RESPOSTAS COMPORTAMENTAIS E FISIOLÓGICAS RELACIONADAS AO BEM-ESTAR EM LEITÕES NA FASE DE CRECHE

Abstract

World pig farms have undergone intense technological innovations in the last decades, mainly aimed at increasing productivity and reducing production costs. Animal welfare is often deprived in favor of high productivity, especially in the nursery phase, which is considered the most critical stage of swine farming. Several ways to minimize stress in piglets have been studied, but more studies are needed in this area. In this way, this work aimed to evaluate the influence of possible strategies to minimize stress in piglets in the nursery phase, being: the supply of environmental enrichment and supplementation with a herbal medicine to evaluate behavioral and physiological parameters related to the well-being of piglets in the nursery phase. We used 300 male and castrated piglets, weaned at 21 days. The treatments used were: T1 - Control, T2 - environmental enrichment and T3 - M. officinalis. In the treatment with environmental enrichment (T2), toys made with PET bottles, chains and tires were distributed. In T3, 1% of dry extract of M. officinalis was added to the feed. The weighing of the piglets happened on days 0; 7; 14; 21 and 35 and the blood collections were performed on days 0; 7; 21 and 35 of the experiment. Locomotor behaviors and ingestion, agonistic relations, interaction with the proposed object as environmental enrichment, interaction with the colleague, interaction with the environment, and stereotypies were evaluated. T2 interfered positively on play behavior, with a 69.8% incidence in relation to T1 (14.7%) and T3 (15.5%). Also, on suction addiction behavior, which obtained 14.1% of the frequency when compared to T1 and T3, which obtained 45.4% and 40.5% of frequency, respectively (P <0.05). There was a moderate negative correlation between play and mating behavior (P <0.001). The tail manipulation behavior had a higher incidence in T1 (50.99%), and lower intensity in T2 (21%) and T3 (28.1%), (P <0.05). There was a moderate negative correlation between exploratory and quarrelsome behavior (P <0.05). And a negative correlation between exploratory behavior and suctioning addiction (P <0.001). In the TBARS test, only on day 7 occurred a difference between the groups treated with environmental enrichment and M. officinalis and also between the control and M. officinalis groups (P> 0.05), where the treated piglets with M. officinalis, presented a lower amount of TBARS, thus demonstrating the efficiency of phytotherapeutic treatment against lipid peroxidation. As for catalase activity, both T1 and T2 showed no significant difference on days 21 and 35 (P <0.05). In addition, there was no significant difference between the three treatments in the evaluation of cortisol, demonstrating that the treatments did not cause stress to the animals. In the evaluation of Vitamin C, the T3 provided greater efficiency, when compared to the other treatments. Exposure to environmental enrichment has potentiated the occurrence of healthy behaviors related to well-being in piglets, such as play and exploratory behavior, as well as reducing behaviors associated with stress, such as sucking addiction and tail handling. The supplementation with M. officinalis improved the biochemical parameters of the animals, since this group had lower levels of TBARS in the 7th day of treatment, higher levels of vitamin C in the 21st and 35th days of treatment and less activity of the Catalase enzyme since the 7th day of treatment until the 35th day. Thus, the strategies used here should be considered as ways of improving animal welfare in the production of piglets in the nursery phase.