Effect Of Calcium Sources And Levels On Growth Performance And Meat Quality Of Broilers

The experiment was conducted to study the effects of different dietary calcium sources and levels on growth performance and meat quality in broilers. A total of 144 healthy 21-day-old broilers were randomly allocated into 4 treatments for 28 days(22~49 day old). Each treatment contained 6 replicates with 6 broilers per replicate. Dietary calcium were composed of two sources and two levels. Namely, to make total dietary calcium level reach 0.90% or 1.15% by adding calcium carbonate or calcium chloride. The optimum dietary calcium level in actual production was 0.09% and the high calcium level was 1.15%. The results showed:Compared with calcium carbonate, dietary calcium chloride could reduce feed intake of broilers at 4, 5, 6 weeks and the entire experimental period(P<0.05), and daily gain of broilers at 4, 5, 6, 7 weeks and the entire experimental period(P<0.01), and improve feed-gain ratio of broilers at 4, 5, 7 weeks and the entire experimental period(P<0.01). High level of calcium could reduce feed intake of broilers at 4, 5 weeks and the entire experimental period(P<0.01), and daily gain of broilers at 4, 5, 6 weeks and the entire experimental period(P<0.05), and improve feed-gain ratio of broilers at 4 weeks and the entire experimental period(P<0.01). The interactions between calcium sources and calcium levels had significant influence on feed intake of broilers at 4, 5 weeks and the entire experimental period(P<0.01), and daily gain of broilers at 4, 5, 6 weeks and the entire experimental period(P<0.05), and feed-gain ratio of broilers at 4 weeks and the entire experimental period(P<0.01).Compared with calcium carbonate, dietary calcium chloride could reduce dressing percentage, eviscerated percentage, semi-eviscerated percentage, percentage of breast muscle, percentage of leg muscle, and percentage of abdominal fat(P<0.05). High level of calcium could reduce percentage of abdominal fat(P<0.05)and other items(P>0.05). The interactions between calcium sources and calcium levels had no significant influence on all indexes(P>0.05).Compared with calcium carbonate, dietary calcium chloride could reduce the level of serum Na~++ K~+- Cl-, TG and LDL-C(P<0.05), and improved the level of serum chloride(P<0.05). High level of calcium could improve the level of serum calcium(P<0.05). And high level of calcium could reduce the level of TC, TG and LDL-C(P<0.05). The interactions between calcium sources and calcium levels had no significant influence on all indexes(P>0.05).Compared with calcium carbonate, dietary calcium chloride could reduce shear stress(P>0.05) and muscle fiber diameter(P<0.05) of breast muscle and leg muscle, but improved muscle fiber density(P<0.05) and meat color of a*(P>0.05) of breast muscle and leg muscle. High level of calcium could reduce shear stress(P<0.05) and muscle fiber diameter(P<0.05) of breast muscle and leg muscle, but improved muscle fiber density(P<0.05) and meat color of a*(P>0.05) of breast muscle and leg muscle. The interactions between calcium sources and calcium levels had no significant influence on all indexes(P>0.05).Compared with calcium carbonate, dietary calcium chloride could reduce the activity of SOD of leg muscle(P<0.01). High level of calcium could reduce the activity of T-AOC, GSH-PX and SOD of breast muscle and leg muscle(P<0.01), and improved the content of MDA of leg muscle(P<0.01). The interactions between calcium sources and calcium levels had no significant influence on all indexes(P>0.05).In conclusion, high level of calcium had influenced growth performance, reduced percentage of abdominal fat and level of blood lipid, and improved meat quality at two levels. Calcium chloride was better than the calcium carbonate in meat quality at two sources.