Estimation of Genetic Parameters among Breeding Soundness Examination Components and Growth Traits in Yearling Bulls

Smith, Barbara A.; Brinks, J. S.; Richardson, G. V.

doi:10.2527/jas1989.67112892x

Cited by 44 publications

(57 citation statements)

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“…The Society of Theriogenology has a standard breeding soundness evaluation for beef bulls in which scrotal circumference receives considerable emphasis (Smith et al, 1989). This evaluation provides for observations on bulls at 12 mo of age.…”

Section: Results and Dlscusslonmentioning

confidence: 99%

Effects of 84-, 112- and 140-day postweaning feedlot performance tests for beef bulls.

Brown

Chewning²,

Johnson³

et al. 1991

Journal of Animal Science

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Changes in performance traits in beef cattle over the last 30 yr necessitate the re-evaluation of central testing procedures to ensure that they are cost effective and appropriate for current test objectives. The objective of this study was to evaluate the potential for reducing the length of evaluation from 140 d to either 112 or 84 d. Data evaluated were postweaning feedlot performance test records (collected from 1977 to 1986) on 1,830 individually fed bulls. Bulls representing 13 breeds (n greater than 25 per breed) were evaluated in the University of Arkansas Cooperative Bull Tests at Fayetteville, Hope, and Monticello, Arkansas. Models were fit for ADG, daily feed intake (FI) and feed conversion (FCONV) from d 1 to d 140 (ADG1-140, FI1-140 and FCONV1-140, respectively) and from d 1 to d 112 (ADG1-112, F11-112 and FCONV1-112, respectively). Models fit for ADG1-140, FI1-140, and FCONV1-140 using information up to d 112 had R2 of .90, .99, .88, and .94, respectively, and using information up to d 84 had R2 of .82, .94, and .80, respectively. Spearman rank correlation coefficients (all P less than .0001) were .93 for ADG1-140 and ADG1-112, .93 for ADG1-112 and ADG1-84, .99 for FI1-140 and FI1-112, .91 for FCONV1-140 and FCONV1-112, and .90 for FCONV1-112 and FCONV1-84. These coefficients indicate that bulls ranked similarly for performance traits at 84, 112, and 140 d. If the primary objective of central station testing is to evaluate ADG during the linear phase of growth, and if testing procedures are those currently recommended by the Beef Improvement Federation, then feeding bulls beyond 112 d has no advantage because the information upon which selection decisions are made is similar at both 112 and 140 d.

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Section: Results and Dlscusslonmentioning

confidence: 99%

Effects of 84-, 112- and 140-day postweaning feedlot performance tests for beef bulls.

Brown

Chewning²,

Johnson³

et al. 1991

Journal of Animal Science

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“…Selection of bulls for increased scrotal circumference is considered to be the most rapid method to genetically improve inherent fertility in beef cattle. Scrotal circumference is a moderate to highly heritable trait (Bourdon and Brinks, 1986;Smith et al, 1989a;Kriese et al, 1991) that is easily measured (Lunstra, 1982). Research has shown favorable relationships between scrotal circumference and growth and reproductive traits.…”

Section: Introductionmentioning

confidence: 99%

“…Research has shown favorable relationships between scrotal circumference and growth and reproductive traits. Scrotal circumference has also been shown to be favorably correlated with seminal measures (Neely et al, 1982;Smith et al, 1989a), whereas a negative correlation has been reported between scrotal circumference and age at puberty of both males and females (Brinks et al, 1978;Lunstra, 1982;Smith et al, 1989b). Measures of reproductive performance after puberty are also favorably affected by increased scrotal circumference of sire (Smith et al, 1989b).…”

Section: Introductionmentioning

confidence: 99%

Estimation of variance components and prediction of breeding values for scrotal circumference and weaning weight in Limousin cattle.

Keeton

Green

Golden

et al. 1996

Journal of Animal Science

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Variance and covariance components were estimated for yearling scrotal circumference and weaning weight from Limousin field data. Records of 8.226 bulls were used to evaluate 584 sires and 653 maternal grandsires. Data included all herdbook records of bulls with a recorded scrotal circumference and their weaning contemporaries. Analyses were performed by restricted maximum likelihood techniques employing the expected maximization algorithm and fitting both single- and two-trait models. Scrotal circumference was first fitted in a single-trait, sire model to obtain starting values for variances for a later analysis. Likewise, weaning weight was fitted in a single-trait, sire-maternal grandsire model to obtain priors for (co)variances for a later analysis. Scrotal circumference and weaning weight were then fitted together in a two-trait model to estimate variance components. Estimates of variance components were calculated by equating (co)variances obtained from the models to their expectations. Estimates of heritability of scrotal circumference, direct weaning weight, and maternal weaning weight were .46, .25, and .19, respectively. Estimates of genetic correlations between yearling scrotal circumference and direct weaning weight, scrotal circumference and maternal weaning weight, and direct weaning weight and maternal weaning weight were .14, -.22, and -.44, respectively. The estimate of the environmental correlation between scrotal circumference and weaning weight was .61. Genetic parameters obtained were then used in two-trait, reduced animal mixed-model equations for a maternally influenced trait to predict breeding values for animals.

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“…The value and sign of the correlation found at present study were similar to those previously found in pigs by Smith et al (1989). However, as in other previous research, genetic correlations in which seminal traits are involved showed high standard errors due to the low heritability estimates of those traits and the relatively small number of records.…”

Section: Correlations Between Dg and Semen Traitssupporting

confidence: 91%

“…With regard to the latter, some authors have predicted that bulls genetically superior for growth would be expected to sire sons with testicles of larger circumference and with the ability to produce larger quantities of semen (Knights et al, 1984, Smith et al, 1989. This finding is due to the fact that large testicles produce more testosterone that implies higher accessory glands which in turn could produce more seminal plasma.…”

Section: Discussionmentioning

confidence: 99%

Genetics of fresh and frozen-thawed semen traits and their relationship with growth rate in rabbits

García¹

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The general aim of this thesis was to study the genetic determinism for some traits related to artificial insemination (AI) dose production of fresh and frozenthawed semen, in order to explore the interest and limitation of different strategies for their genetic improvement in a paternal line of rabbits selected for growth rate during the fattening period (28-63 days).In chapter 1, genetic parameters of sperm production traits are estimated as well as the genetic relationship with daily gain (DG). The heritabilities (h 2 ) of the semen traits were 0.13±0.05, 0.08±0.04 and 0.07±0.03 for ejaculate volume (V), sperm concentration (CN) and sperm production (PROD) per ejaculate, respectively. A favourable and moderate genetic correlation was observed between V and DG (0.36±0.34). From this chapter it may be concluded that if a seminal trait is to be included as a selection objective, a useful one could be sperm production, as it is a trait in which both volume and concentration are included.Moreover, there is currently no evidence to suggest that selection for DG in rabbits will affect sperm production adversely.The aim of chapter 2 was to explore the genetic determinism of some sperm quality traits and their genetic relation with the selection criteria of the paternal rabbit line. The heritabilities (h 2 ) of semen quality traits commonly evaluated in a classic spermiogram were 0.18, 0.19 and 0.12 for NAR (%, percentage of sperm with intact acrosome), ANR (%, percentage of sperm abnormalities) and MOT (%, percentage of total motile sperm cells) respectively. We also estimated the h 2 of some motion CASA parameters 0.09, 0.11, 0.10, 0.11, 0.11 and 0.11 for VAP (µm/s; average path velocity), VSL (µm/s; straight-line velocity), VCL (µm/s; curvilinear velocity), LIN (%, linearity index), ALH (µm; amplitude of the lateral head displacement), STR (%, straightness). Genetic correlations between DG and semen traits showed a high HPD95% (interval of highest density of 95%).However there is some consistent evidence of the negativity of the genetic correlations of DG with NAR and MOT (-0.40 and -0.53, respectively).Chapter 3 aims to determine the repeatability and heritability of sperm head characteristics: width (W, μm), area (A, μm2),length (L, μm) and perimeter (P, μm), and explore the relationships between them and with the selection The environmental and male effects that could have an influence on sperm freezability are studied in Chapter 4. Six different traits were evaluated: sperm concentration (CONC, 10 6 spermatozoa/mL), acrosome integrity in fresh (NAR, %) and frozen-thawed semen (Nar-FT, %), sperm motility in fresh (MOT, %) and frozen-thawed semen (Mot-FT, %) and the percentage of viable sperm in frozen-thawed semen (Live-FT, %). In addition, two synthetic traits were computed: the relative reduction of acrosome integrity (Rnar, %) and relative reduction of motility (Rmot, %) after the freezing-thawing process. A multipletrait recursive model was used to analyse the relationships between the semen traits...

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Estimation of Genetic Parameters among Breeding Soundness Examination Components and Growth Traits in Yearling Bulls

Cited by 44 publications

References 0 publications

Effects of 84-, 112- and 140-day postweaning feedlot performance tests for beef bulls.

Effects of 84-, 112- and 140-day postweaning feedlot performance tests for beef bulls.

Estimation of variance components and prediction of breeding values for scrotal circumference and weaning weight in Limousin cattle.

Genetics of fresh and frozen-thawed semen traits and their relationship with growth rate in rabbits

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