Uticaj starosti brojlerskih roditelja hibrida COBB 500 i dužine skladištenja jaja na efikasnost inkubacije pilića

Abstract

U cilju utvrđivanja produktivnih i reproduktivnih osobina brojlerskih roditelja hibrida Cobb 500 sprovedena su istraživanja na jednom matičnom jatu koje je gajeno od 23. do 60. nedelje starosti (38 nedelja). U toku istraživanja praćeni su sledeći proizvodno – reproduktivni parametri: intenzitet nosivosti jaja različitih kategorija, mortalitet i vitalnost roditeljskih parova, utrošak hrane po grlu i proizvedenom jajetu. Posebna pažnja data je reproduktivnim osobinama, tj. proizvodnji jednodnevnih brojlerskih pilića, kao finalnog proizvoda. Osnovni cilj rada bio je utvrđivanje uticaja pojedinih paragenetskih faktora na rezultate inkubacije, u prvom redu, starosti brojlerskih roditelja (SR) i perioda skladištenja jaja, odnosno starosti jaja (SJ). U tri faze proizvodnog ciklusa gajenja, odnosno različite starosti brojlerskih roditelja (SR25, SR41 i SR58) i kod jaja skladištenih do 7 i preko 7 dana (SJ<7 i SJ>7) utvrđeni su: masa jaja različitih kategorija, oplođenost jaja, izvodljivost pilića, embrionalni mortalitet u toku inkubacionog perioda (rani, srednji i kasni), masa jednodnevnih pilića, relativni udeo pileta u masi jajeta, kao i fenotipska korelaciona (rp) povezanost između većine praćenih reproduktivnih pokazatelja. Pored osnovnih produktivnih i reproduktivnih parametara utvrđivan je uticaj starosti brojlerskih roditelja po fazama proizvodnog ciklusa i dužine skladištenja, odnosno starosti jaja na embrionalni razvoj pilića i rezultate inkubacije. Posmatrano po fazama gajenja, brojlerski roditelji su najbolje proizvodne, odnosno reproduktivne vrednosti pokazali sredinom proizvodnog ciklusa (SR41), u odnosu na početnu (SR25) i završnu fazu (SR58) produkcije jaja za nasad. U tom periodu po useljenoj nosilji proizvedeno je 5,08 jaja, 4,74 oplođenih jaja, 4,40 jednodnevnih pilića, dok je prosečan dnevni utrošak hrane po useljenom grlu iznosio 181,00 g. Prosečna masa jaja skladištenih do 7 dana je bila u optimalnim granicama, i iznosila je 63,11 g., oplođenost jaja iznosila je 97,43%, leženost pilića 87,62% (od inkubiranih jaja), odnosno 89,93% (od oplođenih jaja). Masa jednodnevnih pilića bila je na zadovoljavajućem nivou (44,02 g) i relativni udeo pileta u masi jajeta iznosio je 69,73%. Pored toga, starost brojlerskih roditelja je uticala na povećanje mase jaja (P<0,001) i izleženih pilića (P<0,001), dok se procenat pileta u masi jajeta smanjivao, a period skladištenja jaja, kod sve tri faze proizvodnog ciklusa, negativno je uticao na procenat pileta, tj. sa produžavanjem perioda skladištenja jaja, relativni udeo pileta u masi jajeta se smanjivao, posebno u početnoj (SR25) i završnoj fazi (SR58) proizvodnog ciklusa (P<0,001).

The research was conducted on one breeding flock of hybrid Cobb 500 broiler parents bred in the interval between 23rd and 60th week of age with the objective of determining their production and reproduction characteristics. The following production – reproduction parameters were inspected: carrying capacity of different category eggs, mortality and vitality of parents couples, the consumption of food per head and per egg produced. Special attention was paid on reproduction characteristics, i.e. on the production of diurnal broiler chicken as a final product. The main objective of this doctoral dissertation was to determine the effect of certain paragenetic factors, primarily broiler parents’ age (PA) and storage eggs period i.e. eggs age (EA), on incubation results. In the course of the three stages of production breeding cycle, i.e. regarding different age of broiler parents (PA25, PA41 and PA58) and regarding eggs stored up to seven and over seven days (EA<7and EA>7), the following was substantiated: different category eggs mass, the degree of fertilization of eggs, chicken feasibility, embryo mortality during incubation period (early, middle, late), diurnal chicken mass, the relative proportion of chicken in the egg mass, and phenotype correlative (rp) relatedness among the majority of observed reproduction indicators. Beside basic production and reproduction parameters, the effect of broiler parents’ age during the stages of the production cycle and storage period length i.e. eggs age on chicken embryo development and incubation results was substantiated. Observing each breeding stage, broiler parents showed the best production and reproduction values in the middle of the production cycle. Namely, compared to the initial (PA25) and final (PA58) stage of clutch eggs production, broiler parents had the best production and reproduction characteristics in the middle of the production cycle (PA41). In this period, 5.08 eggs, 4.74 fertilized eggs and 4.40 diurnal chickens were produced per occupied layer hen, whereas the average daily consumption of food was 181.00 g per occupied head. The average mass of eggs stored up to seven days was 63.11 g, which falls within the optimal boundaries, the fertilization of eggs was 97.43%, chicken hatching was 87.62% among incubated eggs and 89.93% among fertilized eggs. Diurnal chicken mass was on a satisfying level (44.02 g) and a relative proportion of chicken in the egg mass was 69.73%. Besides, broiler parents’ age caused the egg mass increase (P<0.001) and hatched chicken increase (P<0.001), whereas the percentage of chicken in the egg mass decreased. Egg storage period, in each of the three stages of the production cycle, negatively affected the chicken percentage: with the prolongation of egg storage period, the relative proportion of chicken in egg mass was reduced, especially in the initial (PA25) and final (PA58) stage of production cycle (P<0.001).