potential methane reducer fumaric acid on the fattening performance and acid-base balance of growing bulls fed two different silage types as roughage (maize and grass silage). A total of 62 fattening bulls (German Holstein breed, initial body weight: 266 +/- 42 kg), randomly assigned to eight feeding groups, received four levels of fumaric acid (0, 100, 200 or 300 g/d) at each silage type. The daily feed and water intake and the live weight were measured over the whole testing period of 280 days. In blood samples, blood cells and blood gases as a parameter of acid-base status were analysed. Feed and faeces were collected to determine the apparent nutrient digestibility. Five animals from each group fed maize or grass silage, supplemented with 0 g or 300 g fumaric acid, were slaughtered at 580 kg body weight. After slaughter, rumen fluid pH was measured and dressing percentage was calculated. Neither the total feed intake (8.81 +/- 0.07 kg/d) nor the daily weight gain (1277 +/- 24 g/d) was influenced significantly by treatments. Fumaric acid supplementation did not influence the erythrocyte count or the blood gas concentration. The silage type significantly influenced the apparent digestibility of the whole diet. The dressing percentage was slightly higher (p < 0.1) after fumaric acid supplementation. No signs of an incompatibility to fumaric acid on the animals were observed over the whole experimental period. However, it seems to be necessary to conduct more long-term studies with different silage types and addition of organic acids combined with direct measurements of methane.
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Braunschweig, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Remling
authors.forename: Sabrina
authors.initials: S
authors.lastname: Hachenberg
authors.forename: Ulrich
authors.initials: U
authors.lastname: Meyer
authors.forename: Martin
authors.initials: M
authors.lastname: Höltershinken
authors.forename: Gerhard
authors.initials: G
authors.lastname: Flachowsky
authors.forename: Sven
authors.initials: S
authors.lastname: Dänicke
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology*; D000818:Animals; D002417:Cattle / Q000254:growth & development*; D019587:Dietary Supplements; D005650:Fumarates / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D006109:Poaceae; D012820:Silage / Q000032:analysis*; D015430:Weight Gain / Q000187:drug effects; D003313:Zea mays / Q000737:chemistry*
chemical_list: D005650:Fumarates; C032005:fumaric acid