Evaluation of Breeding Value and Selection of Bull Dams in the Danish Dairy Breeds: II. Model Calculations of the Effect of Bias on the Efficiency of Selection

1995 ◽  
Vol 45 (1) ◽  
pp. 32-35
Author(s):  
Gert Aamand Pedersen ◽  
Poul H. Petersen ◽  
Lars Gjøl Christensen
Author(s):  
YuE Kravchenko ◽  
SV Ivanov ◽  
DS Kravchenko ◽  
EI Frolova ◽  
SP Chumakov

Selection of antibodies using phage display involves the preliminary cloning of the repertoire of sequences encoding antigen-binding domains into phagemid, which is considered the bottleneck of the method, limiting the resulting diversity of libraries and leading to the loss of poorly represented variants before the start of the selection procedure. Selection in cell-free conditions using a ribosomal display is devoid from this drawback, however is highly sensitive to PCR artifacts and the RNase contamination. The aim of the study was to test the efficiency of a combination of both methods, including pre-selection in a cell-free system to enrich the source library, followed by cloning and final selection using phage display. This approach may eliminate the shortcomings of each method and increase the efficiency of selection. For selection, alpaca VHH antibody sequences suitable for building an immune library were used due to the lack of VL domains. Analysis of immune libraries from the genes of the VH3, VHH3 and VH4 families showed that the VHH antibodies share in the VH3 and VH4 gene groups is insignificant, and selection from the combined library is less effective than from the VHH3 family of sequences. We found that the combination of ribosomal and phage displays leads to a higher enrichment of high-affinity fragments and avoids the loss of the original diversity during cloning. The combined method allowed us to obtain a greater number of different high-affinity sequences, and all the tested VHH fragments were able to specifically recognize the target, including the total protein extracts of cell cultures.


2016 ◽  
Vol 52 ◽  
pp. 194-202
Author(s):  
S. L. Voitenko ◽  
L. V. Vishnevsky

The article shows the state of Ukrainian Whiteheaded cattle, which includes distribution of cattle, the number of animals belonging to respective bloodlines, evaluation of young animals with live weight in the process of growing and milk production of cows during the first lactation. It reflects the historic development of the breed when it was colonism whiteheaded cattle, which turned into the original breed, undergone a significant expansion in livestock and increase of productivity, decreased in the number, was as basis for creation of Ukrainian Black-and-White dairy breed and now bred only in one breeding farm. Visual estimation of animal exterior showed good development of cows and calves and their belonging to the dairy type. In the vast majority the cows of the herd have a black suit, a white head with " glasses" around the eyes, white belly, udder, lower legs and brush of the tail. The youngsters aren’t consolidated by the exterior, and among them there are animals which are not typical for Ukrainian Whiteheaded breed. The young animals have some lag in live weight behind the breed standard [12] to 7 months’ age with exceeding of this trait in certain periods quite significantly in the future. It was established that selection of heifers on live weight will be effective at the early age (1-5 months), given the coefficient of variation of live weight – 22,63-30,21% and will not have a significant influence in the future. Milk yields of first-calf heifers vary considerably depending on the origin. The milk yield of first-calf heifers in the herd was 4238,5 kg on average, the heifers belonging to Mart 171 and Ozon 417 bloodlines had the best milk performance – 4483,1 and 4254,9 kg accordingly. The most aligned milk yield during the first lactation was in the cows belonging to Ozon 417 bloodline, the limits of the trait are 4128,5-4327,4 kg with the average value by the line 4254,9 kg. In contrast, the first-calf heifers of Ryezvyi 33 bloodline with average milk yield 4048,9 kg had limits of the trait 2199,3-4736,1 kg. Even greater range in cows’ milk yield during the first lactation R= 4939 kg (limits 1687 – 6626 kg) is characterized for the herd in general, it shows, on the one hand, the possibility of qualitative improvement of cows’ productivity due to selection on the investigated trait and lack of selection in the herd on the other hand. It was established that daughters of bull Chardash belonging to Ryezvyi 33 bloodline produced 4736,1 kg of milk for 305 days of the first lactation with fat content 3,6%, whereas Zlak’s descendants of the same line were characterized by the lowest milk yield for the first completed lactation – 2199,3 kg with fat content 3,7% and the average value by the line – 4048,9 kg of milk, fat content 3,6%. Similar variability of first-calf heifers’ milk yields, depending on the origin, is typical for other bloodlines of Ukrainian Whiteheaded breed. To increase milk productivity of Ukrainian Whiteheaded cows is recommended to repeat successful combinations of parental forms, and to preserve the breed – to carry out an objective assessment of animals by a range of traits, given the efficiency of selection of heifers on live weight at early age.


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.


2003 ◽  
Vol 46 (2) ◽  
pp. 167-176 ◽  
Author(s):  
L. Panicke ◽  
E. Fischer ◽  
B. Fischer ◽  
R. Staufenbiel

Abstract. Title of the paper: Level estimation of metabolic parameters in the glucose tolerance test (GTT) of young bulls The metabolic parameters of the glucose tolerance test are suitable for an additional recommendation for the valuation of the breeding bulls before the start of the offspring’s test could be given. Very important is the level of glucose half live to the begin of lactation of the cows. The other limit is the hyperglycemias greater than 10 mmol/l (or 180 mg/dl) in the glucose level in the blood. The glucose half live measured nearly 48 minutes is comparable in the 8th week post partum in lactation of cows with the young bulls in the age one year. Their combination with the pedigree breeding value is leading to increase of information, that could be utilised to the selection of improper bulls if the present results were confirmed.


2021 ◽  
Vol 1 (19) ◽  
pp. 194-196
Author(s):  
O.F Kandarakov ◽  
A.V. Bruter ◽  
A.V. Petrovskaya ◽  
A.V. Belyavsky

The possibility of using HA- and FLAG–tags embedded into CD52 surface protein for magnetic separation of transduced cells in vitro was investigated. The efficiency of selection of transfected cell lines, both with single and binary tags, was shown to exceed 85%. Thus, surface markers on the basis of CD52 protein with integrated HA- and FLAG-tags are applicable for cell selection by the MACS method.


2011 ◽  
Vol 50 (No. 10) ◽  
pp. 439-449
Author(s):  
P. Šafus ◽  
J. Přibyl

Genetic and economic responses to genetic gain were evaluated for these breeding arrangements: single use of bulls under testing; single and repeated use of proved bulls for two years and for three years (in combination with selection intensity 1%, 5% or 10% of the best bulls for the use of proved bulls); negative selection of cows in the herd &ndash; 10%, 20% or 30% of animals are discarded from reproduction and the animals are left in the herd and used for breeding by beef bulls; negative selection of first-calvers in the herd &ndash; 10%, 20% or 25% of animals are discarded for slaughter; discarding of heifers and purchase of animals with higher breeding value, and embryo transfer &ndash; a group of selected recipients accounts for 10%, 20% or 30% of the cows with lover breeding value in the dairy herds. Simulations for single use of breeding arrangements and their consequences over a fifty-year period were carried out for the above models using the gene flow method. Only minimum changes will occur since the 25<sup>th</sup> year of observation. A comparison of the particular models showed the highest gain of proved bulls selected from 1% of the best bulls whose cumulative genetic gain was 41.558 kg of milk proteins on average per cow for the whole observed period. Single use of bulls under testing in the herd resulted in the second highest cumulative genetic gain. Use of proved bulls selected with lower selection intensity (5% or 10%) had worse results. Culling of cows and discarding of first-calvers for slaughter led to lower genetic and economic contribution. The gain of embryo transfer was also lower; moreover, it is not economically advantageous for its very high costs, so it should not be used in production herds generally. High genetic and economic gain was recorded for replacement of all heifers by animals with higher breeding value from other populations. &nbsp;


2016 ◽  
Vol 41 (4) ◽  
pp. 175 ◽  
Author(s):  
S. Said ◽  
P. P. Agung ◽  
W. P. B. Putra ◽  
S. Anwar ◽  
A. S. Wulandari ◽  
...  

Selection of livestock was purposed to increase productivity. A performance test was conducted using 25 males and 25 females of Sumba Ongole (SO) cattle. The performance test were conducted in three periods (2014, 2015 and 2016) for about 535 days. Descriptive statistics ws used to analyze data of body weight. Cattle with age between 300 to 600 days were used for evaluation. Result showed that heritability value of yearling weight (YW365) was 0.77+0.68 as a high category. The highest breeding value of YW365 were 66.05 kg (male) and 41.89 kg (female). The average of corrected final weight (CFW) weight were 172.55+34.22 kg (male) and 159.80+37.73 kg (female). The performance test in this study obtained six A class (1 bull and 5 cows) based on the standard minimum of body measurements for SO cattle.


1987 ◽  
Vol 45 (1) ◽  
pp. 87-96 ◽  
Author(s):  
A. C. Parratt ◽  
G. Simm

AbstractSelection indices to improve lean meat production of terminal sire breeds of sheep were derived. An aggregate breeding value which comprised growth rate, killing-out proportion and carcass lean proportion was examined. Selection criteria included growth rate and ultrasonic or X-ray computer tomography (CT) estimates of carcass composition. Correlations betwen the index and the aggregate breeding value were about 0·38 for indices using ultrasonic fat measurements, and about 0·40 for those using CT measurements. Dropping ultrasonic or CT measurements from the indices reduced the correlations with the aggregate breeding value by only about 0·01 and 002 respectively, indicating that selection on growth rate alone under current economic conditions was highly efficient. Changes in economic weights, and genetic parameters had little effect on the efficiency of selection. The total national discounted value of returns from a single round of selection on the indices was expected to be between £6 and £30·5 million, depending on penetration rates of improved stock, the breeding scheme used, and with a time horizon of 20 years.


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