Four Luxi beef cattle (400±10 kg) fitted with ruminal, duodenal and ileal cannulas were used in a 4×4 Latin square to assess the effects of soybean small peptide (SSP) infusion on rumen fermentation, diet digestion and flow of nutrient in the gastrointestinal tract. The ruminal infusion of SSP was 0 (control), 100, 200 and 300 g/d. Ruminal SSP infusion linearly (p<0.01) and quadratically (p<0.01) increased microbial protein synthesis and rumen ammonia-N concentration. Concentrations of total volatile fatty acid were linearly increased (p = 0.029) by infusion SSP. Rumen samples were obtained for analysis of microbial ecology by real-time PCR. Populations of rumen Butyrivibrio fibrisolvens, Streptococcus bovis, Ciliate protozoa, Ruminococcus flavefaciens, and Prevotella ruminicola were expressed as a proportion of total Rumen bacterial 16S ribosomal deoxyribonucleic acid (rDNA). Butyrivibrio fibrisolvens populations which related to total bacterial 16S rDNA were increased (p<0.05), while Streptococcus bovis populations were linearly (p = 0.049) and quadratically (p = 0.020) decreased by infusion of SSP. Apparent rumen digestibility of DM and NDF were (Q, p<0.05; L, p<0.05) increased with infusion SSP. Total tract digestion of DM, OM and NDF were linearly (p<0.01) and quadratically (p<0.01) increased by infusing SSP. The flow of total amino acids (AA), essential amino acids (EAA) and individual amino acids were linearly (p<0.01) and quadratically (p<0.01) increased with infusion SSP. The digestibility of Lysine was quadratically (p = 0.033) increased and apparent degradability of Arginine was linearly (p = 0.032) and quadratically (p = 0.042) increased with infusion SSP. The results indicated that infusion SSP could improve nutrient digestion, ruminal fermentation and AA availability.

The objective of this study was to evaluate the effect of diets containing different amounts of wheat, as a partial or whole substitute for corn, on digestibility, digestive enzyme activities, serum metabolite contents and ruminal fermentation in beef cattle. Four Limousin×LuXi crossbred cattle with a body weight (400±10 kg), fitted with permanent ruminal, proximal duodenal and terminal ileal cannulas, were used in a 4×4 Latin square design with four treatments: Control (100% corn), 33% wheat (33% substitution for corn), 67% wheat (67% substitution for corn), and 100% wheat (100% substitution for corn) on a dry matter basis. The results showed that replacing corn with increasing amounts of wheat increased the apparent digestibility values of dry matter, organic matter, and crude protein (p<0.05). While the apparent digestibility of acid detergent fiber and neutral detergent fiber were lower with increasing amounts of wheat. Digestive enzyme activities of lipase, protease and amylase in the duodenum were higher with increasing wheat amounts (p<0.05), and showed similar results to those for the enzymes in the ileum except for amylase. Increased substitution of wheat for corn increased the serum alanine aminotransferase concentration (p<0.05). Ruminal pH was not different between those given only corn and those given 33% wheat. Increasing the substitution of wheat for corn increased the molar proportion of acetate and tended to increase the acetate-to-propionate ratio. Cattle fed 100% wheat tended to have the lowest ruminal NH3-N concentration compared with control (p<0.05), whereas no differences were observed among the cattle fed 33% and 67% wheat. These findings indicate that wheat can be effectively used to replace corn in moderate amounts to meet the energy and fiber requirements of beef cattle.

Fourteen 24-month-old castrated crossbred bulls (Luxi × Limousin) weighing 504.7±15.6 kg were used to study the effect of feeding soyabeans with different particle size on fatty acid composition of longissimus dorsi muscle, backfat and liver. The cattle were divided into three groups with 5, 5 and 4 bulls in groups 1, 2 and 3, respectively. The cattle were fed diets containing 69.4 kg dry matter finely ground roasted soyabeans, coarsely ground roasted soyabeans, or roasted whole soyabeans as Treatments 1, 2 and 3, respectively. The cattle were slaughtered at the end of the 28-day experiment and longissimus dorsi muscle, backfat and liver were sampled for fatty acid analysis.It was found that the total conjugated linoleic acid (CLA) content of liver in Treatment 3 was significantly higher than in Treatments 1 and 2 (P<0.05). The total CLA content of backfat of Treatment 3 tended to be higher than that of Treatments 1 and 2, and the total CLA content of Treatment 2 tended to be higher than that in Treatments 1 and 3, but the differences did not reach statistical significance (P>0.05). It is concluded that the supplementation of roasted whole soyabeans to fattening beef cattle was feasible for increasing the total CLA content of backfat and liver in beef cattle. Higher supplementation levels of soyabeans in the diet of beef cattle and longer feeding experiments to validate the effect are needed. 389 SUN W. ET AL.

The influences of differently processed wheat products on rumen fermentation, microbial populations, and serum biochemistry profiles in beef cattle were studied. Four ruminally cannulated Limousin × Luxi beef cattle (400 ± 10 kg) were used in the experiment with a 4 × 4 Latin square design. The experimental diets contained (on a DM basis) 60% corn silage as a forage source and 40% concentrate with 4 differently processed wheat products (extruded, pulverized, crushed, and rolled wheat). Concentrations of ruminal NH-N and microbial protein (MCP) in cattle fed crushed and rolled wheat were greater ( < 0.05) than the corresponding values in cattle fed pulverized and extruded wheat. Ruminal concentrations of total VFA and acetate and the ratio of acetate to propionate decreased ( < 0.05) with increased geometric mean particle size (geometric mean diameter) of processed wheat, except for extruded wheat; cattle fed extruded wheat had the lowest concentrations of total VFA and acetate among all treatments. The relative abundance of , , ciliated protozoa, and was lower in cattle fed the pulverized wheat diet than in the other 3 diets ( < 0.05), whereas the relative abundance of was decreased in cattle fed extruded wheat compared with cattle fed crushed and rolled wheat ( < 0.05). No treatment effect was obtained for serum enzyme activity and protein concentration ( > 0.05). Our findings suggest that the method of wheat processing could have a significant effect on ruminal fermentation parameters and microbial populations in beef cattle and that crushed and rolled processing is better in terms of ruminal NH-N and MCP content, acetate-to-propionate ratio, and relative abundance of rumen microorganisms.

The development of massively parallel sequencing technologies enables the sequencing of total cDNA to identify unigene expression and to discover novel regions of transcription. Here, we report the first use of RNA sequencing (RNA-Seq) to find the digital gene expression profiles (DGEs) associated with the growth and development of muscle in Chinese Luxi and Angus beef cattle. More than 9 243 921 clean reads were found in samples of muscle tissue. We found 232 DGEs between Luxi cattle and Angus cattle (false discovery ratio 0.001 and |log2 ratio| !1). Among the DGEs, we determined that 147 genes were downregulated and 85 genes were upregulated. Gene Ontology and KEGG Pathway analyses were performed to analyse the biological role of the DGEs and determine their contribution to the differences seen in muscle growth and development between local Chinese Luxi cattle and the introduced Angus cattle. The results suggest that RNASeq is a useful tool for predicting differences in gene expression between Luxi and Angus beef cattle; moreover, our results provides unprecedented resolution of mRNAs that are expressed across the two breeds.