One of the projected effects of climate change is a reduction in rainfall in certain regions of the world. Hence, the agricultural and livestock sectors will have to cope with increasing incidences of water shortage while still maintaining productivity levels to feed an ever increasing global population. This short communication reports on the effect of a 2-week water stress on Pelibuey sheep in Cuba. Three treatments were compared, viz. supply of water ad libitum, water supplied once every 3 or 6 days. Following exposure to the water stress, the results showed no changes in sheep body weight or rectal temperature. However, respiration frequency was affected with water stress causing a reduction from 23.3 to 13.3 respirations per min in control and water-deprived animals, respectively. Furthermore, there was evidence for hemoconcentration in response to water stress (levels of hemoglobin increased from 9.2 to 13.1 g L−1 and hematocrits from 27.6 to 39.3% in the control group and animals restricted to water once every 6 days. The imposed water stress was also evident in the reduction of lymphocytes (from ±63 to 43%), and in increase of neutrophils (from approximately 38 to 54%) and leukocytes (from 3133 to 4933 per mm3). The results indicated a decline in the levels of antioxidants, i.e., SOD from approximately 13 to 10 U mg−1 protein and CAT activity from 23 to 9 U mg−1 protein. To the best of our knowledge, this is the first report on the response of Pelibuey sheep to short-term water shortage stress under Cuban environmental conditions.

Projections of warming temperatures as a consequence of climate change will have impacts on food production globally. This heat stress coupled with increased solar radiation, will affect the well-being of livestock. In many regions of the world, local breeds are reared as they demonstrate improved tolerance to local conditions resulting in minimal effects on production when compared with commercial breeds. However, it is still critical to assess the consequences of increased heat and radiation stress on local breeds to ensure that on-farm productivity is not adversely affected. This short communication describes the effects of radiation intensity during daylight on Pelibuey sheep (intact male calves). Three treatments were tested: control (no shade; asymptotic to 50 lux at 14:00 h), one layer of shade mesh (asymptotic to 35 lux at 14:00 h), and two layers of shade mesh (asymptotic to 15 lux at 14:00 h). Increasing radiation resulted in a decline in sheep body weight from 18 kg to 16 kg. Only animals exposed to 15 lux were capable of gaining in body weight. Exposure to elevated radiation increased the respiratory rate of animals from 130 respirations per min at the lowest exposure level to a maximum of 170 respirations per min in animals kept at 50 lux. The rectal temperature of animals remained consistent (approximately 40 ?C) irrespective of the level of radiation. In contrast, the temperature measured at the head, back and thigh were all similarly affected by radiation. In terms of the hematological parameters measured, radiation stress did not affect the concentrations of hemoglobin or hematocrit. There was a non-significant decrease in the concentration of lymphocytes from 58% to 52%. However, neutrophils showed an increasing trend from 42% in animals at the lowest radiation level to a maximum of 51% in animals exposed to the highest stress level. The concentrations of leukocytes were similar in animals kept at 15 and 35 lux and were significantly elevated in those at 50 lux. Serum proteins and CAT concentrations were not affected by the different levels of radiation tested. However, SOD specific activity significantly declined from 11 to 8 U mg(-1) protein in animals exposed to 15 and 50 lux respectively. To the best of our knowledge, this is the first report on the response of Pelibuey sheep to short-term radiation stress under Cuban conditions.

Livestock farming with sheep represents an important income stream. With climate change, domestic sheep are being exposed to heat stress which can have adverse effects on growth. Here, data regarding sheep behaviour in response to high temperature stress was analysed using the Euclidean distance method to integrate all variables into a single representative outcome that could summarize sheep behaviour. We studied the effects of two shepherding conditions either with or without the provision of shade. The number of animals eating grass, ruminating and resting either in the shade or directly in the sun were recorded over one year at two-week intervals. As the ideal behaviour (expert’s criteria), the following conditions were considered: maximum numbers of animals eating grass, ruminating and resting under shaded conditions were desirable; while the numbers of animals ruminating or resting under direct sunlight should be at a minimum. The statistical evaluation undertaken integrated these variables to identify the most significant effects of heat stress. Sheep spent most of the daylight hours engaged in eating and this activity was more intensive where shaded conditions were available. The Euclidean distance calculated for the group of animals maintained under shaded conditions was statistically lower (indicating better behaviour). Based on this, it is possible to accurately rank the treatments in terms of severity. The analysis indicates that the use of the Euclidean distance could be used to summarize a simplified outcome for observational data collected in behavioural studies in response to differing climatic conditions.

Contamination of water through salinization will affect the well-being of livestock. Therefore, it is necessary to understand how animals respond to increasing levels of salts in their water supply. This short communication describes the effects of a two-week salinity stress (0, 6, 12 g L− 1 NaCl) on Pelibuey sheep. The parameters measured in response to salinity stress were animal weight, rectal temperature, and levels of hemoglobin, hematocrits, lymphocytes, neutrophils, leukocytes and proteins. Specific activities of superoxide dismutase (SOD) and catalase (CAT) in blood samples were also recorded. The results showed that the 6 g L− 1 NaCl treatment resulted in the significantly highest body weight. There were no significant differences in the rectal temperature of animals. In terms of the hematological parameters, animals exposed to 6 g L− 1 NaCl displayed the significantly highest hemoglobin and hematocrit contents. There appeared to be no effect of consumption of saline water on the amount of lymphocytes, neutrophils, leukocytes or proteins. It was found that animals that consumed 12 g L− 1 NaCl supplemented water had the lowest levels of SOD activity. There were no significant differences in CAT specific activities in animals exposed to the saline water or the control. This is the first report on the response of Pelibuey sheep to short-term saline stress under Cuban environmental conditions.

Sheep farming, and the income generated from this endeavor, contributes significantly to the global economy and rural livelihoods. Therefore, it is vital to maintain the productivity of this industry in the face of changing climate patterns. In the context of sheep farming, animals are exposed to a higher heat load as global temperatures are increasing, leading to heat stress. This heat stress conditions can adversely affect animal productivity and welfare resulting in reduced feed intake, physiological (panting, higher respiration, higher heart rate, etc.) and behavioral changes (lying down, standing, seeking shade, etc.) to compensate for increased heat load ultimately leading to lowered productivity. Considering this, it is important to monitor sheep behavior in order to implement improved management practices to compensate for changes in climate. The current short study investigated sheep behavior at different times throughout the day. The data generated was analyzed using the hierarchical cluster analysis method in order to integrate all variables into a single representative dendrogram that could summarize sheep behavior. While hierarchical cluster analysis has been applied in diverse scientific fields, as far as we know, the statistical application reported here is novel in the context of sheep behavior in response to climate change. We studied sheep behavior throughout the day (9:00 – 9:50; 10:00 – 10:50; 11:00 – 11:50; 14:00 – 14:50; 15:00 – 15:50; 16:00 – 16:50). Shade was provided in the form of trees. The following indicators were recorded over a period of twelve months at two week intervals: number of animals eating grass, ruminating and resting. The statistical evaluations undertaken resulted in the generation of a dendrogram which integrated all evaluated variables to categorize the behaviors undertaken at different times during the day. The dendrogram indicated three groupings of sheep behavior that were distinctly different from each other. The analysis shown here indicates that the use of hierarchical cluster analysis culminating in the construction of a dendrogram can effectively synthesize large datasets to outline similar relationships (in this study, this was in the context of observed behaviors). This statistical method applied to sheep physiological studies may help interpret experimental data in the context of climatic change.