Many advances in genetic selection, nutrition, housing and disease control have been incorporated into modern pork production since the 1950s resulting in highly prolific females and practices and technologies, which ...Many advances in genetic selection, nutrition, housing and disease control have been incorporated into modern pork production since the 1950s resulting in highly prolific females and practices and technologies, which significantly increased efficiency of reproduction in the breeding herd. The objective of this manuscript is to review the literature and current industry practices employed for reproductive management. In particular the authors focus on assisted reproduction technologies and their application for enhanced productivity. Modern maternal line genotypes have lower appetites and exceptional lean growth potential compared to females of 20 yr ago. Thus, nutrient requirements and management techniques and technologies, which affect gilt development and sow longevity, require continuous updating. Failure to detect estrus accurately has the greatest impact on farrowing rate and litter size. Yet, even accurate estrus detection will not compensate for the variability in the interval between onset of estrus and actual time of ovulation. However, administration of GnRH analogs in weaned sows and in gilts after withdrawal of altrenogest do overcome this variability and thereby synchronize ovulation, which makes fixed-time AI practical. Seasonal infertility, mediated by temperature and photoperiod, is a persistent problem. Training workers in the art of stockmanship is of increasing importance as consumers become more interested in humane animal care. Altrenogest, is used to synchronize the estrous cycle of gilts, to prolong gestation for 2-3 d to synchronize farrowing and to postpone post-weaning estrus. P.G. 600~ is used for induction of estrus in pre-pubertal gilts and as a treatment to overcome seasonal anestrous. Sperm cell numbers/dose of semen is significantly less for post cervical AI than for cervical AI. Real-time ultrasonography is used to determine pregnancy during wk 3-5. PGF2a effectively induces farrowing when administered within two d of normal gestation length. Ovulation synchronization, single fix展开更多
The objective of this study was to evaluate the effects of supplemental magnesium （Mg） on the performance of gilts and parity 3 sows and their piglets. Fifty-six grits （Trial 1） and 56 sows （Trial 2） were assign...The objective of this study was to evaluate the effects of supplemental magnesium （Mg） on the performance of gilts and parity 3 sows and their piglets. Fifty-six grits （Trial 1） and 56 sows （Trial 2） were assigned to one of 4 treatments according to their mating weight, respectively. The treatments comprised corn-soybean meal based gestation and lactation diets （0.21% magnesium） supplemented with 0, 0.015, 0.03, or 0.045% Mg from mating until weaning. The results showed that magnesium supplementation significantly （P 〈 0.05） reduced the weaning to estrus interval in both gilts and sows. There were significant effects （P 〈 0.05） of supplemental magnesium on the total number of piglets born, born alive and weaned in sows. In late gestation and lactation, the digestibility of crude fiber （quadratic effects, P 〈 0.05）, and crude protein （P 〈 0.05）, were significantly influenced by magnesium in gilts and sows, respectively. There were differences among the 4 groups in terms of the apparent digestibility of dry matter and crude fiber in sows （P 〈 0.0S） during both early and late gestation. The apparent digestibility of gross energy was increased for sows in late gestation （P 〈 0.05）, and lactation （quadratic effects, P 〈 0.0S）. At farrowing and weaning, serum prolactin levels and alkaline phosphate activities linearly increased in sows as the Mg supplementation increased （P 〈 0.0.5）. Serum Mg of sows at farrowing and serum urea nitrogen of sows at weaning was significantly influenced by Mg supplementation （P 〈 0.05）. The Mg concentration in sow colostrum and the serum of their piglets were increased by supplemental magnesium （P 〈 0.05）. In addition, growth hormone levels were linearly elevated （P 〈 0.05） in the serum of piglets suckling sows. Our data demonstrated that supplemental magnesium has the potential to improve the reproduction performance of sows, and the suitable supplemental dose ranged from 0.015% to 0.03%.展开更多
文摘Many advances in genetic selection, nutrition, housing and disease control have been incorporated into modern pork production since the 1950s resulting in highly prolific females and practices and technologies, which significantly increased efficiency of reproduction in the breeding herd. The objective of this manuscript is to review the literature and current industry practices employed for reproductive management. In particular the authors focus on assisted reproduction technologies and their application for enhanced productivity. Modern maternal line genotypes have lower appetites and exceptional lean growth potential compared to females of 20 yr ago. Thus, nutrient requirements and management techniques and technologies, which affect gilt development and sow longevity, require continuous updating. Failure to detect estrus accurately has the greatest impact on farrowing rate and litter size. Yet, even accurate estrus detection will not compensate for the variability in the interval between onset of estrus and actual time of ovulation. However, administration of GnRH analogs in weaned sows and in gilts after withdrawal of altrenogest do overcome this variability and thereby synchronize ovulation, which makes fixed-time AI practical. Seasonal infertility, mediated by temperature and photoperiod, is a persistent problem. Training workers in the art of stockmanship is of increasing importance as consumers become more interested in humane animal care. Altrenogest, is used to synchronize the estrous cycle of gilts, to prolong gestation for 2-3 d to synchronize farrowing and to postpone post-weaning estrus. P.G. 600~ is used for induction of estrus in pre-pubertal gilts and as a treatment to overcome seasonal anestrous. Sperm cell numbers/dose of semen is significantly less for post cervical AI than for cervical AI. Real-time ultrasonography is used to determine pregnancy during wk 3-5. PGF2a effectively induces farrowing when administered within two d of normal gestation length. Ovulation synchronization, single fix
基金The financial support from the Chinese Universities Scientific Fund(No.15059102, 2014JD017,2012QJ102,2012QJ105)National "Twelfth Five-Year" Science& Technology Pillar Program(No.2011BAD26B02)National Department Public Benefit Research Foundation(201403047)
文摘The objective of this study was to evaluate the effects of supplemental magnesium （Mg） on the performance of gilts and parity 3 sows and their piglets. Fifty-six grits （Trial 1） and 56 sows （Trial 2） were assigned to one of 4 treatments according to their mating weight, respectively. The treatments comprised corn-soybean meal based gestation and lactation diets （0.21% magnesium） supplemented with 0, 0.015, 0.03, or 0.045% Mg from mating until weaning. The results showed that magnesium supplementation significantly （P 〈 0.05） reduced the weaning to estrus interval in both gilts and sows. There were significant effects （P 〈 0.05） of supplemental magnesium on the total number of piglets born, born alive and weaned in sows. In late gestation and lactation, the digestibility of crude fiber （quadratic effects, P 〈 0.05）, and crude protein （P 〈 0.05）, were significantly influenced by magnesium in gilts and sows, respectively. There were differences among the 4 groups in terms of the apparent digestibility of dry matter and crude fiber in sows （P 〈 0.0S） during both early and late gestation. The apparent digestibility of gross energy was increased for sows in late gestation （P 〈 0.05）, and lactation （quadratic effects, P 〈 0.0S）. At farrowing and weaning, serum prolactin levels and alkaline phosphate activities linearly increased in sows as the Mg supplementation increased （P 〈 0.0.5）. Serum Mg of sows at farrowing and serum urea nitrogen of sows at weaning was significantly influenced by Mg supplementation （P 〈 0.05）. The Mg concentration in sow colostrum and the serum of their piglets were increased by supplemental magnesium （P 〈 0.05）. In addition, growth hormone levels were linearly elevated （P 〈 0.05） in the serum of piglets suckling sows. Our data demonstrated that supplemental magnesium has the potential to improve the reproduction performance of sows, and the suitable supplemental dose ranged from 0.015% to 0.03%.
