Czech Journal of Animal Science, 2023 (vol. 68), issue 6
Timed artificial insemination protocols in dairy cattle: Functioning, shortcomings, and improvementsReview
Amine Boudaoud
Czech J. Anim. Sci., 2023, 68(6):231-244 | DOI: 10.17221/208/2022-CJAS 
Oestrus detection is currently at the top of the factors limiting the success of artificial insemination in dairy herds. This limitation becomes more pronounced as milk production increases because of higher metabolic clearance rates of steroid hormones leading to low circulating oestradiol concentration near oestrus. The standard OvSynch has overcome this problem by enabling fixed-time artificial insemination, for it synchronises follicular wave emergence, luteolysis, and ovulation. However, it did not improve fertility compared to cycles with spontaneous ovulation, which motivated the development of “fertility programs”. These later...
Effect of biochar or biochar and urea supplementation on feed intake, milk yield, feed conversion and methane production of dairy cowsOriginal Paper
Georg Terler, Manuel Winter, Michael Mandl, Joseph Sweeney, Andreas Steinwidder
Czech J. Anim. Sci., 2023, 68(6):245-254 | DOI: 10.17221/38/2023-CJAS
Feed additives belong to a number of climate change mitigation strategies being sought to reduce methane emissions in ruminants. In this study, the effect of biochar or biochar and urea supplementation on dairy cow performance and methane production was assessed. Eighteen cows were used in a 3 × 3 latin square design with three feeding groups: control with no supplementation (CO), biochar supplementation (BC, 200 g/day) and biochar and urea supplementation (BC + U, 200 g/day biochar and 90 g/day urea). All cows were fed a forage mixture ad libitum and 5 kg of concentrates per day on average. Methane emissions were measured in respiration...
Effects of dietary protease supplementation on behaviour, slaughter performance, meat quality and immune organ indices of broilersOriginal Paper
Xixi Li, Xinxin Wang, Yi Lv, Wenfeng Ma, Xiaohong Wu, Wenrui Zhen, Furong Zhao
Czech J. Anim. Sci., 2023, 68(6):255-265 | DOI: 10.17221/178/2022-CJAS
This study was conducted to investigate the effects of protease supplementation on the behaviour, slaughter performance, meat quality, and immune organ indices of broilers. A total of 240 one-day-old Arbor Acres broiler chickens were randomly allocated to four treatments, with six replicates per treatment and 10 broilers per replicate. Chickens were fed corn-soybean meal basal diets supplemented with 0, 4, 8, and 12 IU/g of protease. Compared with 0 IU/g of protease supplementation, 12 IU/g of protease increased the average and minimum time of feeding and drinking behaviour (P < 0.05); increased the average, maximum, and minimum time...
Effect of urea and molasses supplementation on in vitro digestibility, feed quality of mixed forage silagesOriginal Paper
Esra Gürsoy, Gürkan Sezmiº, Ali Kaya
Czech J. Anim. Sci., 2023, 68(6):266-276 | DOI: 10.17221/212/2022-CJAS
This study aims to investigate using different ratios of urea-molasses in silage of food in vitro fermentation, feed value and quality production in feed. After being withered a little, the fodder plant was fragmented into 2–3 cm long pieces. 0, 2 and 4% molasses and 0, 0.5 and 1% urea were added. The treatment groups were UM1 (control), UM2, UM3, UM4, UM5, UM6, UM7, UM8 and UM9 supplemented with 0, 0, 0, 1, 1, 1, 1.5, 1.5, 1.5% urea and 0, 2, 4, 0, 2, 4, 0, 2, 4% molasses respectively, and a total of 54 silage samples, 9 × 6 parallel, were prepared, vacuumed in ready-made silage bags, and stored at 25 ± 2 °C for 60 days. After the silages...