Effect of citric acid supplementation in diet on growth performance and gut morphology of male Venda chickens

Abstract

Two trials were carried out to see how citric acid supplementation affected the growth performance and gut morphology of male Venda chickens aged one to 90 days. The first trial looked at how citric acid supplementation affected feed intake and growth rate, feed conversion ratio, and live weight in male Venda chickens. A total of 200 male Venda chickens, each with ten chicks, were randomly separated into 20 equal pens. Diets were formulated to contain four different levels of citric acid (CA), CA1 (0 g of CA /kg DM), CA2 (12.5 g of CA/kg of DM), CA3 (25 g of CA/kg DM) and CA4 (50 g of CA/kg DM) and were allocated to the chicks. Each treatment catered for five constant pens for a period of 90 days. A maize-soya bean meal-based diet was formulated to meet the nutritional requirements of male Venda chickens. The diets were iso-energetic and iso-nitrogenous, 12.14 MJ ME/kg DM and 180 g CP/kg DM, respectively. The second experiment commenced from the first experiment at day 90, with the same 200 chickens as no mortality recorded. The second experiment the effect of citric acid supplementation on gut digesta organ weights, crop and gizzard pH, and intestine length. Data on male Venda chickens' live weight, feed intake, average daily body weight gain, feed conversion ratio, gut digesta weights, pH of crops, and gizzards were analysed using one-way ANOVA and the General Linear Model procedure of the Statistical Analysis System (version 9.2). Tukey HSD test was used to separate the significant differences between treatment means at P ≤ 0.05. Citric acid supplementation in a starter diet did not significantly improve (P >0.05) feed intake, feed conversion ratio, live weight, and growth rate of male Venda chicks. Citric acid supplementation levels of 0, 12.5, 25, and 50g of CA per kg DM of the diet were calculated, using quadratic equations, to result in optimal feed intake, feed conversion ratio, live weight at 30 days and growth rate, respectively, of male Venda chickens aged one to 30 days. In conclusion, the lack of impact on feed intake, feed conversion ratio, live weight, and growth rate could be caused by a sour taste diet brought on by citric acid supplementation levels because the chicks during this were still young and more sensitive to sourness, resulting in poor feed intake and poor growth performance. Feed intake, FCR, live weight was much improved (P <0.05) with the supplementation of 12.5 or 25g of CA per kg DM compared to control and 50g of CA per kg DM during grower and finisher phase (31 to 90 days). The pH values of crop and gizzard greatly decreased (P <0.05) with the increasing levels of citric acid supplementation. The lower pH in both crop and gizzard observed in diet supplemented with 50g of CA/kg DM and higher pH value in crop and gizzard observed in control diet, 25g of CA/kg DM in diet recorded to have second lowest value of pH in crop and gizzard and 12.5g of CA/kg DM in diet recorded to have second highest pH value in crop and gizzard. Citric acid supplementation at all levels had has no effect impact (P >0.05) on intestinal length, weight of small intestine segments, crop, pro-gizzard, and ceca of male Venda chickens aged 90 days old. 25g of CA/kg DM supplementation improved (P <0.05) weight of gizzard and crop compared to others supplementation levels in male Venda chickens aged 90 days old. The use of citric acid in the diet of male Venda chickens aged 31 to 90 days improves growth performance and lowers gut digesta pH values, rendering it hazardous to dangerous bacteria and therefore improving gut health and gut functioning. More research is needed, however, to confirm these conclusions.