Aziz Şahin

Lactation curve and persistency of Anatolian buffaloes

The aim of this study was to determine the lactation curve traits of Anatolian buffaloes raised under different conditions in farms in Tokat Province, Turkey. Wood’s gamma curve parameters were employed to identify the lactation curve types, and values for the parameters beginning yield (a), coefficient of rising (b) and coefficient of decreasing (c) were used to determine the shape and type of lactation curve. All parameters in typical lactation curves were positive, and in the event of one parameter being negative, the curve was considered to be an atypical lactation curve. A total of 690 lactation curves were investigated. It was determined that 406 (58.84%) of these curves were typical, while 90 (13.04%) were concave and 194 (28.12%) of a decreasing type. For typical lactation curves, a, b, c, persistency (S), time after parturition until the peak yield occurs (Tmax), maximum daily peak yield (Ymax), and coefficient of determination (R2) were 7.14±0.008, 0.85±2.1, 0.40±0.001, 2.68, 63.6, 6.41 and 76.33, respectively. For concave lactation curves, values for a, b, c, Tmax, Ymax and R2 were 4.94±0.42, -0.73±0.016, - 0.23±0.0038, 95.40, 7.41±0.004 and 71.68, respectively. For decreasing typical lactation curves, values for a, b, c, Tmax, and R2 were 5.31±0.0041, -0.15±0.007, 0.039±0.0023, 3.89±0.11 and 79.94, respectively. Parameters predicted by the Wood model within the scope of this study have the potential of being useful for breeding programmes. Further breeding/selection activities could be conducted by using the female Anatolian buffaloes with typical lactation curves.

Genetic parameters of first lactation milk yield and fertility traits in Brown Swiss cattle.

Abstract This research was carried out to estimate variance components and genetic parameters for first lactation milk yield (lactation milk yield, 305-day milk yield, lactation length, and dry period) and some fertility traits (calving interval, gestation length and number of services per conception) of Brown swiss cattle reared at konuklar state farm located in konya province, turkey. data were collected on milk yield traits of 3, 769 first lactation Brown Swiss cattle during the period from 1990 to 2008. Variance components, genetic parameters, breeding values, and genetic correlations were estimated using multiple trait derivative free restricted maximum likelihood (mtdfreml) fitting an animal model. Heritability estimates were 0.26, 0.25, 0.10, 0.06, 0.07, 0.06 and 0.03 for lactation milk yield (lmy), 305-day milk yield (305 dmy), lactation length (ll), dry period (dp), calving interval (ci), gestation length (Gl), and number of services per conception (nsc), respectively. Genetic correlations between milk yield and fertility traits ranged from 0.31 to 0.95 and phenotypic correlations ranged from –0.026 to 0.75. Breeding values were estimated and used to characterize genetic trends across the time period investigated. The results showed that the first lactation milk yield traits can be used as selection criteria for development of effective genetic improvement programme in turkish Brown swiss cattle. in addition, the results indicate the essential for scheming an effective schedule for growth of genetic variability to improve the milk yield traits of Brown swiss cattle in this farm by way of selection.

The application of six different models to estimate the genetic parameters, variance components and breeding values for birth weight of Holstein calves

ABSTRACT This research was conducted to determine variance component, genetic parameters and breeding values (EBV) for the birth weight (BW) of Holstein calves. In this context, the direct genetic (), maternal genetic () and maternal permanent environmental effects, which affect BW, were separately assessed. The multi-trait, derivative-free restricted maximum likelihood programme was used for determining the effect of the genetic parameters by using models that either included or excluded the maternal genetic and/or permanent maternal environmental effects. The estimation of the BW of Holstein calves was optimized by evaluating six different models. The best model was chosen according to the log-likelihood ratio tests. Within the context of the study, a total of 4443 calves were investigated between 1987 and 2006. Among the six different models, model 4 was selected as the best model, since it had the lowest value for the likelihood ratio. The range of the values for direct heritability () and maternal heritability (m2) were between 0.07–0.13 and 0.04–0.09, respectively. In conclusion, an estimation of the genetic parameters for BW can be used as a selection criteria for Holstein calves.

The Mastitis Case in Water Buffalo

Mastitis manda yetistiriciliginde ekonomik kayiplara neden olan onemli bir hastaliktir. Hastaligin siddeti, suresi ve birincil nedenine gore mastitis, genel olarak klinik ve subklinik olmak uzere ikiye ayrilmaktadir. Subklinik mastitis, surudeki diger hayvanlardan bulasmasi nedeni ile onemli bir suru problemidir. Ancak, klinik mastitis ise memede deformasyonlar ve sut veriminin azalmasi ile sekillenen klinik bir olgudur. Staphylococcus aureus, Escherichia coli, Streptococcus agalactia ve Streptococcus dysgalactia klinik, Escherichia coli, Staphylococcus aureus, Pseudomonas, Streptococcus agalactia ve Streptococcus dysgalactia ise subklinik mastitis olaylarinda en yaygin olarak izole edilen mikroorganizmalardir. Mandalarda bu mikroorganizmalarin neden oldugu mastitis olgulari sonucu, sutun yapisinda anormallik gozlenmekte ve sutun miktarinda meydana getirdigi dususle ureticileri ekonomik kayba ugramaktadir. Bu nedenle mastitis uzerine etkili faktorlerin tespit edilmesi ve gerekli onlemlerin alinmasi buyuk onem tasmaktadir. Bu derlemede, mandalarda mastitis olgusu ve etkileri uzerinde durulmustur.