Evaluation of new biomarkers of stress in saliva of sheep.

Some routine handling procedures can produce stress in farm animals, and an adequate control of these stressors is important to avoid the negative effects on animal health and production. The measurement of biomarkers in saliva can be a suitable tool for the evaluation and control of stress. In this report, lipase, butyrylcholinesterase (BChE), total esterase (TEA) and adenosine deaminase (ADA) activities in the saliva of sheep were evaluated as biomarkers of stress. For this purpose, they were measured after inducing stress by facing a dog (experiment 1) and shearing (experiment 2), and comparing them to other stress salivary biomarkers such as α-amylase (sAA) and cortisol, as well as heart rate (HR). Each analyte was measured at the basal time, and during and just after the end of the stressful stimulus, and at various times for the first hour after the period of stress induction. Values were compared with those obtained from a control group. Lipase was the only analyte that showed significant changes between the stress and the control group in both experiments. Although TEA and ADA increased after stress, no significant differences were seen compared with the control group. Lipase was correlated highly with sAA and HR, in experiment 1; and correlated moderately with cortisol and HR in experiment 2. Lipase showed the greatest percentage increase after the stressful stimuli and less overlap with the control group in the two experiments. From the results of this study it can be concluded that lipase, TEA, BChE and ADA are enzymes present in the saliva of sheep and that they can be measured by using simple and fast colorimetric methods. Further studies should be undertaken with regard to the possible application of lipase as a biomarker of stress in sheep.

Variability in the behavior of kids born of primiparous goats during the first hour after parturition: effect of the type of parturition, sex, duration of birth, and maternal behavior.

The aim of the study was to determine the effect of the type of birth, the sex of the kids, the duration of the birth (categorized as short, medium, or long), and the level of maternal care (categorized as low, medium, or high) on the behavioral variables of kids during the first hour after birth. The parturitions of 78 primiparous goats of Murciano-Granadina breed (46 single-birth and 32 twin-birth) along with the behavior of the kids (44 males and 66 females) during the first hour of life were studied. Birth weight and duration of parturition were greater in single-birth kids (2.94 kg and 60.5 min, respectively) than in twin-birth kids (2.27 kg and 43.2 min, respectively). Birth weight and duration of parturition was greater in males (2.74 kg and 54.61 min) than in females (2.43 kg and 47.70 min). All the kids attempted to stand during the first hour of life, but only 83% attempted to suckle with 65% succeeding. Single-birth kids attempted to stand earlier than twin-birth kids (7.05 vs. 9.08 min), although they achieved this later (16.87 vs. 13.21 min). Compared with twin-birth kids, single-birth kids attempted to suckle later (22.45 vs. 34.76 min, respectively) and achieved it later (25.69 vs. 37.32 min). In the single-birth kids the duration of the first suckling was shorter (16.11 vs. 22.26 s), although total suckling time was greater (5.86 min) than in the twin-birth kids. Males tried to stand sooner than females (7.41 vs. 8.78 min), but took longer (16.12 vs. 13.81 min). The sex factor had no significant effect on suckling-related variables. Compared with medium- and long-duration-birth kids, short-duration-birth kids attempted to suckle earlier, (29.34, 34.23, and 12.82 min, respectively), achieved suckling earlier (31.75, 37.00, and 16.70 min, respectively), and suckled longer at first attempt (0.32, 0.17, and 0.45 min, respectively). Total suckling time was longer in long-duration-birth kids than in medium- and short-duration birth (9.07, 2.63, and 3.86 min, respectively). These results suggest that heavier kids suffer more during birth and are slower to achieve suckling; however, they appear to recover quickly because the total suckling time observed during the first hour was greater.