The lifetime production of Bovec and Improved Bovec sheep breeds

Za potrebe analize dinamike izlučivanja te životne proizvodnje ovaca bovške i oplemenjene (sa istočno-frizijskom) bovške pasmine, korišteni su podaci ovaca ojanjenih u razdoblju od 1989. do 2006. godine. Životna proizvodnja izračunata je za sve izlučene ovce kao zbroj proizvodnje kod svakog janjenja (broj ojanjene i živo ojanjene janjadi te ukupna masa živo ojanjena legla), odbića (broj odbijene janjadi i ukupna masa odbijenog legla) ili tijekom laktacije (količina izmuzenog mlijeka, korigiranog mlijeka na 6,5 % masti i 5,8 % bjelančevina (FPC, fat and protein corrected) te količina mliječne masti i bjelančevina). Svaka je ovca imala podatke od prvog pa sve do zadnjeg janjenja, odbića ili laktacije. U slučaju da svi podaci za pojedino svojstvo nisu bili raspoloživi, podaci ovce za to svojstvo isključeni su iz analize. Također, isključeni su i podaci za one ovce koje su žive izašle iz sustava kontrole - ili zbog prodaje u drugo stado ili zbog istupanja uzgajivača iz sustava kontrole. Na kraju je baza podataka sadržavala ukupno 2254 ovce, 1734 bovške te 520 oplemenjene bovške pasmine. Za pripremu podataka i statističku obradu korišten je statistički program R (R Development Core Team, 2007.) te dodatni paket Zelig i lme4. Na temelju provedenog istraživanja utvrđeno je da su u razdoblju ≤1996. godine ovce bovške pasmine s prosječno 4,4 laktacije za gotovo jednu laktaciju bile dulje u proizvodnji u odnosu na ovce oplemenjene bovške pasmine, dok je u razdoblju poslije 1996. godine najveći udio ovaca bio izlučen u prvoj laktaciji (očekivano zbog dinamike izlučivanja), s nešto većim udjelom ranije izlučenih ovaca oplemenjene bovške u odnosu na bovšku pasminu. Broj ojanjene, živo ojanjene te odbijene janjadi u oplemenjene bovške pasmine ovaca u prosjeku je bio veći za oko jedno janje u odnosu na bovšku pasminu, dok se životni prirast janjadi kod bovške i oplemenjene bovške pasmine nije razlikovao zbog ranog odbića kod oplemenjene bovške pasmine. Ovce oplemenjene bovške pasmine tijekom produktivnog vijeka u prosjeku su producirale oko 200 kg (~34 %) više izmuzenog mlijeka, oko 190 kg (~32 %) više izmuzenog FPC mlijeka, oko 12 kg (~32 %) više mliječne masti, te oko 10 kg (~34 %) više bjelančevina u odnosu na ovce bovške pasmine. Uzimanjem u obzir prosječne metaboličke mase, utvrđena razlika u mliječnosti između oplemenjene i čistokrvne bovške pasmine iznosi samo ~6 % (~2 % za FPC mlijeko). Rezultati ovog istraživanja pokazuju da je čistokrvna bovška pasmina dobre mliječnosti, no ipak premale tjelesne mase za intenzivnu mliječnu proizvodnju, dok je mala tjelesna masa čini pogodnom za ekstenzivan uzgoj u gorskim i planinskim područjima. Oplemenjena bovška pasmina ostvaruje dobre proizvodne rezultate u uzgoju u Sloveniji, što se može objasniti donekle sličnim okolišnim uvjetima koje istočno-frizijska pasmina ima u domovini.Production data of Bovec and Improved (with East-Friesian) Bovec sheep born between years 1989 and 2006 were used for the analysis of culling dynamics and lifetime production. Lifetime production was calculated as the sum of production at each lambing (number of born and liveborn lambs and litter birth weight), weaning (number of weaned lambs and litter weaning weight) or during each lactation (milk yield, fat (6.5 %) and protein (5.8 %) corrected milk yield (FPC; Pulina et al., 2005.), and fat and protein yield) for culled sheep. Animals with any missing records from the first till the last lambing, weaning or lactation were removed from the analysis. Animals that left the system of animal recording alive, due to selling or the cancellation of recording by a breeder were also excluded. Dataset included records for 2254 sheep: 1734 of Bovec and 520 of Improved Bovec breed. Data preparation and statistical analysis were performed with the use of a statistical program R (R Development Core Team, 2007.) and additional packages Zelig (Imai et al., 2007; Bailey and Alimadhi, 2007; Imai et al., 2008) and lme4 (Bates and DebRoy, 2004; Bates, 2007). Results have shown that in the period ≤1996 Bovec breed had on average 4.4 lactations in their lifetime, which was almost one lactation more than in Improved Bovec breed. In the period after the year 1996 the highest proportion of animals were culled in the first lactation (as expected due to culling dynamics), with slightly higher proportion in Improved Bovec breed than in Bovec breed. Lifetime number of born, liveborn and weaned lambs was higher for about one lamb in Improved Bovec breed. Lifetime lamb weight gain did not differ between breeds, due to the high frequency of early weaning in Improved Bovec breed. During lifetime, Improved Bovec sheep produced around 200 kg (~34 %) more milk, around 190 kg (~32 %) more FPC milk, around 12 kg (~32 %) more milk fat, and around 10 kg (~34 %) more milk protein than Bovec breed. However, if the mean metabolic weight of breeds is taken into account the difference in milk production amounts to only ~6 % (~2 % for FPC milk). These results show that Bovec breed has satisfactory milk production, but too low body weight for intensive milk production. On the other hand, low body weight makes this breed suitable for extensive farming in hill and mountain areas. Improved Bovec breed has good results in Slovenian conditions, due to the similarity of environmental conditions with East Friesian’s country of origin

Lambing Interval in Jezersko-Solčava and Improved Jezersko-Solčava Breed

The effects on lambing interval (LI) in Improved Jezersko-Solčava (IJS) breed were studied. Due to the reason that IJS breed originates from Jezersko-Solčava (JS) breed, both breeds were included into the analysis. The data were obtained from the Republic Data Base for Selection of Small Ruminants, between 1993 and 2008. The analysis included 66,755 lambings from 280 breeders. The statistical model included breed, parity, litter size at previous lambing, month of the previous lambing, year of the previous lambing, breed of the ram, geographical location of the flock, interaction between month of the previous lambing and breed of the ram, interaction between parity and month of the previous lambing, interaction between breed of the ewe and month of the previous lambing, and interaction between breed of the ewe and litter size at previous lambing as fixed effects. Flock and interaction between year of the previous lambing and flock were treated randomly. Month of the previous lambing affects LI, which is gradually shortening from February to August, and prolonging from August to February. The number of live born lambs significantly affected LI. LI between the first and the second parity and between the second and the third parity was longer than between higher parities. From 1993 to 1999, the LI was decreasing, and increasing thereafter. Ewes mated with JS ram had longer lambing interval than ewes mated with IJS ram. Among all observed effects, flock affected LI the most

Genetska struktura regionalnih prekograničnih populacija istarske ovce u Hrvatskoj i Sloveniji utvrđena mikrosatelitskim markerima

Istrian dairy sheep is a local breed essential for the identity and development of the Northern- Adriatic karstic region through high-quality products, primarily the hard sheep artisanal cheese. Border changes fragmented the initial Istrian dairy sheep population in three genetically isolated sub-populations in Italy (1000 animals), Slovenia (1150 animals) and Croatia (2500 animals). Due to the drastic reduction of their population sizes and fragmentation, the populations in Croatia and Slovenia are included in governmentally supported conservation programs. The initial subpopulation in Italy was restored after near extinction with stock from Slovenia, and is used today in meat production. The aim of this study was to provide an initial understanding of the current genetic structure and distribution of the genetic variability that exists in Istrian sheep by analysing individuals sampled in two regional groups of Istrian sheep from Croatia and Slovenia. Cres island sheep and Lika pramenka sheep were used as out-groups for comparison. Genetic differentiation was analysed using factorial correspondence analysis and structure clustering over 26 microsatellite loci for a total of 104 sheep belonging to three breeds from Croatia and Slovenia. Factorial correspondence analysis and clustering-based structure analysis both showed three distinct populations: Lika pramenka sheep, Cres island sheep and Istrian sheep. We did not find a marked genetic divergence of the regional groups of Istrian sheep. Istrian sheep regional group from Slovenia showed lower genetic variability compared to the one from Croatia. Variability and structure information obtained in this study considered alongside with socio-cultural-contexts and economic goals for the Istrian sheep reared in Croatia and Slovenia indicate that the cross-border exchange of genetic material of animals carrying private alleles among populations would maintain these alleles at low frequencies and minimize the inbreeding rate.Istarska ovca je autohtona pasmina ključna za identitet i razvoj sjevernojadranske regije zbog visokokvalitetnih mliječnih proizvoda. Promjenama granica inicijalna populacija istarske ovce je fragmentirana u tri genetski izolirane sub-populacije u Italiji (1000 životinja), Sloveniji (1150 životinja) i Hrvatskoj (2500 životinja). Zbog fragmentacije i smanjenja veličine populacija, istarske ovce su u Sloveniji i Hrvatskoj uključene u konzervacijske programe državnih potpora. Talijanska populacija je nakon inicijalnog drastičnog smanjenja broja danas obnovljena isključivo iz slovenskih stada. Cilj ovog istraživanja bio je omogućiti razumijevanje današnje genetske strukture i raspodijele genetske raznolikosti istarske ovce istraživanjem slovenske i hrvatske sub-populacije. Creska i lička pramenka korištene su kao grupe za usporedbu. Genetska diferencijacija istražena je faktorijalnom analizom korespondencije i strukturnim klasteriranjem na temelju 26 mikrosatelitskih lokusa genotipiziranih kod 104 ovce. Obje analize pokazale su tri distinktne populacije: lička i creska pramenka, te istarska ovca. Genetička divergencija istarske ovce iz Slovenije i Hrvatske nije izražena. Istarska ovca iz Slovenije pokazala je nižu genetsku varijabilnost od sub-populacije iz Hrvatske. Temeljem informacija o varijabilnosti i strukturi iz ovog istraživanja, kao i društveno-kulturalnog konteksta te ekonomskih ciljeva za slovensku i hrvatsku sub-populaciju istarskih ovaca, može se reći da bi izmjena genetskog materijala životinja s privatnim alelima omogućila održavanje tih alela u niskoj učestalosti, te smanjila genetske posljedice parenja u srodstvu