Objective. This study is a preliminary step of a larger national program aimed to develop a strategy for “in situ” preservation of Teleorman Black Head sheep population. In this paper we estimated the effect of β-lactoglobulin, casein and prolactin on some quantitative and qualitative milk traits in this local sheep population. Material and methods. Genotyping methodology included PCR for CSN3 (A and B alleles) and PCR-RFLP for LGB (A and B alleles) and PRL (T and C alleles), respectively. Repeated milking and milk composition analysis were used for the polymorphism effect estimation. Results. No association between CSN3 polymorphism and milk traits was found. Effect of LGB on production traits was quite constant. Genotype AA performed better than BB. PRL marker effect showed small differences than LGB. Concerning milk, fat and protein yield, AA genotype for PRL had a smaller positive impact than AA genotype for LGB. Regarding fat and protein content, PRL showed a negative effect for AA and positive for BB genotype, respectively. Conclusions. Positive association between LGB and milk yield and composition recommend this candidate gene like marker for a future MAS program. Although PRL gene is also associated with an increased milk quantity, inverse response over milk composition must be considered in MAS strategy. Our study demonstrated that both LGB and PRL markers could became an advent of MAS utilization in Romanian dairy sheep breeding industry. RESUMEN Objetivo. Este estudio es un paso preliminar de un programa nacional más amplio destinado a desarrollar una estrategia para la conservación “in situ”de la población de ovejas Cabeza Negra de Teleorman. En este trabajo se estimó el efecto de la β-lactoglobulina, caseína y prolactina en algunos rasgos cuantitativos y cualitativos de la leche en esta población de ovejas locales. Material y métodos. Metodología de PCR para genotipificación incluido CSN3 (A y B alelos) y PCR-RFLP para LGB (A y B alelos) y PRL (T y C alelos). Análisis y composición de la leche de ordeños repetidos se utilizaron para estimación el efecto del polimorfismo. Resultados. No se encontró asociación entre el polimorfismo y la leche rasgos CSN3. Efecto de LGB en los rasgos de producción era bastante constante. Genotipo AA obtenido mejores resultados que BB. Efecto marcador PRL mostró pequeñas diferencias que LGB. En cuanto a la leche grasa y proteína el genotipo AA para PRL tuvo un impacto positivo más pequeño que el genotipo AA para LGB. En cuanto a contenido de grasa y proteína, PRL mostró un efecto negativo para AA y positivo para BB genotipo. Conclusiones.La asociación positiva entre LGB y la producción de leche y la composición recomienda este gen candidato como marcador para un futuro programa de MAS. Aunque gen PRL también se asocia con un incrementoen la cantidad de leche, la respuesta inversa sobre composición de la leche debe ser considerado en la estrategia de MAS. Nuestro estudio demostró que los marcadores tanto LGB y PRL podrían venir a ser utilizados en MAS en la industria rumanade cría deovejas lecheras.

Abstract. The state of the local breeds of farm animals is increasingly precarious worldwide because of the aggressive introduction of breeds with improved economical traits. The preference of the breeders for local breeds is due to their higher adaptability to the particular climate and relief conditions of the mountain areas, to the high rate of assimilation of the feeds from these regions and to their increased resistance to diseases. This study analyzes the genetic variation of the main four local Romanian sheep breeds (Tsurcana, Tsigai, Ratska and Teleorman Blackhead) in terms of stock and economic importance, using 18 microsatellite markers. The mean number of alleles per locus was of 9.764. The values of genetic diversity parameters exhibited a high degree of polymorphism for the analyzed breeds, although inbreeding was highlighted particularly in Tsurcana and Tsigai. These breeds also showed an intense gene flow among them and were less differentiated in comparison with Ratska and Teleorman Blackhead. The results of this study may be useful for breeding programs and conservation plans since the genetic resources of the local breeds must be preserved so as to maintain an adequate level of biodiversity in animal husbandry.

No abstract

Abstract:In Romania, suckling lamb meat is on demand during the Easter, but growing suckling lambs just for this purpose is not profitable. The paper performed a comparative study of the fattening aptitudes of the lambs from three local sheep breeds to produce carcasses demanded on the international market. The research was done on three groups (Carabash, Tsigai and Tsurcana breeds) of 16 weaned lambs each, with an initial weight between 21-27 kg and continued until the animals reached an weight of 35-38 kg. The experiment started after a period of accommodation to the experimental maintenance and feeding conditions. The animals were kept indoors under similar conditions of feeding and microclimate. The body weight of the animals was measured at the beginning and end of each fattening period, as well as the average daily gain and the total weight gain for each breed. During the late period of fattening, control weighing was performed until the target weight has been achieved. The Carabash lambs, which had the highest lambing weights of all the investigated breeds, proved to be the most precocious as weight gain. Over 44 fattening days they recorded an average daily gain of 0.258±0.016 kg, reaching a slaughtering weight of 38.46±1.178 kg with a feed conversion ratio of 4.66 FU. The Tsigai lambs, less precocious than the Carabash lambs, recorded an average daily gain of 0.191±0.043 kg, over 86 days 86, reaching a slaughtering weight of 37.16±0.130 kg, with a significantly higher feed conversion ratio, of 6.35 FU. The Tsurcana lambs, on the bottom position as fattening aptitudes, reached and average daily weight of 0.154±0.0142 kg over 91 days, reaching a slaughtering weight of 35.25±1.445 kg with a feed conversion ratio of 6.44FU.

No abstract