Effects of Enrichment Type, Presentation and Social Status on Enrichment Use and Behavior of Sows-Part 2: Free Access Stall Feeding.

Continuing with previous research by our group in an ESF system, four types of enrichment treatments were assessed in gestating sows housed in Free Access Stalls: (1) Constant: constant provision of wood on chain; (2) Rotate: rotation of rope, straw and wood; (3) Stimulus: rotation of enrichments with an acoustic cue; and (4) Control: no enrichment. Treatments had a 12 day-duration. Four groups (28 ± 2 sows) were studied from weeks 6 to 14 of gestation. Groups received all treatments in random order. Three dominant and 3 subordinates per pen were selected using a feed competition test. Digital photos were collected at 10 min intervals for 8 h on days 1, 8, 10 and 12 to record interactions with enrichment. Skin lesions were assessed on days 1 and 12, and salivary cortisol was assessed in weeks 6, 10 and 14 of gestation. More enrichment use was observed in Rotate and Stimulus treatments compared to Constant, and more sows contacted enrichment when straw was provided in the Rotate and Stimulus treatments. There was no difference in the amount of enrichment use by dominants and subordinates, no cortisol concentration elevation in subordinate sows nor any difference in lesion scores. In conclusion, social status had little impact and feeding system is important to reduce stress and aggression.

Getting It Straight: Accommodating Rectilinear Behavior in Captive Snakes-A Review of Recommendations and Their Evidence Base.

Snakes are sentient animals and should be subject to the accepted general welfare principles of other species. However, they are also the only vertebrates commonly housed in conditions that prevent them from adopting rectilinear behavior (ability to fully stretch out). To assess the evidence bases for historical and current guidance on snake spatial considerations, we conducted a literature search and review regarding recommendations consistent with or specifying ≥1 × and <1 × snake length enclosure size. We identified 65 publications referring to snake enclosure sizes, which were separated into three categories: peer-reviewed literature (article or chapter appearing in a peer-reviewed journal or book, n = 31), grey literature (government or other report or scientific letter, n = 18), and opaque literature (non-scientifically indexed reports, care sheets, articles, husbandry books, website or other information for which originating source is not based on scientific evidence or where scientific evidence was not provided, n = 16). We found that recommendations suggesting enclosure sizes shorter than the snakes were based entirely on decades-old 'rule of thumb' practices that were unsupported by scientific evidence. In contrast, recommendations suggesting enclosure sizes that allowed snakes to fully stretch utilized scientific evidence and considerations of animal welfare. Providing snakes with enclosures that enable them to fully stretch does not suggest that so doing allows adequate space for all necessary normal and important considerations. However, such enclosures are vital to allow for a limited number of essential welfare-associated behaviors, of which rectilinear posturing is one, making them absolute minimum facilities even for short-term housing.

Assessing Sustainability in Cattle Silvopastoral Systems in the Mexican Tropics Using the SAFA Framework.

The sub-humid native rainforest in Yucatan is one of the most endangered in Mexico. Cattle production is one of the main causes of land use change and silvopastoral systems are a feasible alternative. This work compares the sustainable performance of silvopastoral (native and intensive) and monoculture cattle farms in the state of Yucatan using the Sustainability Assessment for Food and Agriculture (SAFA) framework. Questionnaires and semi-structured interviews were applied in 9 farms. Responses were fed to the SAFA Tool to obtain sustainability polygons. Percentages of SAFA themes positively and negatively valuated were calculated. Native farms had positive ratings for Participation, Land, Biodiversity and Cultural Diversity, whereas intensive excelled on Holistic Management. Native farms had limited ratings for Decent Livelihood. Native farms (and one intensive silvopastoral farm) had the highest percentages of themes positively valuated compared to monocultures (and one intensive silvopastoral farm), which scored the lowest. Positive evaluations identified native systems as an option for sustainable production; however, areas of opportunity in all farms were discovered. This is the first comparative study using SAFA to evaluate differences in farming systems in the Mexican tropics, providing valuable information to generate policies and incentives on sustainable livestock production, as well as for improving evaluation tools for local application.

La hormona liberadora de tirotropina (TRH) del núcleo paraventricular hipotalámico y sistema límbico como reguladora de la homeostasis energética y de la conducta alimentaria en animales con ayuno, restricción alimentaria y anorexia / Thyrotropin-releasing hormone from the hypothalamic paraventricular nucleus and limbic system regulates energy homeostasis and feeding behavior in fasted, food retricted and anorexic animals

TRH expression and release from hypothalamic paraventricular nucleus (PVN) change with environmental stimuli. Fasted and food-restricted animals present decreased TRH synthesis and release, decelerating metabolic rate and utilization of energy stores, which is an advantageous adaptation of animals with nutrient deficit. Comparing thyroid axis function between prepuberal vs. adult male fasted animals, we found a greater body weight reduction than in adults (30% vs.11%) and TRH release was not decreased; TRH degradation by pituitary PPII enzyme decreased, which maintained energy waste. TRH content of fasted-prepuberal animals changed in hippocampus and nucleus accumbens, and in amygdala of adults vs. ad libitum fed animals. PVN TRH role in food-avoiding behavior was studied by comparing its expression levels and of adolescent, adult females and male animals with anorexic conduct when drinking 2.5% of NaCl solution (AN) vs. a group forced to ingest the amount of food consumed by AN (FFR); also vs. a control group fed ad libitum (C). PVN TRH mRNA and TSH serum levels increased in AN vs. C; both decreased in FFR, supporting the putative anorexigenic role for the peptide. TRH content differentially changed in hippocampus and in frontal cortex of AN and FFR, suggesting its participation in taste perception and memory association. Orexinergic and NPYergic pathways are inactive in anorexic animals. Blocking corticotrophin-releasing hormone signal by an antagonist of CRH-R2 in the PVN reverses TRH high expression and TSH serum levels in AN.

La expresión y liberación de la TRH del núcleo paraventicular hipotalámico (NPV) cambia con estímulos ambientales; en ayuno y restricción de alimentos la liberación del péptido disminuye, reduciéndose la tasa del metabolismo y la degradación de reservas energéticas. Esto es una adaptación ventajosa para los animales con balance negativo de energía. Al comparar el contenido de TRH en la eminencia media entre animales prepúberes y adultos en ayuno de 48 horas, observamos que los jóvenes no tienen una adaptación al déficit de nutrimentos. Su peso baja más que en adultos (30% vs. 11%) y la liberación de TRH no disminuye; la degradación de TRH por PPII en la adenohipófisis (PPII) disminuye, manteniéndose el gasto energético. El contenido de TRH de animales prepúberes en ayuno cambió en el hipocampo y en el núcleo accumbens, así como en la amígdala de los adultos comparado contra los animales con alimentación ad libitum. La TRH se ha propuesto como agente anorexigénico. Evaluamos su contenido y expresión en el NPV de animales que evitan el alimento al beber una solución de NaCl (2.5%)(AN), en otros con restricción de alimento forzada (RAF) que ingieren la misma cantidad que AN y en aquéllos (C) con alimentación ad libitum. La síntesis de TRH en el NPV y el contenido sérico de TSH disminuyen en RAF pero aumentan en AN. La vía orexinérgica y la de NPY de AN están inactivas. La inyección de un antagonista a CRH revierte las alteraciones de TRH y TSH y atenúa la anorexia de AN.

Involvement of CRH-R2 receptor in eating behavior and in the response of the HPT axis in rats subjected to dehydration-induced anorexia.

Wistar rats subjected to dehydration-induced anorexia (DIA), with 2.5% NaCl solution as drinking water for 7 days, decrease by 80% their food intake and present some changes common to pair-fed food restricted rats (FFR) such as: weight loss, decreased serum leptin and expression of orexigenic arcuate peptides, increasing the anorexigenic ones and serum corticosterone levels. In contrast, the response of the HPT axis differs: DIA animals have increased TRH expression in PVN and present primary as opposed to the tertiary hypothyroidism of the FFR. Exclusive to DIA is the activation of CRHergic neurons in the lateral hypothalamus (LH) that project to PVN. Since TRH neurons of the PVN contain CRH receptors, we hypothesized that the differences in the response of the HPT axis to DIA could be due to CRH regulating TRHergic neurons. CRH effect was first evaluated on TRH expression of cultured hypothalamic cells where TRH mRNA levels increased after 1h with 0.1nM of CRH. We then measured the mRNA levels of CRH receptors in the PVN of male and female rats subjected to DIA; only those of CRH-R2 were modulated (down-regulated). The CRH-R2 antagonist antisauvagine-30 was therefore injected into the PVN of male rats, during the 7 days of DIA. Antisauvagine-30 induced a higher food intake than controls, and impeded the changes produced by DIA on the HPT axis: PVN TRH mRNA, and serum TH and TSH levels were decreased to similar values of FFR animals. Results corroborate the anorexigenic effect of CRH and show its role, acting through CRH-R2 receptors, in the activation of TRHergic PVN neurons caused by DIA. These new data further supports clinical trials with CRH-R2 antagonists in anorexia nervosa patients.