Effects of dietary supplementation with herbal extract as methionine replacer on growth performance, meat composition, oxidative stability and liver gene expression in broiler chickens

Abstract

In the present study, an herbal feed additive was tested for partial-to-complete replacement of synthetic methionine in poultry diets, along with its effects on performance, breast and thigh meat chemical composition, oxidative stability during refrigerated storage and the expression of five target genes in liver. In a 35 days trial, 600 one-day-old male chicks were randomly allocated to 4 groups with 10 replicates. Birds in the control group were fed a regular maize–soybean-based diet that covered DL-methionine needs while the second group (Meth40) was similar to control but contained only DL – Methionine at 40% of control diet. Diet in third group contained DLMethionine at 40% of control and the herbal feed additive Methiorep TMMeth40+Mrep) with extracts of Boerhavia diffusa, Azadirachta indica, Vigna mungo and Trigonella foenum-graecum. Diet of fourth group was formulated to totally replace DL Methionine by Methiorep TM (Mrep). Body weight gain and feed consumption were weekly recorded. At the end of the trial, all birds were slaughtered and 2 chickens per pen were selected for meat and liver sampling. The liver was tested for the expression of five target genes, namely Methionine synthase (MTR), Tyrosine aminotransferase (TAT), Spermidine synthase (SMS), Methionine sulfoxide reductase (MSRB1) and Betaine homocysteine S-methyltransferase (BHMT). The results showed that the Meth40 group had reduced body weight compared to the Meth40+Mrep group while the Control and Mrep groups had comparable weights. Feed intake and feed conversion ratio did not differ among the experimental groups. Carcass, breast and thigh meat yield were higher in the Mrep and the Control compared to Meth40 and Meth40+Mrep groups. Also, meat oxidation was significantly lower in herbal groups compared to the control group. After normalization to β-actin expression, quantitative real-time PCR analysis revealed an induction in the expression of MTR and SMS genes in the liver of both herbal treated groups. No changes were observed for the TAT, MSRB1and BHMT genes in the herbal treated groups compared to the control or the Meth40 group. In conclusion, herbal feed additives with specific plant extracts may be able to improve both growth performance and antioxidant activity of broiler chickens, phenolic content; yet, they may also support in amino acid efficient use of broiler.

Dietary Supplementation with Pomegranate and Onion Affects Lipid and Protein Oxidation in the Breast Meat, Thigh, and Liver, Cellular Stress Protein Responses, and Gene Expression of Liver Enzymes Involved in Protein Synthesis in Broilers

“…Despite numerous investigations into the impact of nutrient-deficient diets on chicken growth, the research on liver gene expression related to enzymes involved in methionine cycle synthesis remains notably lacking, both in farm animals and poultry. In a previous study [47], it was shown that specific extracts of Indian herbs such as Boerhavia diffusa, Azadirachta indica, Vigna mungo, and Trigonella foenum-graecum can affect gene expression and modulate the growth performance of chickens, even when they are given diets with limited quantities of methionine. It is possible that animal feed containing plant extracts rich in active phenolic ingredients possesses the capability for metabolic, physiologic, and growth promoting properties, resulting in a decrease in humoral and cellular responses and associated gene expressions in broiler chickens.…”

“…Therefore, gaining insights into the molecular mechanisms that govern the expression of genes related to amino acid metabolism could provide valuable information for optimizing dietary requirements [83]. It is clear that diet supplementation with extracts from aromatic plants may interfere with the gene expression of amino acid in the synthesis of methionine, and, as a consequence, with protein synthesis [47]. Chickens' diets deficient in methionine have been shown to upregulate the gene expression related to the CAT1 amino acid transporter in large skeletal muscles [83].…”

“…Recently, it has been made clear that the identification of genes, as well as their expression, is involved in biological processes, even interfering with feed efficiency and growth rate [46]. Moreover, herbal feed additives of Indian origin have been shown to be involved in gene expression related to the cycle of protein synthesis and the efficient use of amino acids in broilers [47].…”