Effects Of Different Straight / Amylopectin On Growth Performance, Nutrient Digestibility And Meat Quality

The purpose of this research was to evaluated the effects of amylose/amylopectin ratio ongrowth, nutrient digestion metabolism and meat quality of fattening lamb. A total of48malelambs were selected, and randomly allocated to4groups with3replications per group and4lambs per replication. The birth weight of lambs were no significant difference between fourgroups. All lambs were free to diets and water. Pea starch, corn starch wheat starch and tapiocastarch were used as the sole dietary energy source to formulate four iso-caloric, and iso-starchdiets. The amylose/amylopectin ratios were0.48,0.23,0.24,0.12. All diets were feed tofattening lambs for77days. At21,35,56and77days of trial period, To weighed, bloodcollected and one lamb in each replication was slaughtered to determined relevant indexes. Theresults were showed as following:(1)There were no significant difference of feeding four different amylose/amylopectin ratio onaverage daily gain, average daily intake, feed conversion ratio and as for body size (body length,height and bust) at21,35,56and77days (P>0.05).When feeding with pea starch diet, averagedaily gain, average daily intake, feed conversion ratio and as for body size (body length, heightand bust) in fattening lambs were the greatest among the four treatments.(2) There were no significant difference of feeding four different amylose/amylopectin ratioon dry matter, ash and ether extract of nutrient digestion at21,35,56and77days (P>0.05). Peastarch was significantly increased the crude protein digestibility at21,35,56and77days(P<0.05). Significantly high the neutral detergent fiber and acid washing digestibility at21daysand Significantly high the neutral detergent fiber digestibility77days (P<0.05).(3) There were no significant difference of feeding four different amylose/amylopectin ratioon total protein at21,35,56and77days (P>0.05). There were significant difference of feedingfour different amylose/amylopectin ratio on albumin at56,77days, When feeding with peastarch diet, the drop loss in fattening lambs. When feeding tapioca starch diet content of glucosein the blood of the lamb was significantly lower than other three groups at56,77days(P<0.05).When feeding pea starch diet content of blood urea nitrogen of the lamb was significantly higherthan other three groups at77days(P<0.05).(4) There were no significant effects of feeding four different amylose/amylopectin ratio on pH, the drop loss and rib-eye area (P>0.05).When feeding with pea starch diet, the drop loss infattening lambs were the lowest among the four treatments. However, slaughter rate and rib-eyearea in fattening lambs were the greatest among the four treatments. When feeding pea starchdiet content of cooked meat percentage of the lamb was better at21,35days.The above results proved that in fattening lambs provided pea starch diet with the highestamylose/amylopectin ratio was better for improve the immune function, growth and meatquality.