| Duroc pig as the terminal advantageous in the production of conmmercial pigs, its high lean meat rate and well meat quality paly an important role in the development of moderniazation and scale swine industry, which not only good for our swine industry development, but have a good famous in the swine industry of the whole wold. This study measured the physiological indexes and foraging rules, as well as analysised the reproductive performance of duroc pig of new American strain.The body temperature and the frequency of breathing and pulsatin were measured in different seasons and the highest and lowest temperature. The nomal value was 38.32±0.29℃,9.48±2.28 times/min,67.24±7.03 times/min. The body temperature in the highest and lowest temperature were 38.89±0.25℃ and 37.78±0.23℃. The frequency of breathing in the highest temperature was significantly higher than in the lowest temperature(P<0.05), and the summer was also significantly higher than spring, autumn and winter(P<0.05). The frequency of pulsatin in the lowest temperature was significantly higher than other seasons and the highest temperature, the winter was significantly higher than other three seasons(P<0.05), the summer was also significantly higher than spring and autumn, the spring higher than autumn(P<0.05). All of these indexes showed that the duroc pig of new American strain has a good patience in high temperature but low temperature.The observation results of sexual behavior showed that, Duroc pig boar intromission appear day age, initial injection secretions of day age, the age of sex maturity and the earliest actual mating days of age were 22.97±4.01,162.27±4.97,184.46±5.19,273.53±6.12, respectively. The gilts, estrus duration, the first oestrus time and the earliest actual mating time were 183.13±14.36,3.61±0.72,5.04±1.69,261.65±14.51, respectively. The maternal behavior of the overall performance of Duroc pig sow was well, Aberdeen behavior is more obvious, the more active feeding times.The experimental results of the slaughter showed, slaughter of live weight and carcass weight were 102.29kg and 75.87kg. The slaughter rate reached 74.18%, carcass lean meat rate was 64.95%, eye muscle area 49.78cm2, carcass straight long 95.31cm, backfat thickness 8.41mm, hind ratio 31.81%. Meat color and marbling score is 3.31,2.78 respectively, were within normal grading standard. The rate of water loss, drip loss, intramuscular fat content were 13.52%,1.27%,1.93%. Sows and boars at 70 days of age weight were 29.1 and 26.5kg,100 kg body weight day age were 153 and 164 days, the difference reached significant level, and backfat thickness were 8.28,8.51mm, daily weight gain were 866.2 and 792.1g, the overall average daily gain was 825.3g, the ratio of feed and meat were 2.41:1 and 2.49:1, average feed meat ratio is 2.46:1.60 duroc pigs was choosen to measure the foraging rules by using System for the determination of FIRE automatic pig production performance. The results showed that, in the stage of 30-60kg, the average intake times of all day, the average intake times ratio of day, the average daily intake, average daily gain, feed conversion ratio were 9.4,63.8%, 1.52kg,0.68kg,2.23:1, repectively. The average intake times of all day, the average daily intake and average daily gain were gained with weight increase, but foraging time and single foraging time was down.This study analised the effects of parity and season on reproductive performance of sows of duroc pig by using the litter size data of 581 nests, include the total number born, live litter size, malformation number, stillbirth number, birth litter weight, weaning weight of litter, number of piglets weaned, weaning survival rate. The results showed that, the 2nd and 3rd parity’s live litter size significantly higher than 1st, the stillbirth number of 2nd,4th,5th parity were much higher than 1st, the birth litter weight and number of piglets weaned of 2nd, 4th parity were much higher than 1st, but there was no difference in the total number born, weaning weight of litter, weaning survival rate, malformation number. The seasons had no affects on malformation number and stillbirth number, the total number born of autom and winter was much higher than summer, and the live litter size and birth litter weight also much higher than summer and spring. All of this showed that making arrangements for breeding in autom and winter can inprove the reproductive performance of sows of duroc pig of new American strain. |
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