Replacement of dicalcium phosphate by rock phosphate in cattle diets: nutrients digestibility, plasma parameters, ruminal fermentation and microbial synthesis efficiency

Revista Brasileira de Zootecnia

Sabrina Marcantonio Coneglian²  Antonio Ferriani Branco¹  Kátia Cylene Guimarães¹  Daniel Suzigan Mano²  Julio Cezar Barreto²  Vanessa Ruiz Fávaro¹ 

[1] ,Universidade Estadual de MaringáMaringá PR

关键词: phosphorus sources;    plasma phosphorus;    rumen microbial protein;    ruminal fermentation;    fermentação ruminal;    fontes de fósforo;    fósforo plasmático;    proteína microbiana;   

DOI  :  10.1590/S1516-35982010000400017

来源: SciELO

【 摘 要 】

This study was conducted in order to evaluate the effects of replacing dicalcium phosphate by rock phosphate in diets of growing steers. It was determined the following aspects: apparent digestibility of diets; phosphorus (P), calcium and fluorine apparent absorption; ruminal pH; ruminal ammonia concentration; microbial efficiency and plasma P. Five rumen fistulated Holstein steers weighting 275 - 283 kg were used. Experimental design was a 5 × 5 Latin square and diets consisted of 0, 25, 50, 75 and 100% of dicalcium phosphate replacement by rock phosphate in the mineral supplement. Addition of rock phosphate in the diets produced a linear increase on intake, rumen outflow and fecal output and total disappearance of fluorine. Diets did not differ to apparent absorption of calcium as well as dry matter, organic matter, crude protein, neutral detergent fiber and non-fiber carbohydrates intake, excretion, digestion and partial and total apparent digestibility. Plasma phosphorus was not influenced by diets and the average was 5.93 mg/dL. There was no difference for ruminal pH and ruminal ammonia concentration. Dicalcium phosphate replacement did not affect apparent and true protein microbial synthesis. Total replacement of dicalcium phosphate by rock phosphate in growing steer mineral supplement did not affect ruminal environment and protein synthesis in rumen. Considering this, dicalcium phosphate replacement in growing steer diets decreases P absorption and depending on its requirements it should be carefully seen.

【 授权许可】

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