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Context. Our previous study revealed that micronised bamboo powder (MBP) can promote the growth performance of broilers aged 1-22 days by improving oxidation resistance, balancing intestinal microflora and regulating metabolic pathways. Aims. This study evaluates the effects of MBP on growth performance, intestinal development, caecal chyme microflora and metabolic pathways of broilers during the grower period, age 24-45 days. Methods. Slow-growing spotted-brown broilers (n = 880, age 24 days) were randomly divided into two groups according to weight and sex and fed either a maize-based diet (control) or a diet with MBP at 1% replacing equivalent maize. Key results. No significant difference was observed in growth performance between MBP and control groups. Broilers receiving MBP exhibited significantly higher (P < 0.05) caecal organ index, jejunum villus height and villi:crypt ratio. The relative abundance of Firmicutes was higher, and relative abundance of Bacteroidetes was lower in the MBP group. Addition of MBP also significantly (P < 0.05) upregulated abundance of p_Firmicutes, f_Alicyclobacillaceae, g_Acutalibacter, f_Peptococcaceae, f_Clostridiaceae, f_Bacillaceae, g_Enterococcus and f_Enterococcaceae, while downregulating abundance of p_Bacteroidetes, f_Bacteroidaceae, g_Bacteroides, o_Bacteroidales and c_Bacteroidia. For the metabolic pathways, 66 were observed to differ between dietary groups, including alanine, aspartic acid and glutamic acid metabolism, butyric acid metabolism, arginine synthesis, linoleic acid metabolism and ^-alanine metabolism. Correlation analysis revealed that Firmicutes in caecal chyme were significantly positively correlated (P < 0.05) with some fatty acids including syringic, 3-methyl-2-oxovaleric, 3-(2-hydroxyphenyl) propanoic and butyric acids. Bacteroidetes were positively correlated (P < 0.05) with some amino acids including L-alanine, L-threonine, 3-methylthiopropionic acid and L-glutamic acid. Conclusions. Replacing maize with MBP at 1% had no negative effect on growth performance of broilers. Feeding MBP improved intestinal development and increased the relative abundance of bacteria that promotes fatty acid metabolism and fibre degradation. Implications. MBP provides an alternative to maize and is a beneficial source of fibre; further research is warranted to determine the optimum feeding level. [ABSTRACT FROM AUTHOR]

Objective: This study was aimed to explore the efficacy of combination of endo-xylanase (Xyn) and xylan-debranching enzymes (arabinofuranosidase, Afd and feruloyl esterase, FE) in improving utilization of bran in piglet diet. Methods: In vitro experiments were firstly conducted to examine the enzymological properties of Xyn, Afd, and FE, concurrent with their effect on degradation of arabinoxylan (Abx) in bran. In vivo experiment was then implemented by allocating two hundred and seventy 35-d-old postweaning piglets into 3 groups (6 replicates/group), which received bran-containing diet supplemented with Xyn (1,600 U/kg) or its combination with Afd (0.8 U/kg) and FE (4 U/kg) or without enzyme. Results: Both Xyn, Afd, and FE are relatively stable against the changes in temperature and pH value. Combining Xyn with Afd and FE had a superiority (p<0.05) over Xyn alone and its combination with Afd or FE in promoting (p<0.05) degradation of Abx in different brans. Combined treatment with Xyn, Afd, and FE was more beneficial than Xyn alone to induce increasing trends (p<0.10) of average daily gain, final body weight and feed efficiency of piglets fed bran-containing diet. Moreover, combination of Xyn, Afd, and FE showed advantages (p<0.05) over Xyn alone in causing reductions (p<0.05) in diarrhea rate and cecal pH value, concurrent with increases (p<0.05) in cecal and colonic acetic acid and total volatile fatty acid concentrations, as well as cecal butyric acid concentration of piglets fed brancontaining diet. Conclusion: Combining Xyn with Afd and FE was more beneficial than Xyn alone in promoting degradation of Abx in bran, along with growth performance and intestinal volatile fatty acid profile of piglets received bran-containing diet. Thereby, combination of Xyn, Afd, and FE had a superior efficacy relative to Xyn alone in improving application of cereal bran in piglet diet. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the predictability of energy balance and energy efficiency by using dietary chemical composition. Closed-circuit indirect calorimetry was used to determine the apparent metabolisable energy (AME), respiratory quotient, heat increment (HI), net energy (NE) and ratio of NE to AME (NE:AME) of a series of diets with varying levels of chemical constituents. Diets were analysed for DM, gross energy, protein, fat, ash, crude fibre, acid detergent fibre, neutral detergent fibre, starch, sugars (mono- and disaccharides), and soluble, insoluble and total non-starch polysaccharides. Ross 308 male broilers were acclimatised to chambers and diets for 3 days and 12 days, respectively, before O2 consumption and CO2 expiration were measured gravimetrically. Gross energy of feed consumed and excreta voided were measured and AME was calculated. Heat production was calculated using the Brouwer equation based on O2 and CO2. After taking fasting heat production into account by using a value of 450 kJ/BW[sup 0.70], HI was determined. NE was calculated as AME minus HI. The results showed high predictability of AME (R² = 0.89) and NE (R² = 0.85) by using chemical components. HI was less predictable (R² = 0.25). Efficiency of energy utilisation (NE:AME) was predicted (R² = 0.40). Closed-circuit calorimetry was found to be useful for evaluating the contribution of the chemical components of feed ingredients to the efficiency of energy utilisation in broilers. These results may be used to reduce energy costs in broiler feed formulation. Net energy values of raw materials are derived from prediction equations that take into account energy lost as wasted heat. The equations are produced by measuring heat produced in birds fed diets varying in nutrients and other chemical components. The use of a net energy system to formulate broiler feeds has the potential for significant cost savings. [ABSTRACT FROM AUTHOR]

This experiment was conducted to compare carcass and meat quality traits, and muscle fibre characteristics in the longissimus muscle of the Landrace [an European pig breed] and the Lantang [a Chinese native pig breed] at the ages of 60, 90 and 150 days. The characteristics of muscle fibres were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and histological methods (ATPase and succinodehydrogenase, SDH). A significant age difference was observed in loin eye area (LEA), backfat thickness (BF), pH45 min, pH24 h, drip loss, moisture, ash, number percentages of αR and αW fibres, muscle fibre cross-sectional area and mRNA expression of myosin heavy chain (MyHC)-slow and MyHC-IIb. The Lantang showed a higher intramuscular fat (IMF) content and BF than the Landrace, while the Landrace exhibited a higher LEA and ash content than the Lantang. Both breeds exhibited similar developments in muscle fibre composition, and there were small differences in muscle fibre composition and muscle fibre cross-sectional area. However, Landrace pigs showed a significantly higher mRNA relative expression of MyHC-IIb. These results suggested that age was an important factor in the variation of carcass, meat quality traits and characteristics of muscle fibres. The main differences between the breeds at the same age were LEA, BF, IMF and ash contents, and fast glycolytic MyHC-IIb in the mRNA level. [ABSTRACT FROM AUTHOR]