HRP (Capsicum annuum L.) is a spice that is widely used in human food.
The review, published in Poultry Science, was aimed at highlighting the effects of HRP as a phytobiotic in broiler nutrition and its mode of action as a possible alternative to antibiotics.
Various studies, said the authors, suggest that the addition of HRP to broiler feed results in improved bird performance, notably in terms of weight gain, feed intake and FCR.
HRP supplementation, they saw, could also have an antimicrobial effect and that it might enhance intestinal histomorphology in the birds as well.
However, the reviewers said further studies are warranted to investigate the various effects of such feed supplementation, particularly in relation to the claims for HRP around immunomodulation, antioxidant, and anti-inflammatory activity.
The findings
Several studies have demonstrated the effect of HRP on the performance of broiler chickens, said the reviewing team.
The beneficial impact of capsicum in poultry nutrition may be related to capsaicin, which has a bactericidal effect against intestinal pathogens, such as E. coli, Salmonella spp., and Clostridium spp., they noted, referencing work by Omolo et al., 2014; Agarwal et al., 2017; and Salem et al., 2021.
They saw that HRP may boost pancreatic and intestinal enzyme activity, enhance bile acid secretion, and increase body weight in broiler chickens, as well as improve feed digestibility, feed intake (FI), feed conversion efficiency, mortality, carcass features, blood parameters, and production cost, noting the paper by Munglang and Vidyarthi, 2019.
Chili pepper is a rich source of carotenoids such as vitamins C, E, and provitamin A (β carotene), which have well-known antioxidant functions to fight against the hazardous effects of free radicals, including oxidative stress in broilers, according to the findings of studies by Krinsky, 2001, Droge, 2002, and Tawfeek et al., 2014.
And, as HRP is rich in vitamin C, its supplementation could potentially mitigate heat stress in birds, noted the reviewers, citing studies by Yoshioka et al., 2001, Al-Kassie et al., 2012, Abd El-Hack et al., 2018, and Abdelnour et al., 2018.
Meanwhile, Kogure et al. (2002) and Luqman and Razvi (2006) reported that capsicum was more effective than vitamin E in inhibiting lipid peroxidation. “Capsaicin can potentiate the activities of pancreatic and intestinal enzymes (Platel and Srinivasan, 2004), increase bile acid secretion (Abdel Salam et al., 2005), and increase weight gain (WG) in broiler chickens (Puvača et al., 2014, 2015b).”
Capsaicin also increases appetite in poultry, so the addition of HRP to the diet influences broilers' feed consumption (FC), said the reviewers, citing the work done on this by Yoshioka et al., 2001.
Capsaicin may also protect the gastric mucosa through the afferent stimulation of nerve endings, they saw. Approximately 85% of capsaicin is absorbed by passive diffusion, mainly in the jejunum, which improves the digestibility of feeds in broilers, noted Kawada et al., 1984; Iwai et al., 2003.
