Montenegro has a great diversity of indigenous and locally developed sheep breeds, adapted to different regions and climates. However, the current trend of the steady decline in sheep populations means that some of them are threatened with extinction. The aim of this study was the investigation of the genetic diversity and population structure of five Montenegrin sheep populations, using the OvineSNP50K BeadChip. Data from the studied sheep were supplemented with publicly available genotypes of worldwide breeds to determine admixture contributions and genetic relationships. Higher genetic diversity and low inbreeding were observed in Pivska Pramenka and Sjenicka sheep, with Ho = 0.411, He = 0.423, and FROH>2Mb = 0.056 and Ho = 0.421, He = 0.421, and FROH>2Mb = 0.041, respectively. Zetska Zuja had much lower FIS (0.001) and high FROH inbreeding (0.090), indicating a small population size and genetic drift. An analysis of the genetic population structure showed that Montenegrin sheep populations are genetically distinct populations. This analysis revealed the presence of admixture in most sheep populations (high heterogeneity), while genetic purity was observed in Zetska Zuja. The obtained results will help in the conservation management of endangered Montenegrin sheep populations.

The paper presents the chemical composition, nutritional and usable value of sunchoke (Helianthus tuberosus L.) and the possibility of using it for animal nutrition in fresh and canned form. Tests show that sunchoke cut in mid-June contains about 9.43% of crude protein, 2.49% of crude fat, 19.93% of crude cellulose, 50.50% of NFE (nitrogen-free extractives) and 17.65% of ash in the dry matter. Although lucerne biomass had a more favorable chemical composition (18.13% crude protein, 6.72% crude fat, 25.24% crude cellulose, 39.35% BEM and 10.56% ash), the benefits of sunchoke are in the more successful growing in less favorable natural, primarily soil conditions, the more suitable it is for ensiling and the longer it stays on one planted plot. Since it is predominantly an energy (carbohydrate) nutrient, the possibility of ensiling the green biomass of sunchoke in a mixture with 25, 50 and 75% fresh lucerne (25% dry matter) was investigated. The obtained results show that with the increase of lucerne participation, the nutritional value of silage increases, but the quality decreases. In addition to its role in conventional feed production, sunchoke can be an important plant in the system of organic production, production for industrial processing and for extensive cultivation in hunting grounds.

Association of genetic variants of β-lactoglobulin (β-Lg) on milk traits of Montenegrin autochthonous sheep breed -Jezeropivska sheep was studied. Polymorphisms within ovine β-Lg genes were detected using PCR-RFLP method by RsaI restriction endonuclease. Milk yield and milk composition parameters during lactation were determined by using the standard ICAR procedures.The obtained results showed a prevalence of A allele (0.625) compared to B allele (0.375), while the frequencies of genotypes were: 0.364 (AA), 0.523 (AB) and 0.113 (BB). No statistically significant differences in duration of lactation and total milk yield between these three genotypes were found.Daily milk yield was the highest (0.70 kg) in ewes with BB genotype βlactoglobulin then AB genotype follows (0.60 kg) and AA (0.54 kg) genotype. Genotype AA of Jezeropivska breed was linked with the higher protein content (5.86%). The protein content in the milk of AB and BB genotype was the same (5.64%). Significant association between AB genotype of β-lactoglobulin gene with higher lactose content (4.67%) was found.The results presented in this study could be useful in improvement of the concept of conservation and sustainable use of this autochthonous sheep breed, while gene of β-Lg as a potential marker in improving milk traits of sheep.