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The birth weight of lambs has an essential role in satisfying sheep production. Also reflected as primary factor later development of young organism. In the study included: gestation length, sire (two sires in each genotype during parenting), sex of lambs at birth, the birth weight of single lambs from well nourished mature ewes of the next genotypes: Miss (1), Wurttemberg (2) and Ile de France (3). The highest birth weight was obtained in genotype 3 with an average birth weight of 4.63 kg in sire 2 and 4.44 kg in sire 1 with a difference of 0.19 kg. Gestation length of genotype 1 ranged from 144 to 153 days; genotype 2, from 148 to 154 days and the genotype 3, from 144 to 151days. The highest average birth weight in genotype 1 with gestation length of 153 days weighed 5.10 kg. Average birth weights of male lambs in all genotypes were higher than the females. There were a very significant effect of genotype, sire, gestation length on birth weight of lambs (P (lt) 0.01), but sex have no significant effect on birth weight of lambs (0.065;P>0.05). The result achieved therefore can be explained that the effect of genotype, sire and gestation length and the interaction between subjects effects such as the next: Sire*Gestation length; Sire*Sex; Gestation length*Sex; Sire*Gestation length*Sex were highly and significantly affected the birth weight of lambs (P (lt) 0.01; P (lt) 0.05). The interactions between subjects' effects will be a good indicator to be acquainted more on their influence in a certain trait., Masa jagnjadi na rođenju ima bitnu ulogu u proizvodnji ovaca. Takođe se ogleda i kao primarni faktor kasnijeg razvoja mladog organizma. U radu su ispitivani sledeći faktori koji utiči na masu pri rođenju: genotip, otac, trajanje bremenitosti i pol. Istraživanje je obavljeno u populacijama Miss (1), Virtemberg (2) i Il de Frans (3). Najveća porođajna masa je dobijena kod genotipa 3 i to 4,63 kg od oca 2 i 4,44 kg od oca 1, sa razlikom od 0,19 kg. Trajanje bremenitosti genotipa 1 kretalo se u rasponu od 144 do 153 dana, genotipa 2 , od 148 do 154 dana i genotipa 3, od 144 do 151 dan. Najveća prosečna masa od 5,10 kg zabeležena je kod genotipa 1, sa trajanjem gestacije od 153 dana. Prosečne mase pri rođenju kod muških jagnjadi u svim genotipovima bile su veće od ženskih. Utvrđen je veoma značajan efekat genotipa, oca i trajanja bremenitosti na porođajnu masu jagnjadi (P (lt) 0,01), ali pol nije imao značajan uticaj na masu jagnjadi (0,065 ; P>0,05). Rezultati dobijeni u ovim istraživanjima pokazuju da su efekti genotipa, oca, trajanja bremenitosti i interakcije između efekata kao što su : otac *dužina bremenitosti; otac *pol; dužina bremenitosti *pol; otac *dužina bremenitosti *pol, vrlo značajno i značajno uticali na porođajnu masu jagnjadi (P (lt) 0,01, P (lt) 0,05) ispitivanih genotipova. Interakcije između efekata su dobar pokazatelj boljeg upoznavanja njihovog uticaja na masu tela jagnjadi pri rođenju, koja je od ključnog značaja za kasniji razvoj mladog organizma.

The fastest phase of growth, observed in young animals, is often assumed to be linear, and linear regressions or ratios between BW gain and time are used to model growth. However, growth curves, due to their flexibility, are likely to be more suitable to describe even early growth. The research was performed in the region of Sharplanina Mountain in the population of the local Šarplanina breed of sheep. The following traits of lambs were considered: BWB, BW30, BW60 and BW90. Statistical analysis was conducted using the Pearson's correlation and multivariate linear regression model. This involved computing all possible and the best subset regression equation. Each equation was then assessed by its coefficient of determination (R2) and the constant based on the number of variable that used for the prediction. Results showed that weight of lambs from birth to weaning increased by about six times. Specifically lambs achieved an average total gain of 17.66 kg, or 196 g per day. There were a very significant correlation (P (lt) 0.01) between BWB and BW30, BW60 and BW90. Likewise, shown a very significant correlation (P (lt) 0.01) between BW30-BW60, BW30- BW90 and BW60-BW90. Also shown the coefficient of multiple determinations (R-squared R2) was 0.507 which means that 50.7% of the variance BW90, determined variance of the predictor variables represented in the model. Adjusted coefficient of multiple determination (adjusted R2) is 0.506 which means that 50.6% of the variance BW90, determined variance of the predictor variables that are in the model. Any increase in weight of lambs during the observed period of age is associated with an increase of dependent variable BW90. In particular, any increase in BW30 to 1 kg, is associated with an increase in BW90 to 1.928 kg., Istraživanje je sprovedeno u regionu Šar planine u populaciji lokalne šarplaninske rase ovaca. Sledeće osobine jagnjad su posmatrane: masa pri rođenju, sa 30,60 i 90 dana uzrasta (BWB, BW30, BW60 i BW90). Statistička analiza je sprovedena primenom SPSS paketa. Izračunate su Pearson korelacije i multivarijantna linearna regresija. To je značilo računanje svih mogućih i najboljih podskupova jednačina regresije. Svaka jednačina je ocenjena kao i njen koeficijent determinacije (R2). Rezultati su pokazali da je masa jagnjadi od rođenja do odbijanja povećana za oko šest puta. Konkretno jagnjad su ostvarila prosečan ukupan prirast od 17,66 kg, ili 196 g dnevno. Utvrđena je vrlo značajna korelacija (P (lt) 0,01) između BWB i BW30, BW60 i BW90. Isto tako, pokazala se veoma značajna korelacija (P (lt) 0,01) između BW30-BW60, BW30-BW90 i BW60-BW90. Takođe, dobijeni koeficijent višestruke determinacije (R-skuared R2) znači da je 50,7% varijanse BW90, determinisano varijansom prediktorskih varijabli predstavljenih u modelu. Korigovani koeficijent višestruke determinacije (R2 prilagođeni) je 0.506, što znači da je 50,6% varijanse BW90, uslovljeno varijansama prediktorskih varijabli koje su u modelu. Svako povećanje mase jagnjadi u toku posmatranog perioda života je povezano sa povećanjem zavisno promenljive BW90. Praktično, svako povećanje BW30 za 1 kg, je povezano sa povećanjem BW90 za 1.928 kg.

This paper describes a procedure of laparoscopic insemination (LAI) performed in 42 Ile de France ewes with deep-frozen rams' semen. Frozen semen doses was imported from France, originating from two rams (A and B), and used intermittently in three LAI cycles on different females. The ewes were examined ultrasonographically for pregnancy, two months following insemination and data of lambing were recorded at the end. Total achieved lambing rate was 61.90% (26/42) and total number of lambs was 49 (prolificacy 1.88; 1.16 lambs per sheep included in LAI protocol). Three labs from 2 ewes were stillborn and one dyed at 10th day after lambing. Lambing rates for rams A and B were 53.85% (14/26) and 75.00% (12/16), respectively. Introduction of laparoscopic insemination of sheep with imported deep-frozen semen of top quality rams, gaining technical experience and achieving conception rate over 65% could make this technique acceptable in improving genetic potential of top quality sheep flocks., U radu je opisan postupak laparoskopskog osemenjavanja (LAO) primenjen kod 42 ovce rase Ile de France duboko zamrznutim semenom. Tokom tri ciklusa osemenjavanja naizmenično je korišćeno seme dva ovna (A i B), uvezeno iz Francuske. Nakon dva meseca od osemenjavanja ovce su pregledane na sjagnjenost ultrasonografskom metodom i analizirani su podaci o jagnjenju. Ostvarena je koncepcija od 61,90% (26/42) i dobijeno je ukupno 49 jaganjaca (indeks jagnjena 1,88 po ojagnjenoj ovci, odnosno, 1,16 jagnjeta po ovci uključenoj u protokol LAO). Tri jagnjeta od dve ovce bila su mrtvorođena i jedno jagnje je uginulo 10. dana nakon jagnjenja. Sjagnjenost od semena ovna A iznosila je 58,85% (14/26) a od ovna B 75,00% (12/16). Uvođenje laparoskopskog osemenjavanja ovaca, uvoz duboko-zamrznutog semena vrhunskih ovnova, sticanje iskustva i ostvarenje koncepcije od preko 65% može ovu tehniku učiniti prihvatljivom u popravljanju genetskog potencijala kvalitetnih stada ovaca.

Some phenotypic and genetic trends on growth traits of lambs are observed. The research implicated lambs of two local breeds of sheep: Lipska (LP) and Svrljig (SV). All lambs were weighed for the first time at birth (BWB), and thereafter, regularly in two-week intervals. On the basis of the results during weighing the body weight (BW) were adjusted to the average age: 30 (BW30), 60 (BW60) and 90 days (BW90). Results of the effect of genotype on growth showed a significant effect on the growth traits. Sex of lambs had a significant effect at birth and very significant effect at 30 days, but had no significant effect on weight at 60 (BW60) and 90 (BW90) days. Birth type had significant effect on the body weight from birth to weaning and the highest body weights were recorded in singles. Phenotypic correlations were positive and very highly significant between the growth traits. Genetic correlations were significant, but not between all observed ages of lambs., Važniji fenotipski i genetski trendovi osobina porasta jagnjadi su ispitivani. Istraživanje je obuhvatilo jaganjce dveju lokalnih rasa ovaca: Lipska (LP) i Svrliška (SV). Sva jagnjad su merena prvi put na rođenju (BVB) i nakon toga redovno na dve nedelje. Na osnovu rezultata merenja telesne težine (BW) su prilagođene prosečnoj starosti 30 (BW30), 60 (BW60) i 90 dana (BW90). Rezultati uticaja genotipa na rast su pokazali vrlo značajan uticaj. Pol jagnjadi ima značajan efekat na rođenju i veoma značajan efekat sa 30 dana, ali nije imao značajan uticaj na masu sa 60 (BW60) i 90 (BW90) dana. Tip rođenja ima značajan uticaj na telesnu masu od rođenja do zalučenja, a veće mase su zabeležene kod jedinaca. Fenotipske korelacije su pozitivne i vrlo visoko značajne između osobina prirasta. Genetske korelacija bile su značajne, ali ne i između svih posmatranih perioda uzrasta jagnjadi.

Serbia is one of the countries with the continuous import of breeding sows and boars. Boars are usually imported at the age of 4 to 6 months, in the period when the quality of the breeding males cannot be determined due to sexual immaturity (prepubertal and pubertal age). In this paper, the method and results of semen quality control in 40 imported young boars are described, and also the method of documenting the cause for action claim. In the case of suspicious semen quality it is necesseary to perform at least 3 consecutive controls in one month intervals in order to establish a final estimation of quality and usability of semen. Of 40 imported boars, 4 boars (10%) were subject of complaint due to: azoospermia (1 boar), absence or reduction of total and progressive motility, present sperm agglutination (2 boars), and increased number of pathological forms of spermatozoa (78%, 1 boar). Increased proportion of sperm with unstable chromatin structure (SCSA test - 33.2% and 37.1%) was established in two boars. To initiate the complaint it is necessary to have a sales contract that provides possibility for the reclamation, recognized methods of semen quality control and trustful business relationship between all interested parties., Srbija se svrstava u red zemalja sa kontinuiranim uvozom priplodnih nazimica i nerastova. Nerastovi se uglavnom uvoze u dobi od 4 do 6 meseci, u periodu kada se kvalitet priplodnjaka ne može pouzdano utvrditi usled polne nezrelosti (prepubertetsko ili pubertetska dob nerastića). U ovom radu opisan je postupak i rezultati kontrole kvaliteta semena kod 40 mladih nerastova iz uvoza, kao i način dokumentovanja razloga za pokretanje postupka reklamacije. Kod sumnjivog kvaliteta semena potrebno je izvršiti najmanje 3 uzastopne kontrole u razmaku od po mesec dana, kako bi se donela konačna ocena o kvalitetu semena i upotrebljivosti nerasta za priplod. Od 40 uvezenih nerastova, 4 su reklamirana (10%) usled: azoospermije (1 nerast), odsustva ili smanjenje ukupne ili progresivne pokretljivosti, uz prisustvo aglutinacija spermatozoida (2 nerasta), i povećanog broja patoloških formi spermatozoida (78%; 1 nerast). Kod dva nerasta zabeležen je povećan udeo spermatozoida sa nestabilnom strukturom hromatina (SCSA test - 33,2% i 37,1%). Za pokretanje reklamacije neophodno je imati kupoprodajni ugovor koji predviđa mogućnost reklamacije, priznate metode kontrole semena kao i izgrađen poslovni odnos poverenja zainteresovanih strana.

Objective of this study is to determine the correlation between slaughter traits of kids of Balkan goat breed. Research was carried out in underdeveloped region of Serbia, on altitude of approximately 850 m. Semiintensive breeding system, of housing and care of goats was applied. Results of the study of slaughter properties are presented in this paper, also correlation between certain measures on carcass and carcass sides established in 96 kids of Domestic Balkan breed (gender ratio 50:50), slaughtered at the age of 90 days. Average dressing percentage of warm carcass with head and offal of investigated kid population was 58.19%, whereas the value of the dressing percentage of cold carcass with head and offal was 45.19%. Male kids had statistically significantly (at the level of P (lt) 0.05 and P (lt) 0.01) higher values of carcass mass and linear carcass and carcass side measures compared to female kids. Data on established correlation coefficients between slaughter traits of Domestic Balkan kids reflect presence of highly positive and statistically significant (P (lt) 0.001) correlative dependence. Linear regression coefficients of pre-slaughter body mass of kids, as well as coefficients of determination of linear regression (from 0.41 to 0.99) indicate that this trait has very significant effect on all dressing percentages and carcass and carcass side measures. Considering the expression of slaughter traits and correlation between them in kids of Balkan breed, obtained results should be used for formulating of future programs designed to improve the production of meat from autochthonous goat breeds., Cilj ovog rada je da se utvrdi povezanost (korelacija) između klaničnih parametara jarića balkanske rase koza. Istraživanja su izvedena u nerazvijenom području R Srbije na nadmorskoj visini od oko 850 m. Primenjen je poluintenzivan sistem odgoja, smeštaj i nege koza. U radu su prikazani rezultati ispitivanja klaničnih karakteristika i utvrđena korelaciona povezanost osobina pojedinih mera na trupu i polutkama, kod 96 jaradi domaće balkanske koze (sa odnosom polova 50:50) koja su zaklana u uzrastu od 90 dana. Prosečan randman toplog trupa sa glavom i iznutricama kod jaradi ispitivane populacije iznosio je 58,19% dok je vrednost randmana hladnog trupa sa glavom bez iznutrica bila 45,19%. Muška jarad su imala statistički značajno teža i imala su veće linearne mere trupa (na nivou P (lt) 0,05 i P (lt) 0,01) u poređenju sa ženskim. Podaci o koeficijentima korelacije između ispitivanih klaničnih karakteristika jaradi domaće balkanske koze, odražavaju postojanje visoko pozitivne i statistički značajne (P (lt) 0,001), korelativne zavisnosti. Linearni regresioni koeficijenti telesne mase jaradi pred klanje, kao i koeficijenti determinacije linearne regresije (od 0.41 do 0.99), ukazuju na to da ova osobina veoma značajno utiče na sve randmane i mere na trupu i polutkama. Imajući u vidu ispoljenost i povezanost ispitivanih klaničnih karakteristika kod jaradi balkanske rase koza, dobijeni rezultati treba da se iskoriste u formulisanju budućih programa unapređenja proizvodnje mesa kod autohtnonih rasa koza.

The study of the production capacities of cattleaimed at increase of the capacity of cattle to produce milk, milk fat and calves, greatly depends on pehotypic and genetic variability, heritability and correlation between preferable traits, as well as level of production in the population. Objective of the study was to calculate the variability, phenotypic and genetic correlation of milk and type traits by applying the method of linear scoring of cows in the nucleus herd of Holstein-Friesian bull dams and also to determine their significance in cattle selection. For all studied traits, main variation-statistical parameters were calculated by applying method of least squares: arithmetic mean, standard deviation, variation coefficient, standard error and variation interval. Negative phenotypic correlations between production of milk and type traits ranged from -0.12 (rear leg set, side view) to -0.01 (rump height and body depth) and positive from 0.03 (rear teat placement) to 0.23 (suspensory ligament). Phenotypic correlations between milk fat percentage and type traits varied in the range from -0.08 (fore teat placement) to 0.14 (rump height). Negative genetic correlations between milk production and type traits ranged from -0.11 (rear udder height) to -0.01 (rump width and dairy form), and positive from 0.03 (rear legs set, rear view) to 0.23 (suspensory ligament). Genetic correlations between the percentage of milk fat and type traits ranged from -0.15 (pelvic position) to 0.18 (rump height). Information about phenotypic and genetic correlations between milk and type traits can be of multiple significance in cow selection since it offers possibility to select heads of cattle for multiple traits at the same time., Ispitivanje proizvodnih kapaciteta goveda u cilju povećanja proizvodnje mleka, mlečne masti i broja teladi, u velikoj meri zavisi od fenotipske i genetske varijabilnosti, heritabiliteta i povezanosti poželjnih osobina, kao i nivoa proizvodnje u populaciji. Cilj ovih istraživanja bio je da se u nukleus zapatu bikovskih majki holštajn frizijske rase primenom linearnog metoda ocenjivanja krava izračuna varijabilnost, fenotipska i genetska povezanost osobina mlečnosti i tipa, i njihov značaj u selekciji goveda. Za sve ispitivane osobine primenom metoda najmanjih kvadrata izračunati su osnovni varijaciono-statistički parametri: aritmetička sredina, standardna devijacija, koeficijenti varijacije, standardna greška i interval varijacije. Negativne fenotipske korelacije između proizvodnje mleka i osobina tipa kretale su se u intervalu od -0.12 (položaj zadnjih nogu sa strane) do -0.01 (visina krsta i dubina tela), a pozitivne od 0.03 (položaj zadnjih sisa) do 0.23 (centralni ligament). Fenotipske korealacije između procenta mlečne masti i osobina tipa kretale su se u intervalu od -0.08 (pozicija prednjih sisa) do 0.14 (visina krsta). Negativne genetske korelacije između proizvodnje mleka i osobina tipa varirale su u razmaku od -0.11 (visina zadnjeg vimena) do -0.01 (širina karlice i mlečne karakteristike), a pozitivne od 0.03 (položaj zadnjih nogu otpozadi) do 0.23 (centralni ligament). Genetske korealacije između procenta mlečne masti i osobina tipa kretale su se u intervalu od -0.15 (položaj karlice) do 0.18 (visina krsta). Postojanje informacija o fenotipskim i genetskim korelacijama između osobina mlečnosti i tipa, može imati višestruki značaj u selekciji krava, jer pruža mogućnost odabira grla na više osobina istovremeno.

The possibility for improvement of carcass traits and quality of kid meat of the autochthonous Balkan goat breed by crossing with Saanen breed was investigated in this study. The trial was carried out on one group of Balkan goat kids and three groups of kid crosses of Balkan and Saanen goats with different proportion of Saanen genes: 25, 50 and 75%. Each group had 16 male kids, which were slaughtered at the average body weight of 18 kg. With the increase in the proportion of Saanen genes, the age of kids that reached preslaughter weight decreased, the chilling loss increased and the proportion of fat tissue (kidney and pelvic fat) in the carcass side decreased (P (lt) = 0.05). The crossing also increased the proportion of carcass parts of the first category (leg and loin section), as well as muscle tissue in those parts. The highest proportion of muscle tissue in the thigh (74.91%) and loin section (75.66%) was determined in kids from the group with 75% of Saanen genes, and kids from this group also had the highest proportion of intramuscular fat (2.48%) in samples of m. longissimus dorsi. Slight differences between kid groups were established in indicators of technological meat properties, such as water binding capacity and tenderness, with the increase in the proportion of Saanen genes in the genotype. Sensory score for roasted meat was high, and scores for tenderness and juiciness were slightly higher in kid crosses with 50% and 75% of Saanen genes (P (lt) = 0.05). Results presented in this study confirm the positive effect of crossing the Saanen breed with the Balkan breed on carcass traits and for obtaining meat of more desirable quality.

In this paper are described the most important stressors in intensive sheep production on farms and pastures. Stressors on farms and pastures mostly originate from adverse housing conditions, improper zootechnical procedures, veterinary procedures (treatment, vaccinations, blood tests, surgery), animal husbandry procedures (labeling, weaning, grouping, shearing, shortening the tail, hoof care), unsuitable weather conditions (extreme heat and cold) and insufficient nutrition. The paper puts out special emphasis on the consideration of period of life in which sheep were subjected to additional loads and susceptible to effects of these stressors, such as birth, juvenile period, puberty, oestrus, advanced pregnancy, parturition and the puerperal period., U radu su opisani najznačajniji stresori ovaca u intenzivnim uslovima proizvodnje na farmama i pašnjacima. Stresori na farmama i pašnjacima najčešće potiču od nepovoljnih uslova smeštaja i držanja, nepravilnih postupaka odgajivača, veterinarskih postupaka (lečenja, vakcinacije, vađenja krvi, hirurške intervencije), zootehničkih postupaka (obeležavanje, odbijanje, grupisanje, šišanje, skraćivanje repa, obrada papaka), neodgovarajućih klimatskih uslova (ekstremna toplota i hladnoća) i neodgovarajuće ishrane. U radu se poseban akcenat stavlja na razmatranje perioda života u kojima su ovce podvrgnute delovanju dodatnih opterećenja i podložnije delovanju ovih stresora, kao što su rođenje, juvenilni period, pubertet, estrus, visoki graviditet, porođaj i puerperalni period.

Efficiency of sheep production is conditioned by fertility. According to some authors number of offspring obtained per lambing is more important than gain of weight. Genetic relationships involving reproductive traits were seldom studied. Reproductive traits have low heritabilities, a discrete phenotypic expression, and are expressed only in sexually mature ewes leading to low selection intensities and long generation intervals. Documentation of realized selection response is also often complicated by the low heritabilities of fertility traits. Existence of a major gene affecting prolificacy had been suggested and at that time there were many sceptics who strongly doubted that a trait as complex as reproduction could be profoundly influenced by a single gene. Major genes affecting prolificacy in sheep was founded. A mutation in the bone morphogenetic protein 15 gene (BMP15, also known as GDF9B) responsible for high prolificacy in Inverdale sheep had been discovered and evidence of segregating major genes was being reported from flocks around the world. Development of gene mapping techniques, and locating alleles that are responsible for the fertility of sheep began a new chapter in predicting and controlling the fertility of sheep. The beneficial effects of nutrition on reproduction in sheep are well known. This procedure is known as flushing. The effect of Body Condition Score (BCS), before mating, during mating and after mating period, on reproductive efficiency of different breeds of sheep in the different rearing systems were studied. The farm manager has the ability to control or at least to manipulate the factors that have an impact on fertility., Efikasnost proizvodnje ovaca je uslovljena plodnošću. Prema nekim autorima broja potomaka dobijenih po jagnjenju je važnije od prirasta i mase tela. Genetski uticaji koji uključuju reproduktivne osobine se retko izučavaju. Plodnost ovaca ima nizak heritabilitiet, diskretnu fenotipsku ekspresiju, a izražena je samo u seksualno zrelih ovaca, što dovodi do niskog intenziteta selekcije i dugih generacijskih intervala. Otkriće major gena koji utiču na plodnost je u to vreme otkrilo mnogo skeptika koji su snažno sumnjali da takav kompleks reprodukcije može biti duboko pod uticajem jednog gena. Glavne geni utiču na plodnost kod ovaca i ovnova. Mutacija u koštanoj morfogenetsko proteina 15 gena (BMP15, takođe poznatom kao GDF9B) otkrivena je kod mnogih ovaca širom sveta, kao dokaz segregacije major gena. Razvojem tehnika mapiranja gena i lociranja alela koji su odgovorni za plodnost ovaca, počelo je novo poglavlje u predviđanju i kontrolisanju plodnosti ovaca. Povoljni efekti ishrane na reprodukciju u ovaca su dobro poznati. Ovaj postupak je poznat kao flushing, pred oplodnju. Uticaj kondicije tela (BCS), pred parenje, tokom parenja i posle parenja na reproduktivnu efikasnost različitih rasa ovaca u različitim podizanju sistema su takođe proučavali mnogi ovde pomenuti autori. Farmer putem menadžmenta ima mogućnost da kontroliše, ili bar da manipuliše faktorima koji imaju uticaj na plodnostovaca, a što je takođe predstavljeno u ovom preglednom radu.

The aim of this study was to find out is it possible to presume success of boars sperm cryopreservation, based on controlled exposure to heat stress and to investigate in vitro quality parameters of frozen/thawed sperm of previously selected 6 boars with good results (group 1) and 6 boars (group 2) with bad results on thermo resistance test (TT). In this investigation, ejaculates of 12 chosen of 75 AI boars (Landrace, Large White, Pietrain and Durock breeds) from SVC Velika Plana (Serbia) were used. Tolerance to heat stress was performed by Schaetz (1963) method. Ejaculates were extended with Androhep plus (1:1) and kept during 60 minutes on 41oC. In cryopreservation of boars semen Westendorf et al. (1975) method, modified by Bwanga et al. (1990). Very significant changes of progressive motility rate were observed after spermatozoa exposure to controlled thermal stress. High correlation coefficient of progressive motility rate of both groups of boars, but higher in group 2 for progressive motility rate after thawing and after heat stress treatment was established. Average progressive motility rate of all 12 boars did not differ before and after thawing. Presence of boars of all breeds represented in the SVC (Large White, Landrace, Duroc and Pietrain) in both quality groups confirms the assumption that suitability for cryopreservation of sperm is individual trait. According data analysis, sperm deep freezing success requires previous selection for potential donors, which have to be consider standard quality parameters testing and controlled stress exposure tests., Cilj rada je da se ustanovi da li moguće odrediti da li je sperma nerasta pogodna za krioprezervaciju da se na osnovu izlaganja spermatozioda kontrolisanom toplotnom stresu i da se ispitaju in vitro parametri kvaliteta odmrznutog semena dve grupe od po 6 nerastova čije je seme dobro (1. grupa) ili loše podnelo toplotni stres (2. grupa). U istraživanju su korišćeni ejakulati 12 od 75 nerastova rasa: landras, veliki jorkšir, pijetren i durok (L, J, P, D) iz SVC Velika Plana, odabranih na osnovu testa termorezistencije (TT) i svrstanih u dve kvalitetne grupe. Ispitivanje stepena termorezistencije ejakulata u razređenju Androhep-om plus 1:1 60 minuta na 41 oC, je izvedeno metodom po Schaetz-u (1963). Duboko zamrzavanje sperme odabranih nerastova izvedeno modifikovanim postupkom po Westendorf-u i sar. (1975) i Bwanga-i i sar. (1990). Rezultati TT ukazali su na vrlo značajne promene progresivne pokretljivosti spermatozoida posle izlaganja kontrolisanom toplotnom stresu. Ustanovljen je visok koeficijent korelacije kod obe grupe ali ipak nešto viši kod nerastova 2. grupe za odnos procenta progresivne pokretljivosti spermatozoida posle odmrzavanja i progresivne pokretljivosti posle izlaganja temperaturi od 41oC. Prosečna progresivna pokretljivost spermatozoida svih ispitivanih nerastova se nije značajno razlikovala pre i posle zamrzavanja. Slučajni raspored nerastova svih rasa zastupljenih u SVC (Jorkšir, Landras, Durok i Pijetren) u obe kvalitetne grupe potvrđuje pretpostavku da je pogodnost sperme za krioprezervaciju individualna osobina. Za uspešnu krioprezervaciju sperme nerastova je neophodna prethodna selekcija potencijalnih donora na osnovu rezultata ispitivanja standardnih parametara kvaliteta i testova u kojima se spermatozoidi in vitro izlažu različitim kontrolisanom stresu.

Laboratory animals are essential in research, disease diagnostics and pharmaceutical industry in the production of vaccines and serums, as well as in potency and safety testing of pharmaceutical products. Like domestic - farm animals and pets, laboratory animals originate from ancestors that lived in the wild. For breeding in artifi cial conditions of laboratory and use in experiments for scientifi c and other purposes rodents are most acceptable. As a rule, these are animals that are characterized by small size and high fertility, so it is economically to breed and use. The most frequent and most important species of laboratory animals is the mouse. Good knowledge of physiological, medical, genetical, nutritional, behavioural and other characteristics and needs of laboratory mice is essential for proper growth and use. Questions and principles of ethics and ensuring the welfare of laboratory mice in breeding and utilization are important both for scientifi c and professional as well as for the general public. Principles “3Rs” obligate scientists and professionals to use their knowledge in the development of techniques and technologies in breeding and utilization of laboratory mice in order to be more effective and more humane. In Serbia it is needed to make technological and ethical improvements in breeding and utilization of laboratory animals and thus mice, in scientifi c and other purposes, in accordance with international conventions and scientifi c and professional achievements in the fi eld of laboratory animal science.

The most significant welfare problems in dairy calves in intensive rearing conditions have been investigated in this paper. These problems mainly result from inadequate intake of colostrum (separation from the dam), inadequate ventilation (resulting in inappropriate airflow, low or high temperatures, high humidity and poor air quality), poor floor conditions (wet floor, without bedding), inadequate monitoring of health, exposure to pathogens causing respiratory and gastrointestinal disorders and occurrence of iron deficiency. In addition, on cattle farms in our country welfare problems in calves originate from continuous restocking (no 'all in - all out') and mixing calves from different sources, as well as insufficiently balanced solid food, insufficient access to water and generally poor response of farmer to health problems, especially necessary dietary changes. A special welfare problem is insufficient floor space allowance which results in calf's discomfort., U radu su istraženi najznačajniji problemi dobrobiti kod teladi u intenzivnim uslovima gajenja. Ovi problemi su uglavnom posledica neadekvatnog uzimanja kolostruma (odvajanja od majke), neadekvatne ventilacije (dovodi do neodgovarajućeg protoka vazduha, niske ili visoke temperature, visoke vlažnosti i lošeg kvaliteta vazduha), loših uslova poda (vlažan pod, pod bez prostirke), neadekvatnog praćenja zdravlja teladi od strane odgajivača, izloženosti patogenim mikroorganizmima koji izazivaju respiratorne i gastrointestinalne poremećaje i pojave nedostatka gvožđa. Pored toga, na farmama u našoj zemlji problemi dobrobiti kod teladi potiču od kontinuiranog korišćenja staja (ne 'sve unutra- sve napolje'), mešanja teladi iz različitih izvora, kao i od nedovoljno izbalansirane čvrste hrane, nedovoljnog pristupa vodi i generalno lošeg odgovora farmera na zdravstvene probleme teladi, a posebno neophodne promene u ishrani. Poseban problem dobrobiti teladi su nedovoljne površine individualnih boksova koje rezultiraju u neudobnosti teladi.

The effects of general and special biosecurity measures to prevent introduction of infectious agents in a dairy farm or its spreading from farm were analyzed in details in this paper. Investigations were conducted on five different dairy farm production with different technology and capacity using a questionnaire method (Hristov and Stanković, 2009), as well as scrutinizing their positions in relation to possible sources bio-risks from the near and far away environment. Test results showed that there are serious shortcomings on all observed farms, regarding the possibility of introduction of infectious agents in the production herd, and its possible spread to the environment. Although all fenced and a position of the most of the farms mostly favourable, there are some serious threats to the herd health and farm production, regarding open space and lack of green belt, the uncontrolled presence of wild birds and rodents in facilities and even in feed storage, as well as contact of the employees with other cows not belonging to the farm., U radu su detaljno analizirani efekti preduzetih opštih i posebnih mera biosigurnosti koji se odnose na sprečavanje unošenja infektivnog materijala u farmu muznih krava ili njegovog širenja sa farme. Ispitivanja su obavljena na 5 farmi muznih krava različite tehnologije proizvodnje i kapaciteta metodom upitnika (Hristov i Stanković, 2009), kao i sagledavanjem položaja farme u odnosu na moguće izvore biorizika u bližoj i daljoj okolini. Rezultati ispitivanja ukazuju da na svim posmatranim farmama postoje ozbiljni nedostaci u pogledu mogućnosti unošenja infektivnih agenasa u proizvodni zapat, ali i njegovog mogućeg širenja na okolinu. Iako su sve ograđene, a položaj većine ispitivanih farmi uglavnom povoljan, otvorenost prostora i nedostatak zelenog pojasa, nekontrolisano prisustvo divljih ptica i glodara u objektima za držanje krava pa čak i smeštaj hrane, kao i kontakt zaposlenih sa drugim govedima koja ne pripadaju farmi predstavljaju ozbiljnu pretnju po zdravstveno stanje zapata i proizvodnju farme.

The five most important meadow associations on the Stara Planina Mountain in National Park "Stara Planina" were analysed in order to define initial parameters for determination of grassland potential, as well as natural resources for production of biologically valuable and high quality food and revitalization of agricultural production in hilly-mountainous region. Floristic composition of five meadow associations is presented: Medicago falcate - Festucetum rubrae at three locations around the Pirot, Triflolio - Agrostietum stoloniferae Lj. Mark. 1973, Agrostietum vulgaris Z. Pavl. 1955, two ass. Festucetum vallesiaceae - Agrostietum vulgaris Danon et Blaz. 1978 and Festuco-Agrostietum Horv. (1951) 1982.em Trinajest.1972 one. All five associations are around Dimitrovgrad. First association of Festucetum vallesiaceae - Agrostietum vulgaris Danon et Blaz. 1978 had the highest diversity with the total number of 75 species. The number of species in investigated associations was: grasses from 8 to 23, legumes from 8 to 17 and other species from 21 to 34. Participation of major meadow species based on their mass is presented in the paper. On the basis of their productivity the species belong to the associations of useful grasses, useful legumes and other useful species and weeds. The study of grasslands was done in order to establish production potentials and quality of grasslands used for grazing of small ruminants, i.e. sheep and goats.

The present investigation was carried out to study the influence of environmental factors on the birth weight variability of two breeds of sheep. Animals used in this research were taken from the Pirot and Svrljig indigenous sheep breeds. The data were collected from 1999 to 2009 and were analyzed to determine the effect of the year and season, age of the lamb, weight of the lamb, birth type and sex on the birth weight of lambs. Both sheep breeds were managed in the same farm and under the same farm conditions. Statistical analysis was performed by using GLM procedure of SAS statistical package program. Results showed that young (2 to 3 years) and old (6 to 7 years) mothers gave birth to lighter lambs, while sheep in the middle age (4 to 5 years) gave birth to lambs with the heaviest body weight. However, the differences were respectively significant (P (lt) 0.01). Birth weight of lambs also depended on weight of lamb, although differences in the average body weight of lambs were statistically significant (P (lt) 0.05). Type of birth also had effect on the body weight of lambs at birth in both Pirot and Svrljig breeds (P (lt) 0.05). Body weight of lambs at birth were almost the same for both sexes (3.39 and 3.36 kg for male and female in Pirot breed and 3.48 and 3.43 kg for male and female in Svrljig breed, respectively), though the difference was not statistically significant (P > 0.05). The values of birth weight observed for quite a number of years ranged from 3.27 to 3.52 kg in Pirot and 3.34 to 3.51 kg in Svrljig breed (P (lt) 0.01). Lambs born in the spring-summer season has the heaviest body weight at birth. Conversely, the significant difference (P (lt) 0.05) can only be interpreted as the factor of food source.

This paper gives a detailed analysis of the applied biosecurity measures in the production of boar sperm at a swine reproduction center. Biosecurity indicators (existence of a written biosecurity plan, isolation, introduction of newly acquired animals into the herd, herd health, assessment of the personnel attitude towards equipment, traffic control, attitude towards visitors, feeding and watering control, manure management, disposal of dead animal carcasses, attitude towards other animals, rodents and birds control, sanitation) were viewed and evaluated by rating scale: (5) - excellent, (4) - very good, (3) - good, (2) - sufficient, (1) - insufficient, there are resources for improvement (0) - insufficient, with no resources for improvement. Obtained data were analyzed in the SWOT process, taking into account all the strengths, weaknesses, threats and opportunities for improving the biosecurity level. The situation in the center is rated as very good, with an average rating of 4.15. However, one disadvantage is serious and related to the boar facilities isolation possibilities, taking into account their location and the presence of two types of male breeding animals (boars and bulls) in the same location. Newly acquired breeding animals are purchased from various sources, but with a rigorous regime of control and not at the same time., U radu je detaljno analizirana primena biosigurnosnih mera u proizvodnji sperme nerastova u jednom centru za veštačko osemenjavanje svinja. Sagledani su i procenjeni svi indikatori biosigurnosti (postojanje pisanog plana biosigurnosti, izolacija, uvođenje novonabavljenih životinja u zapat, zdravstveni status zapata, ocena odnosa osoblja prema opremi, kontrola kretanja i prometa, odnos prema posetiocima, kontrola ishrane i vodosnabdevanja, izđubravanje, uklanjanje leševa uginulih životinja, odnos prema drugim životinjama na farmi, kontrola populacija glodara i ptica, sanitacija), i ocenjeni prema skali ocena: (5) - odličan, (4) - vrlo dobar, (3) - dobar, (2) - dovoljan, (1) - nedovoljan, ima resursa za poboljšanje, (0) nedovoljan, nema resursa za poboljšanje. U razmatranju rezultata primenjena je SWOT analiza i utvrđene prednosti, nedostaci, rizici i mogućnosti za podizanje nivoa biosigurnosti. Stanje u centru je ocenjeno kao vrlo dobro, uz prosečnu ocenu 4,15. Međutim, jedan nedostatak je veoma ozbiljan i odnosi se na mogućnost izolacije objekata, uzimajući u obzir njegovu lokaciju i prisustvo dve vrste muških priplodnih životinja (nerastova i bikova) na istoj lokaciji. Nove priplodne životinje se nabavljaju iz različitih izvora, ali uz rigorozan režim kontrole i ne u isto vreme. Svakako, izmeštanje objekata za držanje priplodnih nerastova na drugu bezbednu lokaciju predstavlja složen ali prioritetan zadatak, kojim bi se otklonile brojne pretnje po proizvodnju sperme.

The paper presents results of investigation of milk yield by lactation, by order, and mother's body weight on growth rate of kids of the domestic Balkan goat. Daily weight gains of 376 single kids (168 male and 208 female), in three monthly intervals, and their final body weight at 90 days of age were established. Variability of analyzed traits was presented using descriptive statistics parameters, and differences of growth traits for weight gain of kids resulting from the effect of milk yield of female goats by order of lactation were investigated by single analysis of variance. The effect of independent variables, mothers' milk yield and body weight, on body weight of kids was tested using multiple regression analysis. During the entire suckling period, established average values for kids body weight differed significantly (P (lt) 0.001), increasing from the 1st toward later lactations. At 90 days of age the lowest values were established in kids from the youngest mothers (11.86 kg), while for kids of mothers in the fourth or later lactations these values were higher (13.93 kg). Coefficients of determination indicate that the variability percentage for individual growth traits of kids was in the 0.08 - 0.17 interval, indicating its significance. Both 'b' coefficients (b1 and b2) are positive and statistically highly significant, except for coefficient b2 in the analysis of body weight of kids at birth. The positive sign and high statistical significance indicate a pronounced effect of mother's milk yield and body weight on the body weight of kids up to 90 days of age., U ovom radu prikazani su rezultati ispitivanja uticaja količine mleka u laktaciji po redu, i telesne mase majke na porast jaradi domaće balkanske koze do 90 dana. U cilju ispitivanja razvoja telesne mase jaradi u zavisnosti od količine mleka u laktaciji po redu u toku dojnog perioda ukupno je izmereno 376 jaradi jedinaca (168 muških i 208 ženskih). Varijabilnost analiziranih osobina je prikazana parametrima deskriptivne statistike, dok su razlike u osobinama porasta jaradi koje su nastale pod uticajem mlečosti koza u laktaciji po redu, ispitivane jednostrukom analizom varijanse. Višestruko regresionom analizom ispitivan je uticaj nezavisno promenljivih veličina, mlečnost majke i telesna masa majke, na porast jaradi. Utvrđene vrednosti telesnih masa u toku čitavog dojnog perioda značajno su se razlikovale (P (lt) 0,001) i povećavale od prve ka kasnijim laktacijama, pri čemu su u uzrastu od 90 dana najmanje vrednosti utvrđene kod jaradi od najmlađih koza (11,86 kg), dok su kod jaradi čije su majke bile u četvrtoj i kasnijim laktacijama te vrednosti iznosile 13,93 kg. Koeficijenti determinacije ukazuju na to da se procenat varijabilnosti pojedinih osobina porasta jaradi nalazio u intervalu od 0,08 do 0,17, što ukazuje na njihovu značajnost. Oba 'b' koeficijenta (b1 i b2) su pozitivna i statistički visoko značajna, osim koeficijenta b2 u analizi telesne mase jaradi pri rođenju. Pozitivni predznak i visoka statistička značajnost ukazuju na izražen uticaj mlečnosti i telesne mase majki na porast jaradi do 90 dana.

This paper analyzes the present state of sheep farming in Serbia and provide guidance for sustainable development in the future. It also discusses the challenges of the modern age that may affect the viability of sheep production. Today in Serbia grows less than 1.5 million sheep. In terms of breed structures, most of the population makes indigenous Pramenka sheep (80%), while the remaining 20% are: Tsigai, Merinolandschaf, Ile de France, Pirot improved, Mis sheep, and other less important population, as well as the crossbreed with foreign and local domestic sheep. However, due to the intense process of industrialization, from the second half of the twentieth century until today there is a trend of depopulation, demographic discharge of the village, which has resulted in reducing the farms so that the number of sheep in the past two decades fell by about 30%. The greatest reduction in the number of sheep registered in the nineties. After stabilization, a large decrease in the number of sheep was followed by the 2010th year and by 6% compared to 2008 year. Genetical improvement is significantly increased level of production of all species of domestic animals. However, animals selected for high and efficient production are exposed to greater risk. This primarily refers to the physiological and immunological problems, but would generally be said that all this leads to distortion of harmony between the organism and the environment and the repercussions on the molecular level. Sustainable development of sheep breeding in Serbia must be kept in mind this reality. New challenges facing the sheep breeding of Serbia, stems from a political orientation toward membership in the European Union. Sheep Serbia must find its place in this new challenge., Ovaj rad analizira sadašnje stanje ovčarstva u Srbiji i daje smernice za održivi razvoj u budućnosti. On takođe raspravlja o izazovima modernog doba koji mogu uticati na održivost ovčarske proizvodnje. Srbija danas raspolaže sa nešto manje od 1,5 miliona ovaca. U pogledu rasne strukture, većinu čini pramenkalokalne autohtone ovce, dok preostalih 15- 20% su: Cigaja, Merinolandschaf, Ile de France, Pirotska oplemenjena, novo proizvedena Mis ovca, i druge manje važne populacije, kao i melezi sa inostranim rasama. Međutim, zbog intenzivnog procesa industrijalizacije, od druge polovine dvadesetog veka do danas postoji trend smanjenja seoskog stanovništva i pražnjenja sela, što je rezultiralo smanjenjem farmi, tako da je broj ovaca u poslednje dve decenije opao za oko 30%. Najveći pad broja ovaca registrovan je tokom devedesetih. Posle stabilizacije, veliki pad u broju ovaca je usledio 2010. godine za 6% u odnosu na 2008. godinu. Genetsko unapređenje je poslednjih decenija znatno povećalo nivo proizvodnje svih vrsta domaćih životinja. Međutim, životinje selekcionisane za visoku i efikasnu proizvodnju izloženi su većem riziku. Ovo se prvenstveno odnosi na fiziološke i imunološke probleme, ali bi se generalno moglo reći da je sve to dovelo do narušavanja harmonije između organizma i sredine i posledica na molekularnom nivou. Održivi razvoj ovčarstva Srbije mora imati u vidu ovu realnost. Novi izazovi sa kojima se suočava ovčarstvo Srbije, proističu i iz političke orijentacije ka članstvu u Evropskoj uniji. Zbog svih pomenutih razloga ovčarstvo Srbije mora naći svoje pravo mesto u svetlu novih izazova.

Results of the study of the effect of the level of nondegradable protein in diet on fattening performance and digestibility of nutrients in weaned lambs are presented in the paper. Objective of the study was to establish the optimal level of non-degradable protein in diets for weaned and intensively fattened lambs. Experiment was conducted on 60 lambs of F1 generation: Pirot Pramenka x Wurttemberg x Ile de France, weaned at the age of 60 days and divided into three groups. The effect of use of three concentrated mixtures which differed in the share of protein non-degradable at the level of rumen: 43% (I), 51% (II) and 58% (III). Average daily gain of lambs fed types of mixtures I:II:III was 0.169: 0.205 : 0.227 kg, respectively. Dry matter conversion (kg/kg of gain) on analogue treatments was: 4.54 : 3.71: 3.30, respectively, of energy (MJ NEM/kg) : 33.77: 29.37 : 26.25, and of total proteins (g/kg): 732 : 596 : 549. Level of intake of proteins was not influenced by the treatment considering that the digestibility coefficients recorded were: 52.58% : 51.30% : 55.12%. With the increase of the share of non-degradable protein in concentrate mixtures, the tendency of increase of the digestibility of fat was present: 76.13 : 77.98 : 87.17%, as well as of decrease of the intake of fibre: 67.40 : 45.87: 22.39% and NFE: 83.87 : 76.05 : 82.96%. Values of the dressing percentage of warm carcass with giblets according to nutrition types I:II:III were: 58.70 : 58.02 : 57.42%, respectively., U radu su prikazani rezultati ispitivanja uticaja različitih nivoa nerazgradivog proteina u obroku (43:51:58%) na tovne performanse i svarljivost hranljivih materija kod intenzivno tovljene jagnjadi. Ogled je izveden na 3 grupe po 20 meleza F1 generacije : pirotska pramenka x virtemberg x Ile de France zalučenih u uzrastu od 60 dana. Jagnjad su hranjena lucerkinim senom i izoproteinskim krmnim smešama koje su se razlikovale u pogledu udela nerazgradivog proteina. Dobijeni podaci su obrađeni standardnom statističkom analizom. Prosečna telesna masa jagnjadi na početku ogleda, na tretmanima I: II: III je iznosila: 18,08 : 18,12 : 18,17 kg, a na kraju : 30,78, 33,52 i 35,17 kg, dok je prosečan dnevni prirast bio: 0,169 : 0,205 : 0,227 kg. Po kilogramu prirasta jagnjadi je utrošeno: 4,54 : 3,71 : 3,30 kg suve materije; energije: 33,77: 29,37 : 26,25 MJ; ukupnih proteina: 732 : 596 : 549 g; Stepen usvajanja proteina nije bio pod uticajem ispitivanog tretmana, s obzirom da su koeficijenti svarljivosti iznosili: 52,58% : 51,30% : 55,12%. Sa povećanjem udela nerazgradivog proteina u smešama koncentrata, prisutna je tendencija povećanja svarljivosti masti : 76,13 : 77,98 : 87,17%, a smanjenja stepena usvajanja celuloze: 67,40 : 45,87: 22,39% i BEM-a: 83,87 : 76,05 : 82,96%. Vrednosti randmana toplog trupa sa glavom i iznutricama su iznosile: 58,70: 58,02 : 57,42%. Ova istraživanja su pokazala da su najbolje tovne performanse postigla jagnjad na tretmanu sa 58% NP, dok randman nije bio pod značajnijim uticajem ispitivanog tretmana.

Preservation of necessary level of swine herd health status is the most important aspect of bio-security, farm production and successful welfare protection. It involves a list of bio-security measures which must be essential part of production technology, including good rearing conditions and other prophylactic measures appliance. According to previously performed investigations, a list of elements required to establish standards for bio-security for particular pig farm was created. The list includes elements related to assure spatial., microclimate and hygienic conditions for pigs rearing, care, nutrition and watering, surveillance, regrouping and transport of swine, disease outbreak control, barns equipment and production process organization which are performed by veterinarians and zootechnicians. Bio-security standards must concern necessary level of swine herd health status and organization, size and type of operation and anticipate all compulsory measures for health control and disease spreading prevention, particularly those whose outbreak must be reported. In bio-security plan structure present epidemiological situation, potential herd health and production threats, as well as possible solutions must be concerned., Očuvanje potrebnog nivoa zdravstvenog stanja populacije je najvažniji aspekt očuvanja biosigurnosti i uspeha proizvodnje, kao i dobrobiti svinja, i podrazumeva niz biosigurnosnih mera koje moraju biti sastavni deo proizvodne tehnologije, uključujući dobre uslove smeštaja i držanja i primenu profilaktičkih mera. Na osnovu sprovedenih istraživanja je sastavljena lista elemenata neophodnih za uspostavljanje standarda i izradu planova biosigurnosti za konkretnu farmu svinja. Lista sadrži elemente koji se odnose na obezbeđenja prostornih, mikroklimatskih i higijenskih uslova gajenja životinja, negu, ishranu i napajanje, nadzor, pregrupisavanje i transport životinja, mera za sprečavanje pojave bolesti, opremanje staja i organizacija tehnološkog procesa proizvodnje, koje sprovode odgajivači, veterinarski i zootehnički stručnjaci. Standardi biosigurnosti moraju uzeti u obzir neophodan nivo zdravstvenog stanja zapata svinja, organizaciju, obim i vid proizvodnje na farmi i predvideti sve neophodne mere za kontrolu zdravstvenog stanja zapata i sprečavanje unošenja i širenja infektivnih bolesti, posebno onih čije se postojanje mora prijaviti. Pri izradi konkretnih planova biosigurnosti mora se uzeti u obzir trenutna epizootiološka situacija, ali i predvideti potencijalne pretnje po zdravstveno stanje i proizvodnju na farmi i moguća rešenja.

Srbija nema program dugoročnog razvoja kozarstva što onemogućava zainteresovane proizvođače da više ulažu u ovu proizvodnju. Osim toga, kozarstvo se obično uključuje zajedno sa ovčarstvom iako postoje bitne razlike u tehnologiji proizvodnje. Odgajivači najčešće počinju sa malim brojem grla izbegavajući rizike koji mogu proisteći zbog pogrešne lokacije objekta, njegove nefunkcionalnosti, zahteva grla, odnosno neispunjavanja uslova i grešaka u gajenju visokoproduktivnih grla. Različiti sistemi gajenja opredeljuju iznos troškova i prihoda. Da bi se izbegli gubici u proizvodnji potrebno je sistem gajenja prilagoditi konkretnim uslovima, a potom stalnim poboljšanjima organizacije rada smanjivati troškove jer u savremenim uslovima poslovanja dobit se može očekivati smanjenjem troškova, a ne povećanjem cena proizvoda. Stanje na tržištu poljoprivrednih proizvoda ostavlja prostora za povećanje proizvodnje kozjeg mleka i kozijeg i jarećeg mesa, posebno onog proizvedenog u ekološkim uslovima. Potrošnja kozjeg i jarećeg mesa kod nas je još uvek mala. Prihvatljivost kozjeg i jarećeg mesa je pod direktnim uticajem podneblja, vere, tradicije, kulture, običaja i navika potrošača. Kod nas i u okruženju primetno je izvesno zasićenja sa kozjim mlekom i proizvodima od mleka. Iz tog razloga ulaganja u proizvodnju kozjeg i jarećeg mesa može biti isplativo jer su i ulaganja 42 M. Žujović i sar. manja (primera radi, uštede u opremi za mužu, manje osnovno stado, broj radnika i sl.)

For the purpose of realization of the project of development of sustainable sheep production systems, in this paper, the major influences on production parameters of sheep in conditions of Stara Planina Mountain are investigated. Using the knowledge of gene effects, with good breeding programs, it is possible to realize, with more or less success, planned annual genetic progress of traits which are of interest to the breeders. This relates first of all on gain of lambs and milk yield in sheep. As already known, traits of body development and milk production vary depending on the factors of hereditary nature, but also factors of the environment. Therefore, the level of application of selection-breeding criteria is of great practical importance, which is confirmed also in this paper, and level of significance was statistically confirmed. Also, for complete creation of the program of improvement of sheep milk and meat production it is important to be aware of the effect of the breed itself, as well as of type of birth on production parameters, which was taken into consideration during investigation, processing and presentation of data in this paper. Obtained results show that majority of observed factors had significant effect on realized production of sheep., Za razvoj održive ovčarske proizvodnje, između ostalog, neophodna je primena visokih kriterijuma selekcije i odgajivanja. Cilj ovog rada je da ukaže na praktičan značaj nivoa primene kriterijuma selekcije i odgajivanja u proizvodnji mesa i mleka ovaca u ekstenzivnom sistemu gajenja na Staroj planini. Proizvodnja mesa i mleka ovaca na Staroj planini je tradicionalna i istorijski posmatrano, uglavnom je zasnovana na gajenju pirotske pramenke, kao lokalne populacije u ekstenzivnim proizvodnim sistemima. Ova rasa kao i većina lokalnih populacija poseduje solidan genetski potencijal za prirast jagnjadi i mlečnost ovaca, ali da bi se taj potencijal ispoljio, potrebna je primena viših kriterijuma selekcije i odgajivanja, što uglavnom nije slučaj. Pored pramenke od druge polovine XX veka na području pirotskog dela Stare planine uvedena je u primenu i nova populacija-pirotska oplemenjena ovca. Ona se takođe u većini slučajeva gaji kao i pirotska pramenka, mada ove dve rase u genetskom smislu imaju veoma malo zajedničkog. Kao što je poznato, osobine telesnog razvoja i mlečnosti ovaca variraju u zavisnosti od mnogih faktora nasledne prirode ali i različitih spoljnih uticaja. Zato je nivo primene selekcijsko odgajivačkih kriterijuma, od velikog praktičnog značaja, što potvrđuju i rezultati istraživanja u ovom radu, a što je takođe i statistički potvrđeno. Pored toga za kompletno kreiranje programa unapređenja proizvodnje mesa i mleka ovaca, značajno je poznavanje uticaja same rase, kao i tipa rođenja na proizvodne parametre, o čemu se tokom istraživanja, obrade i prikazivanja dobijenih podataka vodilo posebno računa. Dobijeni rezultati istraživanja pokazuju da je većina posmatranih faktora imala značajan uticaj na ostvarenu proizvodnju. .

The aim of the study was to determine effect of environmental and paragenetic factors on body mass of lambs at birth. Investigation was realized on experimental sheep farm of Institute for Animal Husbandry, Belgrade-Zemun. Animal included in this research were representatives of Mis sheep population. The results of the research confirm that values of the birth mass range from 4.43 kg to 4,58 kg observed by years and 4.48 kg to 4.55 kg depending on the lambing season. Statistical analysis showed that the existing differences still significant on the level (P (lt) 0.05). Variations of body mass in lambs depending on the mother's age range in the interval from 4.29 kg to 4.52 kg and statistically very significant(P (lt) 0.01). Type of birth has also expressed a significant effect on the body mass of lambs at birth and variations range from 4.31 kg (twins) to 4.59 kg (single). Existing differences was statistically very significant (P (lt) 0.01). Average body mass in lambs depending on sex of lamb were almost the same, 4.54 kg male and 4.52 kg female, and the difference is not statistically significant (P> 0.05)., Polni žar kod većine ovaca u Srbiji ima sezonski karakter, što znači da ovce ispoljavaju estrus u toku letnjih meseci od jula do septembra. To je povezano sa mnogim genetskim i spoljnim faktorima počev od klime i trajanja svetlosnog dana do ishrane i drugih uticaja na organizam životinje. Najbolja potvrda ovome je da ovce iste rase ispoljavaju polni žar u različito vreme u zavisnosti od geografso-klimatskog područja gde se gaje (na primer: Engleska, Australija ili Srbija). Sa tim u vezi i jagnjenje ovaca pada u različitim sezonama, a kod nas pretežno tokom zimskih meseci, što nije najbolje sa aspekta plasmana jagnjadi. Zato je u primeni i takozvano vansezonsko jagnjenje, gde se ovce jagnje u različitom i planski definisanom periodu godine. Broj potomaka dobijenih po jagnjenju jedan je od najvažnijih pokazatelja produktivnosti ovaca. Drugim rečima, biološka efikasnost ovaca je uslovljena plodnošću odnosno sposobnošću reprodukcije. Masa jagnjadi pri rođenju ima veliku ulogu u ostvarenju profitabilne proizvodnje, jer od početne mase tela zavise ne samo prirast, već vitalnost i mortalitet jagnjadi. Na masu tela pri rođenju utiču brojni faktori genetske i paragenetske prirode. Ovim problemom su se bavili mnogi istraživači, a ta tema je aktuelna i danas. Rezultati naših istraživanja uticaja spoljnih i paragenetskih faktora na masu tela jagnjadi pri rođenju u populaciji Mis ovce, potvrđuju da za procenu genotipa treba poznavati više faktora negenetske prirode. Među njima su spoljna sredina (godina, sezona) koji se pre svega ogledaju preko ishrane, držanja i nege životinja tokom proizvodnog ciklusa, a posebno u toku bremenitosti. Pored spoljnih faktora, bitan uticaj na posmatranu osobinu imaju: starost majke, tip rođenja i pol jagnjadi, dakle faktori koje ne možemo zvati spoljnom sredinom, već određenom biološkom kategorijom, koju je najprikladnije nazvati paragenetskim uticajem. Svi ovi faktori u većoj ili manjoj meri, kako to potvrđuju ova istraživanja, utiču na masu tela

Evaluation of phenotypic value of most present sheep breeds in Serbia is carried out as well as those populations which should have greater significance in the future. In this way, clear picture was obtained of strength and potentials of sheep production in different rearing systems, which will serve better defining of the direction of genetic-selection activities in the future. Researches have shown that there is high variability of traits depending on the observed factors. It is indicative that in the intensive system sheep breeds are forces of production direction meat and meat-wool, whereas in semi-intensive and extensive systems, predominant are breeds of tripartite direction. The best results in intensive rearing system were obtained in Mis sheep. In semi-intensive system, there is huge difference in body mass between Pirot improved sheep and Tsigai sheep, as well as between all investigated breeds in this system in regard to milk traits. Tsigai lambs realized higher body mass at the age of 90 days. Lipska sheep was dominant in regard to quantity of milk in lactation, but its fertility was the lowest. Mass of fleece was the lowest in sheep of Pirot improved population. There were no significant differences in regard to variability of the quantitative traits between sheep in extensive system, except in final body mass of lambs, where Svrljig and Pirot population were behind in comparison to Sjenica sheep., Različiti sistemi gajenja ovaca, raznovrsnost ciljeva, nivo organizacije farmi, stepen uključivanja vladinih institucija u razvoju, implementaciji i održavanju procesa selekcije, su neki od faktora koji utiču na razvoj i napredak ovčarstva jedne zemlje. Stoga se prvi korak ka napretku sastoji od definisanja rasa, odgajivačkih ciljeva, odgovarajuće tehnike i metodologije za merenje proizvodnih osobina životinja. Na uspeh u ovom poslu najveći uticaj imaju: efikasnost kontrola i evidencije proizvodnih osobina, procedura procene genetskih parametara i odgajivačke vrednosti životinja i organizacija sistema za difuziju genetskog materijala. U ovčarstvu Srbije poslednjih nekoliko decenija je nastala vidna promena u sistemu gajenja ovaca, pre svega poboljšanjem ishrane. Pored toga sprovođeno je i oplemenjivanje lokalnih populacija selekcijom, planskim ili neplanskim ukrštanjem sa inostranim rasama. Takođe, neke uvožene rase adaptiravši se na nove uslove, gaje se u čistoj rasi, ali njihov proizvodni potencijal nije uvek adekvatno predstavljen. Konačno, dobijene su i nove domaće produktivnije rase: Mis ovca i Pirotska oplemenjena populacija. Cilj ovog rada je da izvrši procenu fenotipske vrednosti najzastupljenijih rasa ovaca u Srbiji kao i onih populacija koje bi trebale imati veći značaj u budućnosti. Time bi se dao doprinos sticanju prave slike o snazi i potencijalima ovčarstva Srbije u različitim sistemima gajenja i bolje definisao pravac daljeg genetsko selekcijskog rada. Istraživanja su pokazala da postoji visoka varijabilnost osobina u zavisnosti od svih posmatranih faktora. Indikativno je da se u intenzivnom sistemu forsiraju rase ovaca mesnatog ili kombinovanog tipa, smer meso i meso-vuna, dok u poluintenzivnom i ekstenzivnom sistemu dominiraju rase trojnog smera proizvodnje, meso-mleko-vuna. U intenzivnom sistemu gajenja, najbolje rezultate je pokazala populacija Mis ovce. U poluintenzivnom sistemu postoji vrlo značajna razlika u masi tela između pirotske oplemenjen

In this paper current situation is analyzed and sustainable systems introduced in production of milk on small farms. Old production systems used on farms were the reason why milk production wasn't profitable activity and therefore livestock production in mountainous regions had complete collapse and pastures remained almost entirely deserted. In population of Pirot Pramenka sheep and local Simmental population of cattle, our analysis of breed productivity shows that effects in milk production are bad. Application of sustainable systems of milk production would increase the milk yield and revive dairy livestock production. After application of new systems regarding of breeding and farm management, milk yield in sheep cows was increased in average by 12%., U ovom radu se analizira postojeća situacija i uvode održivi sistemi u proizvodnju mleka na malim farmama. Stari proizvodni sistemi koji se koriste na farmama su razlog zašto proizvodnja mleka nije bila profitabilna aktivnost, što je dovelo do kolapsa stočarske proizvodnje u planinskim oblastima I skoro napuštenih pašnjaka. U populaciji pirotske pramenke i lokalne simentalske populacije goveda, naša analiza produktivnosti pokazuje da rezultati u proizvodnji mleka nisu bili dobri. Primena održivih sistema u proizvodnji mleka bi povećala prinos mleka i oživela proizvodnju u stočarstvu. Nakon primene novih sistema odgoja i upravljanja, prinos mleka kod ovaca i krava je povećan u proseku za 12%.