| The data from the performance test during the year 2002 to 2004,which including the growth traits,reproduction traits,fattening and carcass traits of 3-generation Baoshan pigs breeding population,in addition with the main performance of two and three-way cross combinations,were used to study the breed characteristics,selection and cross utilization effects;in order to provide some basis and supports for the further breed preservation. breeding and utilization of Baoshan pig.1.The results from the analysis on the growth,reproduction,fattening and carcass traits of Baoshan pigs showed that the growth speed of Baoshan pig were relative slow,which the average body weights at 6 months of candidate male and female pigs were 49.54kg and 47.57kg,the average daily gains during 70 days to 6 months of male and female pigs were 289.92g and 298.49g,respectively.The total piglets number born(TNB)and number of 70 days per litter of first parity were 8.22 and 7.32 heads,and those of the latter parities were 10.19 and 8.63 heads,respectively.The average teat number of female pigs was 12.38.It means that Baoshan pig has a good reproductive performance.The average age reach to 93.52kg,daily gain during fattening periods,feed conversion rate and carcass meat percentage of pure Baoshan meat pig were 219.46 days,515.43 g,3.92kg and 43.65 percentage, respectively.The main economical traits of Baoshan pig were better than those of Yunnan local pig breeds except Saba pig,which showed the good potential qualities for further breeding and utilization in swine production.2.During the procedure of 3-generation selection,the change of main economical traits was showed the trends,which decreased previous and then increased.The improvement of growth traits was not obvious as reproduction traits.The TNB of first and latter parities were reached to 8.33 and 10.11 heads,and the piglets number per litter at 70 days of those were 7.89 and 8.56 heads,respectively,which shorted the good reproductive performance of Baoshan pig.3.The best three-way cross combination,Yorkshire×(Duroc×Baoshan)(YDB)was preliminary screened by cross experiments analysis.The TNB.piglets number born alive (NBA)and the piglets survival percentage at 70 days of first parity for two-way crossbred sows,Duroc×Baoshan(DB)were 9.13 heads,8.75 heads and 97.19 percentage,respectively. which were significantly higher than those of Baoshan pig.The average age reach to 99.33kg, daily gain during fattening periods,feed conversion rate and carcass meat percentage of YDB meat pigs were 167.00 days,828.82g,3.07kg and 58.76 percentage,respectively,which significantly better than those of Baoshan pigs and the two-way cross combination pigs,and showed the good growth,fattening and carcass performance.The major performance of the cross combination was reached to the requirements of meat-type pigs in the main.4.Considering the breed characteristics of Baoshan pig,the further breeding and utilization of the pig may be taken into account as following two aspects.One is to continue to improve the main performance by effective breeding approaches,and establish a specific dam line.Two is to repeat the different cross combination experiments,and carry standardize cross utilization on the base of determining the best cross combination. |
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