Template-Type: ReDIF-Article 1.0 Author-Name: Agnese Smilga-Spalvina Author-Workplace-Name: Institute of Energy Systems and Environment, Riga Technical University, Riga, Latvia Author-Workplace-Name: Smilga Spalvina Llc., Incukalns, Sigulda district, Latvia Author-Name: Kriss Spalvins Author-Workplace-Name: Institute of Energy Systems and Environment, Riga Technical University, Riga, Latvia Author-Name: Ivars Veidenbergs Author-Workplace-Name: Institute of Energy Systems and Environment, Riga Technical University, Riga, Latvia Title: Field study: Factors influencing virgin queen bee acceptance rate in Apis mellifera colonies Abstract: Regular replacement of old and problematic queen bees is necessary to maintain the strength and productivity of bee colonies. Beekeepers replace queen bees using queen cells, virgin queens, or mated laying queens. In this study, we explored factors influencing the acceptance of the virgin queens. A comprehensive field study was conducted in the summer of 2023, involving the introduction of 754 virgin queens of different age and 194 queen cells into mating nuclei of various states using three different methods. The article aims to provide recommendations to beekeepers for introducing virgin queens, thereby increasing the frequency of successful requeening. The duration of the colony being queenless has a significant impact on the acceptance of queens. If the colony is prepared in advance, at least five days prior, immature and mature virgin queens will be accepted equally well (60‒77%). Conversely, suppose queen replacement is done without preparation for a colony that has been queenless for one day only. In that case, the result will be significantly lower due to the short queenless period (41%), and the age factor of queen bees will come into play. If queen replacement is done with preparation, the chosen timing within the season will play a significant role, as weather conditions can influence acceptance and mating, varying from 48% to 89%. Suppose a bee colony has long lost its queen and has developed laying worker bees. In that case, there is still a 55% chance of successfully introducing a virgin queen into such a colony without using time-consuming methods. Keywords: bee breeding, beekeeping, honey bee, introduction success, requeening, virgin queens Journal: Czech Journal of Animal Science Pages: 155-164 Volume: 69 Issue: 4 Year: 2024 DOI: 10.17221/22/2024-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/22/2024-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-202404-0001.txt Handle: RePEc:caa:jnlcjs:v:69:y:2024:i:4:id:22-2024-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: Anežka Málková Author-Workplace-Name: Department of Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Prague - Suchdol, Czech Republic Author-Name: Martin Ptáček Author-Workplace-Name: Department of Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Prague - Suchdol, Czech Republic Author-Name: Filipp Georgijevič Savvulidi Author-Workplace-Name: Department of Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Prague - Suchdol, Czech Republic Author-Name: Szabolcs Tamás Nagy Author-Workplace-Name: Hungarian University of Agriculture and Life Sciences, Institute of Animal Sciences, Georgikon Campus, Keszthely, Hungary Author-Name: Luděk Stádník Author-Workplace-Name: Department of Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague, Prague - Suchdol, Czech Republic Title: Effects of age and litter-of-origin on cryopreserved spermatozoa in Sumava rams Abstract: This study aimed to evaluate the influence of the internal factors of ram age and litter-of-origin on semen quality during the cryopreservation process in Sumava sheep rams. This breed is included in the protected genetic resources of the Czech Republic. The sires were systematically divided into four groups according to age (under 1.5 years, 1.5 to 2.5 years, 2.5 to 3.5 years, and over 4.5 years) and according to litter frequency (singletons vs twins). Semen was evaluated after equilibration, and after cryopreservation using iSperm® mCASA and flow cytometry. During cryopreservation, there was a significant decrease in total sperm motility by 53.5%, progressive motility by 38%, and cells with intact plasma membrane and acrosome by 47%. Frozen-thawed sperm kinematic parameters showed significant age-related variations, with rams aged 4.5 and older displaying notably higher total and progressive motility (16.2% and 6.24%, respectively). Rams born as twins exhibited 3.77% (P < 0.05) higher progressive motility and 5.5% (P < 0.05) higher total motility compared to those born as singles. The sperm of older rams (> 4.5 years) exhibited higher viability (10.1%) and lower damage to the plasma membrane after freeze-thawing (23.6%), (P < 0.05). Twins showed significantly higher sperm viability (4.98%, P < 0.05) than singletons. These rams produce a larger quantity of higher-quality insemination doses after cryopreservation. For Sumava rams, in particular, broadening the sire selection base helps to select suitable rams for breeding. As the sire ages, his genetic value within the production herd may decline with time. This contrasts with genetic resource protection, where the aim is to preserve and store as many high-quality semen samples as possible. Keywords: internal factors, flow cytometry, motility evaluation, sperm quality, sperm freezing Journal: Czech Journal of Animal Science Pages: 129-138 Volume: 69 Issue: 4 Year: 2024 DOI: 10.17221/32/2024-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/32/2024-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-202404-0002.txt Handle: RePEc:caa:jnlcjs:v:69:y:2024:i:4:id:32-2024-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: Nayanne Rodrigues de Oliveira Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Fabiana Ramos dos Santos Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Maura Regina Sousa Silva Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Isadora da Silva Rissato Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Geyniane Carvalho Roque Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Carollynne Martins Silva Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Hemylla Sousa Santos Barros Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Nathan Ferreira da Silva Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Cibele Silva Minafra Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Author-Name: Francisco Ribeiro de Araújo Neto Author-Workplace-Name: Goiano Federal Institute, Goiás, Brazil Title: Dietary levels of soluble and insoluble fibre sources for young slow-growing broilers Abstract: This study aimed to evaluate the effects of dietary levels of soluble and insoluble fibre on the performance and digestive development of slow-growing broilers during the starter period. A total of 400 one-day-old Isa LabelTM male chicks were used that were distributed in a completely randomized factorial design 2 × 2 + 1 (inclusion of 2% or 4% of corncobs as a source of insoluble fibre IF and citrus pulp as a source of soluble fibre (SF); and a control treatment) with eight replicates of 10 birds each. The addition of IF to diets improved the weight gain and feed conversion of broilers at 7 and 21 days of age. Both fibre sources added to diets resulted in higher relative weights of proventriculus + gizzard, liver, small and large intestine. The diets containing an SF source presented positive effects on the duodenal mucosa. In addition, positive effects on the caecal villus to crypt ratio were observed in broilers fed diets containing different types of fibre. It is concluded that dietary inclusion of IF up to 4% maintains the performance, nutrient metabolism and improves the development of the proventriculus + gizzard in slow-growing broilers. However, for improving the morphological and histomorphological parameters of slow-growing broilers in the starter phase the addition of SF sources is recommended. Keywords: backyard poultry, citrus pulp, corncobs, growth performance, gut morphology, intestinal histomorphometry Journal: Czech Journal of Animal Science Pages: 139-154 Volume: 69 Issue: 4 Year: 2024 DOI: 10.17221/84/2023-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/84/2023-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-202404-0003.txt Handle: RePEc:caa:jnlcjs:v:69:y:2024:i:4:id:84-2023-CJAS Template-Type: ReDIF-Article 1.0 Author-Name: Hew Wei Ee Author-Workplace-Name: Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang, Malaysia Author-Name: Suriya Kumari Ramiah Author-Workplace-Name: Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang, Malaysia Author-Name: Saminathan Mookiah Author-Workplace-Name: Food and Feed Technology Unit, Product Development Research and Advisory Services Division, Malaysian Palm Oil Board, Kajang Selangor, Malaysia Author-Name: Zulkifli Idrus Author-Workplace-Name: Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang, Malaysia Author-Workplace-Name: Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Malaysia Title: Effects of medium-chain fatty acids on growth performance, microbial attributes, and fat deposition in broiler chicken Abstract: Poultry are monogastric animals that share a fat tissue structure that is strikingly comparable to the fat in animal feed. This indicates that the kind and source of fat in animal diets can significantly impact the accumulation and composition of fatty tissue in the resulting carcass. Hence, feeding (or dietary) manipulation is one of the best and commonly employed management strategies to improve of gut health and function in broiler production. Medium-chain fatty acids (MCFAs) are fatty acids with six to twelve carbon atoms that are prevalent in coconut and palm kernel oils. Much research is being conducted on nutritional approaches to enhance gut health and lower the usage of antibiotics in poultry farming. The use of MCFAs as an antibiotic substitute has been shown to have significant positive effects on broilers' health and performance due mainly to their short pathways of absorption and oxidation. However, the fatty acid makeup of these feed additions may vary, and the results are sometimes inconsistent. Although supplementing hen diets with MCFAs can lower intermuscular and abdominal fat, the precise mechanics are not entirely understood. The distinct metabolic roles of fatty acids in chickens are linked to both the degree of saturation and the length of the chain. Detailed information on the effect of MCFAs on the growth performance, antimicrobial properties, and fat deposition in broiler chickens are summarised. Keywords: fatty acids, monogastric animals, bactericidal, animal feed Journal: Czech Journal of Animal Science Pages: 119-128 Volume: 69 Issue: 4 Year: 2024 DOI: 10.17221/175/2023-CJAS File-URL: http://cjas.agriculturejournals.cz/doi/10.17221/175/2023-CJAS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjs-202404-0004.txt Handle: RePEc:caa:jnlcjs:v:69:y:2024:i:4:id:175-2023-CJAS