K. Chitakasempornkul，M. B. Menegat，G. J. M. Rosa，F(xiàn). B. Lopes，A. Jager，M. A. D. Gon?alves，S. S. Dritz，M. D. Tokach，R. D. Goodband，and N. M. Bello

翻譯：劉素利 

養(yǎng)豬生產(chǎn)系統(tǒng)的有效管理需要了解復(fù)雜的生殖生理機(jī)制。本研究的目的是探討高生產(chǎn)力后備母豬和母豬繁殖特性之間潛在的生物學(xué)因果關(guān)系。數(shù)據(jù)來(lái)源于一個(gè)商業(yè)養(yǎng)豬場(chǎng)的一項(xiàng)由200頭母豬和440頭后備母豬組成的營(yíng)養(yǎng)實(shí)驗(yàn)，在妊娠后期按照豬只體重隨機(jī)分配到各日糧處理組中。繁殖性能包括妊娠后期體增重、產(chǎn)仔數(shù)（TB）和產(chǎn)活仔數(shù)（BA）、平均活仔初生重（BABW）、斷奶到發(fā)情間隔以及總產(chǎn)仔數(shù)。將結(jié)構(gòu)方程模型與歸納因果方法相結(jié)合，同時(shí)采用分層貝葉斯框架，去搜索、評(píng)估和推斷每一胎次豬只繁殖性能的因果聯(lián)系。

結(jié)果表明，在后備母豬和母豬的繁殖性能之間存在著潛在的不同的脈絡(luò)聯(lián)系。母豬的繁殖特征之間的聯(lián)系很稀疏，而后備母豬的脈絡(luò)卻是緊密相連的，這表明在年輕雌性機(jī)體上生理機(jī)制是緊密關(guān)聯(lián)的，作為對(duì)早期實(shí)施有針對(duì)性的管理干預(yù)措施的回應(yīng)，在整個(gè)生產(chǎn)周期中存在著潛在的連鎖效應(yīng)。交叉驗(yàn)證分析表明，無(wú)論是對(duì)于一般結(jié)構(gòu)還是對(duì)于各自鏈接，都存在著實(shí)質(zhì)的脈絡(luò)穩(wěn)定，盡管在本研究中關(guān)于這些聯(lián)系的方向性問(wèn)題的結(jié)果并不穩(wěn)定，需要進(jìn)一步研究。對(duì)后備母豬和母豬的相對(duì)統(tǒng)計(jì)能力評(píng)估表明，觀察到的脈絡(luò)差異可以在生物學(xué)基礎(chǔ)得到部分解釋。

綜上所述，我們的研究結(jié)果表明，后備母豬和母豬的生殖生理機(jī)制存在明顯的脈絡(luò)聯(lián)系，這與各組間母豬的生理差異相一致。這些發(fā)現(xiàn)對(duì)后備母豬和母豬的綜合認(rèn)識(shí)和差異管理具有潛在的實(shí)際意義，可以提高豬生產(chǎn)系統(tǒng)的效率。

Efficient management of swine production systems requires understanding of complex reproductive physiological mechanisms. Our objective in this study was to investigate potential causal biological relationships between reproductive performance traits in high-producing gilts and sows. Data originated from a nutrition experiment and consisted of 200 sows and 440 gilts arranged in body weight blocks and randomly assigned to dietary treatments during late gestation at a commercial swine farm. Reproductive performance traits consisted of weight gain during late gestation, total number born (TB) and number born alive (BA) in a litter, born alive average birth weight (BABW), wean-to-estrous interval, and total litter size born in the subsequent farrowing. Structural equation models combined with the inductive causation algorithm, both adapted to a hierarchical Bayesian framework, were employed to search for, estimate and infer upon causal links between the traits within each parity group. Results indicated potentially distinct reproductive networks for gilts and for sows. Sows showed sparse connectivity between reproductive traits whereas the network learned for gilts was densely interconnected, suggesting closely linked physiological mechanisms in younger females, with a potential for ripple effects throughout their productive lifecycle in response to early implementation of tailored managerial interventions. Crossvalidation analyses indicated substantial network stability both for the general structure and for individual links, though results about directionality of such links were unstable in this study and will need further investigation. An assessment of relative statistical power in sows and gilts indicated that the observed network discrepancies may be partially explained on a biological basis. In summary, our results suggest distinctly heterogeneous mechanistic networks of reproductive physiology for gilts and sows, consistent with physiological differences between the groups. These findings have potential practical implications for integrated understanding and differential management of gilts and sows to enhance efficiency of swine production systems.