Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep. 2. Genetic relationships between traits

2016 ◽  
Vol 56 (9) ◽  
pp. 1449 ◽  
Author(s):  
D. J. Brown ◽  
A. A. Swan
Keyword(s):  
Genetic Relationships ◽  
Genetic Correlations ◽  
High Growth ◽  
High Growth Rate ◽  
Eye Muscle ◽  
Internal Parasite ◽  
Internal Parasites ◽  
Negative Effect ◽  
Meat Sheep ◽  
Resistance Traits

Australian sheep breeders aim to simultaneously breed sheep that have high growth rate, superior carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic and phenotypic relationships between 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. Within all trait groups, the different age expressions were moderately to highly correlated. The genetic correlations between liveweight with both fat and eye muscle depth were generally negative ranging between –0.10 and –0.42. Fat and eye muscle depth were moderately correlated (0.27–0.59). Results indicate that selection for an increase in liveweight will have a negative effect on fat and eye muscle depth. The negative correlations of ultrasound scan traits and worm egg count indicates that animals with high genetic merit for fat and eye muscle depth are less prone to infection from internal parasites. The results from this study have been used to review the genetic correlations used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.

Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep. 1. Description of traits, fixed effects, variance components and their ratios

2016 ◽  
Vol 56 (9) ◽  
pp. 1442 ◽  
Author(s):  
D. J. Brown ◽  
A. A. Swan ◽  
J. S. Gill ◽  
A. J. Ball ◽  
R. G. Banks
Keyword(s):  
Genetic Variation ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Eye Muscle ◽  
Internal Parasite ◽  
Internal Parasites ◽  
Genetic Evaluations ◽  
Meat Sheep ◽  
Breed Sheep ◽  
Resistance Traits

Sheep breeders in Australia that focus on lamb production simultaneously breed sheep that have higher growth rate, improved carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic parameters for 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. As the population of meat sheep in this database have become increasingly crossbred this study also investigates the genetic variation within and between breeds. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. The results are averages of analyses of 10 datasets constructed by randomly sampling 25% of these flocks. There was considerable genetic variation in all traits analysed: the lowest heritabilities (0.12) were found for weaning weight and the highest heritabilities (0.31–0.32) for eye muscle depth. There were also significant differences between breeds for most traits, which breeders appear to be utilising through crossbreeding. Direct heterosis effects were small and only significant for the liveweight traits ranging from 2% to 3.4% of the phenotypic means. Maternal heterosis was not significant for any trait studied. The inclusion of heterosis effects in the model did not significantly influence the estimated genetic parameters. The results from this study have been used to review the genetic parameters used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.

Genetic importance of fat and eye muscle depth in Merino breeding programs

2016 ◽  
Vol 56 (4) ◽  
pp. 690 ◽  
Author(s):  
D. J. Brown ◽  
A. A. Swan
Keyword(s):  
Carcass Traits ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Economic Index ◽  
Parasite Resistance ◽  
Eye Muscle ◽  
Breeding Programs ◽  
Dual Purpose ◽  
Internal Parasite ◽  
Reproduction Traits

Australian Merino breeders have traditionally selected animals for breeding predominately on the basis of wool characteristics. Over recent decades, an increasing proportion of Merino breeders are interested in producing a ewe that can be used for prime-lamb production, but that also performs well for wool characteristics. Correlations between ultrasound carcass traits and other traits such as wool, internal parasite resistance and reproduction traits, are not very well known. The aims of this study were three-fold: (1) to estimate the genetic relationships between ultrasound carcass traits and wool, internal parasite resistance and reproduction traits, (2) to determine the value of recording ultrasound carcass traits in Merino breeding programs, and (3) to evaluate the impact of improving ewe genetic merit for fatness on their reproduction performance. Ultrasound fat and eye muscle depth had small to moderate genetic correlations with most traits, with positive correlations observed for bodyweight, fibre diameter, fibre curvature and reproduction, and negative correlations observed for fleece weight, fibre diameter coefficient of variation, worm egg count and breech wrinkle. As expected on the basis of these genetic correlations, estimated breeding values for fat depth of ewes had a positive association with their observed reproduction performance, but the effect explained only minimal variation in reproductive performance, and was extremely variable among flocks and years. A range of measurement scenarios was investigated for three standard MERINOSELECT indexes. Measuring fat and eye muscle depth resulted in 3%, 4% and 21% additional economic index gain for the fine, medium and dual purpose indexes, respectively, whereas measuring reproduction traits directly resulted in 17%, 27% and 45% additional gain in the economic index. Dual purpose index gains benefited more from measuring ultrasound carcass traits as it is the only index with a direct economic value placed on carcass traits. Measuring fat and eye muscle depth also resulted in a greater reduction in worm egg count. The results indicated that desirable genetic progress can be made in wool, ultrasound carcass, internal parasite resistance and number of lambs born and weaned simultaneously using multiple trait selection to account for the mix of favourable and unfavourable correlations between these traits. These results also demonstrated that the best method to maximise economic gain is to measure as many traits (or closely correlated traits) in the breeding objective as possible.

scholarly journals Dietary supplements based on modified and enriched with amino acids zeolite in the cultivation of young turkeys

2022 ◽  
Vol 354 (11-12) ◽  
pp. 20-23
Author(s):  
S. V. Dezhatkina ◽  
N. A. Feoktistova ◽  
E. V. Pankratova ◽  
N. A. Provorova ◽  
E. S. Salmina
Keyword(s):  
Amino Acids ◽  
Hematological Parameters ◽  
Live Weight ◽  
High Growth ◽  
Mineral Elements ◽  
High Growth Rate ◽  
The Body ◽  
Control Group ◽  
Modified Zeolite ◽  
Negative Effect

Relevance. Modern turkey crosses have a genetically determined high growth rate. These farm birds are very sensitive to even minor fluctuations in their diet, are susceptible to a deficiency of amino acids, protein, mineral elements and vitamins, which can contribute to a decrease in their productivity, the development of pathological processes and diseases. The use of modern technologies and scientific achievements has made it possible to prepare a new product — modified zeolite. This natural mineral is already free of impurities and microbes, with open pore windows, has a high ability to selectively exchange, and is obtained by various methods of activating zeolite in industrial conditions. At the same time, Ulyanovsk specialists have mastered the technology of enriching modified zeolite with useful substances.Methods. The aim of the work was to study the effect on the body of turkeys and the level of their productivity of additives based on modified zeolite enriched with amino acids. The experiment was organized for 60 days on 250 turkeys of the breed Hybrid Cread-mayker aged 55–60 days in the conditions of the Ulyanovsk region. The control group received the main ration (MR), the experimental group was given once a day in addition to the MR in the morning feeding in a mixture with mixed feed 5% additives of modified zeolite enriched with amino acids.Results. The inclusion of a supplement based on modified zeolite enriched with amino acids in the diet of turkeys does not have a negative effect on the hematological parameters of their blood, all indicators corresponded to the physiological norm. During the experiment in the 2nd group, the live weight of poultry was obtained larger by 8.70%, which amounted to 12,296 kg, respectively, more profit was obtained from the sale of turkey meat, total revenue was 133,210, and additional profit was 27,960 rubles, 2.41 rubles of profit was received for 1 ruble of costs. Тhe data indicate the normalization of mineral homeostasis in the body of turkeys and better absorption of nutrients in the feed diet.

Maternal body composition in seedstock herds. 4. Genetic parameters for body composition of Angus and Hereford cows

2018 ◽  
Vol 58 (1) ◽  
pp. 145 ◽  
Author(s):  
K. A. Donoghue ◽  
S. J. Lee ◽  
P. F. Parnell ◽  
W. S. Pitchford
Keyword(s):  
Body Composition ◽  
Body Condition Score ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Fat Percentage ◽  
Muscle Area ◽  
Eye Muscle ◽  
Life Traits ◽  
Condition Score ◽  
Over Time

The genetics of body composition traits measured before calving and at weaning in the first and second parities were evaluated in 5975 Angus and 1785 Hereford cows. Traits measured were liveweight, body condition score and hip height and ultrasound scanned measurements of subcutaneous P8 and 12/13th rib fat depth, loin eye muscle area and intramuscular fat percentage. Corresponding yearling measures on these animals were obtained for analyses of relationships between yearling information with later-in-life traits. There was moderate genetic variation in all body composition traits measured at pre-calving and weaning in Angus (h2 = 0.14–0.59) and Hereford (h2 = 0.14–0.64) cows. Genetic correlations between measurements of the same trait at pre-calving and weaning were consistently positive and high in both parities for both breeds, indicating animals were ranking similarly for the same trait measured over time. Genetic correlations between measurements of different traits were generally consistent over time (pre-calving and weaning) in both breeds, indicating genetic relationships between traits were not changing significantly over time. Genetic correlations with corresponding yearling measures of body composition were consistently positive and high for the first parity, and lower for the second parity. The results of this study indicate that genetic improvement in body composition traits in cows is possible, and that body composition information recorded at yearling age is a reasonably good predictor of later in life performance for these traits.

Quantitative genetic parameters for body traits at different ages in a cultured stock of giant freshwater prawn (Macrobrachium rosenbergii) selected for fast growth

2014 ◽  
Vol 65 (3) ◽  
pp. 198 ◽  
Author(s):  
Dinh Hung ◽  
Nguyen Hong Nguyen ◽  
David A. Hurwood ◽  
Peter B. Mather
Keyword(s):  
Growth Rate ◽  
Genetic Correlations ◽  
Macrobrachium Rosenbergii ◽  
High Growth ◽  
High Growth Rate ◽  
Fast Growth ◽  
Freshwater Prawn ◽  
Giant Freshwater Prawn ◽  
Different Ages ◽  
Variance And Covariance Components

The aim of the current study was to estimate heritabilities and correlations for body traits at different ages (Weeks 10 and 18 after stocking) in a giant freshwater prawn (Macrobrachium rosenbergii) population selected for fast growth rate in Vietnam. The dataset consisted of 4650 body records (2432 and 2218 records collected at Weeks 10 and 18, respectively) in the full pedigree comprising a total of 18 387 records. Variance and covariance components were estimated using restricted maximum likelihood fitting a multi-trait animal model. Estimates of heritability for body traits (bodyweight, body length, cephalothorax length, abdominal length, cephalothorax width and abdominal width) were moderate and ranged from 0.06 to 0.11 and from 0.11 to 0.22 at Weeks 10 and 18, respectively. Body-trait heritabilities estimated at Week 10 were not significantly lower than at Week 18. Genetic correlations between body traits within age and genetic correlations for body traits between ages were generally high. Our results suggested that selection for high growth rate in GFP can be undertaken successfully before full market size has been reached.

Genetics of leg weakness in performance-tested boars

1983 ◽  
Vol 36 (1) ◽  
pp. 117-130 ◽  
Author(s):  
A. J. Webb ◽  
W. S. Russell ◽  
D. I. Sales
Keyword(s):  
Performance Index ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Live Weight ◽  
Rapid Decline ◽  
Large White ◽  
Muscle Area ◽  
Eye Muscle ◽  
Leg Weakness ◽  
And Performance

ABSTRACTGenetic relationships among leg and performance traits were estimated for 23 975 Large White and Landrace boars fed twice daily to appetite from 27 to 91 kg live weight at Meat and Livestock Commission testing stations between 1966 and 1972. For each boar, an overall leg score was derived as the sum of scores for 19 individual leg traits categorized as ‘absent’ (0), ‘slight’ (1) or ‘severe’ (2) at 91 kg. Heritabilities of leg score were 017 ± 0·03 in Large White and 0·19 ± 0·04 in Landrace. Genetic correlations with a visual ‘leg action’ score on a scale from 1 to 5 averaged 0·93 ± 0·02 over breeds. Genetic and phenotypic correlations between leg scores on the same boars at 27 and 91 kg averaged 0·50 ± 0·17 and 0·15 ± 0·01 respectively.Both breeds showed significant adverse genetic correlations ranging from 0·20 ± 0·10 to 0·40 ± 0·08 between leg score and boar ultrasonic backfat. From slaughtered littermates, leg scores showed favourable genetic correlations with eye-muscle area (0·30 ± 0·10) and killing-out proportion (0·35 ± 011) in Large White and unfavourable correlations with carcass length (0·31 ± 0·10), lean content (0·30 ± 0·14) and backfat (0·33 ± 0·11) in Landrace. There were no associations with growth rate, feed efficiency or the performance index on which boars are selected. The study indicates that leg condition and fatness are adversely genetically related, but that selection on the present national performance index would not be expected to cause a rapid decline in leg condition. Culling on leg score would be expected to reduce the frequency of leg weakness.

Genetic relationships of female reproduction with growth, body composition, maternal weaning weight and tropical adaptation in two tropical beef genotypes

2014 ◽  
Vol 54 (1) ◽  
pp. 60 ◽  
Author(s):  
M. L. Wolcott ◽  
D. J. Johnston ◽  
S. A. Barwick
Keyword(s):  
Body Composition ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Female Reproduction ◽  
Muscle Area ◽  
Eye Muscle ◽  
Weaning Weight ◽  
Igf I ◽  
Age At Puberty ◽  
Tropical Adaptation

The genetic relationships of female reproduction with growth and body composition, tropical adaptation traits and maternal weaning weight (descriptive of genetic potential milk production) were estimated in 1027 Brahman (BRAH) and 1132 Tropical Composite (TCOMP) females. Female reproduction was evaluated at puberty, as outcomes of the first and second annual mating periods (Mating 1 and Mating 2, which commenced when females averaged 27 and 39 months of age, respectively), as well as annual averages over up to six matings. Traits evaluated included age at puberty, Mating 1 and 2 pregnancy rate, weaning rate and days to calving, and lifetime annual calving and weaning rate. Traits describing growth and body composition (liveweight, hip height, ultrasound-scanned P8 fat depth and eye muscle area, subjective body condition score and blood IGF-I concentration) were measured in the animals as heifers (at ~18 months of age), and again at the start of Mating 2. Traits describing tropical adaptation included coat-length scores in both genotypes and, in BRAH, buffalo fly lesion scores. Previously reported analyses of these data identified heifer IGF-I and coat and buffalo-fly-lesion scores as potential genetic indicators for age at puberty in BRAH. The results of the present study found that exploiting these relationships would have no unfavourable genetic consequences for later female reproduction and, in some cases, may be indicators of female reproduction, when evaluated as outcomes of Matings 1 or 2, or as lifetime annual calving or weaning rates. For BRAH, heifer liveweight was a genetic indicator for Mating 1 weaning rate (rg = 0.70), and, while standard errors were high, there were also positive genetic correlations of heifer hip height, eye muscle area and blood IGF-I concentration with Mating 1 weaning rate (rg = 0.61, 0.58 and 0.43, respectively). For TCOMP, significant genetic relationships of heifer growth, body composition and tropical adaptation traits with female reproduction were virtually absent, suggesting that there is less opportunity to identify earlier in life measures as genetic indicators of reproduction for this genotype. Higher maternal weaning weight was significantly genetically related to lower lifetime annual weaning rate (rg = –0.50) in BRAH, and with lower Mating 2 calving and weaning rate (rg = –0.72 and –0.59, respectively) in TCOMP, which will need to be considered when making selection decisions that affect genetic milk in these genotypes. Importantly, the results presented revealed no strong genetic antagonisms of heifer growth and body composition traits with female reproduction, suggesting that selection could be undertaken to improve these simultaneously.

Maternal body composition in seedstock herds. 3. Multivariate analysis using factor analytic models and cluster analysis

2018 ◽  
Vol 58 (1) ◽  
pp. 135
Author(s):  
J. De Faveri ◽  
A. P. Verbyla ◽  
S. J. Lee ◽  
W. S. Pitchford
Keyword(s):  
Body Composition ◽  
Genetic Relationships ◽  
Young Animal ◽  
Genetic Correlations ◽  
Muscle Area ◽  
Genetic Covariance ◽  
Eye Muscle ◽  
Factor Analytic ◽  
Analytic Models ◽  
Over Time

Considerable information exists on genetic relationships of body composition and carcass quality of young and finished beef cattle. However, there is a dearth of information on genetic relationships of cow body composition over time and, also, relationships with young-animal body-composition measures. The aim of the present study is to understand genetic relationships among various cow body-composition traits of Angus cows over time, from yearling to weaning of a second calf at ~3.5 years. To determine genetic correlations among various composition traits over time, a multi-trait–multi-time analysis is required. For the Maternal Productivity Project, this necessitates modelling of five traits (namely weight and ultrasound measure for loin eye muscle area (EMA), rib fat, P8 rump fat and intramuscular fat) by five time combinations (recordings at yearling then pre-calving and weaning in first and second parity). The approach was based on including all 25 trait-by-time combinations in an analysis using factor analytic models to approximate the genetic covariance matrix. Various models for the residual covariance structure were investigated. The analyses yielded correlations that could be compared with those of past studies reported in the literature and, also, to a set of bivariate analyses. Clustering of the genetic multi-trait–multi-time correlation structure resulted in a separation of traits (weight and EMA, and the fat traits) and also of time effects into early (heifer = before first lactation) and late (cow = post-first lactation) measurements.

Genetic relationships between live animal scan traits and carcass traits of Australian Angus bulls and heifers

2013 ◽  
Vol 53 (10) ◽  
pp. 1075
Author(s):  
Vinzent Börner ◽  
David J. Johnston ◽  
Hans-Ulrich Graser
Keyword(s):  
Genetic Gain ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Age Effect ◽  
Breeding Value ◽  
Muscle Area ◽  
Live Animal ◽  
Eye Muscle

Genetic parameters of four ultrasound live-scan traits and five carcass traits of Australian Angus cattle were examined with regard to sex and age of the scanned individuals. Live-scans were subdivided according to whether the observation was obtained from a bull or a heifer. In addition, two age subset (‘young’ and ‘old’) within sex were formed by k-means clustering around two centres within sex according to the age at scanning. REML estimates for heritabilities, genetic, residual and phenotypic correlations for each trait and trait combination were derived from a series of uni-, bi- and tri-variate analysis. Statistically significant age effects could be found for heritablities of scan intra-muscular fat content in heifers and scan fat depth at P8 site and scan rib fat depth in bulls, and for genetic correlations between the scan traits fat depth at P8 site, rib fat depth and eye muscle area. However, differences in heritablities between age sets within sex did not exceed 0.05, and genetic correlations between scan traits of ‘young’ and ‘old’ animals were at least 0.9. Differences between genetic correlations of abattoir carcass traits and ‘young’ and ‘old’ live-scan traits, respectively, were not significant due to high standard errors but up to 0.44. The larger of these differences were found for combinations of scan-traits and non-target carcass traits and not for combination of scan-traits and their actual carcass target traits. Thus, although some results suggest an age effect on the genetic parameters of scan traits, the extent of this effect is of limited impact on breeding value accuracy and genetic gain of scan traits. Furthermore, a possible age effect on correlations to economically important carcass traits need to be underpinned by more carcass traits observations in order to get unambiguous results allowing to draw consequences of scanning younger individuals for accuracy of breeding values and genetic gain in carcass traits.

Genetic parameters for bodyweight, wool, and disease resistance and reproduction traits in Merino sheep. 2. Genetic relationships between bodyweight traits and other traits

2008 ◽  
Vol 48 (9) ◽  
pp. 1186 ◽  
Author(s):  
A. E. Huisman ◽  
D. J. Brown
Keyword(s):  
Coefficient Of Variation ◽  
Genetic Relationships ◽  
Fibre Diameter ◽  
Eye Muscle ◽  
Merino Sheep ◽  
Scrotal Circumference ◽  
Reproduction Traits ◽  
Negative Effect ◽  
Selection For ◽  
Fleece Weight

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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