EXPERIMENT 1: Efficacy of yeast and garlic extract mixture on growth performance, tract digestibility, excreta microbiota, gas emission, blood profile, and meat quality in broiler
This experiment was accompanied to determine the use of yeast and garlic extract mixture in broiler diets on growth performance, nutrient absorption, excreta microbiota, blood profiles, and meat quality. A total of 792 male Ross 308 broilers (1-day-old, body weight 41 ± 0.5 g, and 5 weeks trial) were randomly allocated. Birds were arbitrarily assigned to one of four nutritive treatments (11 replicates; 18 birds per replicate). A basal diet (CON) was supplemented with 0.1%, 0.2%, and 0.3% yeast-garlic mixture (YGM). Body weight gain linearly increased during the overall period and tended to increase from day 21 to day 35, while feed intake showed a tendency to increase during the overall period by YGM inclusion. However, Salmonella counts linearly decreased, but Lactobacillus and Escherichia coli counts remained unaffected. Excreta CO₂ emissions were linearly reduced; nevertheless, other noxious gas emissions were not affected. Furthermore, YGM supplementation elicited a tendency for improved lymphocytes and linearly increased IgG. However, feed conversion ratio, mortality, nutrient utilization, and meat quality were not influenced. YGM addition (0.1%, 0.2%, and 0.3%) linearly improved broiler growth performance by decreasing microbiota and gas emission and increasing blood parameters. So, the proper dose of YGM was 0.3%.
EXPERIMENT 2: An evaluation of gallic acid supplementation to corn-soybean-gluten meal-based diet in broilers
Gallic acid (GA) is an endogenous plant polyphenol found in fruits, nuts, and plants that has antioxidant, antimicrobial, and growth-promoting effects. This study aimed to assess the effect of graded doses of dietary supplemented GA on growth performance, nutrient retention, fecal score, footpad lesion score, tibia ash, and meat quality of broilers. A total of 576 1-day-old Ross 308 male broiler chicks with an average initial body weight of 41 ± 0.5 g were used in a 32 days feeding trial. Broilers were sorted into 4 treatments, 8 replications per treatment, and 18 birds per cage. Dietary treatments consisted of corn-soybean-gluten meal-based basal diet and the basal diet supplemented with 0%, 0.02%, 0.04%, and 0.06% of GA. Feeding broilers with a graded doses of GA increased body weight gain (P < 0.05) and feed intake (P < 0.05) linearly on phase 2 (days 9-21). Additionally, the nutrient digestibility of dry matter (P < 0.05) and energy (P < 0.05) were increased linearly by including a rising level of GA in the broiler diet. However, the excreta score, footpad lesion score, tibia ash, and meat quality presented no significant effect (P > 0.05) except meat color of yellowness. Adding GA at increasing doses to broiler diets increased growth efficiency and nutritional absorption without affecting excreta score, footpad lesion score, tibia ash, and meat quality. In conclusion, the inclusion of graded levels of GA to cornsoybean-gluten meal-based diet presented dose-dependent improvement in growth performance and nutrient digestibility of broilers.
EXPERIMENT 3: Assessment of Quillaja saponin as a feed supplement in maize-soybeanoilseed rape meal-based diet for enhanced growing pig performance
The present study evaluated the effects of Quillaja saponin (QS) supplementation on growth efficiency, nutritional digestibility, gas emissions, and faecal score in growing pigs. In a 42-day experiment, 80 growing pigs [(Yorkshire x Landrace) x Duroc] were randomly assigned (29.17 ± 0.23 kg initial average body weight) to 2 different trial groups. Each group had 8 replicates, consisting of 3 male and 2 female pigs in each pen. The nutritional treatments included a control group (CON) receiving a basal diet and a treatment group (TRT1) receiving a basal diet supplemented with 0.01% Quillaja saponin (TRT1). The results of this study indicated that pigs consuming the QS-supplemented diet exhibited significantly higher (P < 0.05) body weight on day 42 compared to the CON group. Furthermore, dietary QS led to higher (P < 0.05) average daily gain and showed a tendency to reduce (P < 0.10) the feed conversion ratio throughout the study period, as compared to the CON diet. Growing pigs that consumed the QS-supplemented diet also showed higher (P < 0.05) nutrient utilization of dry matter and nitrogen compared to the CON group. At day 42, QS supplementation reduced (P < 0.05) NH₃ and H₂S emissions, along with a trend to reduce (P < 0.10) CH₄ generation in the initial stage in comparison to the CON diet. Furthermore, the faecal score in the experimental group was lower (P < 0.05) on day 42 compared to control animals. In conclusion, QS proved to be a suitable supplement for growing pigs as it improved growth efficiency and nutrient digestibility, as well as reduced gas emissions and faecal score.