The Istrian (IS) and the Pag sheep (PS) are local Croatian breeds which provide significant income for the regional economy and have a cultural and traditional importance for the inhabitants. The aim of this study was to estimate some important population specific genetic parameters in IS (N = 1293) and PS (N = 2637) based on genome wide SNPs. Estimates of linkage disequilibrium effective population size (N_e) evidenced more genetic variability in PS (N_e = 838) compared to IS (N_e = 197), regardless of historical time (both recent and ancient genetic variability). The discrepancy in the recent genetic variability between these breeds was additionally confirmed by the estimates of genomic inbreeding (F_ROH), which was estimated to be notably higher in IS (F_ROH>2 = 0.062) than in PS (F_ROH>2 = 0.029). The average F_ROH2–4, F_ROH4–8, F_ROH8–16, and F_ROH>16 were 0.26, 1.65, 2.14, and 3.72 for IS and 0.22, 0.61, 0.75, and 1.58 for PS, thus evidencing a high contribution of recent inbreeding in the overall inbreeding. One ROH island with > 30% of SNP incidence in ROHs was detected in IS (OAR6; 34,253,440–38,238,124 bp) while there was no ROH islands detected in PS. Seven genes (CCSER1, HERC3, LCORL, NAP1L5, PKD2, PYURF, and SPP1) involved in growth, feed intake, milk production, immune responses, and resistance were associated with the found autozygosity. The results of this study represent the first comprehensive insight into genomic variability of these two Croatian local sheep breeds and will serve as a baseline for setting up the most promising strategy of genomic Optimum Contribution Selection.

The aim of this study was to evaluate the effect of dried Cannabis sativa L. leaves as a phytogenic mixture added to broiler feed on CD4⁺ and CD8⁺ T lymphocyte subpopulations, Newcastle disease virus (NDV) antibody titres, and the presence of E. coli in faecal samples. The study was conducted on 100 male Ross 308 broilers, divided into four groups of 25 broilers, for a 42-day research period. The groups were housed separately in boxes on a litter of softwood shavings and were fed starter mixture from day 1 to day 21 and finisher mixture from day 22 to day 42. Industrial hemp (C. sativa) was grown in the Crkvina area, Croatia (latitude: 45°18′46.8″ N; longitude: 15°31′30″ E). The hemp leaves were manually separated, sun-dried, and ground to a powder. The mixture offered to the control group did not contain cannabis leaves, whereas the three experimental groups received mixtures containing mixed cannabis leaves in a quantity of 10 g/kg, 20 g/kg, or 30 g/kg (E_10, E_20, and E_30, respectively). The mean NDV antibody level was uniform in all study groups until post-vaccination day 14 and increased comparably with time. The percentage of CD4⁺ and CD8⁺ lymphocytes in the peripheral blood subpopulation showed statistically significant differences (p < 0.001) in the E_20 group as compared with the control group and both the E_10 and E_30 groups throughout the study period. As the broiler age increased, the CD4⁺-to-CD8⁺ ratios also increased and were statistically significant (p < 0.0001) on day 42 in all experimental groups as compared to the control group. Comparing the control group with the experimental groups indicated that the bacterial count was lower in broiler groups having received feed with the addition of 20 g/kg and 30 g/kg C. sativa leaves. In conclusion, the C. sativa leaves were found to elicit a favourable immunomodulatory effect on cell-mediated and humoral immune responses in broilers via increased CD4⁺ and CD8⁺ lymphocyte subpopulations and higher CD4⁺:CD8⁺ cell ratios, thus indicating enhanced immune function capacity. In addition, C. sativa leaves may have complementary effects on the broiler post-vaccination immune response, increase broilers’ resistance to infectious diseases, reduce the effect of stress associated with vaccination, and improve broiler health and welfare.

The Istrian sheep breed has been subjected to selection for dairy traits for more than two decades. However, a detailed study of some important population-specific parameters such as effective population size ($N_e$) and connectedness between flocks has never been carried out. The aim of the study was to examine the above parameters in dairy Istrian sheep subjected to a national selection program. The $N_e$ was estimated as the mean rate of increase in coancestry, and connectedness was determined using four different statistics. The $N_e$ was estimated at 73 animals with pedigree constraints imposed on 4 equivalent generations and 3 full generations. Analysis of $\Delta N_e$ (“sliding window approach”) revealed a negative $\Delta N_e$ indicating a progressive loss of genetic variability ($\Delta N_e{}_{\mathrm{NEG}\ge 4}$ = −6.6, p < 0.01; $\Delta N_e{}_{\mathrm{NFG}\ge 3}$ = −4.9, p > 0.05). The overall connectedness ($\overline{r}$ ~ 0.0001) was below the acceptable level for unbiased ranking of the animals belonging to different flocks ($r_{i,j}$ = 0.05). OCS appears to be the best option for the long-term survival (self-sufficiency) of the breed, but genetic links between flocks need to be strengthened to allow unbiased ranking of the animals based on the estimated breeding values.

This study aimed to examine the impact of ewe’s age at first lambing (AFL) on days in milk (DIM), average daily milk yield (DMY), and total milk yield (TMY). Symmetrical bimodal distribution of AFL enabled classification of maidens in those mated in the first (47%) or second year of life (53%). After accounting for all available sources of phenotypic variability with the linear mixed model for repeated records, it was estimated that AFL had a statistically significant effect only on DIM (p < 0.001). The litter size had a significant effect only on TMY (p < 0.001), while the effect of the parity was significant for all the examined traits (p < 0.001). The results of the study suggest that prolongation of age at first mating to the second year of life is not justified in dairy-orientated sheep farms. However, more evidence on this issue is needed for generalization, especially considering some other traits that can impact profitability of dual-purpose sheep farms (reproduction traits, growth rate of lambs, etc.).