Porcine skeletal muscle typing in histochemical and in-situ RT-PCR analysis.

Currently, there are plenty of histochemical methods to classify pig muscle fibers, which confused the naming and classification of muscle fibers. This study aims to analyze the difference and correlation of 6 different histochemical methods and select the most suitable method for muscle fiber classification at the molecular and histomological levels by in-situ RT-PCR and enzyme histochemical methods. Muscle fiber samples, including psoas (PM), semitendinosus (SM) and trapezius muscle (TM), were collected from Large Spotted (LS), Lantang (LT) and Landrace (LR) pigs at their market-ages (LS at 150 d, LT at 210 d, and LR at 150 d). 6 kinds of histochemical methods combining actomyosin adenosine triphosphatase (AM-ATPase) with succinate dehydrogenase (SDH) enzyme were conducted to differentiate fiber types. 2 types of fibers (I and II) were differentiated by acid 2-fibre (2-AC) or alkaline 2-fibre classification(2-AL), 3 types of fibers (ßR, αR and αW) by 3-AC or 3-AL, and 4 types of fibers (I, IIa, IIx and IIb) by 4-AC, or 4-AL. Results showed that AC and AL muscle-fiber classification were consistent in reflecting the characteristics of muscle fibers(P > 0.05), but the color of each muscle fiber type was just opposite. AC methods may be superior to AL methods because of their clear staining background, the sensitivity to staining condition. But there were breed differences and tissue specificity in the optimal preincubation condition. The optimal acid preincubation condition for classifying muscle fibers was pH4.30 for LT, while pH 4.35 for the LS and LR pigs. Meanwhile the optimal acid preincubation condition was pH4.35 for PM, while pH4.40 for TM or SM. For further selection from 2, 3, 4-AC, in-situ RT-PCR was applied to detect the mRNA distribution of myosin heavy chain I (MyHC-I). By combining in-situ PCR with enzyme histochemistry methods, MyHC-I gene and its product - Type I fibrocytes were directly located in cells at both molecular level and morphological level. Compared with the cross-sectional area (CSA) of different muscle fibers (i.e. I, II, ßR, αR, αW, IIa, IIx and IIb) identified by enzyme histochemistry, it was found that the CSAs with stronger mRNA expression signal of MyHC-Ⅰ were closer to those of the Type I muscle fiber measured by 4-AC enzyme histochemistry (P > 0.05). Therefore, 4-AC may be considered as the most proper muscle typing method to study muscle fiber typing as well as meat quality. And the combination of in-situ RT-PCR and histochemistry may help better understand porcine muscle fiber characteristics and meat quality in pigs.

Effects from supplementary feeding of bamboo powder in perinatal period on farrowing process, serum biochemical indexes, and fecal microbes of sows and offspring piglets.

Introduction: This study was conducted to explore the effects of supplementary feeding of bamboo powder on the physical parameters of sows during the perinatal period of 7 days ± in parturition, including farrow duration, serum biochemical indexes, fecal physicochemical indexes, and microbial flora. Methods: Thirty pregnant sows were randomly divided into three groups: the control group was fed a basal diet, TRE1 group and TRE2 group were fed a basal diet supplemented with 30 g d-1 and 60 g d-1 bamboo powder, respectively. Multiple parameters of sows and offspring piglets were determined. Results: The contents of serum total cholesterol and triglyceride of sows in TRE2 group were significantly lower than those in the control group. The contents of serum malondialdehyde of sows in TRE2 and TRE1 groups were significantly lower than that in control group. The water content of sow feces in TRE2 group was significantly higher than that in control group, and the pH values of sows in TRE2 and TRE1 groups were significantly higher than that in control group. The richness index (Chao) of sow fecal bacterial community in TRE2 group was significantly lower than that of the control group, and the Ace and Sobs indexes tended to be lower than those of the control group. At the phylum level, the relative abundance of Actinobacteriota in the feces of sows in TRE2 group was significantly lower than that of the control group, while that of Fusobacteriota in the feces of suckling piglets in TRE2 group tended to be lower than that of the control group. At the genus level, among the Top10 dominant bacteria, the relative abundance of Tissierella in the feces of sows in TRE2 group was significantly lower than that of the control group while that of Fusobacterium in the feces of suckling piglets in TRE2 group tended to be lower than that of the control group. The relative abundance of Clostridium_sensu_stricto_1, Terrisporobacter, Turicibacter, and Tissierella in the feces of sows in TRE2 group was significantly lower than that of TRE1 group (p < 0.05), while Lactobacillus tended to be higher than that of TRE1 group (p < 0.10). Discussion: The results suggested that supplementary feeding 60 g d-1 bamboo powder could increase the water content in the feces of sows, reduce the oxidative damage, and tend to reduce the relative abundance of opportunistic pathogenic Fusobacterium for suckling piglets, while it reduced the fecal microbial diversity of sows.

Effects of micronized bamboo powder on growth performance, serum biochemical indexes, cecal chyme microflora and metabolism of broilers aged 1-22 days.

Adding insoluble fiber to diet of broilers has been reported to improve intestinal health and promote growth performance. Bamboo powder is a cheap raw material with rich insoluble fiber. This study aims to explore the effects of feeding micronized bamboo powder (MBP) on growth performance, serum biochemical indexes, intestinal microflora, and metabolism of broilers. A total of 1440 1-day-old slow-growing Ephedra chickens were randomly divided into three groups considering gender and body weight: (1) Group D: feeding with basal diet without antibiotics; (2) Group E: feeding with basal diet supplemented with 5% rice bran (RB); (3) Group F: feeding with basal diet supplemented with 1% MBP. Each group involved 8 replicates feeding for 22 days, with 60 chickens per replicate. Various indexes were detected. For the growth performance, the weight gain and feed consumption ratio (G: F) of Group F supplemented with MBP is 0.57 ± 0.04, which is significantly higher than that of E group supplemented with RB (0.52 ± 0.01, P < 0.05). For the serum biochemical indexes, the glutathione peroxidase activity in Group F is significantly higher than that of Group D, while the malondialdehyde content is significantly lower than that of Group D and Group E (P < 0.05 for all). The fresh cecal chyme is taken for determination. In Group F, the α diversity index Faith_pd is significantly lower in Group F than that of Group D. The microorganism species in cecal chyme of Group F and Group E are also different. The metabolic pathways of Group F, mainly in fatty acid metabolism, amino acid metabolism and intestinal immune IgA production, were different from those of Group D and Group E. Adding 1% MBP to broiler diet can enhance the anti-oxidant capacity, improve chyme microflora, regulate the metabolism pathways responsible for intestinal fatty acids, amino acids, and immunity.