scholarly journals Impact of birth and rearing type, as well as inaccuracy of recording, on pre-weaning lamb phenotypic and genetic merit for live weight1

2017 ◽  
Vol 1 (2) ◽  
pp. 137-145 ◽  
Author(s):  
N. McHugh ◽  
T. Pabiou ◽  
K. McDermott ◽  
E. Wall ◽  
D. P. Berry

Abstract The objective of the present study was to quantify the impact of the systematic environmental effects of both birth and rearing type on pre-weaning lamb live weight, and to evaluate the repercussions of inaccurate recording of birth and rearing type on subsequent genetic evaluations. A total of 32,548 birth weight records, 35,770 forty-day weight records and 32,548 records for average daily gain (ADG) between birth and 40-day weight from the Irish national sheep database were used. For each lamb, a new variable, birth-rearing type, reflecting both the birth and rearing type of a lamb was generated by concatenating both parameters. The association between birth-rearing type and birth weight, 40-day weight, and ADG was estimated using linear mixed models. The repercussions of inaccurate recording of birth type were determined by quantifying the impact on sire estimated breeding value (EBV; with an accuracy of ≥ 35%), where one of the lambs born in a selection of twin litter births was assumed to have died at birth but the farmer recorded the birth and rearing type as a singleton. The heaviest mean birth weight was associated with lambs born and subsequently reared as singles (5.47 kg); the lightest mean birth weight was associated with lambs born and reared as triplets (4.10 kg). The association between birth-rearing type and 40-day weight differed by dam parity (P < 0.001). Lambs reared by first parity dams as singles, irrespective of birth type were, on average, heavier at 40-day weighing than lambs reared as multiples, but as parity number increased, single-born lambs reared as twins outperformed triplet-born lambs reared as singles. Irrespective of the trait evaluated, the correlation between sire EBV estimated from the accurately recorded data and sire EBV estimated from the data with recording errors was strong ranging from 0.93 (birth weight) to 0.97 (ADG). The EBV for sires with progeny data manipulated were 0.14 kg, 0.34 kg and 5.56 g/d less for birth weight, 40-day weight and ADG, respectively, compared to their equivalent EBV calculated using accurately recorded data. Results from this study highlight the importance of precise recording of birth-rearing type by producers for the generation of accurate genetic evaluations.

2020 ◽  
Vol 98 (12) ◽  
Author(s):  
Garrett M See ◽  
Benny E Mote ◽  
Matthew L Spangler

Abstract Numerous methods have been suggested to incorporate crossbred (CB) phenotypes and genotypes into swine selection programs, yet little research has focused on the implicit trade-off decisions between generating data at the nucleus or commercial level. The aim of this study was to investigate the impact of altering the proportion of purebred (PB) and CB phenotypes and genotypes in genetic evaluations on the response to selection of CB performance. Assuming CB and PB performance with moderate heritabilities (h2=0.4), a three-breed swine crossbreeding scheme was simulated and selection was practiced for six generations, where the goal was to increase CB performance. Phenotypes, genotypes, and pedigrees for three PB breeds (25 and 175 mating males and females for each breed, respectively), F1 crosses (400 mating females), and terminal cross progeny (2,500) were simulated. The genome consisted of 18 chromosomes with 1,800 quantitative trait loci and 72k single nucleotide polymorphism (SNP) markers. Selection was performed in PB breeds using estimated breeding value for each phenotyping/genotyping strategy. Strategies investigated were: 1) increasing the proportion of CB with genotypes, phenotypes, and sire pedigree relationships, 2) decreasing the proportion of PB phenotypes and genotypes, and 3) altering the genetic correlation between PB and CB performance (rpc). Each unique rpc scenario and data collection strategy was replicated 10 times. Results showed that including CB data improved the CB performance regardless of  rpc or data collection strategy compared with when no CB data were included. Compared with using only PB information, including 10% of CB progeny per generation with sire pedigrees and phenotypes increased the response in CB phenotype by 134%, 55%, 33%, 23%, and 21% when rpc was 0.1, 0.3, 0.5, 0.7, and 0.9, respectively. When the same 10% of CB progeny were also genotyped, CB performance increased by 243%, 54%, 38%, 23%, and 20% when the rpc was 0.1, 0.3, 0.5, 0.7, and 0.9, respectively, compared with when no CB data were utilized. Minimal change was observed in the average CB phenotype when PB phenotypes were included or proportionally removed when CB were genotyped. Removal of both PB phenotypes and genotypes when CB were genotyped greatly reduced the response in CB performance. In practice, the optimal inclusion rate of CB and PB data depends upon the genetic correlation between CB and PB animals and the expense of additional CB data collection compared with the economic benefit associated with increased CB performance.


Author(s):  
N.V. SIVKIN ◽  
N.V. STREKOZOV ◽  
V.I. CHINAROV

В симментальской породе предусматривается разведение скота, сбалансировано сочетающего молочную и мясную продуктивность. Однако в практике совершенствования племенных стад в подборах быков доминируют улучшатели удоя, что во многом предопределяет результаты селекции и продуктивный тип животных. Объектом нашего исследования стало стадо чистопородного симментальского скота в условиях стойловой системы беспривязного и привязного содержания коров. Для изучения эффективности использования быков-производителей разного племенного достоинства сформировали 2 опытные группы: I состояла из бычков, полученных от отцов с племенной ценностью (ПЦ) по удою 100 кг и более, а во II с ПЦ от 0 до 100 кг молока. Симментальские бычки, отобранные для контрольного убоя, достигали весовых кондиций 500 кг и более в 17,5 мес при среднесуточном приросте 911 г. При использовании на маточном поголовье быков-производителей с улучшающим эффектом по удою 100 кг и более, их сыновья (I группа), на фоне более высоких суточных приростов (на 30 г) и раннем возрасте достижения живой массы 500 кг (на 18 дней) имели массу и выход туши на 21,4 кг и 2,7 ниже, чем у бычков II группы. При формировании молочно-мясного типа быки-производители с умеренной племенной ценностью по удою обеспечивали получение потомства, сочетающего молочную и мясную продуктивность в экономически значимых пропорциях.The Simmental breed provides for the breeding of cattle that combines milk and meat productivity in a balanced proportion. However, in the practice of improving breeding herds, the selection of bulls is dominated by milk yield improvers, which largely determines the results of selection and the productive type of animals. The object of our research was a breeding herd of purebred Simmental cattle in variety feeding and housing practices. To study the effectiveness of using bulls-producers of different breeding values, 2 experimental groups were formed: I consisted of bulls received from fathers with a breeding value (BV) of milk yield 100 kg or more, and II with a BV from 0 to 100 kg of milk. Simmental bulls selected for control slaughter reached weight standards of 500 kg or more in 17.5 months with an average daily increase of 911 g. When used on breeding of bulls with an improving effect on the yield of 100 kg or more, their sons (group I), against the background of higher daily gains (30 g) and an early age of reaching a live weight of 500 kg (18 days), had a mass and carcass yield of 21.4 kg and 2.7 lower than that of group II bulls. When forming a dairy-meat type, producing bulls with a moderate breeding value for milk yield provided for the production of offspring that combined dairy and meat productivity in economically significant proportions.


1995 ◽  
Vol 60 (1) ◽  
pp. 117-124 ◽  
Author(s):  
J. A. Roden

AbstractStochastic simulation was used to compare the results of alternative breeding systems in a sheep population divided into 10 flocks of 120 ewes. The breeding systems compared were selection within closed flocks (CF), a closed nucleus system (CNS), an open nucleus system (ONS) and open nucleus systems with the selection of nucleus replacements being restricted to either nucleus born males (ONSRm) or nucleus born females (ONSRf). Selection was for a best linear unbiased prediction of breeding value for lamb live weight which had a heritability of 0·17. The open nucleus breeding systems (ONS, ONSRm, ONSRf) resulted in higher rates of genetic gain, more predictable selection responses and lower rates of inbreeding than either the closed nucleus system (CNS) or selection within closed flocks (CF). Initial genetic differences between flocks resulted in higher rates of genetic gain in the nucleus breeding systems due to the use of between flock genetic variance. In the ONS system up to 25% of nucleus sires and approximately 50% of nucleus dams were born in base flocks. Nevertheless if selection of either nucleus sires or dams was restricted to nucleus born animals there was very little change in genetic gain or rate of inbreeding.


1973 ◽  
Vol 17 (3) ◽  
pp. 267-273 ◽  
Author(s):  
R. E. Haycock ◽  
D. A. Stewart

SUMMARYIn three successive years cows from an Aberdeen Angus cross Shorthorn herd were mated to pedigree Charolais, British Friesian and Hereford bulls. A comparison of the progeny of the three breeds of sire under controlled conditions was therefore possible using a random selection of dams for mating, and identical rearing of the calves. Results for live-weight gain of the suckled progeny were analysed and showed superiority of the Charolais breed over the other two when used in this form of beef cattle production.For birth weights and daily live-weight gains, particularly during the grazing period, the Charolais cross progeny showed superiority over the other two. There was a consistent although not always statistically significant tendency for these differences between the breed crosses to occur in the male calves only, the females showing little difference between breeds. The data also showed highly significant relationships between gestation period and birth weight, both within and between breed crosses.


1966 ◽  
Vol 8 (3) ◽  
pp. 435-444 ◽  
Author(s):  
J. S. Broadbent ◽  
J. H. Watson

Curves of growth in live-weight, from birth to 16 weeks of age, of 362 Suffolk × Welsh lambs were analysed for the effect of sex, birth type, sire and test centre environment and related to variation in age at slaughter.The relative pre-natal disadvantages of twin lambs resulted in their curves of growth differing from those of single-born animals, particularly in males. Test centre environment exerted a marked effect in such cases. At one centre, male twins showed marked compensatory growth.Differences in growth existed between the 14 sire progeny groups. As the linear component of the growth curves decreased, the quadratic values became increasingly negative. Deceleration of growth was most marked in slowest growing progeny groups and this was accentuated by a poor test centre environment.These factors combined to influence age at slaughter, which was also related to birth weight of the lamb. Lambs at the best test centre reached slaughter weight 10 and 16 days earlier than lambs at the two remaining centres. Sires produced differences in age at slaughter of 10 to 14 days, within centres.


Author(s):  
L. Shiotsuki ◽  
P.H.T. Silva ◽  
K.M. Silva ◽  
A.V. Landim ◽  
O.R. Morais ◽  
...  

SummaryThe objective of the present study was to describe the frequency of the main racial traits of Morada Nova sheep and simulate the impact of this culling on the response to selection for birth weight. The data from sex, coat colour, hoof pigmentation, muzzle pigmentation, polled and cryptorchidism were collected individually at weaning from 385 Morada Nova sheep of the red variety, born between 2010 and 2012, which belonged to four different flocks in the state of Ceará, Brazil. To estimate the impact of culling of animals due to racial pattern on the genetic improvement of the Morada Nova population, the genetic gains in birth weight per generation were calculated considering the following different scenarios of culling due to racial pattern in a simulated population. The present results indicate that the most urgent step is flexibilization of the requirement of dark muzzles and hooves. The selection of Morada Nova sheep based on racial pattern has caused losses in the genetic gain for productive traits such as birth weight. Readaptation of the official racial pattern established for Morada Nova sheep is necessary so that the racial pattern is achieved and an adequate number of animals will be available for selection.


1997 ◽  
Vol 65 (2) ◽  
pp. 199-207 ◽  
Author(s):  
R. E. Crumps ◽  
G. Simm ◽  
D. Nicholson ◽  
R. H. Findlay ◽  
J. G. E. Bryan ◽  
...  

AbstractThis paper reports the procedures put into place in the UK for the genetic evaluation of pedigree beef cattle and estimation of genetic trends using a comprehensive model to allow critical analysis of progress made under previous data recording schemes. Live weights of Simmental, Limousin, Charolais, South Devon and Aberdeen Angus beef cattle, recorded by the Meat and Livestock Commission (MLC) from 1970 to 1992 were analysed, as part of a project to introduce best linear unbiased predictions (BLUP) of breeding value in the British beef industry. Birth weights were available from MLC or the relevant breed society, (4000 to 84000 records, depending on the breed) and 200- and 400-day weights were estimated by within-animal linear regression on all available weights (resulting in 8000 to 48000 records per breed). Animals were retrospectively assigned to contemporary groups within herds, separately for each trait, taking account of observed calving patterns. Records were adjusted to correct for heterogeneity of variance between herds. BLUP evaluations were then performed within breed, fitting a multivariate individual animal model. In addition to additive direct genetic effects, additive maternal genetic and dam permanent environmental effects were included for birth weight and 200-day weight. Unknown parents were assigned to genetic groups, based on estimated date of birth. The model included fixed effects for contemporary group, sex, month of birth, birth type (single or multiple), embryo transfer births, fostered calves, breed of dam, proportion purebred and age of dam. Genetic trends were estimated by regressing estimated breeding values for animals on their year of birth. Trends in birth weight, 200-day weight and 400-day weight between 1970 and 1992 were approximately 0·09, 0·73 and 1·38 kg per annum respectively for the Charolais breed; 0·08, 0·76 and 1·33 kg per annum for the Simmental; 0·06, 0·53 and 0·89 kg per annum for the Limousin; 0·12, 1·02 and 1·86 kg per annum for the Aberdeen Angus; and 0·03, 0·38 and 0·82 kg per annum for the South Devon breed.


2020 ◽  
Vol 50 (4) ◽  
pp. 613-625
Author(s):  
A. Ali ◽  
K. Javed ◽  
I. Zahoor ◽  
K.M. Anjum

Data on 2931 Kajli lambs, born from 2007 to 2018, were used to quantify environmental and genetic effects on growth performance of Kajli sheep. Traits considered for evaluation were birth weight (BWT), 120-day adjusted weight (120DWT), 180-day adjusted weight (180DWT), 270-day adjusted weight (270DWT), and 365-day adjusted weight (365DWT). Fixed effects of year of birth, season of birth, sex, birth type, and dam age on these traits were evaluated using linear procedures of SAS, 9.1. Similarly, BWT, 120DWT, 180DWT, and 270DWT were used as fixed effects mixed model analyses. Variance components, heritability and breeding values were estimated by restricted maximum likelihood. The genetic trend for each trait was obtained by regression of the estimated breeding values (EBV) on year of birth. Analyses revealed substantial influence of birth year on all traits. Sex and birth type were the significant sources of variation for BWT and 120DWT. Season of birth did not influence birth weight meaningfully, but had a significant role in the expression of 120DWT, 180DWT, and 270DWT. Heritability estimates were generally low (0.003 ± 0.018 to 0.099 ± 0.067) for all traits. With the exception of the genetic correlation of 180DWT and 365DWT, the genetic correlations between trait were strong and positive. Only 365DWT had a positive genetic trend. Although the heritability estimates for almost all weight traits were low, high and positive genetic correlations between BWT and other weight traits suggest that selection based on BWT would result in the improvement of other weight traits as a correlated response.Keywords: bodyweight, breeding value, genetic correlation, sheep


2020 ◽  
Vol 60 ◽  
pp. 5-11
Author(s):  
I. V. Verbuch ◽  
H. V. Bratkovska

Goal. To accelerate the selection process and create populations of pigs with high level of productivity to assess the most effective modern methods breeding value of large white pigs in the SE "DG" Pasichna "Institute of Feed and Agriculture Podillya NAAS" Starosinyavsky district of Khmelnytsky region on the basis of a combined assessment of repair young for their own productivity and assessment meat qualities by MD Berezovsky and B. Tyler and the most promising method BLUP. Methods. Comparison, zootechnical and biometric analyzes. Results. The breeding value of pigs of large white breed of the breeding farm of SE "Pasichna" ICSGP NAAS "Starosinyavsky district of Khmelnytsky region by modern effective methods, namely: BLUP. According to the average indicators of the combined assessment of own productivity of animals at control fattening, taking into account their live weight on the date of birth and weaning, average daily gain, live weight and age of 100 kg, body length and fat thickness, boars significantly outweighed pigs. Compared with pigs, their live weight at the date of birth and weaning (at the age of 30 days) was higher by 0.1 and 0.81 kg. The age of reaching a live weight of 100 kg exceeded by 5.43 days, the average daily gain of 0.016 kg. Live weight and body length of pigs on the date of fat thickness measurement was greater by 4.04 kg and 1.03 cm. Lifetime fat thickness at three measurement points at the level of 6–7 thoracic vertebrae, on the buttocks and in the midpoint of the back between withers and buttocks was thinner by 0.92; 0.94 and 1.06 mm. Evaluation indices of fattening and meat qualities by growth energy and fat thickness (Ia) and average daily gain and fat thickness (Iv) in boars indicate their higher level by 2.07 and 7.67 points compared to pigs and are equal to, respectively, 95.12 ± 1.95 and 152.96 ± 2.38 points. The coefficient of variability (Cv, %) of indicators of own productivity and estimated indices of fattening and meat qualities of repair boars ranged from 1.92% (body length on the date of fat thickness measurement, cm) to 15.12% (age of live weight 100 kg, days), repair pigs – from 4.63% (body length on the date of fat thickness measurement, cm) to 28.19% (index of assessment for growth energy and fat thickness, (Ia), points). The best average values of indicators of breeding value of animals are found on the basis of modern, most promising method BLUP, because it is considered in terms of mathematics, statistics and selection is the most accurate, well-founded, has the best theoretical basis and the lowest error variance. The average value of the BLUP index (parent lines) for boars of large white breed is 101.71 ± 1.681, pigs – 96.94 ± 0.724 points. At the same time, boars outweighed pigs by 4.77 points. The most positive correlation between live weight of piglets at weaning with their body length (r = 0.16), average daily gain (r = 0.19) and fat thickness (r = 0.24), the average correlation between the indices of fattening and meat qualities according to MD Berezovsky and B. Tyler (r = 0.56) P > 0.99 and the weak correlation between live weight of piglets at weaning and the BLUR index (r = 0,21) P > 0.99. It should be noted that there are almost no correlations between the fattening and meat quality indices of pigs and the BLUP index. Conclusions. In the conditions of breeding and specialized farms for the production of commercial pork in the region, to determine the breeding value of animals for further reproduction of their own herd and sale to other breeding farms of Ukraine, to systematically assess repair young animals for their own productivity and clear qualities of pigs and the most perfect BLUP index.


2019 ◽  
Vol 1 (2) ◽  
Author(s):  
J. Ducháček ◽  
R. Toušová ◽  
L. Stádník ◽  
Z. Biniová ◽  
M. Ptáček ◽  
...  

The aim of this study was to evaluate growth ability of Charolais calves in different systems of farming. The observations were performed in period of 8 years (2007 - 2014) in one herd, which was transiting from conventional to ecological farming system. Period from 2007 to 2010 was of conventional character, 2010 to 2012 transition phase, and from 2012 to 2014 ecological phase. This transfer is directly linked to changes in cow´s welfare and nutrition. Growth ability (live weight at birth, 120, and 210 days of age, average daily gain from birth to 120, from birth to 210, and from 120 to 210 days of age) of 518 Charolais calves was measured. Statistical analyses were performed using SAS 9.3 software, GLM procedure. The model equations contend effect of sex, number of parity, month of calves birth and type of farming system. Difference in birth weight of calves between farming systems was small and insignificant. This fact may be due to breeding system focused on easy calving. Increase of values measured in different age and average daily gains were statistical significant (P < 0.05) between conventional and ecological farming. The increase of parameters of weight and average daily gain could be largely connected with genetic progress in Charolais population in Czech Republic and following good selection of bulls to insemination and natural breeding. Nevertheless, the transition from conventional to ecological farming system did not affected growth ability of beef cattle negatively and, in contrary, results of growth improved farm economy.


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