The Effect of Dietary Organic Copper and Zinc Trace Minerals on some Yield and Mineral Levels and Histological Structure of Testes.

This study aims to investigate the effects of providing Cu and Zn minerals with an organic structure reduced by 25% compared to the recommended (NRC) inorganic value on parameters such as the age at which lambs achieve 50% sperm motility yield, some developmental parameters, testis histology, as well as serum, wool, and fecal mineral levels in lambs. The study involved 12 male lambs in the T1 group (organic minerals) and 11 in the T2 group (inorganic minerals) of the Kivircik breed. Lambs received minerals from mothers during the last month of fetal period and suckling, continuing individual feeding post-weaning. During individual feeding, T1 received 5.25 mg/kg DM copper-chelate and 15.0 mg/kg DM zinc-chelate, while T2 received 7 mg/kg DM copper-sulfate and 20 mg/kg DM zinc-sulfate. The mothers received identical mineral amounts in the last month of pregnancy and lactation. The ewes birthed offspring solely for the supply of experimental groups. Lambs, averaging about 18.5 kg, underwent bi-weekly electroejaculation, concluding the trial for those with 50% semen motility. Statistical analyses were carried out using the GLM method. No differences were observed between groups in the average age at which lambs achieve 50% sperm motility, live weight, scrotum, and testicular measurements at this age (P > 0.05). Histological analyses revealed no difference in tubule area between T1 and T2 groups (P > 0.05), but tubular epithelium height was greater in T1 (P < 0.01). End-of-trial serum copper, as well as weaning day and end-of-trial serum and fleece zinc mean values, did not differ between groups (P > 0.05). However, T1 had higher mean values for serum Cu on the weaning day (P < 0.01), fleece copper on the weaning day (P < 0.05) and at the end of the trial (P < 0.001). Additionally, the T1 group exhibited lower mean levels of fecal copper (P < 0.05) and fecal zinc (P < 0.001). In conclusion, despite organic copper and zinc levels being 25% lower in the examined parameters, comparable or improved results were achieved with inorganic copper and zinc.

Daily administration of a GnRH analogue enhances sperm quality in bucks during the non-breeding season.

The aim of this study was to determine if daily administration of a GnRH analogue (buserelin acetate) to bucks during the non-breeding season increases testosterone concentration and improves sperm quality. Five bucks received a daily dose of buserelin for 10 days, starting on Day 0 (first administration), and another five bucks remained as controls. Testosterone concentrations were greater in treated than in control bucks during the first hours after buserelin administration (P = 0.05), but greater in controls 10 h later (P < 0.01). Sperm mass motility and percentage of motile sperm were greater in treated (3.9 ± 0.6 and 70.1 ± 7.9%, respectively) than in control bucks (1.0 ± 0.6, P < 0.01; 45.0 ± 7.9%, P < 0.05 respectively) on Day 4. Percentage of sperm with normal morphology tended to be greater in treated than in control bucks (81.8 ± 6.2% compared with 63.5 ± 6.4% respectively, P = 0.08). The treatment decreased the percentage of sperm with mid piece defect and with bent tail (7.0 ± 1.5% compared with 12.0 ± 1.5%; 8.0 ± 1.7% compared with 13.5 ± 1.7%, treated and control bucks, respectively, P = 0.05 for both). The square root percentage of sperm with loose but heads with normal structures tended to be less in treated than control bucks (1.3 ± 0.3% compared with 0.4 ± 0.3% respectively, P = 0.06). It was concluded that daily administration of buserelin during the non-breeding season led to a rapid increase in testosterone concentration and improved sperm quality.

Fattening performance, carcass and meat quality characteristics of Kivircik male lambs.

The objective of this study was to determine the fattening performance and carcass and meat quality characteristics of Kivircik twin male lambs. Twelve lambs at approximately 5 months of age were subjected to a finishing diet for 60 days. Average live weight of lambs at the beginning and the end of the fattening were 23.14 ± 0.84 and 39.0 ± 1.01 kg, respectively. Daily live weight gain and feed conversion efficiency were found as 0.265 ± 0.007 and 6.14 kg, respectively. Hot carcass weight, cold carcass weight, and dressing percentage were 19.6 ± 0.6 and 18.9 ± 0.6 kg and 48.1 ± 0.3%, respectively. Kidney-pelvic fat weight, internal fat weight, and m. longissimus dorsi area were 0.117 ± 0.023 and 0.364 ± 0.041 kg and 15.26 ± 0.70 cm(2), respectively. The percentages of leg, back loin, forearm, shoulder, neck, flank-chest, kidney-pelvic fat, and internal fat in carcasses of the lambs were found as 34.1 ± 0.4%, 19.6 ± 0.3%, 21.0 ± 0.2%, 7.0 ± 0.3%, 10.5 ± 0.3%, 7.2 ± 0.2%, 1.3 ± 0.1%, and 1.8 ± 0.1%, respectively. Averages water content, ash, protein content, and fat content of meat samples were 73.4%, 1.0%, 19.5% and 3.6%, respectively. pH and thiobarbituric acid reactive substances values of meat samples were 5.55 and 0.056 ± 0.017. L*(lightness), a*(redness), and b*(yellowness) values were recorded as 43.87, 12.69, and 10.22, respectively. Thus, we conclude that fattening performance, carcass, and meat quality of Kivircik lambs are satisfactory levels than that of other native breeds.