Mastitis in a flock of milking sheep.

INTRODUCTION: Determination of somatic cell counts (SCC) becomes more and more important also for ewe's milk. SCC can be a useful indicator of milk quality for milk processors while it can be a mastitis indicator for sheep keepers and an important selection criterion for breeders. The objective of our study was to acquire basic information about factors influencing SCC variability in lambing ewes of the Tsigai (T) and Improved Valachian (IV) breeds. Somatic cell counts (SCC) were determined in 866 milk samples in 2017 and 2018, during lamb sucking and during milking period. An instrument Fossomatic 90 (Foss Electric, Hillerød, Denmark) was used for analysis. Average SCC varied from 270 to 1897 × 103 cells/ml during lamb sucking and from 268 to 2139 × 103 cells/ml during milking period. Differences between the sampling periods were statistically significant in 2017. An increase in SCC was observed at the end of both sucking and milking periods. An overall evaluation of lactation brought about the average SCC at 364 × 103 cells/ml in 2017 (log(10) SCC - 2,25) and at 1,091 × 103 cells/ml in 2018 (log(10) SCC - 2,68). The indicator log(10) was significantly influenced by breed in 2017 (T - 2,61; IV - 2,75). The effect of lactation number and number of sucking lambs did not have any significant influence on SCC.

INTRODUCTION: La détermination du nombre de cellules somatiques (CCS) devient de plus en plus importante, y compris pour le lait de brebis. Le CCS peut être un indicateur utile de la qualité du lait pour les transformateurs tandis qu'il peut être un indicateur de mammites pour les éleveurs de brebis et un critère de sélection important pour les sélectionneurs. L'objectif de notre étude était d'acquérir des informations de base sur les facteurs influençant la variabilité de la CCS chez les brebis agnelées des races Tsigai (T) et Valachian améliorée (IV). Le nombre de cellules somatiques (CCS) a été déterminé dans 866 échantillons de lait en 2017 et 2018, pendant la tétée des agneaux et pendant la période de traite. Un instrument Fossomatic 90 (Foss Electric, Hillerød, Danemark) a été utilisé pour l'analyse. Le CCS moyen a varié de 270 à 1897 × 103 cellules/ml pendant la tétée des agneaux et de 268 à 2139 × 103 cellules/ml pendant la période de traite. Les différences entre les périodes d'échantillonnage étaient statistiquement significatives en 2017. Une augmentation du CCS a été observée à la fin des périodes de tétée et de traite. Une évaluation globale de la lactation a permis d'obtenir un CCS moyen de 364 × 103 cellules/ml en 2017 (log(10) CCS ­ 2,25) et de 1 091 × 103 cellules/ml en 2018 (log(10) CCS ­ 2,68). L'indicateur log(10) a été significativement influencé par la race en 2017 (T ­ 2,61 ; IV ­ 2,75). L'effet du nombre de lactations et du nombre d'agneaux de lait n'a pas eu d'influence significative sur le CCS.

Estimation of economic values for traits of dairy sheep: II. Model application to a production system with one lambing per year.

A bioeconomic model for dairy sheep was applied to a production system with one lambing per year. The classical extensive Carpathian system with indoor winter lambing, traditional weaning, sale of surplus lambs before Easter, and a summer milking period with ewes on pasture was modeled. The economic values of 15 performance and functional traits were calculated for the Slovakian Improved Walachian multi-purpose breed. The economic values per unit increase in the traits were 0.32 euro/kg of milk yield during the standardized milking period of 150 d, 0.29 euro/0.1% milk fat, 0.42 euro/0.1% milk protein, 0.28 euro/% and 0.56 euro/% for conception rates of female lambs and ewes, respectively, 0.20 euro/0.01 lamb born, 0.0036 euro/% and 0.0040 euro/% for lamb survival at birth and until weaning, respectively, 0.65 euro/kg of birth weight, 0.032 euro/g per d daily gain from birth until weaning, -0.030 euro/kg of mature weight, -0.38 euro/0.1 and -0.21 euro/0.1 conformation quality grade for weaned lambs and adult sheep, respectively, 0.42 euro/kg of fleece weight and 11.10 euro/year of productive lifetime for ewes.

Additional studies of sheep haemopexin: genetic control, frequencies and postnatal development.

This study presents evidence that sheep haemopexin phenotypes are genetically controlled by three alleles, HpxA, HpxB1 and HpxB2, of a single autosomal locus. Frequencies of two alleles, HpxA and HpxB (HpxB encompasses two isoalleles, HpxB1 and HpxB2), were studied in eight sheep breeds in Czechoslovakia. The frequency of the HpxA allele was highest (ranging from 0.81 in Merino to 1.0 in East Friesian sheep). Qualitative and quantitative changes in haemopexin during postnatal development were studied by starch gel electrophoresis and rocket immunoelectrophoresis respectively. In electrophoresis, 1- or 2-day-old lambs had two very weak zones corresponding in mobility to two slower zones of adult animals. Later, the third more anodic zone appeared and gradually increased in intensity. In 1-month-old lambs the patterns were practically identical with those of adult animals. Using rocket immunoelectrophoresis, the level of haemopexin shortly after birth was practically zero. It rose sharply till the sixth day of life; then the level continued to rise slowly till about 1 month of age. The mean haemopexin level in adult sheep was 64.5 +/- 18.26 (SD) mg/100ml serum, ranging from 30.5 to 116.5 mg/100ml.