Lactation is the most energy demanding part of parental care in mammals, so parent-offspring conflict arises over milk provided by the mother. In some species females commonly become pregnant shortly after parturition of previous young. This further intensifies mother-offspring conflict due to concurrent pregnancy and lactation. In equids it has been well established that pregnant females wean their foals earlier than non-pregnant ones. Intensified mother-offspring conflict was presumed to associate with pregnancy also during the period of intensive lactation, i.e., before the weaning process starts. We investigated the effect of pregnancy on suckling behaviour characteristics as indicators of mother-offspring conflict in domestic horses. Contrary to expectation, here we provide evidence of a decreased mother-offspring conflict related to pregnancy in lactating females during first two trimesters of pregnancy. Pregnant mares provided longer suckling bouts and did not reject or terminate suckling of their foals more often than non-pregnant mares. Our results suggest that pregnant mares cope with parallel investment into a nursed foal and a foetus through enhancing nursing behaviour in early stages of pregnancy before the initially low requirements of the foetus increase. They compensate their suckling foal with the perspective of its early weaning due to ongoing pregnancy.

The preorbital gland plays not only an olfactory role in cervids but also a visual one. Opening this gland is an easy way for the calf to communicate with the mother, indicating hunger/satiety, stress, pain, fear, or excitement. This information can be also useful for farm operators to assess how fast the calves habituate to handling routines and to detect those calves that do not habituate and may suffer chronic stress in the future. Thirty-one calves were subjected to 2 consecutive experiments to clarify if observing preorbital gland opening is related to habituation to handling in red deer calves (Cervus elaphus). Calves were born in 3 different paddocks, handled as newborns (Exp. 1), and then subjected to the same routine handling but with different periodicity: every 1, 2, or 3 wk (Exp. 2). In Exp. 1, preorbital gland opening was recorded in newborns during an initial handling (including weighing, ear tagging, and sex determination). Preorbital gland opening occurred in 93% of calves during this procedure and was not affected by sex, time since birth, or birth weight. Experiment 2 consisted of measuring preorbital opening during the same routine handling (weighing, blood sampling, and rump touching to assess body condition) when calves were 1, 3, and 5 mo old. Binary logistic regression showed that gland opening was associated with habituation to handling, since at 1 and 3 mo the probability of opening the gland decreased with the number of handlings that a calf experienced before (P = 0.008 and P = 0.028, respectively). However, there were no further changes in preorbital gland opening rate in the 5-mo-old calves (P = 0.182). The significant influence of the number of previous handlings on the probability of opening the preorbital gland was confirmed through generalized linear model with repeated measures (P = 0.007). Preorbital gland opening decreased along the phases of the study. Nevertheless, we found a significant trend in individuals to keep similar opening patterns (intraclass correlation coefficient = 0.807, P < 0.001), which suggests that the more stressed individuals can be detected with this method. Therefore, we conclude that preorbital gland opening during routine handlings is related to the number of previous handlings, and thus it can be used as an indicator of lack of habituation to handling in farmed cervids. Copyright © 2014. American Society of Animal Science .

Artificial weaning is often highly stressful for both mother and offspring. We investigated the effect of 2 different weaning and relocation schedules on growth rate and saliva cortisol concentrations in a group of loose-housed domestic horses. We predicted higher acute stress (cortisol concentrations), but a lower long-term effect on weight gain, which would indicate lower chronic stress in foals, if the foals were moved to the new environment immediately after separation from the mothers (“prompt relocation” [PR]) compared with relocation that was adjourned for a week (“stepwise relocation” [SWR]). Within 2 seasons, 56 foals weaned at age of 165-250 days were regularly weighed up to 140 days after weaning. Growth rate significantly differed between SWR and PR foals. The PR weanlings revealed relatively stable increase in their weights, whereas SWR foals experienced a significant drop in growth during the first 3 weeks after weaning. The weight differences were still apparent 5 months after weaning (predicted weight, least squares means ± standard error: 374.40 ± 1.75 kg in PR vs. 362.71 ± 1.66 kg in SWR foals). Cortisol concentrations changed significantly between and within different weaning procedures and were highest in PR foals after weaning and relocation. Compared with pre-weaning values, cortisol levels increased in PR but not in SWR foals, either after weaning or deferred moving. We found large individual variability in foals' growth and in cortisol concentrations for both weaning procedures. There was also a year effect in SWR foals. Stepwise changes of the physical and social environment (deferred removal to the remote facility) within a short period after abrupt weaning resulted in lower acute stress but induced long-term negative effects on foals' growth rate compared with joint weaning and relocation. Our results support rather prompt moving of the weanlings to the new facility, rather than to a stepwise location on horse breeding farms