Diversity of production systems and specific socio-economic barriers are key reasons explaining why the implementation of new technologies in small ruminants, despite being needed and beneficial for farmers, is harder than in other livestock species. There are, however, helpful peculiarities where small ruminants are concerned: the compulsory use of electronic identification created a unique scenario in Europe in which all small ruminant breeding stock became searchable by appropriate sensing solutions, and the largest small ruminant population in the world is located in Asia, close to the areas producing new technologies. Notwithstanding, only a few research initiatives and literature reviews have addressed the development of new technologies in small ruminants. This Research Reflection focuses on small ruminants (with emphasis on dairy goats and sheep) and reviews in a non-exhaustive way the basic concepts, the currently available sensor solutions and the structure and elements needed for the implementation of sensor-based husbandry decision support. Finally, some examples of results obtained using several sensor solutions adapted from large animals or newly developed for small ruminants are discussed. Significant room for improvement is recognized and a large number of multiple-sensor solutions are expected to be developed in the relatively near future.

Heat stress and mastitis are major economic issues in dairy production. the objective was to test whether goat's mammary gland immune response to E. coli lipopolysaccharide (LpS) could be conditioned by heat stress (HS). changes in milk composition and milk metabolomics were evaluated after the administration of LpS in mammary glands of dairy goats under thermal-neutral (tn; n = 4; 15 to 20 °C; 40 to 45% humidity) or HS (n = 4; 35 °C day, 28 °C night; 40% humidity) conditions. Milk metabolomics were evaluated using 1 H nuclear magnetic resonance spectroscopy, and multivariate analyses were carried out. Heat stress reduced feed intake and milk yield by 28 and 21%, respectively. Mammary treatment with LpS resulted in febrile response that was detectable in tn goats, but was masked by elevated body temperature due to heat load in HS goats. Additionally, LpS increased milk protein and decreased milk lactose, with more marked changes in HS goats. the recruitment of somatic cells in milk after LpS treatment was delayed by HS. Milk metabolomics revealed that citrate increased by HS, whereas choline, phosphocholine, n-acetylcarbohydrates, lactate, and ß-hydroxybutyrate could be considered as putative markers of inflammation with different pattern according to the ambient temperature (i.e. tn vs. HS). in conclusion, changes in milk somatic cells and milk metabolomics indicated that heat stress affected the mammary immune response to simulated infection, which could make dairy animals more vulnerable to mastitis.The negative effects of heat stress (HS) on the productivity of dairy animals in terms of milk yield, milk composition and milk quality are well documented 1,2 . Despite advances in cooling systems and environmental management, HS constitutes to be a significant cost for the dairy industry 3 . Goats, originated from hot and arid zones, are considered less sensitive to HS compared to cows. However, milk production losses have been reported in heat-stressed dairy goats, especially at early stages of lactation 4,5 .The effect of HS on performance (e.g. milk yield, milk composition, feed intake, body temperature, respiratory rate) has been intensively evaluated in dairy animals 1,2 . However, only a few studies evaluated the omics of biofluids and tissues in animals exposed to HS such as cow's blood plasma 6 , cow's milk 7 , cow's liver 8 and goat's urine 9 .Besides the negative impact of HS on milk production, HS has been found to disrupt the immune function 5 . With regard to mammary immunity during HS, available data indicate that mammary immunity might be compromised by HS. Thompson et al. 10 reported that cows without cooling during the dry period have higher incidence of mastitis in the ensuing lactation. At the systemic level, Contreras-Jodar et al. 5 evaluated the transcriptomics of blood immune cells in heat-stressed goats and detected a decrease in the hematopoiesis and www.nature.com/scientificreports www.nature.com/scientificreports/ leukocyte diapedesis, which might compromise the innate and the adaptive ...

rights and content Highlights• Tropical animal production systems are subjected to harsh conditions that limit production sustainability • Omics technologies provide insight to resilience mechanisms and product quality at the molecular level • Application of omics in the tropical animal production context could help improve the productivity of low-resource areas

Low winter temperatures in some regions have a negative impact on animal performance, behavior, and welfare. The objective of this study was to evaluate some physiological, metabolic, and lactational responses of dairy goats exposed to cold temperatures for 3 weeks. Eight Murciano-Granadina dairy goats (41.8 kg body weight, 70 days in milk, and 2.13 kg/day milk) were used from mid-January to mid-March. Goats were divided into 2 balanced groups and used in a crossover design with 2 treatments in 2 periods (21 days each, 14 days adaptation and 7 days for measurements). After the first period, goats were switched to the opposite treatment. The treatments included 2 different controlled climatic conditions with different temperature-humidity index (THI) values. The treatments were: thermoneutral conditions (TN; 15 to 20 °C, 45% humidity, THI = 58 to 65), and cold temperature (CT; −3 to 6 °C, 63% humidity, THI = 33 to 46). Goats were fed ad libitum a total mixed ration (70% forage and 30% concentrate) and water was freely available. Goats were milked at 0800 and 1700 h. Dry matter intake, water consumption, rectal temperature, and respiratory rate were recorded daily (days 15 to 21). Body weight was recorded at the start and end of each period. Milk samples for composition were collected on 2 consecutive days (days 20 and 21). Insulin, glucose, non-esterified fatty acids (NEFA), ß-hydroxybutyrate (BHB), cholesterol, and triglycerides were measured in blood on d 21. Compared to TN goats, CT goats had similar feed intake, but lower water consumption (−22 ± 3%), respiratory rate (−5 ± 0.8 breaths/min), and rectal temperature (−0.71 ± 0.26 °C). Milk yield decreased by 13 ± 3% in CT goats, but their milk contained more fat (+13 ± 4%) and protein (+14 ± 5%), and consequently the energy-corrected milk did not vary between TN and CT goats. The CT goats lost 0.64 kg of body weight, whereas TN goats gained 2.54 kg in 21 days. Blood insulin and cholesterol levels were not affected by CT. However, values of blood glucose, NEFA, hematocrit, and hemoglobin increased or tended to increase by CT, whereas BHB and triglycerides decreased. Overall, CT goats produced less but concentrated milk compared to TN goats. Despite similar feed intake and blood insulin levels CT goats had increased blood glucose and NEFA levels. The tendency of increased blood NEFA indicates that CT goats mobilized body fat reserves to cover the extra energy needed for heat production under cold conditions.

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