Effects of Keratinase on Performance, Nutrient Utilization, Intestinal Morphology, Intestinal Ecology and Inflammatory Response of Weaned Piglets Fed Diets with Different Levels of Crude Protein

Abstract

Two experiments were conducted to investigate the in vitro ability of keratinase to hydrolyze soybean glycinin and β-conglycinin and to evaluate the in vivo effects of keratinase when included in corn-soybean diets with different levels of crude protein and fed to nursery pigs. In experiment 1, a saturated keratinase solution (1 ml) was added to two blank controls of either glycinin or β-conglycinin resulting in the hydrolysis of 94.74% glycinin and 88.89% β-conglycinin. In experiment 2, 190 pigs (8.3±0.63 kg BW) were allotted to one of four treatments in a 2×2 factorial arrangement on the basis of body weight, and sex was balanced among the pens. The effects of crude protein (19 vs. 22%) and keratinase (0 vs. 0.05%) were studied. Each treatment was applied to six pens with seven (two pens) or eight pigs per pen. Pigs were fed the experimental diets for 21 d. Weight gain and feed conversion ratio were improved (p<0.05) with keratinase supplementation while feed intake was reduced (p<0.05). Keratinase supplementation increased (p<0.05) the apparent total tract digestibility of dry matter, energy, crude protein and phosphorus. Keratinase supplementation also increased n-butyric acid in the cecum and colon, lactobacilli and total anaerobe counts in the colon as well as the ratio of villus height to crypt depth in the ileum. Additionally, fecal score, ammonia nitrogen and branch chain volatile fatty acids in the colon, E. coli and total aerobe counts in the colon, crypt depth in the jejunum and ileum as well as serum interleukin-1 and interleukin-6 concentrations were also decreased (p<0.05) by keratinase supplementation. A reduction in dietary crude protein decreased (p<0.05) colon ammonia nitrogen concentration and cecal propionic acid and branch chain volatile fatty acid concentrations. In addition, cecal E. coli counts, colon total anaerobe counts, ileal crypt depth, and serum interleukin-1 and interleukin-6 concentrations were also decreased (p<0.05) with the reduction of dietary crude protein.With the exception of fecal scores, there were no significant interactions between crude protein and keratinase. This study provides evidence that dietary keratinase supplementation improved nursery pig performance by improving intestinal morphology and ecology, thus improving nutrient digestibility and alleviating the inflammatory response.

Effects of keratinase supplementation of corn-soybean meal based diets on apparent ileal amino acid digestibility in growing pigs and serum amino acids, cytokines, immunoglobulin levels and loin muscle area in nursery pigs

“…1 was 306 and 612 U/g respectively, for the diets supplemented with 0.05 or 0.1% keratinase, and calculated keratinase activity in keratinase supplemental diets for Exp. Recent in vitro work conducted in our laboratory demonstrated that keratinase hydrolysed both soybean glycinin and b-conglycinin (Wang et al 2011), which reinforced the explanation proposed by Tu et al (1998). The hydrolysing ability of keratinase on various proteins of animal or plant origin has been widely shown in vitro (Yu et al 1972;Lin et al 1996;Gradisˇar et al 2005).…”

Effects of Coated Compound Proteases on Apparent Total Tract Digestibility of Nutrients and Apparent Ileal Digestibility of Amino Acids for Pigs

“…It has been proved that treatment of SBM with appropriate proteases may improve piglet performance at weaning, which would be a potential method for increasing the amounts of SBM in starter diets for weaned piglets (Rooke et al, 1998). Protease had a positive effect on the ATTD of DM, GE, and CP in weaned piglets (Wang et al, 2011a). However, there are still some insignificant proteases in diets (Ji et al, 2008; Adeola and Cowieson, 2011; O’Shea et al, 2014).…”

“…Most of the proteins in SBM are easily digested, but some proteins including glycinin, protease inhibitor and antigenic proteins are difficult to digest, especially for newly weaned pigs, which may damage intestinal health and impair immune function (Brandon and Friedman, 2002; Sun et al, 2008; Zhao et al, 2008; Wang et al, 2011a;b). Fortunately, with the developing of feed enzyme technologies, protease treatment of SBM is an alternative means to reduce the antigenic challenge of SBM and improve performance of animals (Rooke et al, 1998; Piao et al, 1999; Yu et al, 2007; Romero et al, 2013).…”

“…Proteases as supplemental feed enzymes have been added to swine diets routinely for many years (Cowieson and Ravindran, 2008; Wang et al, 2011a; b), however, different proteases with different inherent characteristics may elicit divergent responses in vivo (Adeola and Cowieson, 2011). In our studies, the enzyme products were compounded with acidic, neutral and alkaline proteases produced by Aspergillus niger , Bacillus subtilis , and Bacillus Licheniformis and coated by corresponding coating layers, which could successively dissolve and work in different microenvironment in the digestive tract.…”

Comparative Effects of Coated Compound and Mono-component Proteases on Growth Performance and Nutritional Efficiency in Broiler Diets

“…studies reported an increase in weight gain and reduced feed conversion with protease supplementation in crude protein and amino acid reduced diets [8,9]. In contrast, another study mentioned the inconsistency in body weight gain and feed intake when proteases supplemented with crude protein and amino acid reduced diets [10].…”