Exogenous protease influences protein digestibility, growth performance, and gut microflora in weanling pigs on a limited protein diet.

The study was conducted to evaluate the impact of dietary level of crude protein (CP) and protease supplementation on growth performance, digestibility of nutrients, intestinal morphology, and gut microbiota in weaning pigs. Three hundred cross-bred piglets (Duroc × Landrace × Yorkshire) were allotted to five dietary treatments on the basis of initial body weight (BW) and sex. Pigs were group-housed in pens with each treatment with 10 replicate pens with six pigs per pen. The treatments included a standard diet (STD), STD with 0.6% lower protein (STD0.6), STD with 0.6% lower protein and protease supplementation (Pro0.6), STD with 1.0% lower protein (STD1.0), STD with 1.0% lower protein and protease supplementation (Pro1.0). Results indicated a higher BW (p < 0.05) of piglets in the Pro0.6 group at days 0-42 compared to the STD0.6 and STD1.0 groups. The average daily gain was higher (p < 0.05) in the Pro0.6 treatments at days 0-42 compared to the STD0.6 and STD1.0. The gain to feed ratio was higher (p < 0.05) in the STD, and Pro0.6 groups compared to the STD0.6, Pro1.0 and the STD1.0 groups at days 0-42. Dry matter digestibility was lower (p < 0.05) in the STD1.0 group than the Pro0.6 and Pro1.0 groups. The crude protein digestibility was higher (p < 0.05) in the Pro0.6 group compared to the STD, STD0.6 and STD1.0 treatment groups while crude fat digestibility was higher (p < 0.05) in the STD and Pro0.6 compared with the STD0.6 and STD1.0 groups. Digestibility was higher for histidine (p < 0.05), leucine (p < 0.05) in the protease Pro0.6 and Pro1.0 groups than in the STD0.6 and STD1.0 groups. The digestibility of non-essential AA was higher for alanine (p < 0.05) in the Pro0.6 than the STD1.0 group. For faecal microbial population, Faecalibacterium abundance was higher (p < 0.05) in the Pro0.6 compared to all the other groups while the population of Actinobacteria was greater (p < 0.05) in the STD group and lowest in the Pro1.0 treatment. In the ileum, villus height was greater (p < 0.05) in the protease Pro0.6, and Pro1.0 groups compared to the STD0.6, and STD1.0 groups while the villus height to crypts depth ratio was lower (p < 0.05) in the STD 1.0 group compared to the STD, Pro0.6, and Pro1.0 groups. Based on these results, dietary protease supplementation improved nutrient digestibility and gut histo-morphology translating to improved utilisation of nutrients thus positively impacting growth performance in weaned pigs. Further, reducing the CP content in the diets increased the abundance of Muribaculaceae while protease supplementation increased the population of Faecalibacterium in the gut of the weanling piglets on the STD0.6 diet.

The targeted anti-Salmonella bacteriophage attenuated the inflammatory response of laying hens challenged with Salmonella Gallinarum.

Fowl typhoid is a severe disease caused by Salmonella Gallinarum with considerable mortality and morbidity in laying hen farms. The current study has focused on controlling the infection in laying hens using anti-Salmonella spp. bacteriophage. The treatments included, PC, without challenge; NC, S. Gallinarum challenged (SGC); B5, 5 mg bacteriophage/kg + SGC; B10, 10 mg bacteriophage/kg + SGC. The Salmonella shedding, inflammatory responses, and gene expression of pro-inflammatory cytokines, toll-like receptor (TLR), and heat shock protein (HSP) in the jejunum, liver, and thigh muscle were tested in laying hens. Supplementation of bacteriophage reduced the abundance of S. Gallinarum in the excreta at d 3, 7, and 14. The abundance of S. Gallinarum was lower in the B10 than the B5 at d 7. Supplementation of bacteriophage decreased the abundance of S. Gallinarum in the oviduct, spleen, and cecum at d 14. The laying hens in the NC group showed an increased relative spleen weight compared with the PC and B10 treatments. Among the SGC treatments, the NC treatment showed higher gene expressions of IL-4 compared with the B5, higher gene expressions of interferon (IFNγ), TLR4, and tumor necrosis factor-α (TNF-α) compared with the B5 and B10, and higher gene expressions of HSP27 compared with the B10 in the jejunum. Dietary supplementation of B10 decreased the mRNA expressions of TLR4 and TNF-α compared with the B5 treatment in the jejunum. The NC treatment showed the highest gene expressions of HSP27, TLR4, and TNF-α in the liver. Dietary supplementation of B10 showed lower mRNA expressions of HSP27 compared with the B5 treatment in the liver. Moreover, the IFNγ and HSP27 were upregulated in the NC treatment compared with the B5 and B10 in the muscle. In conclusion, it can be suggested that bacteriophage is an effective supplement to control S. Gallinarum infection in laying hens and possibly lower horizontal contaminations in laying hen flocks.

The Effects of Rhodobacter capsulatus KCTC-2583 on Cholesterol Metabolism, Egg Production and Quality Parameters during the Late Laying Periods in Hens.

An experiment was conducted to investigate the effects of dietary supplementation of Rhodobacter capsulatus KCTC-2583 on egg-yolk and serum cholesterol, egg production and quality parameters during the late laying periods in hens. A total of 160 Hy-Line Brown layers (54 wk-old) were randomly allotted to 4 treatment groups on the basis of laying performance. Each treatment had 4 replicates with 10 birds each (40 birds per treatment). Two hens were confined individually with cage size 35×35×40 cm and each 10 birds (5 cages) shared a common feed trough between them forming one experimental unit. Dietary treatments were; basal diet supplemented with 0 (control), 0.05, 0.10 and 0.15% R. capsulatus KCTC-2583. Experimental diets were fed in meal form for 56 d. Dietary supplementation of increasing levels of R. capsulatus KCTC-2583 reduced (linear, p<0.05) egg-yolk cholesterol and triglycerides (d 28, 42 and 56) concentrations. Also, serum cholesterol and triglycerides (d 21, 42 and 56) concentrations were linearly reduced (p<0.05) with increasing dietary R. capsulatus KCTC-2583. Laying hens fed a diet supplemented with increasing levels of R. capsulatus KCTC-2583 had increased (linear; p<0.05) overall egg production, egg weight, egg mass and feed efficiency. However, dietary treatments had no effect (linear or quadratic; p>0.05) on feed intake of laying hens. At d 28 and 56, breaking strength and yolk colour of eggs were linearly improved (p<0.05) in laying hens fed dietary increasing levels of R. capsulatus KCTC-2583. Dietary treatment had no effects (linear or quadratic; p>0.05) on albumin height, shell thickness and shell weight at any period of experiment. These results indicate that dietary supplementation of R. capsulatus KCTC-2583 has the potential to improve the laying hen performance and lead to the development of low cholesterol eggs during late laying period in Hy-Line Brown hens.