Genotypes, phenotypes and pedigrees of 6 breeds of dairy sheep (including subdivisions of Latxa, Manech, and Basco-Béarnaise) from the Spain and France Western Pyrenees were used to estimate genetic relationships across breeds (together with genotypes from the Lacaune dairy sheep) and to verify by forward cross-validation single-breed or multiple-breed genetic evaluations. The number of rams genotyped fluctuated between 100 and 1,300 but generally represented the 10 last cohorts of progeny-tested rams within each breed. Genetic relationships were assessed by principal components analysis of the genomic relationship matrices and also by the conservation of linkage disequilibrium patterns at given physical distances in the genome. Genomic and pedigree-based evaluations used daughter yield performances of all rams, although some of them were not genotyped. A pseudo-single step method was used in this case for genomic predictions. Results showed a clear structure in blond and black breeds for Manech and Latxa, reflecting historical exchanges, and isolation of Basco-Béarnaise and Lacaune. Relatedness between any 2 breeds was, however, lower than expected. Single-breed genomic predictions had accuracies comparable with other breeds of dairy sheep or small breeds of dairy cattle. They were more accurate than pedigree predictions for 5 out of 6 breeds, with absolute increases in accuracy ranging from 0.05 to 0.30 points. They were significantly better, as assessed by bootstrapping of candidates, for 2 of the breeds. Predictions using multiple populations only marginally increased the accuracy for a couple of breeds. Pooling populations does not increase the accuracy of genomic evaluations in dairy sheep; however, single-breed genomic predictions are more accurate, even for small breeds, and make the consideration of genomic schemes in dairy sheep interesting.

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Space availability is essential to grant the welfare of animals. To determine the effect of space availability on movement and space use in pregnant ewes (Ovis aries), 54 individuals were studied during the last 11 weeks of gestation. Three treatments were tested (1, 2, and 3 m2/ewe; 6 ewes/group). Ewes' positions were collected for 15 minutes using continuous scan samplings two days/week. Total and net distance, net/total distance ratio, maximum and minimum step length, movement activity, angular dispersion, nearest, furthest and mean neighbour distance, peripheral location ratio, and corrected peripheral location ratio were calculated. Restriction in space availability resulted in smaller total travelled distance, net to total distance ratio, maximum step length, and angular dispersion but higher movement activity at 1 m2/ewe as compared to 2 and 3 m2/ewe (P<0.01). On the other hand, nearest and furthest neighbour distances increased from 1 to 3 m2/ewe (P<0.001). Largest total distance, maximum and minimum step length, and movement activity, as well as lowest net/total distance ratio and angular dispersion were observed during the first weeks (P<0.05) while inter-individual distances increased through gestation. Results indicate that movement patterns and space use in ewes were clearly restricted by limitations of space availability to 1 m2/ewe. This reflected in shorter, more sinuous trajectories composed of shorter steps, lower inter-individual distances and higher movement activity potentially linked with higher restlessness levels. On the contrary, differences between 2 and 3 m2/ewe, for most variables indicate that increasing space availability from 2 to 3 m2/ewe would appear to have limited benefits, reflected mostly in a further increment in the inter-individual distances among group members. No major variations in spatial requirements were detected through gestation, except for slight increments in inter-individual distances and an initial adaptation period, with ewes being restless and highly motivated to explore their new environment.

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In order to determine individual variability in the amplitude and duration of the nycthemeral rhythm of the plasma melatonin concentration, 12 ovariectomized estradiol-treated Ile-de-France ewes were submitted to a sequence of 34 long days (LD1, 16L:8D), 21 short days (SD, 8L:16D), and 21 LD (LD2). Intensive blood sampling (hourly from 1 hr before dusk to 1 hr after dawn) was performed for 4 consecutive nights in each of the photoperiodic situations (LD1, SD, LD2), i.e., a total of 12 nights per ewe. Plasma melatonin was assayed by radioimmunoassay. Instantaneous amplitude (difference between each hourly measurement of the plasma melatonin concentration during the nocturnal elevation and the mean diurnal melatonin concentration), mean individual amplitude (same definition but using the mean melatonin concentration during the nocturnal elevation) and duration of elevation of plasma melatonin concentrations were calculated for each ewe and each night and analyzed by variance analysis. Instantaneous amplitude varied significantly with photoperiod, with night intra-photoperiod, with ewes, and time intra-night. Mean individual amplitude varied significantly with photoperiod and with ewe but not with night intra-photoperiod. Dramatic differences between individuals appeared in the amplitude and duration of melatonin rhythms. The lowest mean individual amplitude (all nights of measurement) found was 95 pg/ml and the highest was 544 pg/ml. Overall repeatability coefficient of the mean amplitude of melatonin elevation was 0.71 (P < 0.001). Duration of melatonin elevation varied significantly with photoperiod, with nights intra-photoperiod and with ewes. During LD periods, mean duration of melatonin elevation was equivalent to duration of the night (from 7 to 8 hr), while during SD it varied with ewes from 9 to 16 hr. Repeatability coefficient of the duration of melatonin elevation in SD was 0.57 (P < 0.05). It is concluded that amplitude and duration (in SD) of the nycthemeral rhythm of the plasma melatonin concentration are highly repeatable individual characteristics in the ewe.