豬群生產力為豬場經營成功之關鍵，傳統重要的指標為母豬生產力(sow productivity)，以每年每頭母豬離乳仔豬數(pigs weaned per sow per year, PWSY)表示之。母豬生產力是一種组合性狀，受到諸多遺傳與環境因子的影響，在種母豬终生繁殖過程中，各影響因子環環相扣，相當複雜，為提昇豬群生產力，有必要先了解這些影響的因子，才能運用有效的育種及管理策略，達到改善豬群繁殖效率的目的。相當多的報告指出繁殖屬於低遺傳率性狀，較難以傳統的選拔方法獲致改善；不同的品種由於組成基因頻率不同，性能也有所差異。比如說梅山(Meishan, Ms)女豬的高生產力主要在於發身年齡較早、發情期長、排卵數多、子宮延展性大及胎畜所需子宮空間小。初產母豬的繁殖性能是改善豬場生產力的重要關鍵，其低繁殖力表現於較低的分娩率、較高的重複配種率、較少的每胎產仔數、較長的未生產日數及較輕的離乳時窩仔豬重。泌乳期長度是由生產者直接控管的因子，依其所需而有不同的管理策略，生產者必須平衡泌乳期長短，因為泌乳期延長會導致每年每頭母豬離乳仔豬數下降，及較短泌乳期會導致每胎產仔數下降之經濟損失。管理技術的應用能使母豬於離乳後4至6天內發情，對於高環境溫度的影響，生產者可經由改善畜舍設備與提高餵飼量以增加母豬採食之意願，並應避免生產過程所造成之緊迫。本文針對影響母豬生產力的因子加以探討，生產者應找出其關鍵的管理因子，才能有效的改進豬群生產力。
Pig productivity is the key to a successful pig production system. It is heavily dependent upon the level of sow productivity-the number of pigs weaned per sow per year (PWSY). In the lifetime of a sow reproductive process, many genetic and environmental factors affecting sow productivity. An understanding of factors that influence litter performance is required to improve reproductive efficiency for a pig herd. A number of studies have reported that low heritability of reproductive traits, in which difficult to improve using classical selection methods. Breeds have shown different effects on reproductive performance. For example, the high productivity of Meishan gilts is due to the facts that earlier puberty age, longer estrous length, more eggs ovulated, longer uterine length, and smaller space required for embryos than those of European and American breeds. The reproductive performance of primiparous sows is important to improve pig productivity, because the low reproduction for such sows has shown in lower farrowing rate, higher remating rate, smaller litter size, longer nonproductive days, and lighter litter weight than those of multiparous sows. Lactation length is controlled directly by producers. Thus, producers have to balance the economic loss of the smaller number of pigs weaned per sow per year from longer lactation length and the smaller litter size from shorter lactation length. Most of the sows can be mated within four to six days after weaned by improving management techniques. In addition, improving the structure of the building and management factors can increase the feed intake of high environmental temperature on lactation sows. This study investigated genetic and environmental factors that influence the productivity of sows. Producers need to find out key factors that affect reproductive performance in order to improve their sow productivity.
