Effects of crossing on nutrient digestibilities in Dingyuan sows.
The nutrient digestibility and its heterosis of hybrid pigs with different Dingyuan genes proportion(Ng) were estimated for scientific production and diet formula of hybrid pigs.Twenty-four testing sows about 2-year-old,16 sows in late pregnancy and 8 boars,were from Dingyuan,Duroc,Duroc(male)×Dingyuan(G1) and backcross Duroc×G1(G2),respectively.The dejecta and diets of all pigs fed in single pen were sampled for consecutive 3-day in trial period,and the nutrient contents in fecal and diet samples were detected.Using acid insoluble ash(AIA) for indicator of feed digestibility,the nutrient digestibilities were calculated.The heterosis of nutrient digestibility was analyzed.The digestibilities in boars increased by 6.31%,10.19%,36.94%,4.01%,26.10%(P0.01) and 8.04%(P0.05) for total energy,crude protein,crude fiber,NFE,crude ash and phosphorus compared with that in sows,respectively,and no significant difference(P0.05) on crude fat and calcium.The digestibilities in hybrids with different Ng and Hc no-significantly difference(P0.05),but the regression of digestibility with Ng and Hc was significant(P0.01).Heterosises of digestibilities were 19.14%,9.18%,6.09% and 4.01% for calcium,phosphorus,crude fat and crude fiber,respectively,and the heterosis in G1 was higher than that in G2,but heterosises of digestibilities of total energy,crude protein,NFE and crude ash were lower about-0.5 ~-2.5%.In conclusion,the heterosis of nutrient digestibility indicated that the level of dietary nutrient should be reasonable for nutritional requirements in hybrid pigs with Chinese swine genes,especially in calcium,phosphorus,crude fat and crude fiber.