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1
Tosh, J. J., and J. W. Wilton. "A terminal-sire index for selecting rams." Canadian Journal of Animal Science 82, no. 4 (December 1, 2002): 591–93. http://dx.doi.org/10.4141/a02-024.
Повний текст джерелаАнотація:
A terminal-sire index for selecting rams was developed. It combines genetic evaluations for growth traits and carcass characteristics measured ultrasonically on live animals into a single criterion. Weightings for component traits are averages from the indexes of four slightly different breeding goals, determined using economic values and parameters from the literature. The weightings for breeding values of component traits are -1.45 for birth weight, +1.86 for weight at 50 d of age, +2.27 for gain from 50 to 100 d, -0.51 for ultrasonic fat depth, and +1.36 for ultrasonic loin muscle depth, in phenotypic standard deviation units. Selection that is based on the index will increase growth while simultaneously decreasing fat and increasing muscle. Key words: Breeding strategies, carcass characteristics, growth, selection, sheep
2
Wall, E., M. P. Coffey, S. Brotherstone, J. A. Woolliams, and A. P. F. Flint. "Developing a UK Dairy Fertility Index." Proceedings of the British Society of Animal Science 2003 (2003): 47. http://dx.doi.org/10.1017/s1752756200012060.
Повний текст джерелаАнотація:
National dairy records have shown that correlations between production and fertility are generally unfavourable. There has therefore been a genetic downward trend for fertility due to the increase selection pressure on yield and as a genetic problem it requires a genetic solution. The effect of sire genetics on daughter fertility is included in many genetic indices around the world. As part of a DEFRA LINK project to produce an UK fertility index this study estimates genetic parameters and sire predicted transmitting ability (PTAs) for fertility traits in the UK.
3
Amer, P. R., R. Crump, and G. Simm. "A terminal sire selection index for UK beef cattle." Animal Science 67, no. 3 (December 1998): 445–54. http://dx.doi.org/10.1017/s1357729800032859.
Повний текст джерелаАнотація:
AbstractA selection index which incorporates estimated breeding values of traits recorded in the United Kingdom pedigree beef cattle breeds is described. The breeding objective is made up of commercial carcass, calving difficulty and gestation length traits. Economic values for these breeding objective traits are summarized from related studies, while partial genetic regression estimates of breeding objective traits on recorded traits are derived mainly from the literature.The selection index is described in terms of the reduction in expected genetic response from selection on the index when individual recorded traits are omitted and the expected genetic responses in breeding objective traits with selection on the index under the assumption of mass selection. Failure to record all calving traits (birth weight, calving difficulty and gestation length) resulted in a reduction in expected economic response to selection of 8% from the situation where both calving traits and production traits (400-day weight, ultrasonic fat and muscle depths, and muscling score) are recorded. With a few stated exceptions, the index is relatively robust to errors in estimates of individual parameters.It is suggested that the total index be used to assist commercial bull and semen buyers in their selection decisions but that two sub-indices for calving and production traits also be published to allow buyers to adjust emphasis on the two groups of traits depending on their individual production circumstances.
4
Astriana, Baiq Hilda, and Chandrika Eka Larasati. "Diversitas Plankton di Perairan Pantai Sire Kabupaten Lombok Utara." Jurnal Ilmu Kelautan Lesser Sunda 1, no. 1 (May 27, 2021): 9–14. http://dx.doi.org/10.29303/jikls.v1i1.26.
Повний текст джерелаАнотація:
Plankton has an important role for aquatic ecosystems, especially in the food network in a waters. This study aims to assess the abundance and diversity index of plankton in Sire Beach, North Lombok Regency. The study was conducted in September 2019 using purposive sampling with 9 sample points. The water sample was filtered using plankton net then put into the sample bottle for identification in the laboratory. Shannon-Wienner Index was used for determining diversity of plankton species. The types of plankton found were 12 genera of phytoplankton from the Bacillariophyta group, including: Biddulphia, Coscinodiscus, Cocconeis, Cylindrotheca, Diploneis, Fragilaria, Gyrosigma, Licmophora, Navicula, Nitzschia, Pleurosigma, and Triceratium. The highest abundance of phytoplankton belonged to Coscinodiscus species as many as 1.380 cells/l at station 2.3. The high abundance of Coscinodiscus might be due to a nutrient supply in these waters. Seagrass ecosystem was thought to have an important role in obtaining nutrients for phytoplankton. Diversity index has a value which ranges between 1.117505-1.841236 showing that it is in the medium category. The uniformity index ranges from 0.450718-0.673373 indicating that the distribution of plankton species in each station is even. The dominance index ranges from 0.233508-0.522215. This shows that there is no type of plankton that dominates the waters of Sire Beach. This is due to the abundance of plankton species at each station which is fairly evenly distributed.
5
van Heelsum, A. M., R. M. Lewis, M. H. Davies, and W. Haresign. "Growth and carcass characteristics in wether lambs of a crossbred dam line." Animal Science 76, no. 1 (February 2003): 43–53. http://dx.doi.org/10.1017/s1357729800053303.
Повний текст джерелаАнотація:
AbstractWhile crossing of specialized sire and dam breeds can be biologically efficient overall, a by-product is produced in the form of (crossbred) males of the dam line that are unwanted for breeding. In the UK sheep industry, most commercial females are first crosses between males of ‘longwool’ crossing sire breeds, predominantly the Bluefaced Leicester, and females of hill breeds. Genetic improvement of carcass quality in longwool breeds would benefit the surplus F1 males as well as filter through to the terminal sire cross lambs produced by the F1 ewes. As a first step, this paper aims to describe the growth and carcass characteristics of crossbred ‘Mule’ wether offspring of Bluefaced Leicester sires and Scottish Blackface and Hardy Speckled Face dams, and relate the crossbred performance to the ‘lean’ index and live conformation score of the sires and the breed of the dams. In each of 3 years, 1500 hill ewes divided over three sites were mated to 15 ram lambs, selected using an elliptical design to best represent the full spectrum of lean index (designed to improve muscle and decrease fat content while keeping live weight unchanged) and live conformation score present in the Penglas Bluefaced Leicester Group Breeding Scheme. Full growth and slaughter records were available on 2192 Mule wether lambs slaughtered after reaching finished condition, defined as the borderline between MLC fat class 2 and 3L. Measurements included live weight, ultrasonic muscle and fat depth, live conformation score, carcass hot and cold weight, MLC fat score (on the standard seven-point scale) and conformation score (EUROP and 15-point scale) and a visual estimation of subcutaneous fat cover. Nearly 800 carcasses were dissected; 20% had a full side and 80% a shoulder dissection. In part-dissected carcasses, shoulder dissection results were used to predict the fat and lean content of the other joints. Fat and lean percentages and absolute weights were then regressed on the lean index and the residual live conformation score of the sire. At the same finished condition, Scottish Blackface offspring were heavier, older, and had less fat and more lean based both on ultrasound and on carcass dissection measurements compared with Hardy Speckled Face offspring. The index score of the sire had a positive effect on the lean content and a negative effect on fat content of all joints. Conformation of the sire did not have a significant effect on any of the carcass composition measurements, but most conformation traits measured on the animal itself (live or on the carcass) were positively related to fat and negatively to lean content in the carcass. When taking into account differences in visually assessed subcutaneous fat percentage, the carcass conformation traits persisted only in having a positive effect on carcass fat content; none of the conformation traits had an effect on carcass lean content. The results show that selection of sires on lean index is an effective way to improve carcass composition in Mule wethers, but selection on conformation is ineffective.
6
Lewis, R. M., G. Simm, W. S. Dingwall, and S. V. Murphy. "Selection for lean growth in terminal sire sheep to produce leaner crossbred progeny." Animal Science 63, no. 1 (August 1996): 133–42. http://dx.doi.org/10.1017/s1357729800028368.
Повний текст джерелаАнотація:
AbstractA progeny test was designed to test whether genetic superiority for lean growth in terminal sires is expressed in their crossbred progeny when reared in a different environment. In each of 1986, 1987 and 1988, 22 Suffolk rams were chosen at the conclusion of an indoor, intensive performance testing regime on an index score that rated their propensity for lean growth, while constraining fat growth, at 150 days of age. Half of these rams had high index scores and half had low index scores. In each year, around 400 crossbred ewes were mated and the resulting lambs were finished on grass to one of three target live weights (35·5, 41·5, and 47·0 kg). Shoulder joints were dissected on 1505 lambs whilst half carcasses were dissected on 372 lambs. Double sampling techniques were then used to combine the data from the shoulder and half carcass more precisely to predict the lean, fat and bone weight and content in the carcass.With each increment in target live weight, the carcasses were heavier and had proportionally more fat. The progeny of high index rams consistently had 144 (s.e.d. 32) g more lean, 66 (s.e.d. 12) g more bone, and 186 (s.e.d. 32) g less fat in a 19·7 (s.e. 0·5) kg carcass than progeny of low index rams, from the double sampling procedure. This improved composition reflected a correlated response to ram selection on the index. One standard deviation increase in ram index score corresponded to 51 g more lean and 64 g less fat in the 20 kg carcass of their crossbred offspring. These results show that the use of rams with high lean index scores in a crossbreeding system will produce lambs with leaner carcasses. Visual appraisals of fat and conformation both increased as the weight and, consequently, the fatness of the carcass increased. Offspring of high index rams were consistently scored as less fat than offspring of low index rams. But, at the lighter weights (35·5 and 41·5 kg), they were also scored lower in conformation — in effect, a penalty for their higher genetic merit for lean growth.
7
Cameron, N. D., and J. Bracken. "Selection for carcass lean content in a terminal sire breed of sheep." Animal Science 54, no. 3 (June 1992): 367–77. http://dx.doi.org/10.1017/s0003356100020821.
Повний текст джерелаАнотація:
AbstractA divergent selection experiment for carcass leanness in Texel-Oxford sheep was established to examine the differences between genetically lean and fat animals derived from the same base population. The selection criterion was designed to change body composition without a corresponding change in live weight, using an index of ultrasonic backfat depth and live weight at 20 weeks of age. The index was constructed using estimates of genetic and phenotypic parameters, which were available at the start of the experiment in 1985. The difference between the high and low lines, after 3 years of selection, for the selection index, live weight at 20 weeks of age, ultrasonic backfat and muscle depths was 0·59,1·30 kg, -0·76 mm and 0·88 mm respectively. The estimated difference for carcass lean and fat weight was 0·72 kg and -0·04 kg respectively with 13·5 g/kg and -13·8 g/kg for carcass lean and fat proportion. The realized heritability for the selection index, estimated from the regression of cumulative response on cumulative selection differential was 0·42, with a standard error of 0·25, after taking account of genetic drift. The selection index heritability, estimated with residual maximum likelihood (REML) methodology, was 0·46 (s.e. 0·14). REML heritability estimates for live weight at 20 weeks of age, ultrasonic backfat and muscle depths were 0·20 (s.e. 0·13), 0·35 (s.e. 0·14) and 0·43 (s.e. 0·14) respectively.
8
McEWEN, P. L., and L. R. SCHAEFFER. "COMPARING MATE QUALITY BETWEEN PROVEN AND UNPROVEN DAIRY BULLS." Canadian Journal of Animal Science 69, no. 1 (March 1, 1989): 57–60. http://dx.doi.org/10.4141/cjas89-008.
Повний текст джерелаАнотація:
Holstein service sire information was obtained from Eastern Breeders Incorporated to compare mate quality between proven and unproven sires. Proven sires were mated to females having higher conformation scores for final classification, mammary system, feet and legs and rump. Size score of mates favored unproven bulls. Advantages in mate estimated transmitting ability value for milk and fat index favored proven sires by 0.60 and 0.63 BCA points, respectively. In general, the difference in mate quality between the two sire groups was relatively small. However, proven sires showed a slight advantage in mate quality for the majority of traits studied. Key words: Dairy, sire, mate
9
Famula, T. R. "A comparison of restricted selection index and linear programming in sire selection." Theoretical and Applied Genetics 84-84, no. 3-4 (July 1992): 384–89. http://dx.doi.org/10.1007/bf00229497.
Повний текст джерела
10
Brotherstone, Susan, and W. G. Hill. "A retrospective evaluation of the weights in the cow genetic index." Animal Science 44, no. 3 (June 1987): 355–61. http://dx.doi.org/10.1017/s0003356100012289.
Повний текст джерелаАнотація:
ABSTRACTThe fat plus protein yield of 70 011 records of pedigree British Friesian/Holstein cows was regressed on various components of their dam's Cow Genetic Index (CGI) in order to obtain the regression coefficients for comparison with the index weights currently used in the calculation of the CGI. For the first and later (2 to 5) lactation components of the CGI, the regression coefficients obtained by analysis were consistent with the tabulated index weights, but the coefficients for the sire component tended in some cases to be lower than the table values. The analysis was repeated using only dams that had widely used sires. The partial regression coefficients for the first and later lactation components were again consistent with the tabulated weights, and the coefficient for the sire component lay within one s.d. of the table values. In all cases, a cow's CGI is shown to take full account of her first and later lactation information and her sire's and dam's transmitting abilities.
11
Cole, J. B., G. R. Wiggans, P. M. VanRaden, and R. H. Miller. "Stillbirth (Co)Variance Components for a Sire-Maternal Grandsire Threshold Model and Development of a Calving Ability Index for Sire Selection." Journal of Dairy Science 90, no. 5 (May 2007): 2489–96. http://dx.doi.org/10.3168/jds.2006-436.
Повний текст джерела
12
Lewis, R. M., G. C. Emmans, G. Simm, W. S. Dingwall, J. FitzSimons, J. C. Fraser, and J. E. Donbavand. "The consequences of index selection on carcass composition in Suffolk sheep." Proceedings of the British Society of Animal Science 1999 (1999): 46. http://dx.doi.org/10.1017/s1752756200002015.
Повний текст джерелаАнотація:
Early in the 1980s a selection index was designed at SAC to improve the rate of lean growth in terminal sire sheep which combined ultrasound measurements of fat and muscle depth, and live weight at 150 days of age (Simm and Dingwall, 1989). Beginning in 1985, this index was applied in the SAC Suffolk flock in a performance test. In 1994, rams from a line selected on this index weighed on average 12% more (8 kg) and had 12% lower fat depth (– 0.9 mm) and 10% higher muscle depth (2.9 mm) than rams from an unselected Control line. Comparison of Selection and Control line animals has thus far been based on live predictors of carcass composition at weights substantially heavier than typical market lamb weights. The aims of this study were to test whether selection decisions based on the lean growth index produced an improvement in actual carcass composition in purebred terminal sire sheep and whether these changes persisted at live weights different from those under which selection was carried out.
13
Tölü, C., T. Savas, A. Pala, and H. Thomsen. "Effects of goat social rank on kid gender." Czech Journal of Animal Science 52, No. 3 (January 7, 2008): 77–82. http://dx.doi.org/10.17221/2235-cjas.
Повний текст джерелаАнотація:
Mechanisms of gender ratio in progeny are complex and the fine details are still largely unknown, even in mammals. Though the 50% ratio of males and females is expected, various factors have been shown to be effective in diverting the ratio from the expected. In this study, dominance index, effects of sire, age of dam, birth type and year of birth on the gender ratio of Turkish Saanen goat kids were investigated in a full model. The analysis indicated that dominance index (DI) of the dam had a significant influence on the gender ratio of kids (<I>P</i> = 0.036). Certain sires tended to father female descendants repeatedly and the dams with high dominance index gave birth to male kids. Effects of sire on kid gender approached significance (<I>P</i> = 0.094). Age of dam, year and birth type were insignificant.
14
Banos, G., S. Brotherstone, R. Thompson, J. A. Woolliams, E. Wall, and M. P. Coffey. "Calculation of multiple-trait sire reliability for traits included in a dairy cattle fertility index." Animal Science 79, no. 1 (April 2004): 1–9. http://dx.doi.org/10.1017/s1357729800054473.
Повний текст джерелаАнотація:
AbstractThe advent of genetic evaluations for fertility traits in the UK offers valuable information to farmers that can be used to control fertility problems and safeguard against involuntary culling. In addition to estimated genetic merit, proof reliabilities are required to make correct use of this genetic information. Exact reliabilities, based on the inverse of the coefficient matrix, cannot be estimated for large data sets because of computational restrictions. A method to calculate approximate reliabilities was implemented based on a six-trait sire model. Traits considered were interval between first and second calving, interval between first calving and first service, non-return rate 56 days post first service, number of inseminations per conception, daily milk yield at test nearest day 110 and body condition score. Sire reliabilities were calculated in four steps. Firstly, the number of effective daughters was calculated for each bull, separately for each trait, based on total number of daughters and daughter distribution across herd-year-seasons. Secondly, multiple-trait reliabilities were calculated, based on bull daughter contribution, applying selection index theory on independent daughter groups. Thirdly, (great-) grand-daughter contribution was added to the reliability of each bull, using daughter-based reliability of sons and maternal grandsons. An adjustment was made to account for the probability of bull and son or grandson having daughters in the same herd-year-season. Without the adjustment, reliabilities were inflated by proportionately 0·15 to 0·25. Finally, parent (sire and maternal grandsire) contribution was added to the reliability of each bull. The procedure was first tested on a data subset of 28 061 cow records from 285 bulls. Approximate reliabilities were compared with exact estimates based on the inverse of the coefficient matrix. Mean absolute differences ranged from 0·014 to 0·020 for the six traits and correlation between exact and approximate estimates neared unity. In a full-scale application, sire reliability for the fertility traits increased by proportionately 0·47 to 0·79 over single-trait estimates and the number of bulls with a reliability of 0·60 or more increased by 42 to 115%.
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O. V. Larina, O. V. Larina, M. I. Fedorova, Yu N. Kholodov, and A. V. Bakhtina. "Evaluation of sires according to offspring beef quality." Glavnyj zootehnik (Head of Animal Breeding), no. 8 (July 20, 2021): 35–41. http://dx.doi.org/10.33920/sel-03-2108-05.
Повний текст джерелаАнотація:
Beef production in the Russian Federation is mainly based on the use of over-replacement young animals and culled adult cattle of dairy and dual purpose breeds, and only 10 % of it is obtained from cattle of specialized beef breeds and their crossbreds. The selection and widespread use of the best breeding sires will help to increase the dairy and meat productivity of cows and overcome the negative correlation between the most important selected traits in large numbers of livestock. The results of the evaluation of the off spring of sires of Simmental breed of domestic and foreign selection (Canadian), as well as the sire of Red-and-White dairy breed have been presented in the article. The complex index of the sire Sokol 1335/6330 TS-2811 of Simmental breed of the Canadian selection (purebred), born in 1999 in the collective farm of name after Ilich in the Kalacheyevsky district in the Voronezh region (color pale-mottled), according to the beef characteristics of the off spring was 116, which corresponds to the international category EX – “excellent” (KI[sub]1[/sub]). From this it follows that the sire Sokol 1335/6330 TS-2811 is an improver for beef productivity with the assignment of category C[sub]1[/sub]. The sire Redky 6631 TS-2710 belongs to the line Signal 4863, born in 1989 in the state farm “Moskovsky” in the Kharkiv region (color pale-mottled) of domestic selection received the complex index 102 for the beef productivity of off spring, corresponding to KI[sub]3[/sub] (G) – “good” with the assignment of category C[sub]3[/sub]. The sire Pamir 9060,2566 CGF-123 of Red-and-White breed belongs to the line Siling Traijun Rocket 252803, which has the A[sub]3[/sub]B[sub]3[/sub] breeding category, is the loser in terms of the meat productivity of the off spring. It follows from this that the sons of sires of Simmental breed of the domestic and Canadian selection have the advantage in beef productivity over the sons of the sire of Red-and-White breed.
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Petrovic, Milica, Milovan Pusic, Dragan Radojkovic, Milan Mijatovic, Olga Kosovac, and Cedomir Radovic. "The effect of breed, sire and sex on the quality of carcass sides." Biotehnologija u stocarstvu 22, no. 1-2 (2006): 79–88. http://dx.doi.org/10.2298/bah0602079p.
Повний текст джерелаАнотація:
Investigation of quality variability of pig carcass was carried out on 1443 fatlings (gilts and barrows). They were progenies of 22 (Farm A) and 12 sires (Farm B), 5 breeds-crossbreds (Swedish Landrace, Large White, Duroc Hampshire, Duroc x Hampshire). Animals were fed with standardized feed mixture semi ad libitum. The quality of carcass sides was determined on the slaughter-line according to Regulation (1985). Investigation included following traits: weight of warm carcass (MTP, kg), meat in carcass sides (KMP, kg and SMP, %), total mass and ratio of leg+shoulder+loin (MFO, kg and UFO, %). Obtained results were processed using several models (Harvey, 1990) which included sire genotype, sire, sex progeny and mass of warm carcass (regression effect). All investigated traits varied under the influence of sire genotype (P<0.01) on farm B. The effect of sire genotype was significant (P<0.01) on KMP and SMP on the Farm A. All traits of carcass quality varied under the influence of sires. Gilts had higher KMP, SMP, MFO and UFO compared to male castrated heads. Difference in Total Breeding Value between best and worst boar was 10.41 (Farm A) and 11.24 index point (Farm B).
17
JANSEN, G. B., L. R. SCHAEFFER, E. B. BURNSIDE, and H. M. WILSON. "PEDIGREE INDEXING YOUNG HOLSTEIN DAIRY BULLS USING ANCESTRAL INFORMATION FROM DIFFERENT COUNTRIES." Canadian Journal of Animal Science 66, no. 4 (December 1, 1986): 889–95. http://dx.doi.org/10.4141/cjas86-098.
Повний текст джерелаАнотація:
A model is described for utilizing ancestor estimated transmitting abilities from different countries to increase the accuracy of prediction of the performance of young dairy bulls in artificial insemination within a country. The model was applied to young Canadian Holstein bulls having pedigree information from Canada and the United States. Models with varying sources of pedigree information were compared. When sire, dam and maternal grandsire were in the model, the correlations between pedigree index and actual progeny test were 0.64, 0.70 and 0.55 for milk yield, fat yield and fat percentage, respectively. There was little difference in accuracy using a sire and dam model. Average pedigree indices were calculated for bulls in artificial insemination in Canada. The average pedigree index has increased 0.87 BCA (breed class average) per year for milk yield over the last ten years. Key words: Holstein sires, pedigree indexes, production traits
18
Sivanadian, B., M. M. Lohuis, and J. C. M. Dekkers. "Expected genetic responses from selection indexes for Canadian dairy cattle under present and future milk pricing systems." Canadian Journal of Animal Science 78, no. 2 (June 1, 1998): 157–65. http://dx.doi.org/10.4141/a97-053.
Повний текст джерелаАнотація:
Expected selection responses and profit under alternative milk pricing scenarios for various selection indexes were compared: Lifetime Profit Index (LPI) with 60:40:0:0 emphasis on production:type:herdlife:somatic cell score and 9:2:0 relative weights on Protein:fat:milk, and Total Economic Value (TEV) reflecting the present pricing system, Neutral Total Economic Value (NTEV) and Future Total Economic Value (FTEV) reflecting future milk prices, each with 64:0:26:10 emphasis on production:type:herdlife:somatic cell score and 9:2:0, 1:0:0 and 18:–2:–5 relative weights, respectively, on protein:fat:milk and Large Herd Operator Index (LHO) with 83:17:0:0 emphasis and 13.5:–1.5:0 relative weights. Among the correlations between indexes the lowest was.93 (correlation of LPI with NTEV and FTEV) and the highest was 0.99 (between TEV and NTEV). For present and probable future milk pricing the most profitable sire selection indexes were TEV and FTEV in both whole and grade-only populations. When selection intensity and number of daughters per sire were equal to 1.0 and 50, respectively, profit expressed in Canadian dollars in net present value of lifetime profit of a milking daughter were 231.75 (226.62 in grade population) and 234.89 (229.89 in grade population) from TEV and FTEV respectively. The choice of sire selection indexes depends on individual farmer goals. However, if the total economic merit resulting from typical dairy production is the goal, then TEV and FTEV are advised for short-term and long term selection, respectively. Key words: Index, selection, genetic response, profit, milk pricing
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Heelsum, A. M. van, R. M. Lewis, D. W. Jones, W. Haresign, and M. H. Davies. "Genetic parameters for live weight, ultrasonic measurements and conformation in Bluefaced Leicester sheep." Proceedings of the British Society of Animal Science 1999 (1999): 122. http://dx.doi.org/10.1017/s1752756200002775.
Повний текст джерелаАнотація:
Currently fewer than 50% of UK lambs produce carcasses of acceptable quality for the domestic and export markets, which compromises the competitiveness of sheep farming. Carcass quality can be changed by selection, and this is now being taken advantage of in terminal sire breeds and, to a lesser extent, in hill breeds. However, little attention has yet been focused on the crossing breeds, which have relatively poor carcass quality, in spite of the large impact such breeds have on the slaughter generation. Recently, a long-term project began to develop breeding programmes relevant to crossing sire (‘longwool’) breeds. Its objective is to produce a selection index to improve carcass quality without compromising the reproductive performance or maternal ability of these breeds. The Bluefaced Leicester is the most prevalent crossing sire breed with its crossbred (‘Mule’) daughters out of draft hill ewes accounting for 89% of crossbred (longwool x hill) ewes in the UK (Pollot, 1998).
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Bijma, P., and J. A. M. van Arendonk. "Maximizing genetic gain for the sire line of a crossbreeding scheme utilizing both purebred and crossbred information." Animal Science 66, no. 2 (April 1998): 529–42. http://dx.doi.org/10.1017/s135772980000970x.
Повний текст джерелаАнотація:
AbstractA selection index procedure which utilizes both, purebred and crossbred information was developed for the sire line of a three-path crossbreeding scheme in pigs, to predict response to best linear unbiased prediction (BLUP) selection with an animal model. Purebred and crossbred performance were treated as correlated traits. The breeding goal was crossbred performance but methods can be applied to other goals. A hierarchical mating structure was used. Sires were mated to purebred dams to generate replacements and to F^ from the dam line to generate fattening pigs. Generations were discrete, inbreeding was ignored. The selection index included purebred and crossbred phenotypic information of the current generation and estimated breeding values for purebred and crossbred performance of parents and mates of parents from the previous generation. Reduction of genetic variance due to linkage disequilibrium and reduction of selection intensity due to finite population size and due to correlated index values was accounted for. Selection was undertaken until asymptotic responses were reached. The index was used to optimize the number of selected parents per generation and the number of offspring tested per litter, and to make inferences on the value of crossbred information when the breeding goal was crossbred performance. It was optimal to test a maximum number of offspring per litter, mainly due to increased female selection intensities. Maximum response reductions due to linkage disequilibrium and correlated index values were 32% and 29% respectively. Correcting for correlated index values changed ranking of breeding schemes. Benefit of crossbred information was largest when the genetic correlation between purebred and crossbred performance was low. Due to high correlations between index values in that case, the optimum number of selected sires increased considerably when crossbred information was included.
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MacNeil, M. D., and S. Newman. "Selection indices for Canadian beef production using specialized sire and dam lines." Canadian Journal of Animal Science 74, no. 3 (September 1, 1994): 419–24. http://dx.doi.org/10.4141/cjas94-060.
Повний текст джерелаАнотація:
Relative economic values and literature estimates of genetic and phenotypic variances and covariances were used to develop selection indices for specialized maternal and terminal strains of beef cattle. The envisioned commercial production setting used three maternal strains mated in rotation. Yearling heifers were mated to a terminal sire strain (M3) to minimize dystocia and neonatal mortality without closely monitored calving. Mature cows were bred to a second terminal strain (TX) to produce market progeny. Acccuracies for all indices were low: 0.22, 0.22 and 0.19 for the maternal strains, M3 and TX, respectively. Predicted correlated responses to index selection were not economically favorable for all traits within strain but were offsetting between strains. At the production system level, genetic improvement in profitability resulted from all traits except feed conversion. Fertility and calf survival were improved in all strains. Direct genetic potential for growth was reduced in the maternal strains but was increased in TX and to a lesser degree in M3. There was a tradeoff between maternal and terminal strains in responses of carcass traits. Maternal strains increased in dressing percentage and decreased in cutability, while M3 and TX decreased in dressing percentage and increased in cutability. Arduously slow improvement in profitability is anticipated: $1.07 per breeding female per unit of selection response. Key words: Beef cattle, selection program, selection index
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van Heelsum, A. M., R. M. Lewis, W. Haresign, D. Jones, S. Williams, M. H. Davies, and O. Davies. "Growth and carcass characteristics of crossbred (Mule) sheep." Proceedings of the British Society of Animal Science 2002 (2002): 195. http://dx.doi.org/10.1017/s1752756200008516.
Повний текст джерелаАнотація:
With increasing emphasis in the meat sector on better and more consistent quality, carcass leanness and conformation is now an important issue for sheep breeders. In 1999, only 47% of all carcasses in the UK met the target specifications for weight, fat and conformation (MLC, 2000), highlighting the potential for improvement. In the current stratified crossbreeding system, crossbred wether lambs are a by-product of the production of dam line ewes for the lowland sector. If their carcass quality is sufficient, they can give a valuable boost to the economics of the breeding programme. Genetic improvement of carcass quality in crossing sire breeds would benefit the crossbred wethers, as well as filter through to the terminal sire cross lambs produced by the crossbred ewes. This work aims to assess the influence of selection index and live conformation score of crossing sires (in this case Bluefaced Leicesters) on growth and carcass quality traits of their crossbred progeny, as a first step towards designing a genetic improvement programme for crossing sire sheep.
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Koh, Daeyoung, Taejeong Choi, Yunho Choy, Sidong Kim, Byoungho Park, Chungil Cho, Kwanghyun Cho, Seungsoo Lee, and Jaegwan Choi. "Changes in Genetic Potentials According to the Weights for Terminal Sire Index in Duroc Breed." Annals of Animal Resource Sciences 25, no. 1 (June 30, 2014): 1–6. http://dx.doi.org/10.12718/aars.2014.25.1.1.
Повний текст джерела
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SULLIVAN, P. G., and L. R. SCHAEFFER. "REGIONAL HETEROGENEITY OF VARIANCES AND ITS EFFECT ON CANADIAN HOLSTEIN SIRE EVALUATION." Canadian Journal of Animal Science 69, no. 3 (September 1, 1989): 605–12. http://dx.doi.org/10.4141/cjas89-072.
Повний текст джерелаАнотація:
Heritabilities were estimated within each of four artificial insemination stud regions in Ontario and Quebec, based on a total of 880 329 records for milk and fat yield and 441 230 records for final class score. The pseudo-expectation (PE) and tilde-hat (TH) approaches were used. Estimates ranged from 0.32 to 0.46 for milk yield, from 0.31 to 0.53 for fat yield, and from 0.17 to 0.47 for final class score. Differences between methods (PE and TH) were as large as differences between regions for all traits. TH regional estimates were less variable than PE estimates. Changes in sire rankings were trivial when using regional estimates versus using a common variance ratio in each region during evaluation. Rank correlations were 0.98 and higher between evaluations based on heterogeneous regional variances and evaluations based on homogeneous variances. For all three traits, variance ratios that have previously been assumed for national evaluation were more appropriate than estimates obtained in this study. Use of the previously assumed values resulted in a greater consistency, measured by the correlation, between the regional proofs of a sire and between a sire's proof and pedigree index. Key words: Pseudo-expectation, tilde-hat, heterogeneous variances, Holstein, sire evaluation
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Cameron, N. D. "Physiological responses to selection for carcass lean content in a terminal sire breed of sheep." Proceedings of the British Society of Animal Production (1972) 1991 (March 1991): 25. http://dx.doi.org/10.1017/s0308229600019772.
Повний текст джерелаАнотація:
Sheep breeding programmes for genetic improvement in carcass composition of terminal sires measure livewelght and ultrasonic backfat and muscle depths for inclusion in a selection index to predict genetic merit. Physiological traits which were genetically correlated with carcass traits could be incorporated into the selection index to increase the accuracy of selection and the rate of genetic improvement.This study examined differences in physiological traits between lines selected for high or low carcass lean content. The measured physiological traits were chosen according to their role in protein and lipid metabolism : b-hydroxybutyrate (BHB) and glucose (GLUC) : indicators of energy balance; triglyceride (TRIG) and non-esterified fatty acids (NEFA) : intermediaries of lipid metabolism; UREA and creatinine (CREA) : indicators of nitrogen / amino acid metabolism and insulin-like growth factor-1 (IGF-1): an Indicator of growth hormone status.
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McAnally, Brooke E., Molly S. Smith, Jeffrey G. Wiegert, Vignesh Palanisamy, Sapna Chitlapilly Dass, and Rebecca K. Poole. "27 Bacterial Community Diversity in Fresh Extended Boar Semen." Journal of Animal Science 101, Supplement_1 (May 1, 2023): 23–24. http://dx.doi.org/10.1093/jas/skad068.026.
Повний текст джерелаАнотація:
Abstract Status of bacterial diversity within the male seminal microbiome has previously been linked to fertility status in mammals. However, minimal research has focused on the reproductive microbiome in boar semen. The objective of this study was to analyze the diversity of bacterial communities within fresh extended boar semen samples 1) between studs, 2) over 5 consecutive days, and 3) between pooled and single-sire doses. Eight single-sire (n = 4 per stud) and eight pooled (n = 4 per stud) fresh extended semen doses (80 mL) were obtained from two boar studs (A vs. B). Pooled doses were the composite of boars in single-sire doses. Doses were subsampled (16 mL) for 5 days post-collection. Negative controls remained unopened until the last day. Each day, 5 mL of each subsample were flash frozen and stored at -80°C for bacterial analysis targeting the V4 hypervariable region of the 16S rRNA gene for Illumina sequencing. Quality of all sequences was determined by FastQC before being processed for taxonomic analysis using the qiime2 pipeline. Alpha diversity (difference within sample metric) was analyzed using Kruskal-Wallis test, whereas PERMANOVA was performed for beta diversity analysis (differences between sample metric). According to alpha diversity metrics, Chao1 (P < 0.01) and Shannon’s index (P < 0.01) indicated contrasts in diversity among all days and the negative controls. This was further confirmed with a pairwise comparison between individual groups, in which day 1 exhibited lower alpha diversity when compared with days 2, 3, 4, and 5 using Chao1 (P < 0.01) and Shannon’s index (P < 0.01). Interestingly, reduced diversity was observed for day 1 compared with the negative controls with Chao1 (57.4 ± 6.6 vs. 132.4 ± 22.1, P < 0.01, Q < 0.01; respectively) and Shannon’s index (4.8 ± 0.2 vs. 6.1 ± 0.3, P < 0.01, Q < 0.01; respectively). No differences between boar stud or sire-type were detected for alpha diversity metrics. For beta diversity analyses, both PCoA plots and PERMANOVA for weighted unifrac metric demonstrated no significant clustering between sampling days. However, distinctions between all days and negative controls were identified using PERMANOVA for unweighted unifrac metric. Specifically, differences were discovered between day 1 and days 3, 4, and 5 (P < 0.01, Q < 0.01). PERMANOVA for both weighted (P < 0.01) and unweighted (P < 0.01) unifrac metrics revealed distinct clustering by boar stud. However, there were no differences in beta diversity between pooled and single-sire samples for both weighted and unweighted unifrac metrics. Based on these results, bacterial diversity within a semen sample may be altered over time and could occur between boar stud operations. Additional studies analyzing the reproductive microbiome of semen could help improve the characterization of fertility status in boars.
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Goyache, F., L. J. Royo, I. Alvarez, and J. P. Gutierrez. "Testing a continuous variation in preweaning expression of muscular hypertrophy in beef cattle using field data." Archives Animal Breeding 45, no. 2 (October 10, 2002): 139–49. http://dx.doi.org/10.5194/aab-45-139-2002.
Повний текст джерелаАнотація:
Abstract. The hypothesis of a continuous variation in the expression of muscular hypertrophy has been tested using field data. A modification of NEUVY and VISSAC's cularity index method (Culard Index) was assayed. Expression of muscular hypertrophy showed a broad phenotypical variability. Environmental factors affecting expression of muscular hypertrophy characterised by Culard Index were calving season, age of dam, sex of calf, muscularity of dam, muscularity of sire and age of calf at weaning. In addition, Culard Index influences significantly preweaning growth traits confirming double muscled calves’ higher preweaning growth ability. Culard Index score showed moderate heritability. Expression of muscular hypertrophy could be a relatively different trait with respect to latent muscular hypertrophy that would be, in turn, determined by a partially dominant major gene. Culard Index could be an interesting tool to make use of the observable differences in expression of muscular hypertrophy.
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Swanson, G. J. T., and H. Joanne Bellamy. "A comparison between the actual progeny test of Friesian/Holstein bulls and indexes calculated from pedigree information." Animal Production 48, no. 1 (February 1989): 37–41. http://dx.doi.org/10.1017/s0003356100003767.
Повний текст джерелаАнотація:
ABSTRACTTwo pedigree indexes were calculated for 754 Friesian/Holstein bulls born between 1974 and 1980 and tested by the Milk Marketing Board. Correlations between the indexes and the average progeny performance were used to compare the indexes calculated using information from different ancestors. The first index, or estimated predicted difference (EPD) was calculated as one-half the sire progeny test, known as an Improved Contemporary Comparison (ICC), plus one-quarter the maternal grandsire ICC. The second index or estimated ICC (EICC) was calculated from one-half the sire ICC plus one-half the dam cow genetic index (CGI). The correlations between the deregressed bull evaluations (DICC) and EPD, calculated from 310 bulls, were 0·40 for milk yield, 0·40 for fat yield and 0·39 for protein yield. The corresponding correlations between the DICC and EICC, calculated from 314 bulls, were 0·43, 0·40 and 0·41. The regression coefficients for predicting average progeny performance from the EPD index were 1·00 (s.e. 0·13), 0·97 (s.e. 0·12), 0·96 (s.e. 0·13), 1·09 (s.e. 0·12) and 1·08 (s.e. 0·10) for milk, fat and protein yield, fat and protein percentage respectively. Those for predicting progeny performance from the EICC index were 0·95 (s.e. 0·11), 0·81 (s.e. 0·10) and 0·84 (s.e. 0·10) for milk, fat and protein yield respectively. Although the correlations were lower than the expected values of 0·50 (EPD) and 0·55 (EICC) the regressions were near the expected value of 1. The results indicate that the indexes are useful as a preliminary means of selecting bulls prior to progeny testing.
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Maruapey, Azis, Syarif Ohorella, and Sedek Karepesina. "Nilai Kepentingan Budaya Keanekaragamaan Jenis Sayuran Indegenous Dalam Kehidupan Masyarakat di Kampung Sire Distrik Mare Timur Kabupaten Maybrat Papua Barat." Jurnal Agrohut 13, no. 1 (April 30, 2022): 11–24. http://dx.doi.org/10.51135/agh.v13i1.119.
Повний текст джерелаАнотація:
Sayuran indigenous adalah sayuran asli suatu daerah di Indonesia yang berasal dari daerah atau ekosistem tertentu. Sayuran indigenous merupakan salah satu sumberdaya hayati yang kaya manfaat dan memiliki potensi untuk dikembangkan sebagai sayuran alternative. Studi ini menggunakan metode deskriptif dengan telaah informasi dan dokumentasi dari masyarakat. Pengumpulan data dilakukan dengan teknik wawancara terhadap masyarakat melalui Focus Group Disscusion (FGD) dan observasi lapangan. Jenis jenis sayuran indegenous yang penting dalam kehidupan budaya masyarakat di Kampung Sire Distrik Mare Timur Kabupaten Maybrat ditemukan sebanyak 10 (sepuluh) jenis antara lain Melinjo, Rebung, Paku, Pakis, Kecipir, Labu, Buah merah, Jamur, Gohi dan Gedi. Nilai penting sayuran indegenous berdasarkan nilai manfaat tertinggi ada pada jenis Melinjo (1,34), Paku (1,2) dan Gohi (1,2). Ini membuktikan bahwa jenis sayuran indegenous ketiga jenis tersebut sangan bermanfaat bagi kehidpan masyarakat di Kampung Sire sebagai pangan sayuran alternatif. Nilai Kepentingan Budaya (Index of Cultural Significanse / ICS) jenis sayuran indegenous yang teringgi ada pada jenis Melinjo yakni dengan nilai ICS sebesar 96, sehingga dapat dijelaskan bahwa jenis sayuran indegenous Melinjo tersebut memiliki nilai kepentingan budaya yang tinggi dalam hal nilai intensitas dan nilai eklusifitas bagi kehidupan masyarakat di Kampung Sire.
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NEGUSSIE, E., I. STRANDÉN, and E. MÄNTYSAARI. "Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire." Agricultural and Food Science 16, no. 2 (December 4, 2008): 115. http://dx.doi.org/10.2137/145960607782219373.
Повний текст джерелаАнотація:
Clinical mastitis (CM) records from first-lactation Finnish Ayrshire were analysed by linear and threshold models to assess the effects trait definition on estimates of genetic parameters and sire evaluation. The studied CM traits were defined by dividing lactation into six lactation stages (risk periods) by days (d) after calving: CM1 (-7 to 150 d), CM2 (-30 to 30 d), CM3 (-30 to 150 d), CM4 (31 to 150 d), CM5 (150 to 300 d), CM6 (-30 to 300 d). In addition, two data sets were prepared to assess the effect of excluding (Data I) or including (Data II) records of culled cows on estimates of genetic parameters. Sire variances and heritabilities were larger using Data II. When data from longer intervals was used heritabilities of CM were slightly higher than shorter intervals indicating that longer intervals tend to obscure genetic variation between animals. Of all CM traits, heritability of liability to CM with threshold-liability model was highest for CM2 (h2=0.083) implying that most of the genetic information on CM is in early lactation. In sire evaluation, a multitrait index calculated by combining CM2, CM4 and CM5 had the highest correlation with all other univariate CM trait evaluations. This and the magnitude (less than 1.0) of genetic correlations between CM traits suggest that a multitrait model considering CM from the different risk periods would be appropriate for CM sire evaluation.;
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Lewis, R. M., G. Simm, S. V. Murphy, H. E. Browm, and C. C. Warkup. "Consumer panel assessment of eating quality of lamb from the progeny of Suffolk sires with high or low indices for leanness." Proceedings of the British Society of Animal Production (1972) 1993 (March 1993): 27. http://dx.doi.org/10.1017/s0308229600023564.
Повний текст джерелаАнотація:
With links between saturated fat in the diet and health, consumers are increasingly favouring leaner meats. Increases in carcass lean weight and lean percentage can be achieved within breeds through selection. Yet fat may enhance post-slaughter processing and cooking of red meat and thus reductions in fat depots could detract from eating quality.In the UK, selection decisions within terminal sire flocks are increasingly being based on a combination of liveweight and ultrasonic measures of fat and muscle depth. The underlying goal in these programmes is to increase the daily rate of lean tissue growth. In most pedigree flocks in terminal sire breeds ram lambs are reared on a high plane of nutrition. Yet most lambs in the UK are reared in extensive production systems. Thus it is important to know whether differences in performance of rams reared under feeding practices typical in pedigree flocks translate into detectable differences among their crossbred progeny in carcass composition and eating quality characteristics under grass finishing. In this study, the objective was to evaluate whether consumers could detect differences in the appearance and eating quality in shoulder joints from extensively reared crossbred lambs sired by Suffolk rams, with high or low lean growth index scores.
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Nwakalor, L. N., J. S. Brinks, and G. V. Richardson. "SELECTION IN HEREFORD CATTLE I. SELECTION INTENSITY, GENERATION INTERVAL AND INDEXES IN RETROSPECT." Nigerian Journal of Animal Production 8, no. 2 (January 13, 2021): 97–111. http://dx.doi.org/10.51791/njap.v8i2.1929.
Повний текст джерелаАнотація:
Selection intensity and generation interval were evaluated in a Hereford cattle herd of 14 inbred lines and 14 linecross groups corresponding to the lines of inbred sire at the San Juan Basin Research Centre, Hesperus, Colorado. Selection indexes practised were calculated in retrospect. The records analysed were weaning weight and postweaning traits in males and females collected from 1946 through 1973. Analyses were performed by line for the inbreds and pooled analyses for the inbred and linecross populations. From records of 1,239 calves weaned, age of sire averaged 3.75 years compared with 4.52 years for age of dam, showing faster generation turnover for sires than for dams. Generation interval determined 98 actual age of midparent was 4.13 years.Selection applied, evaluated as annual selection differentials within inbred lines and then pooled over all lines, averaged .55 standard deviations per generation for sires for weaning weight. Selection of females was much less. Midparent selection differential amounted to .33 standard deviations per generation. Pooled standardized selection differentials per generation over all lines for sires were .49, .46, 40, -.20, -.10, and .69, respectively, for initial weight, final weight, feed consumption, unadjusted feed efficiency, adjusted feed efficiency, and average daily gain. Selection of females for postweaning traits was not intense. Selection Indexes actually practiced in retrospect were: for sires, IS = .4661(WW) -.0092(FE) + .6126(ADG); for inbred dams, ID = .1824(WW) -.0284 (12W) + .0736 (18W) - 1097 (SPW) -.1097 (FAW); for linecross dams, ID= .2693 (WW) - 2960 (12W) + .0147 (18W) + 1185 (SPW) -.0354 (FAW). The corresponding index selection differentials were .818, 203, and .209. Sire index selection differentials represent about 79 percent of the total selection differentials.
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Uimari, P., and E. A. Mäntysaari. "Repeatability and bias of estimated breeding values for dairy bulls and bull dams calculated from animal model evaluations." Animal Science 57, no. 2 (October 1993): 175–82. http://dx.doi.org/10.1017/s0003356100006772.
Повний текст джерелаАнотація:
AbstractAn animal model and an approximative method for calculating repeatabilities of estimated breeding values are used in Finnish dairy cow evaluation. Changes in estimated breeding values over time as daughters accumulate were studied. Special emphasis was given to the accuracy and potential bias in the pedigree indices of young sires. The data set used was the same as in the national evaluation and the traits investigated were protein yield and somatic cell count. The average repeatability in evaluation of bulls without daughters was 0·37. The empirical repeatability defined as a squared correlation between the pedigree index and the final sire proof was only 0·15. The reduction in the repeatability was attributed to the selection on pedigree index. The upward bias observed in pedigree indices was 5 kg (approx. 0·3 of genetic standard deviation). The bias was caused by the overestimation of bull dams' breeding value. Also the proofs of bull sires increased after the second crop of daughters. The correlation between the evaluations of the same sire calculated from two separate equal size daughter groups was 0·91 when the bull had 10 to 50 daughters and 0·87 with over 100 daughters. This illustrates how the relative weight of the pedigree decreases while more progeny information is accumulated in the evaluation.
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DAWSON, L. E. R., and A. F. CARSON. "Effects of crossbred ewe genotype and ram genotype on lamb carcass characteristics from the lowland sheep flock." Journal of Agricultural Science 139, no. 2 (September 2002): 183–94. http://dx.doi.org/10.1017/s0021859602002368.
Повний текст джерелаАнотація:
A study was carried out on five lowland farms in Northern Ireland over 2 years to investigate the effects of crossbred ewe and ram genotype on lamb carcass characteristics. Four ewe genotypes were sourced from six hill farms – Bluefaced Leicester×Blackface (BLXB), Texel×Blackface (TXB), Suffolk×Cheviot (SXCH) and Texel×Cheviot (TXCH). On each farm groups of 20 to 30 of each crossbred ewe genotype were crossed with Suffolk or Texel sires. Within each of the ram breeds, high lean growth index rams sourced from UK sire reference schemes (SRS) were compared with rams sourced from flocks not involved in objective genetic improvement programmes (control). Throughout the 2 years of the study the ewes lambed at 1 and 2 years of age. Lambs from each of the crosses were slaughtered at 36, 44 and 52 kg live weight. Assessed on a 5-point scale, lambs from BLXB ewes had the poorest conformation classification values (2.8) (P<0.001) compared with 3.0–3.2 (S.E. 0.051) for lambs from the other ewe genotypes. Lambs from TXB, SXCH and TXCH ewes had similar conformation classification values. The differential in conformation classification values between lambs from BLXB ewes and those from the other genotypes was greater when the ewes were crossed with Texel (0.6 units) compared with Suffolk rams (0.3 units) (P<0.05). Differences in conformation between the sire breeds varied according to ewe genotype (P<0.05). When crossed with BLXB ewes there was no difference between Texel and Suffolk-sired lambs in terms of conformation classification values (2.7 v. 2.8 (S.E. 0.07), while with all the other ewe genotypes, Texel-sired lambs had a significantly higher conformation classification than Suffolk-sired lambs (3.5 v. 3.0 when crossed with T×B; 3.2 v. 2.9 when crossed with SXCH; 3.4 v. 3.0 when crossed with TXCH (S.E. 0.07)). Sire reference scheme-sired lambs had greater growth rates from birth to slaughter (203 g/day) compared with control-sired lambs (193 g/day) (S.E. 3.7 days) (P<0.05) and were of an improved conformation classification (3.1 v. 3.0 (S.E. 0.04)) (P<0.01). There was a significant interaction (P<0.01) between ram breed and ram source on lipid content of the carcass. Within the Suffolk-sired lambs, there was no significant difference between SRS-sired lambs (197 g/kg) and control-sired lambs (190 g/kg) (S.E. 6.2 g/kg). However, within the Texel-sired lambs, SRS-sired lambs had a lower lipid content (174 g/kg) than control-sired lambs (204 g/kg) (S.E. 6.2 g/kg) (P<0.01).
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Simm, G., and W. S. Dingwall. "A selection index for lean meat production in sheep." Proceedings of the British Society of Animal Production (1972) 1987 (March 1993): 59. http://dx.doi.org/10.1017/s0308229600034954.
Повний текст джерелаАнотація:
It is generally accepted that leanness of terminal sire sheep breeds should be increased. However, it is very difficult to define formally a selection goal for these breeds. Put loosely, at a given age, we probably require terminal sires with as much extra lean meat as possible, whilst minimising any increase in fat weight. In the past, selection has been mainly on weight for age, but this may actually increase fatness at the age of selection.Intuitively we expect some in vivo measurements of carcass composition to help in achieving the selection goal. In practice, in vivo measurements of carcass composition in sheep are often imprecise, though the treatment of the animals can affect the relative precision. Ad libitum feeding on a high energy, high protein feed appears to increase the variation in carcass composition of ram lambs compared to those on a lower plane of nutrition (Simm et al, 1985 compared to Cuthbertson et al, 1983). Under these conditions we were able to predict carcass composition reasonably precisely from live weight and ultrasonic measurements (means and original and residual s.d.s for carcass lean weight: 18.30, 1.60 and l.00 kg and for fat weight 13.74, 2.70 and 0.96 kg).
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Li, L., P. M. Gurman, A. A. Swan, and D. J. Brown. "Single-step genomic evaluation of lambing ease in Australian terminal sire breed sheep." Animal Production Science 61, no. 18 (2021): 1990. http://dx.doi.org/10.1071/an21257.
Повний текст джерелаАнотація:
Context Australian sheep breeding values (ASBVs) for the categorical trait of lambing ease are routinely estimated by Sheep Genetics via a threshold model. This has been pedigree-only, and has not utilised genomic information. Aim The present study aimed to update the genetic evaluation model and parameters for lambing ease for terminal sire sheep (dominated by White Suffolk and Poll Dorset breeds). The model includes correlations with birthweight and gestation length. Cross-validation was used to determine the value of the improved models and the inclusion of genomic information. Methods New data-preparation pipelines were developed to accommodate improved data-filtering methods and contemporary group construction. Genetic parameters, including correlations among traits, were estimated using continuous and threshold models, with various combinations of effects in mixed animal models. Cross-validation of breeding values was performed against progeny performance, by using forward prediction. Key results The increased volume of data, improved data preparation steps and enhanced evaluation software now allow a more complex model to be fitted, including maternal, sire by flock-year and genetic group effects, which were significant for all traits, along with the inclusion of multiple sire groups in the pedigree. However, the inclusion of the direct-maternal covariance and sire by flock-year terms resulted in unrealistically inflated estimates of some components, and thus the final covariance matrices required some adjustments. Cross-validation of breeding values was performed against progeny performance using forward prediction. For all traits, the phenotype accuracies and estimated breeding value correlations were higher from the new model without genomics than were those from the current routine evaluation. The benefit from including genomic information based on cross-validation is minimal currently but is expected to improve as the size of the reference population grows. Further work is required to define acceptable data-quality thresholds for the construction of datasets for routine breeding value estimation. Conclusions The new model and parameters resulted in ASBVs with an improved predictive ability, with increased accuracy and reduced bias compared with the current analysis. Furthermore, a small increase in accuracy was observed for all traits from utilising genomic information in the model. Implications The new genetic evaluation procedures and models will be used to update those being applied in the routine Sheep Genetics evaluation system and also support further index development for the terminal sire breeds in Australia.
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Swanson, Rebecca M., Riley D. Messman, and Caleb O. Lemley. "72 Seminal Plasma Uterine Priming Reduces Offspring Growth and Alters Uterine Artery Indices of Vascular Resistance in Embryo-Recipient Beef Cows." Journal of Animal Science 101, Supplement_1 (May 1, 2023): 59–60. http://dx.doi.org/10.1093/jas/skad068.070.
Повний текст джерелаАнотація:
Abstract Uterine priming with seminal plasma has been shown to alter endometrial gene expression as well as uterine cytokines and chemokines. However, the effects of seminal plasma uterine priming on uterine blood flow, fetal and postnatal offspring growth performance have yet to be elucidated. Therefore, we investigated the effects of pooled seminal plasma uterine priming at estrus on embryo crown-rump length, uterine blood flow, and birth weights. Commercial cows (n = 65) were synchronized, evaluated for standing estrus (day 0), and randomly assigned to treatment groups: seminal plasma or control. Seminal plasma treated cows (n = 27) received 0.5 mL of pooled seminal plasma from commercial bulls mismatched from embryo sire placed in their uterine body via artificial insemination rod2 hours after estrus detection (day 0). Control cows (n = 27) were passed through the chute without receiving treatment. On day 7, cows underwent non-surgical embryo transfer and were confirmed pregnant on day 35 via ultrasonography. Final treatment numbers were n = 9 seminal plasma and n = 7 control. On days 35, 40, and 45 embryo crown-rump length was measured via transrectal ultrasonography. On days 140, 180, 200 and 220, uterine artery hemodynamics were measured via Doppler ultrasonography. Birth weights were collected within 24 hours of birth. Data collected over time were analyzed using repeated measures of ANOVA with fixed effects of treatment, day, and their respective interaction. Birth weights and gestation length were analyzed using ANOVA. Embryo sire and dam, side of pregnancy, and fetal sex were included as covariates if P < 0.10. Covariance structure was selected based on lowest AIC and BIC. Embryo crown-rump length was decreased (P = 0.0483) among seminal plasma treated cows compared with controls. Embryo crown-rump length increased (P < 0.0001) by day. Total uterine blood flow increased (P < 0.0001) as gestation proceeded. Ipsilateral resistance index was increased (P = 0.0431) among seminal plasma treated cows compared with controls. Ipsilateral resistance index was increased (P = 0.0107) on day 180 of gestation compared with days 200 and 220 of gestation. Ipsilateral pulsatility index was decreased (P < 0.0001) on day 220 of gestation compared with days 140 and 180 of gestation. Contralateral blood flow was decreased (P = 0.0037) on day 140 of gestation compared with days 180, 200, and 220 of gestation. There were no differences in contralateral uterine artery blood flow, resistance index, or pulsatility index, or gestation length between treatment groups. Birth weights were decreased (P = 0.0102) among calves from seminal plasma treated cows compared with calves from control cows. In summary, seminal plasma uterine priming reduced offspring growth while increasing uterine artery resistance index, which indicates uterine vascular bed anomalies that persisted into the third trimester of pregnancy.
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Simm, G., M. J. Young, and P. R. Beatson. "An economic selection index for lean meat production in New Zealand sheep." Animal Science 45, no. 3 (December 1987): 465–75. http://dx.doi.org/10.1017/s0003356100002956.
Повний текст джерелаАнотація:
ABSTRACTAn economic selection index was derived for terminal sire sheep breeds or strains, using physical and financial results from New Zealand export lamb-producing flocks. The aggregate breeding value of the index comprised carcass lean weight and carcass total fat weight. Index measurements were live weight, ultrasonic fat depth and ultrasonic muscle depth. Economic values used for lean and fat weights (NZ$5·65 and NZ$–1·2 per kg, respectively) were the change in profit per kg increase in lean or fat weight from that in the average carcass of lambs slaughtered in 1984/85. The s.d. of the aggregate breeding value was NZS3·20, and the correlation between the full index and the aggregate breeding value was 0·23. This correlation fell to 0·18, 0·15 and 0·07, respectively, when muscle depth or fat depth or muscle and fat depths were omitted from the index. Selection on the full index, or on the index omitting muscle depth was expected to lead to an increase in carcass lean weight and a slight decrease in carcass fat weight. Selection on the index omitting fat depth, or selection on live weight alone, was expected to lead to an increase in both fat and lean weights.
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Duthie, C., R. Sawalha, E. Navajas, R. Roehe, and T. Roughsedge. "Economic response that can be achieved from including genomic information to the terminal sire index of beef cattle." Advances in Animal Biosciences 1, no. 1 (April 2010): 218. http://dx.doi.org/10.1017/s2040470010003614.
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Gibson, J. P., N. Graham, and E. B. Burnside. "Selection indexes for production traits of Canadian dairy sires." Canadian Journal of Animal Science 72, no. 3 (September 1, 1992): 477–91. http://dx.doi.org/10.4141/cjas92-060.
Повний текст джерелаАнотація:
It would be of benefit to the dairy industry to have sires evaluated for the net economic value of their genetic potential for milk-production traits. Economic weights and selection indexes were derived for a variety of production circumstances, taking into account all returns and costs of dairy production and allowing for the existence of quotas. A single index designed for the average farmer in Ontario under a multiple-component pricing system was highly efficient (>98% of maximum gains) for most situations. Changes in pricing of milk caused the largest changes in the index. An index based on the current volume payment with fat correction would cause a 24% loss in efficiency of selection if protein eventually becomes twice the price of fat. A single index was proposed as highly efficient for farmers across Canada irrespective of their production circumstances, provided payment for milk is based on a multiple-component pricing system giving roughly equal value to fat and protein and low value to milk volume. Key words: Selection indexes, economics, milk production, sire selection
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Amin, A. A., T. Gere, and W. H. Kishk. "Additive genetic variance and covariance in some reproduetive disorders in Hungarian Holstein Friesian using multi-trait animal model." Archives Animal Breeding 43, no. 6 (October 10, 2000): 573–82. http://dx.doi.org/10.5194/aab-43-573-2000.
Повний текст джерелаАнотація:
Abstract. Relationships between some reproduetive disorders in the first 3 lactations of Holstein Friesian cows were investigated for 1886 lactation records. Multiple-trait maximum likelihood procedure which included sire cow within sire as random effect and herd, parity, month and year of calving as fixed effects was used to estimate heritabilities and repeatabilities for the studied traits. Abortion within 60 days, retained placenta, ovarian cysts calving difficulty, dystocia, mastitis, and calving type were coded as 0 and 1 for heritability and repeatability estimations. Pooled and separate analysis were applied on the first 3 lactations. Abortion within 60 days retained placenta, ovarian cysts, calving difficulty, dystocia, mastitis, abortion no. and calving type had moderate heritability estimates which ranged from 0.15 to 0.24. Low heritability estimates and a weak sire variance component were obtained for milk fever. The most frequent disorder traits were mastitis, milk fever abortion no calving type and calving difficulty (0.37 to 0.72). Up word trend of heritability estimates with advancing order of lactation was observed for mastitis, abortion within 60 days, and abortion no. while heritability estimates for calving type, calving difficulty and dystocia had a back word trend. These results help in determining the suitable age of selection. Additive genetic variances and covariances among the studied traits have indicated reducing incidence rates if selection index procedure used in this filed. Strong negative genetic correlation between milk fever and abortion no. (−0.429) while negative phenotypic correlations between all studied traits were not more than −0.120 which was estimated for calving difficulty and abortion no.
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Toro, M. A., L. Silio, J. Rodrigañez, and M. Teresa Dobao. "Inbreeding and family index selection for prolificacy in pigs." Animal Science 46, no. 1 (February 1988): 79–85. http://dx.doi.org/10.1017/s0003356100003135.
Повний текст джерелаАнотація:
ABSTRACTThe use of family selection indices has been proposed as a promising selection method for increasing prolificacy in pigs. Responses of up to 0-50 pigs per litter per generation are predicted from selection programmes using information from the dam and from relatives (full and half-sibs) of the dam and sire. In order to test this method in populations of finite size, the rates of selection response and the accumulation of inbreeding have been studied by simulation along 10 generations in a selected herd of 10 sires and 100 dams using five different family selection indices (Id, Ifd, Ihd, Ifs, Ihs). Two undesirable features were evident: (a) the standard deviations of indices were lower than those expected; and (b) the increase of inbreeding was up to three times that expected without selection. Both effects increased with the complexity of the family index reducing the rates of selection responses per generation, when a genetic model with dominance was assumed, to values close to 0·20 piglets, similar to those obtained with the basic index (Id). Some results of inbreeding effects on reproductive traits in three strains of an old closed herd of Iberian pigs are also presented. Multiple regression analysis of data from 4657 litters indicated a decrease in the number of live born ranging from 0·14 to 0·35 piglets per 10% increase in dam or litter inbreeding coefficient.
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Keller, D. S., and F. R. Allaire. "Relationships of First Lactation Milk and Type Traits to Cow Survival and a Sire Index for Discounted Total Milk." Journal of Dairy Science 70, no. 10 (October 1987): 2116–26. http://dx.doi.org/10.3168/jds.s0022-0302(87)80262-x.
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Boettcher, P. J., J. C. M. Dekkers, and B. W. Kolstad. "Development of an Udder Health Index for Sire Selection Based on Somatic Cell Score, Udder Conformation, and Milking Speed." Journal of Dairy Science 81, no. 4 (April 1998): 1157–68. http://dx.doi.org/10.3168/jds.s0022-0302(98)75678-4.
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Stas, N. M., M. Ellis, N. S. Grohmann, C. R. Schwab, C. M. Shull, and K. Ewing. "030 Effect of swine sire line and selection index category on wean-to-finish growth performance and carcass characteristics." Journal of Animal Science 95, suppl_2 (March 1, 2017): 14. http://dx.doi.org/10.2527/asasmw.2017.030.
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HOPKINS, D. L., and R. S. HEGARTY. "EFFECT OF SIRE TYPE AND PLANE OF NUTRITION ON LAMB LOIN SHEAR FORCE, MYOFIBRILLAR FRAGMENTATION INDEX AND CALCIUM CONCENTRATION." Journal of Muscle Foods 15, no. 2 (June 2004): 109–20. http://dx.doi.org/10.1111/j.1745-4573.2004.tb00715.x.
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Beard, KT. "Efficiency of index selection for dairy cattle using economic weights for major milk constituents." Australian Journal of Agricultural Research 39, no. 2 (1988): 273. http://dx.doi.org/10.1071/ar9880273.
Повний текст джерелаАнотація:
A breeding objective (aggregate genotype) for dairy cattle based on returns, net of feed costs, from yield of fat, protein and carrier (the non-fat, non-protein component of the milk) was developed. Returns were estimated using a forecast of the future Australian dairy market structure, and feed costs were estimated from the metabolizable energy required to produce each of three milk components.The effects of erors in forecasting future conditions on economic weights and efficiency of index selection of sires were examined.Economic weights varied widely when subject to errors in the price of milk components within markets, errors in the export price for milk and errors in feed cost.Selection based on an optimal index of sire expected breeding values for fat, protein and milk was sensitive to low export market prices, high feed costs, high protein price and high carrier price. This index was quite insensitive to variation in prices and costs opposite in sign to those above, to variation in milk prices on the domestic markets, and to variation in the size of quotas on domestic markets.
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Morek-Kopeć, M., and A. Zarnecki. "Genetic evaluation for functional longevity in Polish Simmental cattle." Czech Journal of Animal Science 62, No. 7 (June 17, 2017): 276–86. http://dx.doi.org/10.17221/87/2016-cjas.
Повний текст джерелаАнотація:
The Weibull proportional hazards model was applied for genetic evaluation of functional longevity in Polish Simmentals. Data consisted of production and disposal records for 12 527 Simmental cows, daughters of 294 sires, calving for the first time from 1995 to 2014 in 286 herds. Length of productive life of cows was calculated as number of days from the first calving to culling or censoring. Average length of productive life of 4462 cows with complete (uncensored) survival records was 1198 days (39.3 months); mean censoring time for the remaining 8065 cows was 1093 days (35.8 months). Functional longevity was defined as length of productive life corrected for production. The model included time-independent fixed effect of age at first calving, time-dependent fixed effects of year-season, parity-stage of lactation, annual change in herd size, relative fat yield and protein yield, and random herd-year-season and sire effects. Likelihood ratio tests showed a highly significant impact of all fixed effects on longevity, except for relative fat yield. Estimated sire variance was 0.069, resulting in the equivalent (accounting for censoring level) heritability of 0.09. Standardized relative breeding values (RBV) ranged from 71 to 139 (mean 101.4, SD 9.12). Average reliability of RBVs was 0.47. Moderate heritability supports the possibility of effective selection for functional longevity, which will be included in the total selection index for Polish Simmentals.
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Royal, M. D., E. Wall, and A. P. F. Flint. "The genetic relationship between interval to commencement of luteal activity postpartum and UK national fertility proofs for dairy cattle." Proceedings of the British Society of Animal Science 2003 (2003): 54. http://dx.doi.org/10.1017/s1752756200012138.
Повний текст джерелаАнотація:
The coefficient of genetic variation of fertility traits is of a similar magnitude to that present in production traits, however traditional measurements of fertility have low heritability (h2 < 0.05), and recording is often poor, hindering the identification of genetically superior animals. The effect of sire on daughter fertility has been examined as part of a DEFRA LINK project to produce an UK fertility index. The project is investigating the use of six currently recorded traits to calculate sire genetic merit for fertility: calving interval (CI), interval to first service (DIMFIR), nonreturn rate 56 (NR56), number of services per conception (CINSOBS), milk yield and condition score (Wall et al., 2002). An alternative way to measure fertility is to use endocrine measurements such as interval to commencement of luteal activity postpartum (CLA). This parameter is less influenced by management decisions and has a moderate heritability (0.16; Royal et al., 2002a.) and is measurable early in lactation. Although information on the genetic relationships between CLA and other traits of economic importance have been reported previously (Royal et al., 2002a.; Royal et al, 2002b.) further information would be useful in order to assess the usefulness of incorporating CLA into a future UK breeding programme. The objective of these analyses was therefore to obtain information on the genetic correlation (rA) between lnCLA and the emerging UK national fertility proofs.
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Rahman, Ibadur, Nurliah Nurliah, and Chandrika Eka Larasati. "Efisiensi Teknik Sampling dalam Penentuan Indeks Keanekaragaman Polychaeta di Padang Lamun Pantai Sire, Lombok Utara." Journal of Marine Research 10, no. 2 (May 10, 2021): 291–98. http://dx.doi.org/10.14710/jmr.v10i2.30533.
Повний текст джерелаАнотація:
Padang lamun merupakan salah satu ekosistem yang berperan sebagai tempat tinggal, tempat mencari makan, tempat pembesaran dan daerah pemijahan bagi sejumlah besar biota asosiasinya, termasuk polychaeta. Selain mengambil manfaat dari tumbuhan lamun, polychaeta juga berperan terhadap kesuburan substrat lamun karena kemampuannya dalam menguraikan serasah dan meningkatkan kadar oksigen dalam sedimen melalui aktivitas bioturrbasi. Penelitian ini bertujuan untuk mengetahui indeks keanekaragaman polychaeta di padang lamun Pantai Sire, Lombok Utara menggunakan 2 (dua) teknik sampling yang berbeda. Pengamatan data lamun dilakukan menggunakan kuadran 50x50 cm2, dengan 3 (tiga) transek dimana masing-masing terdapat 10 titik pengamatan. Pengambilan sampel polychaeta dilakukan menggunakan alat Ekman Grab dan PVC sediment corer. Hasil penelitian menunjukkan bahwa terdapat 5 (lima) jenis lamun dan 17 famili polychaeta di perairan padang lamun Pantai Sire, dimana Capitellidae merupakan jenis dengan rerata kelimpahan tertinggi (1.046±32,34 - 1.430±37,82 individu/m2). Hasil uji-t menunjukkan bahwa perbedaan teknik sampling berpengaruh terhadap total kelimpahan polychaeta di padang lamun, dimana teknik sampling menggunakan PVC sediment corer memiliki hasil yang lebih optimal dibandingkan mengunakan Ekman Grab. Hal tersebut menandakan bahwa alat PVC sediment corer lebih efisien digunakan untuk pengambilan sampel polychaeta di lamun karena sesuai dengan karakteristik substrat lamun yang berpasir. Sedangkan alat Ekman Grab lebih baik digunakan pada substrat berlumpur dan pada perairan yang cenderung dalam. Seagrass bed is one of the ecosystems that act as a place to live, foraging for food, rearing and spawning areas for a large number of associated biota, including polychaeta. Apart from taking advantage of seagrass, polychaeta also plays a role in the fertility of seagrass substrate because of its ability to break down litter and increase oxygen levels in the sediment through bioturbation activity. This study aims to determine the diversity index of polychaeta in seagrass bed at Sire Beach, North Lombok using 2 different sampling techniques. Seagrass data observation was carried out using a 50x50 cm2 quadrant, with 3 transects, each of which had 10 observation points. Polychaeta samples were taken using the Ekman Grab and the PVC sediment corer. The results showed that there were 5 specieses of seagrass and 17 families of polychaeta in seagrass of the Sire Beach, where Capitellidae was the species with the highest average abundance (1,046 ± 32.34 - 1,430 ± 37.82 individuals / m2). The t-test result shows that the different sampling techniques have a correlation to the total abundance of polychaeta, where PVC sediment corer has more optimal results than using Ekman Grab. This indicates that the PVC sediment corer is more efficient to use for polychaeta sampling in seagrass because of its suitability to the characteristics of sandy seagrass substrate. Meanwhile, the Ekman Grab is better to use on muddy substrates and in a deep water.