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Variability in seed morphological characteristics, seed germination and seedling growth characteristics was observed among the 40 genotypes of Jatropha selected from the kandi (sub-mountainous) areas of Punjab. Maximum seed weight...
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Variability in seed morphological characteristics, seed germination and seedling growth characteristics was observed among the 40 genotypes of Jatropha selected from the kandi (sub-mountainous) areas of Punjab. Maximum seed weight, seed germination and plant height were recorded in PAU-3, while maximum collar diameter was in PAU-14. Significant correlation between seed parameters (seed weight and seed length) and plant growth parameters (height and collar diameter) was observed. However, the correlation between seed diameter and germination index was found to be non-significant. Heritability and genetic gain was observed to be the highest for the seed weight (0.765, 41.0 per cent) and the lowest for the plant diameter (0.374, 5.30 per cent), respectively. The considerable variation for seed weight and seed length coupled with high heritability indicates the possibility of improvement through selections. The medium to low heritability for growth traits shows the influence of environmental variableson these traits.
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To predict genetic parameters of milk yield and assess the genetic improvement in Jersey cows reared at Karakoy State Farm in Black sea region a total of 1275 records from 460 cows were used. Year, season and lactation number were...
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To predict genetic parameters of milk yield and assess the genetic improvement in Jersey cows reared at Karakoy 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 h(2) (0.37) was estimated for milk yield. As a reflection of the environmental influences, both Vc (14.93) and C-2 (< 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.
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Genetic parameters were estimated for traits measured in the first year of production in a multi-bloodline flock of fine wool Merino sheep. Between 5025 and 9271 animals were measured, depending on the trait, and these animals wer...
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Genetic parameters were estimated for traits measured in the first year of production in a multi-bloodline flock of fine wool Merino sheep. Between 5025 and 9271 animals were measured, depending on the trait, and these animals were the progeny of up to 430 sires. Heritability estimates for fleece weight traits ranged from 0.37 to 0.49, while estimates for five wool quality traits ranged from 0.34 for staple strength to 0.66 for mean fibre diameter. For bodyweight, the heritability estimated at weaning was 0.20, and at the yearling age was 0.51. Maternal genetic effects were significant for fleece weight and bodyweight traits and were highly correlated between these trait groups, indicating that these effects are determined by similar groups of genes in both trait groups. While most genetic correlation estimates were either favourable or neutral, there were economically antagonistic correlations between fleece weight and mean fibre diameter, ranging from 0.15 to 0.30, and between mean fibre diameter and staple strength (0.26). Overall, the heritabilities and genetic correlations estimated in this fine wool population were similar to estimates from other strains, indicating that outcomes from selection programs will be similar across strains and that fine wool sheep can be included in across flock genetic evaluations with other strains.
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Genetic parameters of growth traits were estimated for first-generation selections of black spruce (Picea mariana (Mill.) BSP) in northwestern Ontario from 720 open-pollinated families and more than 42000 trees. Unbiased estimates...
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Genetic parameters of growth traits were estimated for first-generation selections of black spruce (Picea mariana (Mill.) BSP) in northwestern Ontario from 720 open-pollinated families and more than 42000 trees. Unbiased estimates of narrow-sense heritability for tree height growth averaged 0.19, 0.18, and 0.14 at ages 6, 11, and 19years, respectively, from combined-site analyses compared with 0.25, 0.23, and 0.16 for the same ages from single-site analyses. Heritability estimates for diameter at breast height and stem volume were lower than that of height at age 19, suggesting that tree height is a more desirable trait for selection in black spruce. The moderately high estimates of type B genetic correlations implied limited operational importance of genotype× environment interactions. Estimates of age-age genetic correlation were high (>0.88) among cumulative tree height growth at 6, 11, and 19years but lower between height increments from different age intervals. Estimates of type B age-age genetic correlation were more than 0.2 lower than their type A counterparts, suggesting strong effects of common environments on the estimates of type A genetic correlations. Based on the relative selection efficiencies, selection on cumulative tree height between ages 6 and 11 was more efficient than at age 19.
Les auteurs ont estimé les paramètres génétiques pour les caractères de croissance chez les sélections de première génération d'épinette noire (Picea mariana (Mill.) BSP) dans le nord-ouest de l'Ontario, à partir de 720 descendances uniparentales et plus de 42 000 arbres. Les estimations non biaisées d'héritabilité au sens strict pour la croissance en hauteur des arbres affichaient des moyennes respectives de 0,19, 0,18 et 0,14 à 6, 11 et 19 ans avec l'analyse combinée des différents sites, comparativement à 0,25, 0,23 et 0,16 aux mêmes âges avec l'analyse des sites pris individuellement. Les estimations d'héritabilité pour le diamètre à hauteur de poitrine (DHP) et le volume de la tige étaient plus faibles que pour la hauteur à 19 ans, indiquant que la hauteur des arbres constitue un meilleur caractère pour la sélection chez l'épinette noire. Les estimations de corrélations génétiques de type B étaient modérément élevées, ce qui implique que les interactions génotype × environnement ont une importance opérationnelle limitée. Les estimations de corrélations génétiques entre différents âges étaient élevées (>0,88) pour la croissance cumulative en hauteur des arbres à 6, 11 et 19 ans, mais plus faibles entre les accroissements en hauteur pour différents intervalles d'âge. Les estimations de corrélations génétiques de type B entre différents âges étaient inférieures de plus de 0,2 à leurs contreparties de type A, ce qui porte à croire que la similitude des environnements a des effets importants sur ces dernières. À partir des valeurs d'efficacité relative en sélection, la sélection à partir de
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To assess the potential for genetic improvement to help meet the increasing demand for high-yielding beef carcasses, the heritability of muscle score (MS) plus genetic and phenotypic correlations with weight and fatness traits wer...
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To assess the potential for genetic improvement to help meet the increasing demand for high-yielding beef carcasses, the heritability of muscle score (MS) plus genetic and phenotypic correlations with weight and fatness traits were estimated on 1856 yearlings and 2596 weaners born from 1992 to 2012 in a predominantly Angus herd divergently selected for High/Low MS. In 2005, after noting that some cattle were positive for the 821_del11 myostatin mutation that causes muscle hypertrophy, procedures were modified to create a third group (High(Het)) of High animals with one copy of this major gene. This allowed the additive genetic effects of MS to be assessed, and also the effect of the 821_del11 mutation. MS traits were found to be highly heritable (h(2) = 56-63%), with an extremely high estimated genetic correlation of 99% between weaning and yearling MS. Estimated genetic correlations of MS with rib eye muscle area (EMA) in weaners and yearlings adjusted for either age or weight were 53-56%. Genetic correlations of MS with other traits were relatively low: liveweight (yearlings 5%, weaners 20%), rump fat (yearlings - 7%, weaners 11%), rib fat (yearlings - 17%, weaners - 3%). Apart from weaning liveweight, the estimated genetic correlations were not significantly different from zero. MS had smaller estimated genetic correlations with fatness and weight traits than EMA adjusted for age. For yearlings and weaners born from 2010 to 2012, large significant differences were evident in MS of High and Low calves (4.5-point difference for yearlings; 3.4 points for weaners, on a 15-point scale) and significant differences in EMA (yearlings 2.5, weaners 1.5 cm(2)). In addition, the 821_del11 mutation reduced fatness, increased MS by 1.5-1.9 points and increased EMA by 2.8-3.6 cm(2). With high heritability, low correlations with weight and fatness in weaners/yearlings, plus other research (Cafe et al. 2012, 2014a) showing no detrimental effect on maternal productivity or meat quality, but improvements in dressing percent, retail meat yield, meat : bone ratio and feedlot feed efficiency, the development of an estimated breeding value for MS could help improve the efficiency and profitability of beef production
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The performance of Holstein × Indigenous (H×I) crossbred dairy cattle in Iran was considered?between?1991?and?2003.?Milk, fat yield and fat percentage traits were considered in this research. Variance components were estimated u...
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The performance of Holstein × Indigenous (H×I) crossbred dairy cattle in Iran was considered?between?1991?and?2003.?Milk, fat yield and fat percentage traits were considered in this research. Variance components were estimated using animal model (single trait) and derivative-free restricted maximum likelihood method for different traits.?Crossbred animals with 50?to?70% of Holstein gene ratio have shown higher performance. The average performances for?the?mentioned traits were 2722.68,?122.97 and 3.97%,?respectively. The estimation of the heritability for milk yield, fat yield, and fat percentage were 0.332, 0.3277 and 0.145. The research results showed that production potential has been increased by crossbreeding.?Key word:?Genetic parameter, crossbreeding, Holstein.
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Estimates of variances due to differential expression of paternally and maternally derived genes can be obtained from animal model type analyses by fitting appropriate gametic effects. This is feasible for large-scale analyses, be...
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Estimates of variances due to differential expression of paternally and maternally derived genes can be obtained from animal model type analyses by fitting appropriate gametic effects. This is feasible for large-scale analyses, because the inverse of the gametic relationship matrix can be set up directly from a list of pedigrees. We present a series of analyses applying such a model to large sets of records for birth, weaning, yearling and final weights of Australian Angus and Hereford cattle. On one hand, results show that maternal genetic effects on these traits are largely confounded with maternal parent of origin effects, so that it is difficult to reliably separate the respective variance components. On the other hand, paternal parent of origin effects tend to act similarly to sire x herd effects so that estimates of their variance are inflated by any effects not modelled and contributing to such apparent interaction. Fitting an animal model with both parent of offspring effects, maternal genetic and permanent environmental effects as well as sire x herd and maternal grand-sire x herd of origin of dam interactions as additional random effects yielded estimates of the variance due to paternal parent of origin effects of 5-7% of the phenotypic variation for birth and weaning weights and of 0-1% for yearling and final weights. Corresponding estimates for maternal parent of origin effects were 0-11% for birth and weaning weights and 7-8% for yearling and final weights, while sire and maternal grand-sire interaction effects explained from 0 to 4% of the phenotypic variance.
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The Australian Merino is the predominant genetic resource for both the prime lamb and sheep meat industries of Australia. There are very few studies that provide good information on the relationships between wool and non-wool trai...
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The Australian Merino is the predominant genetic resource for both the prime lamb and sheep meat industries of Australia. There are very few studies that provide good information on the relationships between wool and non-wool traits. The objective of this paper was to describe genetic relationships within bodyweight traits and between bodyweight and other traits recorded in Merino sheep. The genetic correlation between bodyweight, fleece weight and fibre diameter was positive (0.1 to 0.2). While fibre diameter coefficient of variation, staple length, staple strength, mean fibre curvature, and faecal egg count were not correlated with bodyweight. Scrotal circumference (0.4), number of lambs born (0.1), and number of lambs weaned (0.1) were positively correlated with bodyweight. Results indicate that selection for an increase in bodyweight will have a positive effect on eye muscle depth, fleece weight, and reproduction traits, while selection for an increase in bodyweight will have a negative effect on fibre diameter and fibre diameter coefficient of variation.
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Estimates of genetic parameters and genetic trends for reproductive traits and for liveweight at the commencement of breeding were obtained using data from a pair-mated ostrich flock located at Oudtshoorn in South Africa. Heritabi...
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Estimates of genetic parameters and genetic trends for reproductive traits and for liveweight at the commencement of breeding were obtained using data from a pair-mated ostrich flock located at Oudtshoorn in South Africa. Heritability estimates were 0.17–0.18 for egg production, 0.15–0.17 for chick production and 0.35–0.37 for liveweight. Female permanent environmental effects amounted to 0.11–0.17 for egg production, 0.14–0.19 for chick production and 0.30–0.31 for liveweight. Service sire exerted significant effects only on egg production (0.03–0.08) and chick production (0.05–0.10). Genetic correlations of reproductive traits with liveweight were not different from zero. Initial selection in the flock was based on reproduction, in the sense that replacements were descended from the females with the highest uncorrected number of chicks produced during their season of hatch (Chick Production line). Animals that were hatched during the period from 1996 to 2006 were used to establish two more populations. The heaviest birds at ~16 months of age were used as replacements in the line selected for liveweight (Liveweight line). Birds selected for the Control line were of average uncorrected liveweight at ~16 months, and were descended from females that produced an average number of chicks in their season of hatch. Overall, the Liveweight line had higher breeding values than the Control line for the period from 1996 to 2006. The response seemed to be associated with screening from the larger population on breeding values for liveweight, as no cumulative genetic gains were evident since 1996. Breeding values for chick production in the Chick Production line were increased by 3.1% per year from 1990 to 2006. Regressions of individual breeding values in the Control line on the year of hatch indicated no genetic change in either liveweight or chick production. Genetic change in particularly reproduction thus seems feasible in commercial ostriches.
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Calcium, Mg, P, and K are of great importance for the health and productivity of dairy cows after calving. So far genetic studies have focused on clinical hypocal-cemia, leaving the genetic parameters of these macroelements unstud...
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Calcium, Mg, P, and K are of great importance for the health and productivity of dairy cows after calving. So far genetic studies have focused on clinical hypocal-cemia, leaving the genetic parameters of these macroelements unstudied. Our objective was to estimate the genetic parameters of Ca, Mg, P, and K serum concentrations and their changes during the first 8 d after calving. The study was conducted in 9 herds located in northern Greece, with 1,021 Holstein cows enrolled from November 2010 until November 2012. No herd used any kind of preventive measures for hypocalcemia. Pedigree information for all cows was available. A total of 35 cows were diagnosed and treated for periparturi-ent paresis and, therefore, excluded from the study. The remaining 986 cows were included in genetic analysis. The distribution of cows across parities was 459 (parity 1), 234 (parity 2), 158 (parity 3), and 135 (parity ≥4). A sample of blood was taken from each cow on d 1, 2, 4, and 8 after calving and serum concentrations of Ca, P, Mg, and K were measured in each sample. A final data set of 15,390 biochemical records was created consisting of 3,903 Ca, 3,902 P, 3,903 Mg, and 3,682 K measurements. Moreover, changes of these concentrations between d 1 and 4 as well as 1 and 8 after calving were calculated and treated as different traits. Random regression models were used to analyze the data. Results showed that daily heritabilities of Ca, P, and Mg concentrations traits were moderate to high (0.20-0.43), whereas those of K were low to moderate (0.12-0.23). Regarding concentration changes, only Mg change between d 1 and 8 after calving had a significant heritability of 0.18. Genetic correlations between Ca, P, Mg, and K concentrations and their concentration changes from d 1 to 4 and 1 to 8 after calving were not significantly different from zero. Most phenotypic correlations among Ca, P, Mg, and K concentrations were positive and low (0.09-0.16), whereas the correlation between P and Mg was negative and low (-0.16). Phenotypic correlations among macromineral concentrations on d 1 and their changes from d 1 to 4 and 1 to 8 after calving varied for each macromineral. This study revealed that genetic selection for normal Ca, P, Mg, and K concentrations in the first week of lactation is possible and could facilitate the management of their deficiencies during the early stages of lactation.
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