Journal of Animal Science and Technology (JAST) is a peer-reviewed, open access journal publishing original research, review articles and notes in all fields of animal science. Topics covered by the journal include: genetics and breeding, physiology, nutrition of monogastric animals, nutrition of ruminants, animal products (milk, meat, eggs and their by-products) and their processing, grasslands and roughages, livestock environment, animal biotechnology, animal behavior and welfare.

The aim of the study was to evaluate the effect of storage length (7, 14, 21 and 28 days), turning frequency (0, 1 and 24 times per day) and egg position (pointed end up, blunt end up and horizontal) on egg weight loss during storage and incubation; hatchling chick weight, incubation length and hatchability results in 56-week-old chukar partridges (Alectoris chukar). A total of 1800 daily collected eggs was assigned to 36 subgroups (4 × 3 × 3 experimental design) consisting of 50 eggs for each subgroup. Progressive decrease in egg weights and increase in egg weight loss during storage was observed with the lengthening of storage period (p < .001). Prominent effects were observed in total egg weight loss rate and incubation length when the eggs were stored more than 21 days (p < .001). The highest hatchling chick weights were observed in horizontal eggs stored for 7 days (p < .001). Most indices of hatching results showed detrimental effects when turning wasn’t applied and the eggs were stored with the position of blunt end up. General recommendations from the hatching results showed that chukar eggs can be stored up to 21 days of storage length irrespective of turning and egg position. If the chukar eggs are to be stored more than 21 days, turning should be implemented and the eggs should be placed with the position of pointed end up for optimum hatching results.

Amaç: Bu çalışmada kahverengi ve sarı tüy renkli Japon bıldırcınlarında büyüme eğrisi parametrelerinin tahmini ve en uyumlu modelin tespit edilmesi amaçlanmıştır. Gereç ve Yöntem: Araştırma materyali olarak 80 adet kahverengi ve 80 adet sarı tüy renkli Japon bıldırcını kullanılmıştır. Bıldırcınlar 0, 7, 14, 21, 28, 35 ve 42 günlük yaşlarda tartılmıştır. Büyüme eğrilerini belirlemek için Gompertz, Logistic, Von Bertalanffy ve Richards modelleri kullanılmıştır. Bulgular: Uyum iyiliği açısından Gompertz modeli kahverengi ve sarı tüy renkli Japon bıldırcınları için en iyi model olarak tespit edilmiştir. Belirleme katsayısı (R2), düzeltilmiş belirleme katsayısı (R2adj), Akaike Bilgi Kriteri (AIC), Bayesian Bilgi kriteri (BIC) ve hata kareler ortalaması (HKO) kahverengi ve sarı tüy renkli bıldırcınlarda sırasıyla 0,9968; 0,9952; 24,8801; 24,7179 ve 25,9657; 0,9975; 0,9963; 22,9149; 22,7527 ve 19,6099 olarak tespit edilmiştir. Modele ait β0, β1 veβ2 parametreleri kahverengi ve sarı tüy renkli bıldırcınlar için sırasıyla 234,89; 3,630; 0,072 & 236,58; 3,516 ve 0,069 bulunmuştur. Bükülme noktası yaşı ve bükülme noktasındaki canlı ağırlık ise sırasıyla 17,91 gün ve 86,41 g; 18,15 gün ve 87,03 g olarak hesaplanmıştır. Öneri: Sonuç olarak, bu çalışmada hem kahverengi hem de sarı tüy renkli Japon bıldırcınlarında Gompertz modeli en iyi model olarak belirlenmiştir. Farklı tüy renklerindeki Japon bıldırcınlarının büyüme eğrisi özelliklerinin belirlenmesinde sonraki araştırmalarda kullanılması önerilebilir. Öte yandan, Japon bıldırcınlarının bir alt türü olan Jumbo bıldırcın yetiştiriciliği, kahverengi tüy renkli Japon bıldırcınlarının yanı sıra yüksek erginleşme indeksi nedeniyle bıldırcın eti üretiminde dikkate alınmalıdır.

The lowland area of Indonesia has economic potential to develop as a major centre for dairy farming businesses. Still, there is a foremost matter: overheated irradiation immersed in damped air would increase the heat stress level. The present study was conducted to assess the heat stress tolerance level of lowland Indonesian Holstein cows, characterized by a dominant level of Black and White (B/W) pigmented skin coat. This study involved 34 heads of Holstein cows that were cared for in Eastern Jakarta. Breathing frequency (BF), rectum's warmth (RW), pulse rate (PL), white-skinned spot temperature (WSST), black-skinned spot temperature (BSST), average temperature rounded skin (ATRS), back region temperature (BRT), chest region temperature (CRT), upper-leg temperature (ULT), lower-leg temperature (LLT), skin's temperature (ST), body's temperature (BT), and heat tolerance coefficient (HTC) as variables were checked statistically with R 4.4.2 type software comprised correlation and independent t-test. Cows B/W classification performed with the imageJ 1.54g series program. Those analyses showed that most lowland Indonesian Holsteins were characterized by black-pigmented dominant cows (BDC). The pigmentation of both lateral sides of the body generated a significant correlation (p<0.05 and p0.05) in all measurable vital symptoms; all variables showed trends indicating that the BDC class had a greater response to heat stress. The BDC Holstein type selection base had high expectations of elevating the HTC score in Indonesian lowland cows, as the closing decision.

The performance and health status of dairy calves may benefit from further transition milk feeding during the early postnatal period. However, transition milk obtained from cows during the first three to seven postpartum milkings is usually commingled with bulk tank milk by farmers. Therefore, this study aimed to evaluate the growth performance and health status of Holstein calves provided with extended transition milk feeding for the first three weeks of life. Twenty newborn singleton Holstein calves without any health problems or dystocia were blocked by birthweight, sex, and parity and assigned to two groups: control (fed normal milk after day 5, n = 10) and transition (fed transition milk up to day 21, n = 10). The calves were housed in individual hutches and weighed to determine their growth rate, and blood samples were collected on days 1, 7, 14, and 21. Residual calf starter pellets were weighed daily to calculate the feed conversion efficiency. The calves were monitored and their faecal scores were recorded daily. Feeding transition milk until 21 days of age improved the calves’ daily growth and calf starter pellet feed conversion efficiency. The calves’ faecal scores and blood parameters were not affected by transition milk feeding. No treatment × week interactions were observed in the calves’ growth performance, faecal scores, and blood parameters, except for the serum concentrations of aspartate aminotransferase and beta-hydroxybutyrate. In conclusion, feeding Holstein calves transition milk for the first three weeks of life is recommended to improve growth performance. (Submitted 07 March 2023; Accepted 19 September 2025; Published 07 October 2025)