Zafer Ulutaş

The effect of maternal nutrition level during mid-gestation on postnatal muscle fibre composition and meat quality in lambs

Maternal nutrient intake during early- and mid-gestation can alter fetal growth and development with long-term consequences on the postnatal productivity and health of offspring. The aim of this study was to investigate the effects of maternal nutrition level during mid-gestation on postnatal growth rate, carcass composition, muscle fibre characteristics and meat quality in lambs. Ewes were fed from Days 30 to 80 of gestation as follows: 100% (control group, C), 50% (undernutrition, UN) or 175% (overnutrition, ON) of their daily requirement. During the rest of the gestation, the ewes in all groups were fed 100% of their daily requirements. Birth and weaning (at Day 90) weights of lambs born to ewes in nutritional groups were similar, but slaughter weights (at Day 150) and daily weight gain during finishing period of lambs born to the UN group were lower (P < 0.05). Similarly, a decrease in weights of semitendinosus (ST), semimembranosus and gastrocnemius muscles was observed in the lambs born to the UN group (P < 0.05). Lambs born to the ON group had a higher (P < 0.05) concentration of DNA in longissimus dorsi (LD) and ST muscles than UN groups, but they had a lower (P < 0.05) total protein and other proteins concentrations in LD and ST muscles than those to C and UN groups. Protein to DNA ratio in LD and ST muscles of lambs born to ON group were lower than those to C and UN groups (P < 0.05). However, lambs born to the ON group had a higher number of Type IIA and IIB muscle fibres in ST muscles but not in LD muscles than those in the C and UN groups (P < 0.05). Additionally an increase in the number of fibres/mm2 muscle area in lambs born to the ON group was observed in LD and ST muscles (P < 0.05). There were no significant differences between treatment groups in terms of meat quality parameters studied. This study confirms that maternal nutrition level during mid-gestation alters the postnatal growth and muscle fibre development of lambs.

Genetic and environmental parameters and trends for milk production of Holstein cattle in Turkey

Data from 4143 Holstein cattle from three herds in Turkey were used to study the influences of genetic and environmental factors on milk production traits as well as genetic and environmental trends over 20 years from 1987 to 2006. First lactation mean values for 305-day milk yield, actual lactation milk yield, and lactation length were 6222±35.8 kg, 6651±42.6 kg, and 327±1.3 days. Second and third 305-day lactation yields were proportionately 8% and 11% greater, respectively. The effects of herd and calving year were the largest sources of variation for all traits. Heritabilities of actual lactation milk yield, 305-day milk yield, and lactation length for first lactation records were 0.24±0.007, 0.23±0.007, and 0.08±0.035. Estimates of variances and genetic parameters were consistent with estimates reported throughout the literature. Trends were inconsistent with some phenotypic increase in yields during the period between 2001 and 2005. This improvement was associated with increased environment parameter estimates during that period. No consistent genetic improvement was observed.

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.

Estimates of (co)variance components for direct and maternal effects on birth weight of Karayaka lambs

The purpose of this study was to estimate the genetic parameters for birth weight of Karayaka lambs by separating direct genetic, maternal genetic, and maternal permanent environmental effects. Records of 1013 Karayaka lambs born between 2005 and 2010 were analyzed. Six different animal models were examined, all including direct additive genetic variance and various combinations of genetic and environmental maternal effects. The most appropriate model was chosen based on log-likelihood ratio tests. Since model 1 had the smallest likelihood value, it was chosen as the best model in this study. Depending on the model, direct heritability varied from 0.37 to 0.55 and maternal heritability ranged from 0.08 to 0.20 for birth weight.

Some Gastrointestinal Tract Characteristics of Karayaka Ram Lambs Slaughtered at Different Weights

Thirty-one Karayaka ram lambs were slaughtered at different body weights (30 (n  =  7) , 35 (n  =  6) , 40 (n  =  7) , 45 (n  =  6) , and 50 (n  =  5)  kg of body weight at fast) to evaluate the growth of their gastrointestinal tract (GIT) characteristics, to determine the relationship among slaughter body weight (SBW) and empty body weight (EBW), whole GIT and segments, and the influence of slaughter weight on the pH of rumen, jejunum, and cecal contents. The effects of the SBW on GIT weight (P  <  0.05) , stomach ( P  <  0.001) , and intestine (P  <  0.05) , the body length (P  <  0.001) and caecum (P  <  0.05) , and the relative weights of GIT (P  <  0.05) , stomach (P <  0.001) , and intestine (P  <  0.001) were linear whereas that for the length of intestine were quadratic. The effect of SBW were quadratic (P  <  0.05) on ratios of stomach to GIT weight and intestine length to intestine weight and rumen pH while, for the intestine to GIT weight ratio (P  <  0.001) and caecum pH (P  <  0.05) , this effect was linear. The results indicated that for all parameters studied, with the exception of intestinal length and cecal pH, linear relationships were observed with SBW indicating steady growth rates for these tissues.

Genetic Parameters of Milk Yield in Jersey Cows

Abstract Ulutas, Z., Sahin, A. and Saatci, M. 2008. Genetic parameters of milk yield in Jersey cows. J. Appl. Anim. Res., 34: 29–32. To predict genetic parameters of milk yield and assess the genetic improvement in Jersey cows reared at Karaköy State Farm in Black sea region a total of 1275 records from 460 cows were used. Year, season and lactation number were added in the model as fixed effects for the preliminary analyses. The highest h2 (0.37) was estimated for milk yield. As a reflection of the environmental influences, both Vc (14.93) and C2 (< 0.001) had low values for the studied herd. Genetic correlation between the lactation length and calving interval was strong (0.90). Permanent environmental effect due to cow (PEEC) did not show any sharp movement among the years (0.17 to −0.48). It is concluded that most of the influence on milk was genetic and very limited environmental.

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.

Effects of birth weight and feeding system on fattening performance and feeding behaviour of Karayaka male lambs

To determine effects of birth weight (BtW) and feeding system on fattening performance and behavioural responses of lambs, after birth 28 Karayaka male lambs were divided into two BtW groups, namely a low BtW (4.1±0.06 kg) and high BtW (5.0±0.09 kg). After weaning (90 days of age), seven lambs in each of these groups were fed individually ad libitum with total mixed ratio (TMR), consisted of 80% of a compound feed and 20% of roughage based on a dry matter basis (140 g crude protein and 2550 kcal ME/kg) and the other seven lambs were fed on the same ingredients as that of TMR but each ingredient was put in separate troughs (free choice feeding, FCF). Therefore the lambs were distributed into four groups according to 2 (low vs high BtW) × 2 (TMR vs FCF) factorial design. Live weight gains and intakes of dry matter, feedstuffs and nutrients of the lambs were affected by the FCF, but not by the BtW and their interaction. The daily weight gain (P<0.01), intakes of soybean meal and corn (P<0.01), dry matter (P<0.05), protein and energy (P<0.01) of FCF-fed lambs were higher than those of TMR-fed lambs. FCF-fed lambs consumed less alfalfa hay, wheat bran and barley than TMR-fed lambs (P<0.01). The FCF increased rumination (P<0.01) and tend to rest more (P<0.05) compared to the TMR. The study suggests that FCF system can assist in enhancing the live weight gain by promoting the protein and energy intakes and by improving the welfare of lambs.