Studies On Breed Characteristics Of Xiaomeishan Pig And Utlization Of Their Hybrids

In order to provide scientific basis for the breed conservation and utilizing ofXiaomeishan pig, we studied on breed characteristics of the local fine breed-Xiaomeishan Pig, which is including its growth and development, reproductiveperformance, finishing ability, carcass quality and so on, from 2003 to 2006 inXiaomeishan Pig Breeding Center of JSAFC. The methods can be listed as follows:one is to analyze the center's yearly statistics records, the other is to carry aboutdifferent kinds of experiments, mainly including the planned raising and slaughtering.1. Growth and DevelopmentThe growth and development records for 120 boars and 280 sows are studied.As for the weight and size indexes changes rule (different periods, different sexes),Xiaomeishan pig is no more differences with other local species. The weight and sizeindexes, no matter for boar or sow, vary most obviously between the 180th-360th age(P＜0.05). The sow is, except its height, beyond the boar in all other indexes on the180th age (P＜0.05). By the 360th age, there is no remarkable difference except itscircumference of cannon bone between the boar and the sow (P＜0.05). After the 360thage, the sow is, both in its size and weight growth, lower than the boar, and the weightgrowth index for the sow is 40.07kg, for the boar 49.79kg (P＜0.05 or P＜0.01).2. Reproductive PerformanceThe reproductive performance records for Xiaomeishan (M) pig are analyzed.The sexual maturity of Xiaomeishan pig is early and its reproductive capacity isrelatively strong. The average day age is 73.4±7.5 days when the little sow hasobvious estrous signs, and its proper first mating age is around 6 months. Its firstmating behavior—step to climb, appears about at 78.6±4.2 days, and its proper firstmating age is around 8 months. As for the first gestation period, the average litter sizeis 10.31±1.44 and litter size born alive is 9.85±0.21, while the average litter size is15.3±1.82, litter size born alive 14.87±0.60, the weaning number 13.38±0.48 for themultiparous sow. It has a better performance than the first in the average litter size, such as the average pig birth weight, the 20th days age litter weight and the 45th daysage litter weight (P＜0.05 or P＜0.01). By hybridizing with the Yorkshire (Y) andLandrace (L) pigs, the average litter size born alive is over 12, and the averageweaning number is over 11, and the 45th days age littler weight is as much as116.71±6.97 Kg and 100.77±5.86 Kg respectively.3. Finishing AbilityThe experiment on M, YM, LM, LYM (the number is 15 respectively andcastrated) is illustrated. Average Daily Gain (ADG) for M is 404.4 grams, andFeeding Conversion Ratio (FCR) is 3.68:1. There are high maternal hybrid advantageswith two-way crossing or three-way crossing among the mating systems of LM, YM,LYM. Their progeny have better performance in ADG and FCR than M, and theperformance order is LYM, YM, LM, and M. Between the two-specie-hybridizing,LM has a better performance, and ADG for YM is 546.1 grams (P＜0.01), for LM553.7 grams (P＜0.01)), for LYM 622.2 grams (P＜0.01, P＜0.05), and FCR for theLYM is 3.02:1(P＜0.01). So the combinations of LM and LYM are well worthyspreading.4. Carcass Quality and Meat QualityThe slaughtering experiment (taking 4 pigs per group) is carried out. While itsweight is around 68.5kg, Average Back-fat Thickness over three positions (ABF) isaround 29.76±1.61 mm, which is much thinner than other local species, and LeanMeat Percentage (LMP) is 46.23％, which is higher than the average level of localspecies in China. By hybridizing with the Yorkshire pig and Landrace pig, DressingPercentage (DP) is much higher, and the three-specie-hybridizing is about 77.26％(P＜0.01); ABF is thinner; also LMP for the two-specie-hybridizing (P＜0.01) and thethree-specie-hybridizing is more satisfied to 57.83％(P＜0.01). Comparing betweenYM and LM, the latter has a slight better performance both in LMP and Lion EyeArea (LEA) (P＞0.05). By hybridizing with the Yorkshire pig and Landrace pig, waterof carcass and meat is more, Cooked Meat Rate(CMR) of M is higher significantly(P＜0.01) than that of LYM, and YM. Water of LD is less than that of ST in everygame(P＜0.05). The crude protein percentage of LD is less significantly (P＜0.05) thanthat of YM and LM. Intramuscular fat of M is more significant (P＜0.05) than that ofLM, and YM. The phosphorus in LD of M is less significant (P＜0.05) than that ofLYM. The phosphorus in ST of YM is more significant (P＜0.05) than that of M and LYM. PH of LD is more different (P＜0.05) among four games. Water HoldingCapacity (WHC) of LD is from 93.54％to 84.34％, and that of M is less significant(P＜0.05) than that of other games. Fiber diameters of LD are increased gradually asxiaomeishan consanguinity increased, and that of LYM is larger significantly (P＜0.05)than that of other games. Meat Color Value (MCV) is from 2.33 to 3.63. The highestone is M, the lowest one LYM. That of M is higher significantly (P＜0.05) than that ofother games. Meat Marbling Score (MMS) are decreased gradually from 4.09 to 2.82as xiaomeishan consanguinity increased. The score of M is higher significantly(P＜0.05) than that of other three games. Through analyzing the genetic correlation ofmeat qualities, we know that the genetic correlation are strong between WHC andPH, between WHC and MCV, and between PH and MCV.