In order to verify the fattening performance, slaughter and carcass characteristics and to investigate the changes in some meat quality traits of Karayaka lambs weaned at 3 months of age, 39 lambs (23 males and 16 females) were used as experimental animals. The lambs were fed a concentrate mixture and alfalfa hay (120 and 168 g crude protein and 2,700 and 1,951 ME/kg, respectively) for a period of 60 days of fattening period. Male lambs were superior (p < 0.05) to female lambs in terms of daily weight gain (270.4 vs. 205.4 g; SEM = 9.46), hot and cold carcass weights (16.7 and 16.0 vs. 14.1 and 13.4 kg, respectively; SEM = 0.35), intra-muscular fat ratios (1.9% vs. 2.5%; SEM = 0.12) and dripping loss of semitendinosus muscle 3 days postmortem (8.1% vs. 10.2%; SEM = 0.36). The relative weights of some organs, the meat quality traits (pH, cooking loss, shear force, CIELab colour characteristics) and proximate analyses (dry matter, protein and ash) of longissimus dorsi and semitendinosus muscle samples from lambs were not affected by sex (p > 0.05). Dripping loss, pH and colour characteristics were affected by storage time (p < 0.05). These results provide a basic understanding of performance and meat quality of Karayaka sheep which may have potentials in improving sheep production using an indigenous sheep breed in Turkey.

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.

The study conducted a comparison of meat quality, fatty acid profile, and cholesterol amounts of longissimus dorsi (LD) and semitendinosus (ST) muscles of male lambs born to Turkish indigenous sheep breeds raised under intensive conditions. A total of 36 singleton male lambs were used as experimental animals of the Akkaraman (A), Morkaraman (M), Awassi (IW), Karayaka (KR), Kıvırcık (KV), and Middle Anatolian Merino (MAM) pure breeds. All lambs were fed the same diet until they reached a target weight of 40 kg weight. After the feeding period, all lambs were slaughtered and LD and ST muscle samples were collected to determine meat quality traits, fatty acid profile, and cholesterol amounts. Although there were no significant differences between lambs in terms of the fatty acid profile of LD and ST muscles, KR lambs had a higher cholesterol content in both muscles in comparison with the lambs born to other breeds (p<0.05). While water-holding capacity, dripping loss, pH, color, dry matter, ash, and intramuscular fat values of ST muscles showed differences among breeds (p<0.05), dripping loss, pH, cooking loss, color, dry matter, ash, protein, and intramuscular fat values of LD muscles differed between breeds (p<0.05). The data of the current study indicated that meat quality characteristics and cholesterol contents of Turkish indigenous breeds showed differences, and these differences may be used for alternative lamb meat production for the consumer.

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.

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The purpose of this study was to examine the importa~zce of the genetic arld maternal enviroizmental factors ilifluencing the 12-week weight ( 1 2 W W ) of Welsh Mountain lambs arzd to estimate genetic parameters for this trait. Records of 8880 Welsh Mourztain lambs borrl betweeiz 1979 and 1995 were analysed. The records werefrom the rlucleus flock of the C A M D A cooperative breeding group. In this flock selection of replacements had been based on a multi-trait index incorporating lamb growth and materrzal ability as importaizt objectives and 1 2 W W as one of the selection criteria. Twelve models were examined, all including direct additive genetic variance urzd various combinations of genetic and environmental maternal effects. The most appropriate model was chosen based oil loglikelihood ratio tests. It included appropriate fixed effects, and direct additive, maternal additive, maternal permanent environment and maternal common environment (litter) random effects that defined proportionally 0.21 (h2), 0.09 (mZ), 0.06 (pe2) and 0.18 (ce2) of the pherlotypic variance. Ignoring the additive maternal effect resulted in inflated estimates of direct heritability and ignoring the environmental effects associated zuith dam irzflated the direct and maternal heritabilities. There was no correlation (P < 0.05) between the additive direct and additive maternal effects. Additive direct and maternal breeding values increased by 0.12 (s.e. 0.006) kglyear and 0.03 (s.e. 0.003) kglyear respectively. The results demonstrate the effective incorporation of selectiorl index methodology in the context of a hill sheep flock and also the importance of several categories of maternal effects.

This study focused on the estimation of genetic relationships between weekly live weights and sexual maturity of male and female Japanese quail. The live body weight data of a laying-type quail line over time were collected from hatching to six weeks of age. Sexual maturity was determined as the day of production of cloacal gland foam for males, and the day of laying the first egg for females. (Co)Variance components and genetic parameters were estimated, using MTDFREML, a restricted maximum likelihood (REML) procedure using a model with direct and maternal genetic effects. Heritability estimates of weekly live weights ranged from moderate to high (0.20 -0.60), and were higher for males than for females. The variance due to maternal effects disappeared gradually for males but rapidly for females as the chicks grew older. Heritability of age of sexual maturation was 0.24 ± 0.008 and 033 ± 0.136 for males and females, respectively. Genetic correlations between ages of reaching sexual maturity and live weights (except hatchling weight) were favourable for males (-0.16 to -0.45) and unfavourable for females (0.14 to 0.22). Genetic correlations between males and females ranged from moderate (0.46 ± 0.083) to high (0.98 ± 0.139) for weekly live weights, and were 0.71 ± 0.24 for age of reaching sexual maturity. Sexual size dimorphism can be explained by the differences in pattern of heritability and correlation estimates between reaching sexual maturity and live weights for males and females.