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

ABSTRACT

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.

KEYWORDS:

• amino acids
• weaning pig
• protease
• digestibility
• histo-morphology

Acknowledgments

The authors would like to appreciate the workers Kangwon National University Animal Farm, Chuncheon, South Korea where the research was done for the support, they offered especially in carrying out the daily routine animal husbandry practice.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors contributions

Conceptualization: J.S.K., J.M., A.H. Data curation: J.M., S.H.H., E. N. K. Formal Analysis: J.M., A.H., S.R.P. Funding acquisition: J.S.K., S.I. Investigation: S.H.H., H.T. Methodology: A.H., J.M., S.I.P. Project administration: J.M., J.S.K. Resources: S.H.H, J.S.K. Software: A.H., J.Y.M. Supervision: J.S.K. Validation: J.M., S.H.H., H.T. Visualization: A.H., J.S.K. Writing: J.M., A.H.

The authors confirm that they reviewed the manuscript.

Data availability statement

Datasets of this study can be available from the corresponding author upon request.

Ethical approval

Approval of experimental protocols and animal care applied in the current study were granted by the Committee for Animal Care and Use, Kangwon National University, Chuncheon, South Korea.

Additional information

Funding

The present research was conducted by the research fund from Advanced Enzymes Technologies Ltd., India.