Pramenka Sheep Research Articles

Hematological and blood biochemical variations in Pramenka sheep under thermal stress conditions

Climate change is one of the greatest global concerns regarding livestock production. The indigenous Pramenka sheep is well known for its ability to survive in difficult environmental conditions, although there is insufficient scientific evidence. This study aimed to evaluate the seasonal variations in some hematological and blood biochemical parameters in two strains of Pramenka sheep – Hercegovačka and Dubska, under natural thermal stress conditions. The calculated Temperature-Humidity Index (THI) data indicated mild to severe heat stress in the localities where the Hercegovačka Pramenka strain was being held, while cold stress was found in all the examined localities. Numerous statistically significant differences in hematological parameters were found between seasons, and within and between the two Pramenka strains. The Dubska strain exhibited significantly higher levels of red blood cells (RBC) and packed cell volume (PCV) compared to Hercegovačka, whereas the Hercegovačka strain displayed significantly higher white blood cells (WBC) and platelet (PLT) levels in comparison to Dubska. Similar patterns were noticed in the blood biochemical parameters - the Dubska strain had more seasonal variations compared to the Hercegovačka Pramenka. During the winter, the Hercegovačka strain demonstrated significantly higher levels of total protein (TP), albumin (ALB), urea (UREA), and creatine kinase (CK) compared to Dubska. Conversely, during the summer, the Hercegovačka strain exhibited significantly higher globulin (GLO) levels, whereas the Dubska strain showed higher levels of ALB and chlorine (Cl). On the basis of our results, both Pramenka strains showed a high adaptive capacity to harsh environmental conditions, the Hercegovačka Pramenka being more adapted to heat stress, and Dubska to cold stress conditions.

Referentne vrijednosti za odabrane hematološke i biokemijske parametre u pelagonijske pramenka ovce

The Ovcepolian type of Pramenka sheep is most prevalent in Pelagonia region. It is considered a valuable source of genetic diversity, characterised with a number of beneficial traits. Haematology and biochemistry measurements is important for health assessment of animals. The aim of this study was to determine the reference ranges for selected haematology and biochemistry parameters in the Pelagonian Pramenka sheep breed. The study was carried out on 55 clinically healthy, non-pregnant sheep, 1 to 3 years old, during spring season, from three different locations in the Pelagonia region, North Macedonia. Blood samples were collected from the jugular vein into vacuum tubes with an anticoagulant for haematological analysis and vacuum tubes free of anticoagulant for biochemical analysis. Reference values may be more adequate as it is later, for biochemistry parameters. Reference values for hematology parameters were: leukocytes, lymphocytes, midsize cells, cells correlating to monocytes, eosinophils, basophils, blasts and other precursor white cells, granulocytes, haemoglobin, haematocrit, erythrocytes, erythrocyte indices (average volume per litre, average haemoglobin in erythrocytes, average haemoglobin concentration per litre, and platelets). Reference values for biochemistry parameters were: total proteins, albumins, total bilirubin, total cholesterol, creatinine, glucose, HDL-cholesterol LDL-cholesterol, triglycerides, urea, aspartate aminotransferase, alanine amino transferase, alkaline phosphatase, glutamyl transferase, lactate dehydrogenase, and the concentrations of calcium, magnesium and inorganic phosphate. Most obtained values were comparable to other strains of Pramenka sheep. There was a clear deviation of certain reference values compared to the literature. Further analysis should be conducted to determine the reference values in rams and lambs.

Physico-Mechanical Properties of Dupska Pramenka Wool as Breed Characterization Descriptors

Summary The characterization of animal genetic resources includes morphometric, production and genetic characterization. This paper aims to determine the annual yield, staple length, and physico-mechanical properties of the wool of the Dupska Pramenka sheep. The average annual wool yields of a total of 130 ewes and 14 rams enrolled in the study were 2.120 kg and 3.340 kg, respectively. Wool samples were taken from the left shoulder, posterior rib, and pelvis of a total of 50 sheep (36 ewes and 14 rams). The lengths of wool staples collected from three body sites of the ewes were 20.92 cm, 21.75 cm, and 22.25 cm, respectively. The lengths of wool staples collected from three body sites of rams were 23.50 cm, 22.14 cm, and 23.64 cm, respectively. The height and length of wool fibers of the ewes were 21.97 cm and 22.85 cm on the shoulder, 22.38 cm and 23.10 cm on the posterior rib, and 23.06 cm and 23.77 cm on the pelvis. The height and length of wool fibers of the rams were 22.00 cm and 22.89 cm on the shoulder, 22.54 cm and 23.26 cm on the posterior rib, and 22.61 cm and 23.40 cm on the pelvis. The average fineness of wool fibers of the ewes was 43.08 µ, whereas the fineness of wool fibers of the rams was 45.43 µ. The Dupska Pramenka sheep were found to have mixed fibers: axillary (over 45µ), accounting for51.64% in the ewes and 54.91% in the rams, and transitional (30–45µ), accounting for 28.76% in the ewes and 32.80% in the rams. Fiber fluff (10–30µ) accounted for 19.83% and 12.98% in the fleeces of ewes and rams considered, respectively.

Influence of Heat Stress on Body Temperatures Measured by Infrared Thermography, Blood Metabolic Parameters and Its Correlation in Sheep.

The aim of this research is to examine the influence of heat stress (HS) on body temperature (BT) measured rectally (RT) or by infrared thermography (IRT) of the nose (NT), eye (ET), leg (LT) and abdominal (AT) regions in intensively and extensively breed sheep and to detect a correlation between body temperature and metabolic response in sheep. A total of 33 Wurttemberg × Sjenica Pramenka sheep breeds were examined, 17 ewes were from outdoors and 16 were from indoor housing systems during three experimental periods (thermoneutral period, severe HS and moderate HS). Sheep under HS have a higher BT, and the magnitude of BT measured by infrared thermography (IRT) was higher than RT. LT and AT showed positive linear correlations with the temperature-humidity index (THI), while other ways of measuring BT did not give statistically significant correlations. Sheep under HS showed higher cortisol, insulin, total protein, albumin, urea, creatinine, bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, lactate dehydrogenase, creatine kinase and index of insulin resistance, with lower values of triiodothyronine (T3), thyroxine (T4), non-esterified fatty acids, beta-hydroxybutyrate (BHB), glucose, calcium, inorganic phosphates, magnesium and cholesterol. BT and metabolic response were different in the function of the housing method of sheep. LT and AT showed a significant correlation with almost all blood parameters, and the strongest connections were made with T3, T4, BHB and the revised quantitative insulin sensitivity check index of insulin resistance. The abdomen and legs are good thermal windows because LT and AT are good summative responses to external ambient THI and internal metabolic changes in sheep under heat stress.

Comparative exterior measures of pramenka sheep raised in three localities in Bosnia and Herzegovina

Comparative exterior measures of pramenka sheep raised in three localities in Bosnia and Herzegovina

Morphometric characterization and body measurment correlations in Lipska Pramenka sheep

Lipska sheep is an autochthonous Serbian population from the group of Pramenka (Zapfel) sheep, bred in the area around Smederevo, Pozarevac and Mladenovac. The average weight of male animals (BW) is 95 kg and 62 kg of female animals. Other measurements of female animals are: wither height (WH) 74 cm, body length (BL) 78 cm, chest width (CW) 23 cm, chest depth (CD) 40 cm and hearth girth (HG) 91 cm. In the last sixty years, adult female animals gained in average ten kilograms of weight. Other linear measures also increased. The increase is a consequence of better animal management, especially improved diet. Since the reduction of the size of the population, larger animals have dominated, which probably caused the change in the genetic constitution of the breed. Female animals of Lipska sheep are higher compared to the animals of other fifteen Pramenka breeds with the exception of Istrian sheep. The area from which Lipska sheep originates has better soil and richer vegetation compared to the areas of other Pramenka breeds. Partial correlations corrected for weight between individual linear measures were positive, with values between 0.196 and 0.814. Most correlations range between 0.30 and 0.55. Body measurements were studied with ANOVA on females only. The effect of flock influenced all linear measures with the exception of CW, whereas the age of animals had no effect on BL, CW and CD. The increase of individual linear measures was 0.5 to 2.1 mm per kg of BW. The increase of most body measurements from the first to the fifth year was statistically significant (P<0.05).

The influence of season and age on the levels of lipids, lipoproteins and enzymes in the serum of Lička pramenka sheep

This study aimed to identify seasonal and age related variability in triglycerides (TRI), paraoxonase (PON), stimulated PON (PON I) and cholesterol (CHOL, HDL, LDL) in extensively reared Lička pramenka sheep. The study was conducted 30 randomly chosen non-gravid Lička pramenka sheep on an extensive farm, grouped into three age groups in the Karlovac County, Croatia. Blood was collected by venepuncture of the jugular vein, twice in one year - the first sampling in spring (April) and the second in autumn (October). The results showed that age had no significant effect on any of the investigated indicators, while seasonality significantly affected five out of the six parameters examined. Significantly higher levels of serum lipid components in autumn can be explained by the influence of the traditional way of rearing and feeding Lička pramenka sheep. Furthermore, the results of PON I in all three age groups showed that the sheep are well adapted to the environment and to the rearing system. Future research should be carried out on higher number of farms, and should include more sheep in order to determine objective benchmarks for serum lipids and the enzymes connected to those lipids.

Nasljeđivanje porodne mase kod križanaca Istarske, Awassi, Istočnofrizijske i Travničke pasmine ovaca u Hrvatskoj: studija sa jedne farme

The purpose of the study was to estimate the influence of the additive and non-additive genetic effects on the birth weight, using two different crossbreed models. Data on 1176 birth weights were collected. The animals were crosses, with different ratios of Awassi, East-Friesian, Istrian, and Travnik Pramenka sheep breed. The focal breed in this study was Istrian, which is an autochthonous breed in Croatia. In both models mixed procedure was used with random effect of sire and fixed effects of sex, year and month of birth, litter size, and direct inbreeding. The first model contained the additive breed effects, while the second model additionally included non-additive effects of heterosis and recombination loss. Sex, litter size, year and month of birth significantly affected birth weight in both models. Effect of direct inbreeding was negative and significant only in second model. Significant positive additive breed effect was estimated for Awassi breed in both models. The East-Friesian additive breed effect was positive in both models, but it was significant for the first one only. The positive and significant heterosis effect for the birth weight was estimated for the crosses between East-Friesian and Travnik Pramenka, as well as between Travnik Pramenka and Istrian breed. Same crosses showed significant and positive effect of recombination loss. The negative effect of recombination loss was estimated for the crosses of Awassi breed.

Morphometric characterization of Pirot pramenka

The strategy of conservation of endangered sheep populations implies morphological and genetic characterization, as basic preconditions for their conservation. The aim of this study was to determine the morphometric characteristics, their correlations and the index of physical development of Pirot pramenka, which has the status of the most endangered population in Serbia. The measuring was performed on 30 sheep, aged 3 years, reared in the area of Stara Planina. The descriptive statistical procedure was performed using the statistical package Statistica (version 8). The average height at the withers was 56.31 cm, body length 62.93 cm, chest width 18.37 cm, chest depth 25.96 cm, chest circumference 77.59 cm, shin circumference 6.70 cm. The strongest and significantly positive correlation (P <0.05) was found between chest depth and height at withers (0.65), body length (0.58) and body weight (0.56). Pirotska pramenka has slightly higher indices of format, chest and massiveness, in relation to breeds Vitoroga Zuja and Travnik Pramenka. These morphometric traits suggest that, compared to previous research, the body frame of Pirot pramenka sheep did not change significantly, which means that there were no crosses with other breeds due to geographical isolation and enthusiasm of breeders to preserve the indigenous Pirot pramenka which was the starting point for following authentic brands: Pirot lamb, cheese and carpet. Hence the biological and moral imperative: to preserve this highly endangered population.

Evaluation of lactation models in pasture-based dairy ewes in Bosnia and Herzegovina

Milk of Kupres, Privor and Stolac dairy ewe breeds is used for the production of the fine cheese varieties. To the best of our knowledge there are no information about milk production and milk composition of these pasture-based dairy ewes. The aim was to determine the best lactation curve model in autochthonous pasture-based dairy ewes in Bosnia and Herzegovina. Milk production was recorded and milk composition sampled (milk fat and protein) during early, mid and late lactation in 129 Kupres, 141 Privor and 129 Stolac pramenka ewes. Four lactation models (Wilmink, Cubic, Ali-Shaeffer and Guo-Swalve) were compared and selected based on the lowest coefficient of determination and root mean square error. The Guo-Swalve model described all of the measured variables most successfully. Kupres pramenka dairy ewe was the highest producing breed with 139 kg of milk during 175 days of lactation (0.79 kg/d; between lactation day 50 to 225) and showed the standard lactation curve. Privor pramenka produced 118 kg of milk during 175 days of lactation (0.67 kg/d) and Stolac pramenka 101 kg of milk during 175 days of lactation (0.58 kg/d). Both showed atypical constantly decreasing shape of the lactation curve common in low producing dairy ewes. The prediction of milk yield and milk composition from the Guo-Swalve model could be used by the national breeding program for the Kupres, Privor and Stolac pramenka sheep breeds. Additional research during a more stable management conditions is recommended for Privor and Stolac pramenka.

Concentrations of mercury and other elements in ewes’ milk: Effect of lactation stage

There is an increased production and demand for ewes’ milk in the Republic of Croatia, as well as globally. There is also a growing concern about its quality, since milk from farm animals may become contaminated with mercury and other toxic elements. Thus, the aim of this paper is to determine the influence of lactation stage on the ewes’ milk quality in western Croatia by considering concentrations of mercury and other elements in ewes’ milk. The research was conducted on 36 Travnik pramenka sheep during different lactation stages. The digested milk samples were analysed with continuous flow hydride generation technique by using inductively coupled plasma mass spectrometry. Samples were taken during 40th, 80th and 120th d of lactation. Yield and quality of ewes’ milk was within lactation curve. As lactation progressed, significantly lower concentrations of Hg (on 80th d compared to 40th d) and of Cd (120th d compared to 80th d) were noted, and Hg on 120th d was below the detection limit. Concentrations of Ca and Cu were lower on the 120th d compared to 40th d, while P, Mg, Fe, Zn, Mn, and Se were lower on the 80th and 120th d compared to the 40th d. Concentrations of K, Mo, and Cr differed among all stages of lactation. Regarding toxic elements, the observed low concentrations of Hg, Co, Cd and As suggest that ewes’ milk in western Croatia is safe for human or animal consumption.

Determination of free and total bisphenol A in the urine and feces of orally and subcutaneously dosed sheep by high-performance liquid chromatography with fluorescence detection

An analytical procedure has been introduced to enable a study of the excretion of free bisphenol A (BPA), total BPA and its main metabolite bisphenol A glucuronide (BPA–GLUC). In the experiment, in which 100 μg/kg b. w. BPA was administered daily to one Istrian Pramenka sheep for 5 days with consecutive urine and feces samples being taken, BPA and total BPA were determined in samples using high-performance liquid chromatography (HPLC) with fluorescence detection. Because of their good recovery, precision, and sensitivity, the methods have also proved applicable to further ecotoxicological studies of free BPA, BPA–GLUC and total BPA. The results were subsequently compared with reported field studies of BPA in livestock excreta.

A de novo variant in OTX2 in a lamb with otocephaly

BackgroundOtocephaly is a rare lethal malformation of the first branchial arch. While the knowledge on the causes of otocephaly in animals is limited, different syndromic forms in man are associated with variants of the PRRX1 and OTX2 genes.Case presentationA stillborn male lamb of the Istrian Pramenka sheep breed showed several congenital craniofacial anomalies including microstomia, agnathia, aglossia, and synotia. In addition, the lamb had a cleft palate, a small opening in the ventral neck region, a cystic oesophagus and two hepatic cysts. The brain was normally developed despite the deformed shape of the head. Taken together the findings led to a diagnosis of otocephaly. Whole-genome sequencing was performed from DNA of the affected lamb and both parents revealing a heterozygous single nucleotide variant in the OTX2 gene (Chr7: 71478714G > A). The variant was absent in both parents and therefore due to a de novo mutation event. It was a nonsense variant, XM_015097088.2:c.265C > T; which leads to an early premature stop codon and is predicted to truncate more than 70% of the OTX2 open reading frame (p.Arg89*).ConclusionsThe genetic findings were consistent with the diagnosis of the otocephaly and provide strong evidence that the identified loss-of-function variant is pathogenic due to OTX2 haploinsufficiency. The benefits of trio-based whole-genome sequencing as an emerging tool in veterinary pathology to confirm diagnosis are highlighted.

The effect of the botanical composition of pastures on the immune status of the Lika Pramenka sheep breed

Procjena botaničkog sastava pašnjaka na različitim područjima s posebnim osvrtom na udjele terpena, koji osim učinka na terpenski profil arome mesa preživača mogu imati i potencijalni imunomodulacijski učinak, od bitnog je interesa suvremenog ovčarstva u R. Hrvatskoj. U istraživanjima u okviru ovog rada, pokazano je da ljekovite svojte bogate terpenima poput gospine trave (Hypericum perforatum L.), stolisnika (Achillea millefolium L.) i matičnjaka (Melissa officinalis L.) zbog statistički značajno veće učestalosti, gustoće i pokrovnosti na pašnjacima Velike Crkvine, u odnosu na pašnjake u Kvarte, potencijalno utječu na bolji imunosni status ovaca. Stoga su u ovom radu dobiveni rezultati znanstvena preporuka za daljnju procjenu biljnog sastava pašnjaka u Velikoj Crkvini tijekom istraživanja HRZZ projekta IP-2016-06-3685 u cilju postizanja dodatnih saznanja o učinku terpena na zdravlje i aroma sastav janjećeg mesa i to sve u svrhu proizvodnje inovativnih funkcionalnih proizvoda od janjećeg mesa.

DNA MICROSATELLITE INFORMATIVENESS, ALLELE FREQUENCIES AND THEIR DISTRIBUTION IN THE GENOME OF MACEDONIAN AUTOCHTHONOUS SHEEP POPULATIONS

As a result of natural selection, management system, environment pressure, different populations of Pramenka sheep in South East Europe developed distinctive productive and phenotype characteristics which are sufficient to distinguish them. In this study, the informativeness of fifteen DNA microsatellite markers in the genome of 105 individuals from three indigenous sheep populations in the country (Sharplaninian, Karakachanian and Ovchepolian) was analysed. In overall population, 281 different alleles were observed. The average number of alleles per locus in total population was 18.73, the mean He in overall population was 0.824, so all loci were highly polymorphic with PIC value higher than 0.5. Mean number of alleles per locus, at population level, were 12.13, 11.53 and 13.27 alleles in the genome of Sharplaninian, Ovchepolian and Karakachanian sheep populations, respectively. Results from this research will improve knowledge of the sheep genetic resources in the country at DNA level and will provide appropriate information for further conservation.

A New Method of Assessing Sheep Red Blood Cell Types from Their Morphology.

Simple SummaryHaematological tests are an important diagnostic tool for animal diseases. However, little is known beyond the standardly used haematological methods in sheep, especially those in which the detection of sheep red blood cells (RBCs) shape changes is crucial. Our goal is to obtain sheep RBC morphometric parameters as well as RBC subpopulations based on their morphometric parameters. Morphometric parameters of RBC size and shape were determined from stained blood smears using SFORM, a computer-assisted program for automated cell morphometric measurements. Based on their morphometric parameters, three RBC subpopulations were obtained using principal component and cluster analysis: the smallest and most elongated RBCs, the biggest and most rounded ones, and RBCs of average size and shape. When the values of RBC haematological parameters were higher or above the physiological range, a significantly higher proportion of both average size and shape RBCs, as well as the biggest and most rounded RBCs, was obtained. Since they were obtained from healthy animals, these results indicated the importance of determining morphometric parameters of RBCs and the proportion of each RBC subpopulation, which could serve as a basis for future possibilities in the diagnostic interpretation of haematological disorders in sheep, especially those for which the detection of shape changes in ovine RBCs is crucial.Data concerning the morphometric parameters of sheep red blood cells (RBCs) obtained using computer-assisted image analysis have not yet been investigated, and there are no data on any analyses of ovine RBC subpopulations based on their morphometric parameters. The aims of this study are to determine the values of RBC haematological and morphometric size and shape parameters, to form groups according to the obtained values of haematological parameters; to determine the differences in RBC morphometric parameters between the formed groups, and to determine RBC subpopulations and their respective proportions in the formed groups. Thirty-six blood samples were collected from the jugular vein of clinically healthy Lika pramenka sheep, aged between 2 and 5 years. Haematological parameters including haemoglobin (HGB), haematocrit (HTC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and RBC distribution width were analysed using a haematology analyser. Haematological parameters were categorized into two groups: those with lower values or values below the physiological range (Groups 1) and groups with higher values or values above the physiological range (Groups 2). Morphometric parameters of RBCs were determined from stained blood smears using SFORM, a computer-assisted program. Significantly higher values of RBC area, outline, convex, minimal and maximal radius, as well as length and breadth were established in Groups 2 compared to Groups 1 of HGB, HCT, MCV, MCH, and MCHC, respectively. Based on the morphometric parameters of RBCs, three RBC subpopulations were obtained using principal component and cluster analysis: ES 1—the smallest and most elongated RBCs, ES 2—the biggest and most rounded RBCs, and ES 3—average size and shape RBCs. Significantly higher proportions of ES 2 and ES 3 subpopulations, as well as a significantly lower proportion of ES 1 subpopulation, were established in Groups 2 compared to Groups 1 of HGB, HTC, MCV, and MCH, respectively. It can be concluded that ovine RBC subpopulations, based on their morphometric parameters, can be obtained by using computer-assisted image analysis of RBC morphometry and multivariate statistical methods, including principal component and cluster analysis. RBC morphometry, including classification into subpopulations, could serve as a basis for future possibilities in the diagnostic interpretation of anaemic syndromes in veterinary medicine, especially in normocytic, macrocytic, and microcytic anaemias in sheep.

Differentiation of some Pramenka sheep breeds based on morphometric characteristics.

For the purpose of the morphometric characterization and differentiation of local sheep breeds that belong to the group of breeds called Pramenka or Zackel, two Slovenian (Bela Krajina and Istrian Pramenka) and four Montenegrin sheep breeds (Bardoka, Sjenička, Pivska Pramenka, and Zeta Žuja) were studied. The variation of morphometric measures and nine morphometric indices were analysed. Principal component analysis (PCA) was applied in order to provide an easier description of body size and shape. Regarding body size, the Sjenička breed was one of the largest breeds (body weight 76.4 kg, wither height 72.7 cm, chest circumference 100.3 cm), while Zeta Žuja had the smallest body size (37.1 kg, 64.8, and 81.9 cm). On the other hand, Slovenian Istrian Pramenka had the largest body length, chest depth, chest width, and rump width among all included breeds (79.4, 33.6, 22.7, and 21.2 cm). Bela Krajina, Istrian Pramenka, and the Sjenička breed, according to the index of body frame (IBF) value (107–114), have a rectangular body frame, Bardoka and Pivska Pramenka have a square body frame (99.3–100), and Zeta Žuja has a short body frame (91.8). The PCA of all morphometric parameters extracted three components accounting for 96.6 % of the cumulative variance. An unweighted pair–group method with arithmetic mean (UPGMA) cluster analysis by Euclidian distance shows diversity among the studied breeds, through it grouped Pivska Pramenka with Sjenička and Istrian with Bela Krajina Pramenka in two clusters, while Bardoka and Zeta Žuja were clustered separately.

Biochemical and Endocrine Profiling of Bosnia and Hercegovina, s Native Pramenka Sheep

Biochemical and Endocrine Profiling of Bosnia and Hercegovina, s Native Pramenka Sheep

Effect of mother’s age on body weight of lambs from birth to weaning in various strains of domestic sheep Pramenka

This study has been conducted on the domestic sheep Pramenka that is a dominant breed in Serbia. The purpose is to determine the effects of mother?s age on suckling and growth of lambs, and to find out at which week the lambs are normally weaned. Research was carried out on 1800 lambs of four strains (Svrljiski, Pirotski, Sjeni?ki, Sarplaninski) of sheep Pramenka (450 lambs per strain) for body weight. The weight of lambs was measured at the time of birth, 30, 60 and 90 days after birth during three years of experiment (2011-2013). Obtained results refer to variability of body weight of lambs at the time of birth, 30, 60 and 90 days after birth depending on mother?s age within each of four strains of Pramenka sheep. At the time of birth, the highest average weight (3.79 kg) of lambs was found in second age group of Pirotska genotype, while the highest average weight in third age group was found in remaining three Svrljiska (3.91 kg), Sjeni?ka (3.74 kg) and Sarplaninska (3.97 kg) strain of Pramenka sheep. Thirty days after birth the highest average weight of lambs was found in the second age group of Pirotska genotype (9.36 kg), in the first age group in Svrljiska (9.89 kg), while the highest average weight in third age group was found in remaining two Sjeni?ka (9.51 kg) and Sarplaninska (9.41 kg) strain of Pramenka sheep. Sixty days after birth, the highest average weight of lambs was found in third age group of Pirotska genotype (15.85 kg), in second age group in Svrljiska (15.51 kg) and Sjeni?ka (15.50 kg) genotypes, while the highest average weight in first age group was found in Sarplaninska (14.45 kg) strain of Pramenka sheep. Ninety days after birth, the highest average weight of lambs was found in second age group of Pirotska (20.58 kg) and Sarplaninska (20.45 kg) genotype, while the highest average weight in first age group was found in Svrljiska (24.38 kg) and Sjeni?ka (23.76 kg) strain of Pramenka sheep. The variability in body weight of lambs at birth, as well at different stages of growth after weaning at early growth stages is influenced by direct maternal genotype, strains of Pramenka sheep and age of ewes.

Strategy for Sustainable Development and Utilization of Sheep and Goat Resources in Serbia

The aims of this study were to determine the status of small ruminant production in Serbia and to provide projections for their sustainable use with optimal strategy of genetic improvement of sheep and goats in the future. For sustainable sheep and goat production, it is necessary to know a number of biological, technological, organizational and market factors. Number of sheep in Serbia during the past two decades fell by about 20%. This country grows more than 1.7 million sheep. In terms of breed structures, most of the populations are indigenous Pramenka sheep (80%), while the remaining 20% are Tsigai, Merinolandschaf, Ile de France, Pirot improved, Mis sheep, and other less important populations, as well as the crossbreed with foreign and domestic sheep. Interest of goat rearing is constantly increasing in last years for 20-30%. In regard to the breed structure, the least represented are goats of Alpine breed – approx. 2- 3%, White Serbian goat - 15%, different types of crosses – approx. 35% same as goats of low land Balkan type, and approx. 12% of high land Balkan type. Strategy of sheep and goat breeding programs in Serbia is focused on the improvement of indigenous breeds, because they are less demanding, and most importantly, the input is lower and their products have higher quality. Keywords: sheep; goat; sustainable; resources; meat; milk