Uticaj đubrenja azotom na proizvodne i kvalitativne osobine sejanih travnjaka u sistemu održive proizvodnje

Nitrogen fixation in grass-leguminous mixtures is not sufficient to satisfy the nitrogen requirements of plants, therefore it is necessary to compensate this deficiency by nitrogen from mineral fertilizers. Objective of this study is to present the effect of N application in grass-leguminous mixtures on their production and qualitative properties, i.e. to give an answer to the question if application of nitrogen fertilizers results in the increase or decrease of yield, quality and changes in the structural composition of the grassland. N from mineral fertilizers, especially considerable amounts of nitrogen, changes the structural composition of grasslands - the share of leguminous plants decreases and share of grasses increases. Yield of dry matter increases with added nitrogen fertilizers. The amounts of nitrogen fertilizer which exceed the requirements of plants reduce the economical justification of fertilization and sometimes can have even opposite effect. Nitrogen fertilization increases the content of crude proteins and protein yield, whereas other quality parameters decrease or remain unchanged. Too much nitrogen in crops leads to nitrate accumulation in plants which is undesirable quality parameter.Azotofiksacijom u travno-leguminoznim smešama nije moguće zadovoljiti potrebe biljaka za azotom, pa je potrebno taj nedostatak nadoknaditi azotom iz mineralnih đubriva. Cilj ovog rada jeste da prikaže efekat primene N đubriva u travno leguminoznim smešama na njihove proizvodne i kvalitativne karakteristike, odnosno da da odgovor na pitanje da li upotrebom azotnih djubriva dolazi do povećanja ili smanjenja prinosa, kvaliteta kao i promena strukturnog sastava travnjaka. N iz mineralnih đubriva, naročito visoke količine azota, menjaju strukturni sastav travnjaka tako što smanjuju udeo leguminoza, a povećavaju udeo trava. Prinos suve materije se povećava dodavanjem azota đubrivima. Količine koje prevazilaze potrebe biljaka za azotom smanjuju ekonomsku opravdanost đubrenja i nekad mogu da imaju suprotan efekat. Đubrenje azotom povećava sadržaj sirovih proteina i prinos proteina, dok se ostali parametri kvaliteta smanjuju ili ostaju nepromenjeni. Prevelike količine azota u usevu dovode do nagomilavanja nitrata u biljkama kao nepoželjnog parametra kvaliteta

Nerazgradiv protein - značajan faktor balansiranja obroka za jagnjad u tovu

Although sheep breeding in our country mainly had extensive character, there is still room for implementation of the new concept of expression of nutritional value of proteins, primarily in fattening of lambs. For the purpose of maximum use of the genetic potential of high-yielding meat/fattening sheep breeds, share of undegradable protein in diet must be taken into consideration, since high protein requirements of such animals cannot be satisfied by microbial protein synthesis from usual protein and energy sources. Therefore, in contemporary, science based systems for assessment of protein value of feeds, degradability of proteins from food in rumen plays major role. In absence of data in domestic literature related to undegradability of proteins in certain feeds, results obtained in this study should be perceived as direction for future norming of diets in fattening of lambs in the intensive rearing system.Iako ovčarska proizvodnja u našoj zemlji ima uglavnom ekstenzivan karakter, u njoj ipak ima mesta za primenu novog koncepta izražavanja hranidbene vrednosti proteina, pre svega u tovu jagnjadi. U cilju maksimalnog iskorišćavanja genetskog potencijala visokoproizvodnih rasa ovaca za meso, mora se voditi računa o udelu nerazgradivog proteina u obroku, s obzirom da se mikrobiološkom sintezom proteina iz uobičajenih izvora proteina i energije ne mogu zadovoljiti visoke potrebe takvih grla u proteinima. Zbog toga, u savremenim, naučno zasnovanim sistemima za ocenu proteinske vrednosti hraniva, važno mesto zauzima razgradivost proteina hrane u buragu. U nedostatku domaćih podataka o nerazgradivosti proteina pojedinih hraniva, rezultate istraživanja u ovom radu treba shvatiti kao davanje određenih rešenja i putokaz za normiranje obroka za tov jagnjadi u intenzivnom sistemu gajenja

Uticaj goveđeg loja u ishrani jagnjadi na tovne i klanične karakteristike

Trial was carried out on 60 suckling lambs of Mis sheep population, divided into three groups. Beside milk, lambs consumed alfalfa hay and iso-protein concentrate mixtures (15% CP) ad libitum. Forage mixture I was of standard composition, whereas mixtures II and III contained 4 and 6% of beef tallow, respectively. Energy value of used mixtures I, II and III was 7,29, 7,71 and 7,94 MJ, respectively. Fattening duration was 60 days. Statistical processing of obtained data was performed using standard mathematical-statistical methods. Lambs on treatments I:II:III realized average daily gain of: 0,280 : 0,303 : 0,277 kg. Conversion of dry matter of diet was: 2,68: 2,58: 2,93 kg; of energy: 19,08 : 18,37 : 20,71 MJ NEM; of protein: 481 : 451: 514 g. Values of the meat yield of warm carcass were: 57,89 : 58,63 : 58,46%. The best production results in regard to gain, and feed conversion were realized by lambs on treatment with 4% of beef tallow in the mixtures.Ogled je izveden na 60 neodbijene jagnjadi Mis populacije ovaca koji su bili podeljeni u tri grupe. Osim mleka, jagnjad su konzumirala seno lucerke i izoproteinske smeše koncentrata (15% SP) ad libitum. Krmna smeša I je bila standardnog sastava, dok su smeše II i III sadržavale 4, odnosno 6% goveđeg loja. Energetska vrednost korišćenih smeša I, II i III je bila 7,29, 7,71 i 7,94 MJ, respektivno. Trajanje tova je bilo 60 dana. Statistička obrada podataka je urađena standardnim matematičko-statističkim metodama. Jagnjad na tretmanima I:II:III su ostvarila prosečni dnevni prirast od 0,280 : 0,303 : 0,277 kg. Konverzija suve materije obroka je bila 2,68: 2,58: 2,93 kg, energije, 19,08 : 18,37 : 20,71 MJ NEM, proteina, 481 : 451: 514 g. Vrednosti za prinos mesa u toplom trupu su bile 57,89 : 58,63 : 58,46%. Najbolje proizvodne rezultate u pogledu prirasta i konverzije hrane su ostvarila jagnjad na tretmanu sa 4% goveđeg loja u smešama

Procena gentskog potencijala ovaca u različitim proizvodnim sistemima

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 oplemenjene ovce i cigaje, kao i između svih ispitivanih rasa ovog sistema u pogledu mlečnosti. Jagnjad cigaje su ostvarila najveću masu tela sa 90 dana. Lipska ovca po količini mleka u laktaciji dominira. Sa druge strane plodnost lipske ovce je najmanja, dok je masa runa najmanja kod ovaca pirotske oplemenjene populacije. Ekstenzivno gajenje ovaca je najviše zastupljeno u planinskim krajevima Srbije. Nema značajnih razlika u pogledu varijabilnosti kvantitativnih osobina između svrljiške, sjeničke i pirotske ovce, osim u završnoj masi tela jagnjadi, gde su Svrljiška i Pirotska populacija u zaostatku u poređenju sa sjeničkom ovcom

Uticaj spoljnih i paragenetskih faktora na varijabilnost mase tela jagnjadi Mis populacije

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 jagnjadi pri rođenju i zato ih treba uzimati u obzir prilikom procene genetske vrednosti ovaca Mis populacije

Genetsko poboljšanje plodnosti ovaca selekcijom po fiziološkim kvantitativnim parametrima

In this paper, fertility parameters of sheep are discussed and principles analyzed in order to obtain the optimal methods for their evaluation. Mathematical procedures for evaluation of genetic and phenotypic parameters and anticipation of genetic values, today, are mainly based on different linear and non-linear concepts, therefore it is necessary to accept the reality that there is no absolute accuracy. Special emphasis is on the possibility of use of physiological quantitative fertility indicators in sheep selection, considering that there is correlation between them and fertility traits. In this regard, the degree of response to direct and indirect selection within population is analyzed in order to established the nature of parameters necessary for evaluation of data and determine the relative degree of such response.U radu se razmatraju parametri plodnosti ovaca i analiziraju principi iznalaženja optimalnih metoda za njihovu procenu. Ističe se da su matematički postupci za procenu genetskih i fenotipskih parametara i predviđanje genetskih vrednosti danas uglavnom zasnovani na različitim linearnim i ne linearnim konceptima, pa je zbog toga potrebno prihvatiti realnost da potpuna tačnost za sada ne postoji. Poseban akcenat se stavlja na mogućnost korišćenja fizioloških kvantitativnih pokazatelja u selekciji ovaca na plodnost, s obzirom da postoji korelacija između njih i osobina plodnosti. U tom smislu, analizira se stepen odgovora na direktnu i indirektnu selekciju unutar populacije, kako bi se ustanovila priroda parametara neophodnih za ocenu podataka i utvrdili relativni stepeni takvog odgovora

Identifikacija i kvantifikacija gljiva u travno-leguminoznoj silaži

Objective of the research was to determine the presence, total count and species of fungi in samples of grass-leguminous silages depending on the botanical composition of mixture, nitrogen fertilization and crop utilization phase. Most of identified fungi species are of Fusarium genus (80-91%). In analyzed samples of silage total fungi count in average for three year period of research (2005-2007) was 2.31-3.09 log10 CFU g-1 and it varied depending on the investigated factors. Factor of type of mixture had significant effect on fungi count in first two investigation years, whereas nitrogen fertilization caused variations in fungi count in the first and third investigation year. Cutting in early utilization phases statistically significantly influenced total fungi count only in one investigation year (2006).Cilj istraživanja je bio da se odredi prisustvo, ukupan broj i vrste gljiva u uzorcima silaža travno-leguminoznih smeša u zavisnosti od botaničkog sastava smeše, đubrenja azotom i faze iskorišćavanja useva. Većinom su identifikovane vrste gljiva iz roda Fusarium (80-91%). U ispitivanim uzorcima silaže ukupan broj gljiva u proseku za trogodišnji period istraživanja (2005-2007) je bio od 2.31-3.09 log10 CFU g-1 i varirao je u zavisnosti od ispitivanih faktora. Faktor vrsta smeše je značajno uticao na broj gljiva u prve dve godine istraživanja, dok je đubrenje azotom prouzrokovalo variranja u broju gljiva u prvoj i trećoj godini istraživanja. Kosidba u ranijim fazama iskoršćivanja statistički značajno je uticala na ukupan broj gljiva samo u jednoj godini istraživanja (2006)

Influence of environmental factors on birth weight variability of indigenous Serbian breeds of sheep

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