Although sheep are known to be seasonal breeders and give birth in winter, not all of them follow this trend. A few breeds can be mated and give birth all year round, meaning that mothers and neonates will have to face contrasting climatic conditions. The aim of this study was to test whether lambing season affects maternal and neonatal behaviors in D’man sheep. During four different lambing seasons (winter, autumn, summer and spring), periparturient ewes (n = 111) and their lambs (n = 213) were kept under 24-h-video surveillance in order to record postpartum behaviors. Mother-young preference was tested around 48 h after parturition. Lamb vigor was studied by the determination of birth weight, early postnatal behavior and rectal temperature at birth and 48 h later. Litter expulsion time was not affected by lambing season, but birth weight was biased against summer and winter born lambs. Ewes provided a higher intensity of care to their offspring in winter: latency for grooming was shorter and time spent grooming was longer compared to lambing in spring and summer (P = 0.01 in all cases). On the other hand, lambs were the most active in spring as they were faster to extend their hind legs (P = 0.01), stand up (P = 0.04) and reach the udder (P = 0.04). Rectal temperature at 48 h was affected by season of birth (P < 0.001) with higher values observed in summer. Glycemia variation between birth and 48 h was the lowest in spring born lambs and plasma levels increased less in spring born lambs than in winter (P < 0.0001), autumn (P < 0.0001) and summer born lambs (P < 0.0001). In the choice test, mothers clearly preferred their own young and no season effect was detected except that in the first minute of the test they spent less time near their own young in winter than in the other seasons (P = 0.04). Lambs also chose their mother successfully without any major effect of the season however, but winter born lambs were the least vocal (P = 0.01). Overall, this study show that maternal care, lamb behavior and vigor vary lightly according to seasons, albeit not in a consistent manner. In conclusion, a season is no more detrimental than another for the onset of mother-young relationships.

尽管众所周知绵羊是季节性繁殖者，并在冬天出生，但并非所有人都遵循这种趋势。一些品种可以全年交配，这意味着母亲和新生儿将不得不面对相反的气候条件。这项研究的目的是检验产羔季节是否会影响德曼羊的母体和新生儿行为。在四个不同的产羔季节（冬季，秋季，夏季和春季），将围产期母羊（n = 111）及其羔羊（n = 213）置于24小时录像监控之下，以记录产后行为。产后48小时左右对母亲的偏好进行了测试。通过测定出生体重，出生后早期行为和出生后以及48小时后的直肠温度来研究羔羊活力。产仔时间不受产羔季节的影响，但出生体重与夏，冬季出生的羔羊有偏差。母羊在冬季为其后代提供了更高的照护强度：与春季和夏季的羔羊相比，修饰的等待时间更短，修饰的时间更长（在所有情况下，P = 0.01）。另一方面，羔羊在春季最活跃，因为它们更快地伸展后腿（P = 0.01），站起来（P = 0.04）并到达乳房（P= 0.04）。48 h的直肠温度受出生季节的影响（P <0.001），夏季的温度更高。出生至48小时之间的血糖血症变化在春季出生的羔羊中最低，春季出生的羔羊的血浆水平升高低于冬季（P <0.0001），秋季（P <0.0001）和夏季出生的羔羊（P <0.0001）。在选择测试中，母亲显然更喜欢自己的年幼孩子，没有发现季节影响，只是在测试的第一分钟，冬天他们在靠近自己的年幼孩子的时间比其他季节少（P = 0.04）。羔羊也成功地选择了自己的母亲，但对季节没有任何重大影响，但是冬季出生的羔羊的声音最小（P= 0.01）。总体而言，这项研究表明，产妇的护理，羔羊行为和体力随季节而略有不同，尽管不一致。总而言之，一个季节对母婴关系的发作没有比另一个季节更有害。