The Effect of Garlic (Allium Sativum L.) on Growth Performance, Mortality Rate, Meat and Blood Parameters in Broilers

The effect of garlic extract on body weight, feed intake, feed conversion rate, mortality rate, dressing percentage, carcass traits, chemical composition of breast muscles and blood plasma parameters was investigated in a feeding trial with 640 Ross 308 broiler chickens of both sexes. The experiment was characterised by a two-factor design, with liquid garlic extract (GFA ) and sex as factors. In comparison with the unsupplemented control group, supplementing diets with 1.00 (GFA 1), 1.50 (GFA 2), and 2.25 (GFA 3) ml kg^-1 for 42 days increased body weight, with a significant difference for the GFA3 group (P≤0.01). Bird mortality was 2.78% in the control group and 0.10%, 0.63%, and 0.60% in the GFA1, GFA2, and GFA3 supplemented groups, respectively (P≤0.01). Feed intake (kg/42 days) was 4.50 per broiler in the control group and 4.51, 4.68, and 4.85 kg^-1 per broiler in the experimental groups (P≥0.05), respectively. Feed conversion rate was 1.80 in the control group and 1.77, 1.76, and 1.80 kg/kg in the GFA1, GFA2, and GFA3 groups, respectively (P≥0.05). GFA increased European Production Efficacy Factor (EPEF) from 331 in the control group to 347, 363, and 356 points in the experimental groups, respectively (P≤0.01). Dressing percentage in the GFA3 group was significantly higher than in the control group (74.8% vs 72.5%; P≤0.01). GFA at the concentration of 2.25 ml kg^-1 significantly increased the weight of breast muscles. Supplementing the diet with GFA at the level of 1.50 ml kg^-1 caused a significant increase in liver weight (P≤0.01). Feeding with GFA at a rate of 1.5 ml kg^-1 caused a significant increase in the protein and crude ash content of breast meat compared to the control group (P≤0.05). The highest dose of GFA significantly increased total protein content of serum compared to the control group (P≤0.01). No significant interaction of GFA by sex on the analysed parameters was found. It is concluded that GFA at 2.25 ml kg^-1 caused a significant improvement in the body weight of broilers and their carcass parameters, while a significant reduction in bird mortality for the GFAsupplemented groups was observed during the rearing period. It appears that the optimum level of GFA , when the crude protein concentration in the commercial starter and grower diets ranges between 210 and 220 g kg^-1 is 1.5-2.25 ml kg^-1 of the starter and grower diets.