An enriched maternal environment and stereotypies of sows differentially affect the neuro-epigenome of brain regions related to emotionality in their piglets

Epigenetic mechanisms are important modulators of neurodevelopmental outcomes in the offspring of animals challenged during pregnancy. Pregnant sows living in a confined environment are challenged with stress and lack of stimulation which may result in the expression of stereotypies (repetitive behaviours without an apparent function). Little attention has been devoted to the postnatal effects of maternal stereotypies in the offspring. We investigated how the environment and stereotypies of pregnant sows affected the neuro-epigenome of their piglets. We focused on the amygdala, frontal cortex, and hippocampus, brain regions related to emotionality, learning, memory, and stress response. Differentially methylated regions (DMRs) were investigated in these brain regions of male piglets born from sows kept in an enriched vs a barren environment. Within the latter group of piglets, we compared the brain methylomes of piglets born from sows expressing stereotypies vs sows not expressing stereotypies. DMRs emerged in each comparison. While the epigenome of the hippocampus and frontal cortex of piglets is mainly affected by the maternal environment, the epigenome of the amygdala is mainly affected by maternal stereotypies. The molecular pathways and mechanisms triggered in the brains of piglets by maternal environment or stereotypies are different, which is reflected on the differential gene function associated to the DMRs found in each piglets' brain region . The present study is the first to investigate the neuro-epigenomic effects of maternal enrichment in pigs' offspring and the first to investigate the neuro-epigenomic effects of maternal stereotypies in the offspring of a mammal.

Identification of potentially relevant metals for the etiology of autism by using a Bayesian multivariate approach for partially censored values

Heavy metals are known to be able to cross the placental and blood brain barriers to affect critical neurodevelopmental processes in the fetus. We measured metal levels (Al, Cd, Hg, Li, Pb and Zn) in the cord blood of newborns and in the serum of the same children at 5 years of age, and compared between individuals with or without (controls) autism spectrum disorder (ASD) diagnosis. The samples were from a biobank associated with the All Babies in Southeast Sweden (ABIS) registry. We proposed a Bayesian multivariate log-normal model for partially censored values to identify potentially relevant metals for the etiology of ASD. Our results in cord blood suggest prenatal Al levels could be indicative of later ASD incidence, which could also be related to an increased possibility of a high, potentially toxic, exposure to Al and Li during pregnancy. In addition, a larger possibility of a high, potentially beneficial, exposure to Zn could occur during pregnancy in controls. Finally, we found decisive evidence for an average increase of Hg in 5-year-old ASD children compared to only weak evidence for controls. This is concordant with previous research showing an impaired ability for eliminating Hg in the ASD group.

Donkey Skin Trade and Its Non-compliance With Legislative Framework

Donkeys (Equus asinus) are facing a global crisis. Their welfare, and even survival, is being compromised as the demand for their skins increases. This demand is driven by the need to supply raw materials to produce ejiao, a Traditional Chinese Medicine made from collagen extracted from donkey skins. Since there is no productive chain for donkey skin production outside of China, the global trade is an entirely extractive industry that has resulted in the decimation of some local donkey populations. The donkey skin trade is demonstrably unsustainable, from the ethical issues associated with poor welfare, to the biosecurity and human health risks the trade poses; and it violates both legal frameworks and moral expectations at both a national and global level.

The human-animal relationship and its influence in our culture: the case of donkeys

Donkeys (Equus asinus) face a global crisis. Their health, welfare, and even their local survival are compromised as the demand for their skins increases. Such demand for donkey skins aims to supply the ejiao industry. Ejiao is a traditional remedy made from the collagen of donkey skins. Some people believe it has medicinal properties. It is estimated that the ejiao industry currently requires approximately 4.8 million donkey skins per year. Although the future of the donkeys is still uncertain, we must guarantee a life free from suffering to the animals under our responsibility. The trade of donkey skins also undermines the cultural role of donkeys. Donkeys have developed an essential role in Brazil, especially in the Northeast region of the country, carrying on their backs construction materials, water, and food, and, as a consequence, helping people build cities in the deepest hinterland. The close relationship between people and donkeys affords donkeys a unique place in the local culture. This central importance has been recognized by Brazilian artists throughout history. We have many examples of songs, books, “cordeis” (typical Brazilian literature), poems, documentaries, movies, woodcuts, paintings, and sculptures, created to honor this important actor. Here we describe some examples of this human-donkey relationship, and its influence on our culture.

Donkey skin trade: is it sustainable to slaughter donkeys for their skin?

 Donkeys (Equus asinus) face a global crisis. The health, welfare, and even survival of donkeys are being compromised as the demand for their skins increases. It is driven by the production of ejiao, a traditional Chinese remedy believed by some to have medicinal properties. It is estimated that the ejiao industry currently requires approximately 4.8 million donkey skins per year. Since there is no productive chain for donkey skin production outside of China, the activity is extractive and has resulted in the decimation of donkeys. Gestation is 12 months in donkeys, increasing the risk of extinction if such practices are not controlled. In this scenario, the donkeys are collected (purchased for low prices, stolen, and collected from the side of the roads) and are then often transported for long distances, usually without water, food, or rest. The trade, in Brazil, poses significant biosecurity risks, particularly because examinations are rarely conducted and therefore infectious diseases, such as glanders and infectious anemia, remain undetected. Furthermore, in chronic stress situations, the immune system is suppressed, increasing the biosecurity risk, especially because donkeys are a silent carrier of diseases. Rarely there is traceability with animals from different origins being put together in “fake farms”, before being delivered to slaughterhouses. The opportunistic strategy of collecting animals, or buying for low prices, keeping them without access to food and veterinary assistance, is what makes this trade profitable. Our experience in donkey welfare and the global skin trade suggest that it will be enormously challenging and cost-prohibitive to run a trade at the standards required to be considered humane, sustainable, and safe. Although donkeys are being blamed for the involvement in road accidents, it is not an ethical solution to maintain this trade as an alternative. Moreover, the ecological role of donkeys in native ecosystems has not been elucidated, and some studies indicate they could even have a positive effect. Regardless of the future the donkeys will have; we must guarantee a life with the least dignity to the animals under our responsibility.

Low Luminosity Reduces Agonistic Behaviour of Nile Tilapia

In confrontations, many behaviors are based on visual information. To establish the importance of visual signals in the aggression of cichlid fish, we observed the behavior of groups in three juveniles of Nile tilapia (six groups in each condition), for 30 minutes under two extremes of light condition: high luminosity and low luminosity (dark condition for humans - only infrared light). The average number of bites and chases in the low luminosity was lower than observed in high luminosity. We conclude that the low luminosity condition diminishes but does not eliminate fights, and the fish can rely on nonvisual senses and low intensity of light to interact with conspecifics. The artificial high luminosity in artificial environments is potentially compromising welfare for increasing the number of agonistic interactions. Moreover, it is possible that in experimental designs studying behavior the high luminosity is a variable interfering in the conclusions about agonistic behavior in cichlid fish.

Juvenile Nile Tilapia Fish Avoid Red Shelters

Shelters are frequently used for fish rearing to improve welfare conditions. In this study, whether Nile tilapia prefers specific shelter colors was evaluated. Thus, fish preference for white, red, blue, green or yellow shelters was tested. A high variation of individual preference responses for the shelter colors among fish was found. Even so, while red shelter was clearly avoided by Nile tilapia, a clear-cut preference could not be concluded. Thus, avoiding red shelters for rearing Nile tilapia is recommended, assuming fish preference, or non-preference, as important elements considering welfare conditions. Moreover, individual variability should also be considered whenever possible.

Stereotypic Behavior in Sows Is Related to Emotionality Changes in the Offspring

Some effects of expressing stereotypic behavior have not yet been elucidated. During gestation, the environment has the potential to interfere with offspring development and to have prenatal or longer-term consequences. We tested the hypothesis that the occurrence of stereotypic behavior during gestation could affect the phenotype of the offspring. Twenty-eight pregnant sows were studied by comparing two groups differing in the amount of stereotypy shown. We analyzed emotionality in the offspring from sows showing high or low stereotypy frequency using the open field and novel object tests. In the open field test, piglets from sows with a high rate of stereotypies walked more in central sectors (p < 0.0001) and lateral sectors (p = 0.04) than piglets from sows with a low rate of stereotypies. In the novel object test, the offspring from low stereotypy sows vocalized more (p = 0.008). We demonstrate for the first time that the stereotypic behavior by the mother during gestation changes the phenotype of the offspring, in particular, their emotionality.

Sham-Chewing in Sows Is Associated With Decreased Fear Responses in Their Offspring

We hypothesized that sham-chewing expressed by the dam during gestation affects fetus programming. The goal of this study was to assess the effects of maternal sham-chewing on offspring welfare indicators, such as behavior and physiology. Sows that exhibited consistent sham-chewing on at least two of 6 days of observation (N = 7) were compared with sows that had never performed sham-chewing (non-sham-chewing sows; N = 4) during these 6 days. Salivary samples from sows and piglets were collected and cortisol concentrations were analyzed to assess the hypothalamic pituitary adrenal (HPA) axis activity as cortisol is a physiological indicator of welfare. Moreover, placental tissue was collected, right after farrowing, to assess cortisol and cortisone concentration. Piglet behavior and fear tests were performed after weaning (one couple per sow). In the fear tests, data was collected in an open field test to determine the states of fear indicators. Non-sham-chewing sows had lower concentrations of cortisol on days 91 and 92 of gestation in the morning. In addition to this, placental cortisol was higher among sham-chewing sows than non-sham-chewing sows. In the open field test, piglets born from non-sham-chewing sows demonstrated more latency to move in the arena and less activity, indicating more fear. Based on our data, we concluded that the expression of maternal sham-chewing is related to less fear in their offspring. Although stereotypies have been studied, attention has not been devoted to the effects of the prenatal period in considering a fetal reprogramming approach.

Piglets Born from Sows Fed High Fibre Diets during Pregnancy Are Less Aggressive Prior to Weaning

Aggressive interactions, and their consequences, are the most important causes of poor welfare in piglets. Aggressive behaviour can be modulated by the prenatal and neonatal environment in several species. Commercially kept pregnant sows are often subjected to food restriction, which can compromise their welfare. Limited information is available on the consequences of sow hunger during pregnancy on welfare outcomes for their piglets. High fibre diets can mitigate the feeling of hunger and, consequently, it may improve welfare and productivity measures. The aim of this study was to assess the consequences of feeding pregnant gilts with high fibre diets (HFD) on agonistic behaviour, as manifested by skin lesions, and indicators of fear in their piglets at weaning. Twenty-two pregnant gilts were fed either HFD, 12.86% of crude fibre, 2.4 kg per day (N = 14), or low fibre diet (LFD), 2.53% of crude fibre, 2.0 kg per day (N = 8). During lactation, both treatments received the same diet, ad libitum. We investigated the impact of HFD on behaviour and performance measures (birth weight, average daily gain, weaning weight, see S3 File) in the offspring. Skin lesions were evaluated before and after weaning in 156 piglets (100 HFD and 56 LFD), and 142 piglets were subjected to an open field test and a novel object test (87 HFD and 55 LFD). We found no treatment effect on the performance measures. Piglets born from gilts that received HFD had fewer skin lesions before weaning (D28) than the offspring of LFD gilts, while no difference was found during days 29 and 30. In the open field and novel object tests, there was no treatment effect on the behaviour of piglets. The improved skin health at weaning in piglets of sows fed HFD suggests less agonistic interactions amongst these littermates than in piglets of sows fed LFD.