The shape of the lactation curve for 475 Turkish Holsteins was estimated by fitting a gamma function to daily milk yields from monthly recording of 754 lactations. Lactation curve traits that were analyzed included a scaling factor associated with yield at the beginning of lactation, the inclining and declining slopes before and after peak yield, DIM at peak yield, and peak and lactation yields. Persistency of lactation yield was measured from 1) the gamma function, 2) the coefficient of variation for monthly test-day yields, and 3) the ratio of lactation yield to peak yield. The log-transformed gamma function explained 71% of variation in daily yield. Effects of farm operation, calving year, calving season, parity, and service period were significant for the various lactation curve traits. Peak and lactation yields were higher for cows that calved in fall and winter, and persistency was higher for cows that calved in summer and fall. Peak and lactation yields were lower, but persistency was higher during first lactation. Repeatability estimates were moderate for peak (0.26) and lactation (0.34) yields and lower (0.06 to 0.20) for other lactation curve traits.

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The objective of this study was to determine the relationships between milk yield and calving interval in first lactation and breeding efficiency, herd life and length of productive life of 1 293 Holstein cows maintained at Ceylanpinar State Farm in Southeast Anatolia from 1990 to 2002.The least-squares means of first lactation milk yield, lactation length and calving interval were 5 620.1 ± 76.6 kg, 315.5 ± 2.0 and 386.9 ± 2.6 days. The values for breeding efficiency, herd life and length of productive life were 94.9 %, 2 095.9 ± 34.7 and 1 257.2 ± 34.4 days. The year of first lactation had significant effect (P<0.05) on all traits except for calving interval and lactation length, and breeding efficiency was only affected by age at first insemination and age at first calving (P<0.05).Heritabilities were 0.27 ± 0.08 for milk yield, 0.02 ± 0.05 for lactation length, 0.06 ± 0.05 for calving interval, 0.05 ± 0.05 for breeding efficiency, 0.30 ± 0.08 for herd life and 0.29 ± 0.08 for length of productive life. Genetic and phenotypic correlations between different traits ranged from −0.49 to 0.99 and −0.37 to 0.99 respectively. Keywords

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Öz Amaç: Bu araştırma sıklık stresi altındaki broylerlerde rasyona farklı düzeylerde organik ve inorganik manganez (Mn) ilave edilmesinin performans, karkas ve kan parametreleri üzerine etkilerinin incelenmesi amacıyla yapıldı. Gereç ve Yöntem: Araştırmada toplam 1000 adet günlük yaşta broyler civciv her biri 100 civcivden oluşan 1 kontrol ve 9 deneme grubuna ayrıldı. Kontrol grubu temel rasyonla, deneme grupları ise temel rasyona sırasıyla 6.25, 12.5 ve 25 mg/kg düzeylerinde organik Mn (Mn-metiyonin), 12.5, 25 ve 50 mg/kg inorganik Mn (Mn-oksit), 3.125 + 6.25, 6.25 + 12.5 ve 12.5 + 25 mg/kg organik + inorganik Mn (Mn-metiyonin+Mn-oksit) ilave edilerek beslendi. Bulgular: Araştırmada yaşama gücünün organik ve inorganik Mn ilavesi ile 29-49 ve 0-49 günlük dönemlerde arttığı belirlendi (P<0.001). Canlı ağırlık artışının 15. güne kadar 3.125 + 6.25 mg/ kg Mn-metiyonin + Mn-oksit grubunda arttığı bulundu (P<0.05). Relatif dalak ağırlığının 49. gün yemlerine 12.5 mg/kg Mn-metiyonin ve 6.25 + 12.5 mg/kg Mn-metiyonin + Mn-oksit gruplarında diğer gruplardan daha yüksek olduğu (P<0.05), 6.25 mg/kg + 12.5 mg/ kg Mn-metiyonin + Mn-oksit grubunda abdominal yağ miktarının kontrol grubuna göre daha düşük olduğu (P<0.05) bulundu. Heterofil/lenfosit oranının ise Mn-metiyonin grupları ile 25, 50 mg/kg Mn-oksit ve 3.125 Mn-metiyonin + 6.25 mg/kg Mn-oksit karışımı eklenen gruplarda 49. gün düşük olduğu bulundu (P<0.05). Öneri: Barındırma stresinde bulunan broyler piliçlerde 12.5 mg/kg organik Mn ile 3.125 + 6.25 mg/kg ve 6.25 + 12.5 mg/kg organik ve inorganik Mn karışımı ilave edilmiş yemlerle beslenmesinin performans, yaşama gücü ve stres yanıtı üzerine olumlu etkiler oluşturduğu kanaatine varıldı.

The aim of the study was to evaluate live weights, body measurements, and real-time ultrasound carcass traits of F1 and BC1 genotypes in a marker assisted introgression (MAI) process. Effects of some factors on live weight and body measurements including ultrasonographic assessments in Musculus longissimus dorsi (MLD) were investigated at the F1 (n=51) and BC1 (n=99) cross lambs born in 2015 -2017 period. Variance analysis showed that genotype had significant (P < 0.001) effect on pre-and post-weaning growth characteristics. The birth type had significant (P < 0.05) effect on pre-and post-weaning growth traits. Live weights at twelve months of age were higher in heavier born lambs. The growth performance of F1 lambs was between Texel and Ramlıç. Myostatin heterozygous BC1 lambs had been potentially heavier than the non-carriers and pure Texel. MLD depth and area were also statistically higher (P < 0.05) in BC1 lambs carrying myostatin than non -carriers. As a result, the beginning phase of introgression processes implemented was found to be successful.

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Abstract. The aim of the study was to evaluate the growth, body and ultrasonic measurements and some carcass traits of purebred Ramlıç, Texel and crossbred (87.5 % Ramlıç and 12.5 % Texel) lambs in a marker-assisted introgression (MAI) project. The effects of some environmental factors such as genotype, sex, birth type, dam age, weaning age, and birth weight on growth, ultrasound measurements, and carcass traits were significant (P<0.05). There were no significant differences between pure Ramlıç and its myostatin carrier (+/-) and non-carrier (-/-) second backcrosses (BC2) for birth weight, daily live weight gain, and weaning weight. The BC2 genotype (+/-) was statistically caught up with pure Ramlıç for wither height, body length, and rump width. Differences in the longissimus muscle depth indicated that the BC2 (+/-) genotypes tended to be better for both pure Ramlıç and Texel lambs. Texel lambs were superior to Ramlıç in the aspect of some carcass characteristics such as leg length, cold right-half carcass weight, foreleg weight in the left-half carcass, and muscle weight in the left leg. BC2 (+/-) lambs were in the middle of both breeds for the traits. BC2 lambs carrying myostatin did not vary from Ramlıç morphologically. The new type of Ramlıç was also closer to Texel in the aspect of carcass characteristics. In this connection, improvement of indigenous breeds could be achieved by MAI without changing the essential characteristics. For the summary, please visit http://www.mustafatekerli.com (last access: 14 June 2022).