Calcitriol combined with fish oil in the diet of Chukar partridge can ameliorate laying performance by improving oviduct histomorphometry and functions.

The effects of calcitriol (CT) and/or fish oil (FO) on performance, oviposition time, sex ratio and morphology of the reproductive system of laying Chukar partridges were studied. Female (n = 48) and male (n = 16) partridges were used in a completely randomised design using a 2 × 2 factorial arrangement and were randomly allocated to either of four experimental treatments with four cage replicates of three females and one male each. Female birds received no FO (CON - FO) or were orally administered with 0.2 mL (0.24 g)/500 g body weight FO (CON + FO) or 0.2 mL solution containing 10 µg CT (CT - FO), or their combination (CT + FO) for 42 successive days. The eggs were collected every two hours between 07:00 and 23:00 h. Administering FO along with CT had considerably increasing effect on the male-biased sex ratio. FO and CT administration interacted to increase serum calcium concentration. Experimental treatments increased the number of leucocytes and erythrocytes. Serum cholesterol was decreased in CON + FO partridges compared with those of the CT - FO and CON - FO birds. There was an interaction between FO and CT on the weight of eggs and hatchlings, number of medium white follicles, diameter and the number of small yellow follicles, the weight and diameter of the fifth follicles (F5), and thickness of secondary mucosal folds in both uterus and vagina. Administering CT alone or with FO increased the feed intake, egg production, oviductal weight, diameter and number of large yellow follicles, the weight and diameter of the second (F2) and first (F1) follicles compared with those of the CON - FO females. Further studies are required to elucidate the mechanisms by which such changes in the sex ratio skew, ovary and oviduct are mediated.

Reproductive performance and progeny sex ratio of female Chukar (Alectoris chukar) breeder partridges reared on restricted feeding regimens.

A hypothesis was tested that quantitative feed restriction affects the reproductive performance and offspring sex ratio of female Chukar breeder partridges. A total of 160 2.5-year-old male and female partridges were randomly allotted to four treatment groups. The birds in the control group were fed ad libitum, whereas those in treatments G95 , G90 , and G85 received 26.1, 24.7, and 23.3 g of feed per bird/day to provide 95%, 90%, and 85% of ad libitum feeding level, respectively. The reproductive performances of female Chukar partridges including egg production, egg quality, fertility rate, duration of fertility, hatchability, chick quality, mortality rate, and offspring sex ratio (using a PCR procedure) were investigated. Feed restriction of all levels decreased the body weight and egg production compared with the ad libitum birds; however, restricted feeding had no significant effect on the egg quality traits. Non-significant effects of treatment on fertility and hatchability rate were found. The restricted feeding reduced the duration of fertility. Furthermore, maternal restricted feeding resulted in decreased chick weights. The results of this study showed that embryonic mortality was not affected by the restricted feeding of Chukar breeder partridges. Interestingly, restricted feeding was associated with a decreased proportion of male offspring. Overall, body weight, egg production, duration of fertility, progeny chick weight, and sex ratio were responsive to restricted feeding where their changes make the restricted feeding regimens to not be practically recommended in breeder partridge production. These results are in contrast to the conventional restricted feeding program implemented in broiler breeder industry.

Effects of dietary oil sources (sunflower and fish) on fermentation characteristics, epithelial gene expression and microbial community in the rumen of lambs fed a high-concentrate diet.

The feeding of high-concentrate diets commonly results in lowered pH and ruminal dysbiosis which cause shifts in uptake dynamics of short-chain fatty acids (SCFA) and altered epithelial function. Therefore, the current study evaluated the effect of dietary polyunsaturated fatty acids (PUFA) on ruminal fermentation products, gene expression in the ruminal epithelium and the associated changes in ruminal microorganisms in lambs fed a high-concentrate diet. Twenty-six Afshari lambs adapted to a high-concentrate diet during a completely randomised design were fed with a basal diet supplemented with 100 g oil supplement (OS; 60 g sunflower oil and 40 g fish oil) for 10 (OS10), 20 (OS20) and 30 (OS30) d, respectively (n = 6). Lambs with no oil supplementation (OS0, n = 8) were considered as control and slaughtered at d 0 of the experiment, and the remaining lambs were slaughtered at 10, 20 and 30 d on feed. After slaughter, ruminal digesta was collected for evaluating fermentation and microbial community. Ruminal papillae were taken for assessment of epithelial gene expression. Compared with OS0 lambs, supplemental PUFA in OS30 lambs tended to decrease total SCFA concentration with decreased acetic and increased propionic acid concentrations. Acetate:propionate ratios were decreased and ruminal pH was increased in OS20 and OS30 lambs compared to OS0. All groups with included OS had decreased concentrations of iso-valeric and valeric acids compared to OS0. Relative mRNA abundance of monocarboxylate transporter isoforms 1 and 4, insulin-like growth factor binding protein 3, sterol regulatory element-binding proteins 1 and 2 decreased with increasing OS duration. The relative abundance of 3-hydroxy-3-methylglutaryl-CoA synthase 1 mRNA transcript was higher for OS10 and OS20 lambs relative to OS0 lambs. OS20 and OS30 showed a decrease of lipopolysaccharide binding protein mRNA expression compared with OS0. Feeding supplemental PUFA decreased Ciliate protozoa and increased Butyrivibrio fibrisolvens in OS20 and OS30 lambs, whereas Megasphaera elsdenii was increased in OS30 lambs. In conclusion, combined supplementation of sunflower and fish oil to a high-concentrate diet affects the ruminal microbial community with prominent decreases in ruminal ciliate protozoa and increases in B. fibrisolvens and M. elsdenii. These results lead to a more stabilised ruminal pH and a fermentation shift towards more propionate generation. Consideration of nutrients digestion will help to fully understand the benefits of feeding PUFA with a high-concentrate diet.