Park Hyeon-Suk, Oh Sang-Hyon
Department of Animal Sciences, College of Agriculture and Environmental Sciences, North Carolina Agricultural and Technical State University, Greensboro, NC 27410, USA.
Asian-Australas J Anim Sci. 2017 May;30(5):749-754. doi: 10.5713/ajas.16.0587. Epub 2016 Nov 17.
The objective of the present study was to investigate the effects of farrowing month (FM), parity and sex on the growth performance of Berkshire swine raised in alternative production systems.
A total of 40 farrowing records from 27 sows and 1,258 body weight (BW) records from 274 piglets collected over a two-year period were used for the analysis. The BWs were recorded at birth, weaning (28 d), 56, 84, 112, and 140 days. Any BW not recorded on schedule was recalculated to conform the days of age among corresponding BW records, using growth curves drawn with polynomial functions whose power was determined by the number of existing observations for each individual.
The mean parity (±standard deviation) of the sows was 3.42±2.14. The sows that farrowed in June had the lowest number of total born with an average of 6.25±2.22 piglets per sow. However, the lowest average number of piglets weaned at day 28 was found in sows that farrowed in May, as well as the highest number recorded for the stillborn piglets with an average of 2.67 piglets per sow. Moreover, the smallest increase in weight from birth to weaning occurred in piglets that were farrowed in May, which also corresponds with the average daily gain (ADG) of 0.29 kg and the last recorded weight measurement on day 140 of 41.69±1.45 kg. Contrastingly, the highest growth rate was found among pigs farrowed in June, with the largest increase in weight of 7.55 kg from birth to weaning, the highest ADG of 0.51 kg from birth to 140 day of age and the highest BW of 74.70±1.86 kg recorded on day 140.
Pigs farrowed in June also had the least number of piglets that died between birth and weaning. The zone of thermal comfort found in sows reared in indoor confinement systems did not improve the reproductive performance of the sows reared in an outdoor, alternative production system, while the growth performance of the piglets was improved when the ambient temperature was consistently hot or consistently cold.
本研究的目的是调查产仔月份（FM）、胎次和性别对采用替代生产系统饲养的伯克夏猪生长性能的影响。
分析了在两年期间收集的来自27头母猪的40条产仔记录和来自274头仔猪的1258条体重（BW）记录。在出生、断奶（28日龄）、56、84、112和140日龄时记录体重。对于未按计划记录的任何体重，使用由多项式函数绘制的生长曲线进行重新计算，以使相应体重记录之间的日龄一致，多项式函数的幂由每个个体的现有观测值数量确定。
母猪的平均胎次（±标准差）为3.42±2.14。6月份产仔的母猪总产仔数最低，平均每头母猪产仔6.25±2.22头。然而，5月份产仔的母猪在28日龄时断奶仔猪的平均数量最低，死胎仔猪的记录数量也最高，平均每头母猪2.67头。此外，5月份产仔的仔猪从出生到断奶体重增加最小，这也与平均日增重（ADG）0.29千克以及140日龄时最后记录的体重测量值41.69±1.45千克相对应。相比之下，6月份产仔的猪生长速度最高，从出生到断奶体重增加最大，为7.55千克，从出生到140日龄的最高ADG为0.51千克，140日龄时记录的最高体重为74.70±1.86千克。
6月份产仔的猪在出生至断奶期间死亡的仔猪数量也最少。在室内圈养系统中饲养的母猪所发现的热舒适区并未改善在室外替代生产系统中饲养的母猪的繁殖性能，而当环境温度持续炎热或持续寒冷时，仔猪的生长性能得到了改善。
