Microbial efficiency, abomasal nitrogen compounds flow, ruminal ammonia and ruminal pH in cattle fed diets containing tifton 85 bermudagrass hays at different regrowth ages

Revista Brasileira de Zootecnia

Cecon, Paulo Roberto¹  Valadares Filho, Sebastião de Campos¹  Garcia, Rasmo¹  Pereira, Odilon Gomes¹  Ribeiro, Karina Guimarães² 

[1] Universidade Federal de Viçosa, Viçosa;Fundação do Ensino Superior de Rio Verde, Rio Verde

关键词: bacterial composition;    microbial N;    N balance;    N-ammonia;    non ammonia N;    passage rate   IntroduçãoOs requerimentos de proteína dos ruminantes são atendidos pela quantidade de proteína verdadeira absorvida nos intestinos (proteína metabolizável);    que é suprida pela proteína microbiana e proteína dietética não-degradada no rúmen;    além da proteína endógena;   

DOI  :  10.1590/S1516-35982001000200038

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

- The microbial efficiency synthesis, the abomasum nitrogen compounds flow, the nitrogen compounds balance, the passage rate of ruminal digest, the ruminal ammonia concentration and ruminal pH in cattle fed diets containing Tifton 85 bermudagrass hay with different regrowth ages were evaluated. Four rumen and abomasum fistulated zebu cattle with average 340 kg LW were allotted in a 4x4 Latin square. All diets contained 60:40 forage to concentrate ratio. The forage was consisted in Tifton 85 bermudagrass hay with 28, 35, 42 and 56 days of age, and the concentrate contained corn meal and mineral mix. The amount of microorganisms was determined using purines as a marker. The pH and N-ammonia were determined in the ruminal fluid before and 2, 4 and 6 hours after feeding. The passage rate was determined by unicompartimental model using the chromic oxide as a marker. The microbial efficiency synthesis was not affected by the age of the hay in the diet, presenting mean values of 31.32 g Nbact/kg RDOM, 30.74 g Nbact/kg RDCHO, 33.74 g DMbact/kg RDCHO and 12.5 g CPbact/100 g TDN. The maximum estimates of total nitrogen compound flows, ammonia and non ammonia were 119.0, 9.76 and 109.6 g/day, with the inclusion of hay with 39.7; 37.6 and 39.9 days of regrowth age, respectively and the bacterial nitrogen compounds flow of 80.54 an average. Nitrogen balance, passage rate, ruminal ammonia concentration and ruminal pH also were not affected by the age of the hay, with values of 30.67 g/day, 3.2%/h, 9.7 mg/100mL (maximum at 1.38h) and 6.08 (minimum at 6.64 h), respectively.

【 授权许可】

CC BY-NC