Effect of a Phytogenic Feed Additive on Growth Performance, Nutrient Digestion, and Immune Response in Broiler-Fed Diets with Two Different Levels of Crude Protein

Abstract

The aim of this experiment was to evaluate the effect of a phytogenic feed additive (PFA) on growth performance and nutrient digestibility of broilers fed corn and soybean meal-based diets containing two different levels of crude protein. A 2 × 2 completely randomized factorial arrangement (eight replicates/treatment, 30 birds/replicate) was conducted with a positive control (PC) and negative control (NC) containing crude protein at standard or reduced by 1.5% (equivalent to a reduction of 15 g/kg), respectively, and supplementation of PFA at 0 or 125 ppm of diet. There were no significant interactions found between PFA and CP levels in the current study. Main effect analysis showed that during 0–42 d of age NC diets decreased body weight gain (p < 0.05), but increased feed intake (p < 0.05) and feed conversion ratio (FCR, p < 0.01), whereas supplementation of PFA resulted in a lower FCR (p < 0.01). The ileal nutrient digestibility was reduced (p < 0.05) in the broilers fed a reduced protein diet at 21 d compared to the standard protein level group, but there were no effects for PFA levels. Similarly, supplementing PFAs showed no effects on digestive enzyme (Alkaline phosphatase, amylase, and lipase) activity in jejunal digesta and jejunal brush border enzyme (maltase, sucrase, and aminopeptidase) activity. Supplementation of PFA downregulated (p < 0.05) the mRNA expressions of cytochrome P450 1A and interleukin 6 in the ileum but had no effects on nutrient transporter genes in the jejunum. In conclusion, supplementation of PFA reduced broiler FCR during the whole grow-out period and positively regulated the immune responses in the ileum.

Effect of Herbal Blend and L-arginine Supplementation on Growth Performance, Intestinal Morphology, and Caecal Microflora of Growing Guinea Fowls

“…The improved feed conversion ratios obtained for guinea fowls fed the diet with HB and birds fed the diet with antibiotic notwithstanding L-Arg supplementation than birds fed control diet having no supplemental L-Arg supported previous findings that inclusion of phytogenic feed additive (Brenes & Roura, 2010;Jamroz et al, 2005) and L-Arg supplementation improved feed conversion ratio of broilers when compared with the control group (Filho et al, 2021;Pramujo et al, 2019). In addition, Wang et al (2021) reported an improved feed conversion ratio of broilers fed a diet supplemented with phytogenic feed additives (containing oregano, cinnamon, citrus peel, and fructooligosaccharides). Better feed conversion ratio obtained for guinea fowls fed the diet with HB could be attributed to the additive effect of antimicrobial properties exhibited by constituent scent leaf (Prabhu et al, 2009), antioxidant and antimicrobial properties of turmeric (Quiles et al, 2002), and moringa leaf (Ogundare & Onifade, 2009) contained in the blend.…”

Assessing the potential of phytogenic feed additives: A comprehensive review on their effectiveness as a potent dietary enhancement for nonruminant in swine and poultry

“…Conversely, for poultry-fed diets treated with PFAs, nutritional digestibility, nutritional carrier gene expression and gastrointestinal enzyme activity were unaffected (Wang et al, 2021). As mentioned by Yan, Meng, et al (2012), the incorporation of herbs into a piglet diet enhanced the energy digestibility of nutrients.…”

Rapid growth of antimicrobial resistance: the role of agriculture in the problem and the solutions

“…This can be detrimental in poultry since the industrialised hatching practices involve separating eggs from the mother hen, disinfecting them and hatching in clean and bacteria-deprived environment, resulting in unnatural microbial communities that can only further suffer from continual supplementation of antibiotics in the feed (Stanley et al 2013). The industry invested in alternative and natural antimicrobial products capable of controlling pathogens, such as biochar (Willson et al 2019), zeolite (Prasai et al 2017) or plant-derived complex phytogenic products (Bajagai et al 2020;Flees et al 2021;Greene et al 2021;Wang et al 2021). Recently, using a mixed phytogenic alternative product, RNAseq analysis showed that herb-based antibiotic alternative triggers ileum gene expression response significantly matching the response to doxycycline and geldanamycin (Bajagai et al 2022), indicating a broad spectrum of the antibiotic alternative products.…”