ABSTRACT The objective of this study was to evaluate the effects of stereotypic behavior on productivity measures in sows. Frequent expression of stereotypies by pigs has been reported, even when pigs are not maintained in crates. This behavior is only observed in animals kept in captivity and is a wide-range welfare indicator, since it is considered to develop in situations of chronic stress or frustration. When comparing groups of sows showing low or high frequency of stereotypy expression, we found that stereotypic behavior did not affect productivity. Moreover, it did not affect physiological welfare indicators, such as salivary cortisol concentration or glucocorticoids in the placenta. There were no differences in productivity parameters, including weight of sows, weight of piglets, number of piglets weaned, or piglet mortality. Our study was conducted in group-housing pens, where the sows were not confined. Even in this condition, which is considered for increasing welfare, the barren environment did not meet the behavioral and sensory needs of sows, which were naturally selected to perform complex behavioral repertoire and to spend part of their time engaging in exploratory behavior.

ABSTRACT This study focused on stress physiology by characterizing cortisol responses to stressors in tail biters (n = 10), victims (n = 10), and control pigs (n = 10) of two different breeds (Landrace × Yorkshire, LY; Landrace/Yorkshire × Landrace/Duroc; LYLD) and sexes (females and castrated males). We exposed pigs to 10 min of isolation with a human at the farm and transported them to a controlled environment. There, the behaviour was registered for 10 min during sessions when subjected to a novel object test and to a novel arena test. Sampling times of salivary cortisol were in all the fear tests before testing and 60 min thereafter, while for transportation as well 120 min after the beginning of transportation. We additionally measured cortisol at 7:00 and 16:00 h during three days following transportation. The basal stress axis activity followed a distinct diurnal rhythm between sexes and breeds, with castrated males having higher cortisol level than females and LY pigs higher than LYLD pigs. Following isolation at the farm and transportation, the concentration of salivary cortisol was higher in LY than in LYLD pigs. Pigs considered the exposure to a novel arena, but not to a novel object, stressful by showing a cortisol level after testing higher than before testing. The results suggest a genotypic effect on sensitivity to stress in pigs that have performed tail biting, have been victimized, or have not been involved in tail biting.

ABSTRACT In the present study, we investigated behavioural responses and determined parameters of heart rate variability (HRV) to elucidate a relative activation of autonomic nervous system (ANS) during baseline (10 min) and in response to potentially stressful situations (10 min) in two pig breeds and sexes. Gilts (n = 21) and barrows (n = 9) of the Landrace × Yorkshire (LY; n = 15) and Landrace/Yorkshire × Landrace/Duroc (LYLD; n = 15) breeds were subjected to a novel object test (NOT) and a novel arena test (NAT). Basal ANS state differed in pigs across breeds but not sexes. Landrace × Yorkshire pigs had a significantly lower basal heart rate (HR) and low-frequency band (LF) with a higher root mean square of successive interbeat intervals (RMSSD) and high-frequency band (HF) than LYLD pigs. In the NOT, despite having similar cardiac responses, gilts had a longer duration of contact with a novel object, higher lying and standing duration, and a lower duration of walking compared with barrows. In the NAT, we found similar behaviour across sexes but a different degree of ANS state, with barrows having a significantly higher increase in LF/HF (power of the low frequency component divided by the power of the high-frequency band) compared with gilts. Landrace/Yorkshire × Landrace/Duroc pigs showed longer duration of contact with a novel object in the NOT accompanied by less lying and standing than LY pigs in both tests. No difference in ANS activation between breeds was found in the NOT. In the NAT, HR increased more from baseline to testing in LY pigs than in LYLD pigs. There is a complex and often contradictory nature of relationships between behaviour and cardiac responses to novelty in pigs of different breeds and sexes.

Este trabalho foi realizado com o objetivo de estudar o comportamento de suínos submetidos a diferentes sistemas de pastejo (contínuo, alternado e rotativo) em pastagem de trevo-branco (Trifolium repens L.) com livre acesso à ração. Foram utilizados 36 suínos machos, castrados, em fase de terminação, com peso médio de 80 kg. As atividades comportamentais (ingerir ração, pastejar, beber água, ficar em pé, deitar, sentar, caminhar, urinar, defecar, brincar, coçar, fuçar e cavar o solo) foram registradas por meio de observações visuais durante três dias consecutivos, das 7 às 18h. As observações foram feitas a cada 10 minutos, registrando-se o número de animais e suas respectivas atividades em cada sistema de pastejo. O delineamento experimental foi de blocos ao acaso, com três tratamentos e três repetições. Deitar, beber água, ingerir ração, pastejar e caminhar foram as atividades mais freqüentes, independentemente dos sistemas de pastejo estudados. Suínos criados em pastejo alternado ingeriram ração com maior freqüência que os criados em pastejo contínuo e rotativo. No primeiro dia de observação, suínos em pastejo contínuo e rotativo apresentaram maior freqüência de pastejo que aqueles em pastejo alternado. Suínos em pastejo contínuo e rotativo apresentaram atividades comportamentais semelhantes. O comportamento de suínos em fase de terminação foi influenciado pelo sistema de pastejo.

This work aimed to study the behaviour of pigs submitted to different grazing systems (continuous, alternated or rotational) in white-clover (Trifolium repens L.) pasture and fed ad libitum. Thirty-six finishing pigs, castrated males, averaging 80 kg were used. The behaviour activities (feeding, grazing, drinking, standing, laying, sitting, walking, urinating, defecating, playing, itching, rooting, and digging) were recorded by visual observations during three consecutive days, from 7:00 a.m. to 6:00 p.m. The experiment was analyzed as a complete randomized blocks, with three treatments and three replicates. The observations were made every 10 minutes and the number of animals and the respective activities on each grazing system were recorded. Lying, drinking, feed intake, grazing and walking were the activities that showed higher frequencies, regardless of the grazing system. Pigs on alternated grazing system showed higher frequency feed intake activity than pigs on continuous or rotational grazing systems. During the first day of observation, pigs on continuous or rotational grazing systems showed higher frequency grazing activity than pigs on alternated system. The pigs on continuous and rotational grazing systems showed similar behaviour activities. The behaviour of growing pigs was affected by the grazing system.