This breeding procedure also accumulated 21 non-productive days (NPD), and resulted in a 9% chance that sows would not stand to be bred on the second estrus.
The data on the changing reproductive characteristics of contemporary commercial sows suggests that the response to skip-a-heat breeding in first-parity sows needs to be reevaluated. All sows were fed a standard lactation diet “to appetite” for the 21-day lactation. (在台灣夏季，因各場設備不同，這個數字變異很大且與加拿大的氣候比較，差別會很大)．
Of all sows weaned, 95% returned to estrus within 10 days. All PE2 sows exhibited a second postweaning estrus at an average of 22 days after their first postweaning estrus (range 19.1 to 28.4 days). All PE1 sows and 96% of PE2 sows were bred. There were no differences between PE1 and PE2 sows for pregnancy rates, which exceeded 90%.配種率差4%，表示PE2組的NPD(吊車)增加或淘汰率增加.....
Current expectations are that one additional pig born/litter will cover the additional cost of 21 NPDs ($2/day × 21 days = $42). If the use of this management practice increases the number of pigs born by more than one, a positive cost:benefit ratio would be anticipated.在台灣，母豬每多養一天的成本是NT$............................
此篇文獻介紹包含了二篇文獻中許多母豬繁殖管理上很重要的觀念，且在台灣更嚴苛的條件下，不失為一個好的解決方向，套用時建請注意上述藍字部份..............
First postweaning estrus skipped and bred on second postweaning estrus (PE2).
離乳後第二次發情才配種 (PE2)
Breeding Parity 1 sows at their second postweaning estrus has been shown to increase the number of live embryos detected at Day 30 of gestation. This increase in embryo viability may negate the effects of the second-parity dip in reproductive performance
利用跳過第一胎母豬離乳後的第一次發情 於第二次發情時才給于配種 然後于懷孕第30天偵測其胚胎存活數 顯示胚胎存活數有增加的情形 也許可以抵銷第二胎次繁殖效益低下的效應
Recent work at the University of Alberta has shown excellent reproductive performance of contemporary dam-line, first-parity sows. Even when these sows lose large amounts of body tissues through imposed feed restriction during peak lactation, there is a relative lack of effect on many measures of postweaning fertility. Still, a second-parity “dip” - or lack of an increase - in the size of the second litter is often observed.
University of Alberta 先前的研究顯示 即使有優秀繁殖表現的第一胎次母豬群 因為泌乳期採食量限制的關係而耗損期體況(大量體組織) 造成第二胎次繁殖相關效益低下的效應
In earlier studies, first- and second- parity sows subjected to “skip-a-heat” breeding (bred at the second estrus after weaning) averaged two pigs/litter more than sows bred at first post-weaning estrus. However, this breeding procedure also accumulated 21 non-productive days (NPD), and resulted in a 9% chance that sows would not stand to be bred on the second estrus.
此試驗則重新比較分析PE1 PE2 組的 (follicular development), (size of the largest ovulatory follicle0, (ovulation rate )and (embryonic survival to Day 30 of gestation).
Of all sows weaned, 95% returned to estrus within 10 days. All PE2 sows exhibited a second postweaning estrus at an average of 22 days after their first postweaning estrus (range 19.1 to 28.4 days). All PE1 sows and 96% of PE2 sows were bred. There were no differences between PE1 and PE2 sows for pregnancy rates, which exceeded 90%.
PE1組全數配種
PE2組則只有96%於第二次發情時配種
但兩組的懷孕率卻沒有差異性 都超過90%
其他結果請參閱以下網址圖表
(貼上後便亂了 請自行參閱)
Table 1. Weight at First Postweaning Estrus and Breeding, and Weight Change from Weaning to Breeding for PE1 and PE2 Sows
PE1*PE2*Number2725Weight at PE1, lb.375.3376.0Breed weight, lb.375.3422.6Weight change (wean-breed), lb.-15.826.2*PE1=sows bred at first postweaning estrus; PE2=sows “skipped” and bred on second postweaning estrus.
Table 2. Largest Detected Pre-Ovulatory Follicle size (mm) in PE1 and PE2 Sows
PE1PE2Number27251st postweaning estrus (PE1)7.27.1Range4.7 - 9.14.9 - 9.12nd postweaning estrus (PE2)-8.2Range-4.8 - 9.9
Table 3. Effect of Breeding at First (PE1) or Second (PE2) Postweaning Estrus on Reproductive Performance
PE1PE2Number2522Ovulation rate19.019.6Number of live embryos12.915.2Embryo survival to Day 30, %68.177.4
IP卡
狗仔卡
發表於 2008-1-1 14:51:23
提升卡
置頂卡
沉默卡
喧囂卡
變色卡
搶沙發
千斤頂
顯身卡
...自己的{如題一下}.....
[信息未更新]
發表於 2008-1-1 23:05:58
樓主
