title: [Effect of various sources of phosphorus on the apparent digestibility of crude nutrients, growing and slaughtering performance as well as selected parameters of metabolism in fattening bulls].
abstract: Two long-term individual feeding experiments (336 and 307 days) were carried out with 52 (experiment I; Black and White dairy cattle) and 22 (experiment II; Yellow cattle) growing bulls. Rations varied in P-content. In experiment I straw: concentrate-mixture (1:2.5) were fed, phosphorus content of rations amounted to 2, 3 or 4 g/kg DM. In experiment II maize silage was fed ad lib. supplemented with 2.4 kg concentrate per animal per day. P-content of rations amounted to 3 and 4 g/kg DM. Apparent digestibility of rations was determined during experiments. Blood samples were taken to analyse selected parameters of metabolism. Various P-supply did not significantly influence apparent digestibility of organic matter and crude nutrients in both experiments. Bulls fed 2 g P/kg DM decreased DMI in experiment I already after 50 days of experiment. After 168 experimental days daily weight gain of bulls fed with 2 g P/kg DM was 124 or 132 g lower than that of bulls fed with 3 or 4 g P/kg DM respectively. P-concentration of inorganic P in serum decreased to < 2 mmol/l, bone mineralisation was reduced. There exist no significant differences in feed intake, weight gain and metabolic parameters of bulls fed with 3 or 4 g P/kg DM. Increase of P-supply from 2 to 3 or 4 g/kg DM compensated partially the lower weight gain. Application of 3 or 4 g P/kg DM in experiment II effected daily weight gains of > 1200 g and did not significantly influence all investigated criterions.
authors.affiliation: Institut für Tierernährung, Bundesforschungsanstalt für Landwirtschaft (FAL) Braunschweig, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Flachowsky
authors.forename: M
authors.initials: M
authors.lastname: Klosch
authors.forename: A
authors.initials: A
authors.lastname: Schneider
authors.forename: G H
authors.initials: GH
authors.lastname: Richter
authors.forename: H J
authors.initials: HJ
authors.lastname: Löhnert
mesh_terms: D000821:Animal Feed; D000818:Animals; D002118:Calcium / Q000032:analysis; D002417:Cattle / Q000254:growth & development*; D004063:Digestion; D002149:Energy Intake; D005527:Food, Fortified; D008297:Male; D009752:Nutritional Status; D010710:Phosphates / Q000032:analysis / Q000097:blood; D010758:Phosphorus; D013045:Species Specificity; D015430:Weight Gain
chemical_list: D010710:Phosphates; D010758:Phosphorus; D002118:Calcium
vernacular_title: Einfluss unterschiedlicher Phosphorgaben auf die scheinbare Verdaulichkeit der Rohnährstoffe, Mast- und Schlachtleistung sowie ausgewählte Stoffwechselparameter von Jungmastbullen.