Effects Of Small Peptide On Ruminal Fermentation And Digestion Of Nutrition On Beef Cattle

Four Luxi Yellow beef bulls with ruminal cannula, proximate duodenal (simple T-piece) and terminal ileal fistulae, averaging initial BW = 400±10 kg were used in a 4×4 Latin square. The ruminal infusion of soybean small peptide (SSP) was 0 (control), 100, 200 and 300 g/d. the experiment was designed to study the effects of soybean small peptide (SSP) infusion on rumen fermentation and ruminal microbial, diet digestion and flow of nutrient in the gastrointestinal tract.SSP ruminal infusion significantly increased microbial protein synthesis (P<0.05). Rumen ammonia-N concentration was increased by 24.8%, 12.8% and 16.4% compared to control. Infusion SSP had no effect on ruminal pH (P>0.05). And total VFA concentration and molar proportion of propionate were increased (P<0.05) with addition of 200 and 300 g/d of SSP. Acetate proportion was deceased (P<0.05) when 100 and 200 g/d SSP were added. Molar proportion of butyrate was higher (P<0.05) with 100 and 300 g/d SSP than the control. Inclusion of SSP decreased (P<0.05) acetate to proportion ratio.Butyrivibrio fibrisolvens population which relative to total bacterial 16 S rDNA were increased (P<0.05), while Streptococcus bovis population were decreased (P<0.05) by infusion of SSP. Infusion SSP had no effect on Prevotella ruminicola, Ruminococcus ?avefaciens and Ciliate protozoa (P>0.05).The results showed that DM, OM, and NDF digestibilities were significantly increased for 300 g/d group. EE, CP, and ADF apparent digestibilities were not affected by infusion soybean small peptide significantly (P>0.05). Retained N, Urinary N, and N apparent digestion were significantly increased with small peptide addition (P<0.05). The rate of retained N and digestion N of 200 g/d group were significantly higher than other three group (P<0.05). The result also showed that plasma urea N and glucose of 300 g/d group were significantly higher than other group (P<0.05).Except for Arg, Thr, Val, Met and Ile, flows of other individual AA in ileum were higher than control. SSP increased the digestibility of Lys and Phe in small intestinal (P<0.05). The flows of total AA, EAA and individual amino acids were increased (P<0.05) with infusion SSP. Except for Arg, Thr, Val Met and Ile, flows of other individual AA in ileum were higher (P<0.05) than the control. Apparent degradability of Phe and Lys were increased by 200 g/d SSP, and apparent degradability of Arg was increased with all levels SSP. Other individual AA apparent degradability was not affected by SSP.The results indicated that infusion SSP could improve nutrient digestion, ruminal fermentation and amino acid availability.