Chalkias H, Ekman E, Lundeheim N, Rydhmer L, Jacobson M
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, SE-750 07 Uppsala, Sweden
Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, SE-750 07 Uppsala, Sweden.
J Anim Sci. 2014 Jun;92(6):2587-94. doi: 10.2527/jas.2013-7387. Epub 2014 Mar 26.
In the modern pig industry, the increasing number of piglets born per litter augments the importance of the number of functional teats in the sow. The aim of this study was to evaluate the function and importance of inverted teats during nursing and to analyze structural and functional differences between the mammary glands of inverted teats versus normal teats. Nine farrowing gilts (8 purebred Swedish Yorkshire gilts and 1 cross between Swedish Yorkshire and Norwegian Landrace) and 94 piglets (59 piglets suckling normal teats, 32 piglets suckling protruded teats [i.e., previously inverted], 2 piglets suckling inverted teats, and 3 piglets suckling considerably smaller teats) were included in the study. Teat fidelity (keeping the same teat between the nursings) was registered, excluding the first 48 h postpartum. Piglet weight was recorded daily during the first week of life and thereafter once a week until weaning at 4 wk of age. Weight and growth rate were analyzed using repeated observation mixed-model analysis of variance. The 2 piglets that suckled the inverted teats were not able to emerge the teats and they were euthanized 4 and 8 d after birth, respectively, due to loss of BW. The average weight at weaning (28 d of age) was 8.1 kg (range 3.2-13.8 kg). In the normal teats (n = 53), the weight of the corresponding mammary gland tissue at necropsy was positively correlated to the piglet average daily weight gain during wk 2 (r = 0.33, P < 0.05), 3 (r = 0.55, P < 0.001), and 4 (r = 0.47, P < 0.001). In the protruded teats (n = 32), the weight of the corresponding mammary gland tissue was positively correlated to the piglet average daily weight gain during wk 2 (r = 0.63, P < 0.001) and 3 (r = 0.43, P < 0.05). Among the piglets nursing normal teats, 82% kept fidelity to its teat and the corresponding percent for the protruded teats was 26%. In 7 of the 9 sows, the weaning weight of the piglets suckling protruded teats was numerically lower compared to the piglets suckling normal teats, although the difference was not statistically significant. Piglets nursing small teats had lower weaning weight (4.8 kg) and the corresponding mammary tissue also had lower weight (335 g). This study indicates the importance of an adequate number of well-developed and well-functioning teats in healthy sows for the growth and development of the piglets but also emphasizes the complexity of the interaction between the nursing sow and her piglets.
在现代养猪业中，每窝出生仔猪数量的增加提升了母猪功能性乳头数量的重要性。本研究的目的是评估哺乳期间内翻乳头的功能及重要性，并分析内翻乳头与正常乳头的乳腺在结构和功能上的差异。本研究纳入了9头分娩小母猪（8头纯种瑞典约克夏小母猪和1头瑞典约克夏与挪威长白猪的杂交母猪）和94头仔猪（59头 suckling normal teats、32头 suckling protruded teats [即之前内翻的乳头]、2头 suckling inverted teats以及3头 suckling considerably smaller teats）。记录了乳头忠诚度（哺乳期间保持使用同一个乳头），产后前48小时除外。在仔猪出生后的第一周每天记录其体重，此后每周记录一次，直至4周龄断奶。使用重复观测混合模型方差分析对体重和生长速率进行分析。那2头 suckling inverted teats的仔猪无法含住乳头，分别在出生后4天和8天因体重下降而实施安乐死。断奶时（28日龄）的平均体重为8.1千克（范围为3.2至13.8千克））。在正常乳头组（n = 53）中，尸检时相应乳腺组织的重量与仔猪在第2周（r = 0.33，P < 0.05）、第3周（r = 0.55，P < 0.001）和第4周（r = 0.47，P < 0.001）的平均日增重呈正相关。在 protruded teats组（n = 32）中，相应乳腺组织的重量与仔猪在第2周（r = 0.63，P < 0.001）和第3周（r = 0.43，P < 0.05）的平均日增重呈正相关。在 suckling normal teats的仔猪中，82%保持对其乳头的忠诚度，而protruded teats组的相应百分比为26%。在9头母猪中的7头，suckling protruded teats的仔猪断奶体重在数值上低于suckling normal teats的仔猪，尽管差异无统计学意义。 suckling small teats的仔猪断奶体重较低（4.8千克），相应的乳腺组织重量也较低（335克）。本研究表明，健康母猪拥有足够数量发育良好且功能正常的乳头对仔猪的生长发育至关重要，但同时也强调了哺乳母猪与仔猪之间相互作用的复杂性。 （注：文中部分英文表述未准确翻译，推测可能是因为原文有拼写错误或不规范表述，如“suckling normal teats”等，若能明确准确英文表述，可进一步完善译文。）
