Veterinarija ir Zootechnika

This study aimed to study the effect of oreganum on forced molting in laying Japanese quails to improve the physiological performance and restore the reproductive capacity of females. A total of 120 female Japanese quails (Coturnix coturnix Japonica) aged 18 weeks were divided randomly into six groups: group A – pre-molting from weeks 18 to 19; group B – supplemented with oregostim at a dose of 0.3 mL\1000 mL; group C (molting from weeks 20 to 22) – fed a restricted diet; group D – fed a limited diet with oregostim at the same dose and post-molting from week 23 to week 37; group E – fed a basal diet; and group F – fed a basal diet and treated by oregostim. The results showed that the molting group caused a significant reduction in the weight of body and ovary in group C and group D, while the weights were restored in group E and group F relative to other groups. Besides, there was a significant decrease of WBCs and RBCs count in group C and group D with a significant elevation in group E and group F compared with group A and group B. The percentage of egg production and large follicle number in group C and group D decreased significantly compared with group A and group B, while they restored to normal values in group E and group F compared with group A and group B and showed a significant increase as compared with group C and group D, respectively. We concluded from this study that oregostim does not have adverse effects on the molting period. Thus, the standard diet supplemented with oregostim was considered as a better molting technique.

This study focuses on enhancing daily milk yield (DMY) in the Saharan environment by exploring the relationships among milking frequency, heat stress, and lactation stage in 187 Holstein dairy cows in the Saharan Ghardaia region over a 12-year period. Key findings indicate that milking three times daily boosts DMY by about 22.67% compared with twice daily milking, with this increase being most significant (P < 0.0001) in cows during their second and third lactations. The temperature-humidity index (THI) plays a pivotal role in DMY. The study shows that the best milk production occurs (P < 0.0001) at lower THI values (below 74), underscoring the importance of optimal environmental temperature and humidity for maximum milk yields. Cows exposed to these lower THI values and milked three times daily achieve the highest milk production (+25%). Thus, combining the right THI conditions with increased milking frequency can significantly (P < 0.0001) enhance milk production. Effective heat stress management is also crucial for optimal milk yields. The study recommends practical strategies like offering sufficient shade, ensuring good ventilation, and giving cows access to cool water. Adjusting their nutrition during high heat stress periods is also vital. Moreover, the timing of milking sessions, especially during the cooler parts of the day, is a key factor in milk production. In conclusion, the research highlights the intertwined roles of various factors, especially milking frequency and THI, in determining the DMY of dairy cows in Saharan areas. It supports the implementation of improved management practices to counter environmental challenges and maximize milk production in such demanding environments.

The purpose of this study was to compare the effects of high temperatures on the behavior, comfort and thermoregulation energy consumption of cows at free-stall keeping in two barns. The first barn had the system of forced ventilation and air irrigation, and the second one had only fans. Barn parameters were (Length × Width × Height) 94 × 32.1 × 10.5 m. The research was conducted in central Ukraine (Kyiv region) during July 2021. The average daily ambient temperature during the study period was +26.4°C. In each of the barns, the groups of similar of non-pregnant and lactating animals (107 ± 14 days in milking) of Holstein breed were formed. Cows were fed the total mixed ration twice a day in both barns. Hours of air cooling elements operation in the barns were from 10.00 to 18.00. The use of fans in combination with irrigation systems during hot periods had a positive effect on the heat transfer of cows compared with the heat transfer of cows that were in the barn with fans. With this combination, the temperature of the skin and the resting place under the lying cow and energy consumption for heat production were 0.5°C and 0.8°C and 3.1 MJ lower. In addition, this combination of air cooling systems had a positive effect on the duration of lying down and eating food (32 and 16 minutes longer, respectively), and the indicators of standing time, physical activity and drinking were lower by 16, 21 and 6 minutes, respectively. Accordingly, the best values were the cow comfort index (CCI), stall use index (SUI) and cow feeding index (CFI) (4.78, 4.87 and 0.08). In terms of stall standing index (SSI), stall perching index (SPI) and cow drinking index (CDI), slightly higher rates were observed in the barn using fans only (3.72, 1.06 and 0.013).