Tsuma V T, Einarsson S, Madej A, Kindahl H, Lundeheim N, Rojkittikhun T
Department of Obstetrics and Gynaecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Acta Vet Scand. 1996;37(4):481-9. doi: 10.1186/BF03548088.
The effect of group housing sows during early pregnancy on maternal endocrine changes and on embryonic survival was studied. Twenty crossbred (Swedish Yorkshire x Swedish Landrace) primiparous sows were used. On day 11 +/- 1 of pregnancy 3 unacquainted sows were randomly assigned to a single pen measuring 3 m x 3 m in area. A fourth sow in each group was housed in an individual pen and used as a control. This procedure was repeated 5 times to collect data from 5 animals in each rank as well as in a control group. Blood samples were collected from the day before grouping to day 5 after grouping for cortisol, corticosteroid-binding globulin (CBG), progesterone (P4), oestradiol-17 beta (E2) and prostaglandin F2 alpha metabolite (PG-metabolite) analysis. A rank-order test and an ACTH test were performed on day 4 and day 5 of grouping respectively. The sows were slaughtered on day 17 +/- 1 of pregnancy and embryos recovered. Aggression accompanied by elevations (p < 0.05) in cortisol concentrations occurred in all grouped sows on the first day of grouping. The cortisol increase was greater (p < 0.01) in the subordinate than in the other ranked sows. Cortisol concentrations and the level of aggression decreased on subsequent days during grouping, but the cortisol levels were still higher than on the pre-grouping day except for the intermediate ranked sows. Cortisol concentrations after the ACTH test were similar in the grouped as well as the control sows. The dominance hierarchy was confirmed during the rank order test. Concentrations of P4, E2, PG-metabolite and CBG were similar between the group-housed sows and with the controls. Mean embryonic recovery was 66.8% +/- 11.5%, 71.3% +/- 6.0%, 70.0% +/- 16.0%, and 69.9% +/- 5.8% for the dominant, intermediate, subordinate, and control sows respectively. Hence, group housing during early pregnancy did not influence reproductive hormones or embryonic survival.
研究了妊娠早期群饲母猪对母体内分泌变化及胚胎存活的影响。选用20头杂交（瑞典约克夏×瑞典长白）初产母猪。在妊娠第11±1天，将3头互不相识的母猪随机分配到一个面积为3米×3米的单栏中。每组的第四头母猪饲养在个体栏中作为对照。此过程重复5次，以收集每个等级以及对照组中5头动物的数据。从分组前一天到分组后第5天采集血样，用于分析皮质醇、皮质类固醇结合球蛋白（CBG）、孕酮（P4）、雌二醇-17β（E2）和前列腺素F2α代谢物（PG-代谢物）。分别在分组第4天和第5天进行等级排序试验和促肾上腺皮质激素（ACTH）试验。母猪在妊娠第17±1天屠宰并回收胚胎。分组第一天，所有群饲母猪均出现攻击行为，同时皮质醇浓度升高（p<0.05）。从属母猪的皮质醇升高幅度更大（p<0.01），高于其他等级的母猪。分组期间随后几天，皮质醇浓度和攻击水平下降，但除中间等级的母猪外，皮质醇水平仍高于分组前一天。ACTH试验后，群饲母猪和对照母猪的皮质醇浓度相似。等级排序试验确定了优势等级。群饲母猪与对照母猪之间的P4、E2、PG-代谢物和CBG浓度相似。优势、中间、从属和对照母猪的平均胚胎回收率分别为66.8%±11.5%、7
