Clinical footscald and footrot in a New Zealand Romney flock: phenotypic and genetic parameters

1988 ◽  
Vol 39 (5) ◽  
pp. 907 ◽  
Author(s):  
TM Skerman ◽  
DL Johnson ◽  
DW Kane ◽  
JN Clarke
Keyword(s):  
New Zealand ◽  
Genetic Parameters ◽  
Birth Date ◽  
Production Traits ◽  
Severity Scale ◽  
Annual Variations ◽  
Birth Rank ◽  
Selection Of

Phenotypic and genetic parameters for clinical footscald and footrot were investigated in a pedigree flock of New Zealand Romney sheep inspected during outbreaks over six years. At inspections, each sheep's overall status with regard to footscald and footrot was summarized on a combined severity scale (Rating). Sheep were also categorized in terms of two binomial variables specifying the presence or absence of footscald or footrot (FI) and the presence or absence of footrot only (FR). A trinomial variable specified no infection, infection limited to footscald, or footrot with or without footscald (FSR), all variables being derived from the Rating value. Notwithstanding marked annual variations in prevalence of FI, F1 prevalence increased with age among ewes, and a higher prevalence of FI among male than female lambs was noted. Birth rank, birth date and dam's age had no significant effect on Rating in lambs. Repeatability of ewe Rating over successive annual inspections was low. Heritabilities of Rating, FI, FR and FSR, estimated by half-sib analyses were 0.14, 0.28, 0.17 and 0.25, respectively. Heritability of Rating estimated from dam-offspring regression was 0.12. Production traits did not appear to be genetically associated with liability to footrot. Selection of the top 5% of progenytested sires for breeding could be expected to reduce the prevalence of FI by approximately 45% per generation.

Use of productive data to predict length of productive life in Iranian Holstein cattle

2005 ◽  
Vol 2005 ◽  
pp. 126-126
Author(s):  
A. Abdolmohammadi ◽  
M. Moradi Shahrebabak ◽  
S. R. M. Ashtiani
Keyword(s):  
Milk Production ◽  
Genetic Parameters ◽  
Selection Index ◽  
Direct Selection ◽  
Holstein Cattle ◽  
Production Traits ◽  
Milk Production Traits ◽  
Direct Evaluation ◽  
Productive Life ◽  
Selection Of

Improvement of longevity by direct selection of sires based on theirs daughters’ longevity measures is impractical because of a low heritability and generation intervals prolonged by waiting until all cows complete their productive life. As an alternative to direct evaluation of sires for longevity is indirect prediction from genetically correlated production traits measures in the first lactation. The objectives this study were 1) to estimate genetic parameters of longevity and production traits 2) to examine relationships between longevity and first lactation milk production traits and 3) to determine selection index for sires’ longevity based on production traits.

scholarly journals Genetic parameters for production traits in New Zealand dual-purpose sheep, with an emphasis on dagginess1

2012 ◽  
Vol 90 (5) ◽  
pp. 1411-1420 ◽  
Author(s):  
N. K. Pickering ◽  
K. G. Dodds ◽  
H. T. Blair ◽  
R. E. Hickson ◽  
P. L. Johnson ◽  
...  
Keyword(s):  
New Zealand ◽  
Genetic Parameters ◽  
Production Traits ◽  
Dual Purpose

scholarly journals Genetic parameters for egg production traits in crosses between local and exotic chickens estimated by Bayesian inference

2021 ◽  
Vol 44 (3) ◽  
pp. 1-8
Author(s):  
I. Udeh ◽  
S. I. Omeje
Keyword(s):  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Breeding Value ◽  
Appreciable Amount ◽  
Production Traits ◽  
Base Population ◽  
Egg Weight ◽  
Highest Posterior Density ◽  
Selection Of

Estimates of genetic parameters for economic traits are important to enable the breeder estimate the breeding value of individuals available for selection. Thus, this study was carried out to estimate genetic parameters namely heritability and genetic correlations among egg production traits in two strain crosses using bivariate animal model in Bayesian (MCMC) method. The egg production data were obtained from four generations which comprised the base population of two commercial egg strains and the local chicken, the inbred population derived from the base population, the F1 crossbred population obtained from the crossing of the local and exotic inbred chickens and the backcross population obtained from the backcrossing of the crossbred to their parents. A total number of 1,138 daughters of 62 sires and 620 dams were used for the study. The autocorrelations among samples in the MCMC chain were less than 0.1 for all lag values indicating that all samples of the posterior distribution were independent. The estimated heritability for age at first egg, body weight at first egg, hen day egg number, weight of first egg, egg weight at thirty week and egg weight at forty week were 0.62, 0.48, 0.47, 0.53, 0.54 and 0.56 for strain 1 crosses and 0.43, 0.48, 0.49, 0.52, 0.52 and 0.53 for strain 2 crosses. The corresponding highest posterior density interval ranged from 0.22 to 0.91 for strain 1 crosses and 0.07 to 0.83 for strain 2 crosses. The genetic correlations among egg production traits ranged from 0.06 to 1.97 in strain 1 and 0.06 to 2.59 in strain 2 crosses. The estimates were within the range reported in literature for egg production traits in chicken and imply that appreciable amount of additive genes exist in the strain crosses which could be used for the selection of superior birds. The magnitude of genetic correlations implies that selection of one trait could lead to correlated response to the other traits.

THE PERFORMANCE OF S170 TALL FESCUE IN CANTERBURY

1974 ◽  
pp. 214-215
Author(s):  
B.R. Watkin
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Tall Fescue ◽  
Trifolium Repens ◽  
Festuca Arundinacea ◽  
Sheep Grazing ◽  
Selection Of

AN Aberystwyth selection of tall fescue (Festuca arundinacea Schreb.), known as S170, was sown with certified New Zealand white clover (Trifolium repens) and re' clover (T. pratense) and compared under sheep grazing with other grass/clover pastures at the Grasslands Division Regional Station at Lincoln (Watkin, 1975) .

Genetic parameters for reproduction and production traits of Landrace sows in Thailand1

2007 ◽  
Vol 85 (1) ◽  
pp. 53-59 ◽  
Author(s):  
N. Imboonta ◽  
L. Rydhmer ◽  
S. Tumwasorn
Keyword(s):  
Genetic Parameters ◽  
Production Traits

scholarly journals Agro-Morphological Characterization and Assessment of Variability in Aromatic Rice Germplasm

2012 ◽  
Vol 37 (1) ◽  
pp. 1-8 ◽  
Author(s):  
M Parikh ◽  
NK Motiramani ◽  
NK Rastogi ◽  
B Sharma
Keyword(s):  
Genetic Parameters ◽  
Agronomic Traits ◽  
Morphological Characterization ◽  
Aromatic Rice ◽  
Spikelet Sterility ◽  
Plant Parts ◽  
Rice Germplasm ◽  
Spikelets Per Panicle ◽  
Plant Habit ◽  
Selection Of

The present studies were carried out to characterize seventy-one aromatic rice germplasm from IGKV, Raipur. These germplasm were characterized and grouped on the basis of anthocyanin pigmentation, plant habit, and awning character. On the basis of pigmentation distribution in 10 plant parts, a total of twelve groups were formed with group one having no pigmentation and group twelve with pigmentation in 9 plant parts. On the basis of plant habit and awning character, three groups of each were formed. The genetic parameters for the ten agronomic traits indicated that the selection of genotypes may be done for fertile spikelets per panicle, spikelet density, spikelet sterility percentage, and hundred seed weight. Thus, on the basis of above characters, the genotypes Tulsi Mala, Baanspati, Ganga Balu, Samund Chini, Tulsi Amrit, Dudh Dhan, Kari Gilas, Shankar Jeera, and Jata Shankar may be selected for future study. DOI: http://dx.doi.org/10.3329/bjar.v37i1.11168 Bangladesh J. Agril. Res. 37(1): 1-8, March 2012

scholarly journals Selection of cotton lines for high oil content

2017 ◽  
Vol 52 (7) ◽  
pp. 530-538 ◽  
Author(s):  
Luiz Paulo de Carvalho ◽  
Josiane Isabela da Silva Rodrigues ◽  
Francisco José Correia Farias
Keyword(s):  
Oil Content ◽  
Genetic Parameters ◽  
Fiber Quality ◽  
Rio Grande ◽  
Field Trials ◽  
The State ◽  
The Other ◽  
Expected Gain ◽  
High Heritability ◽  
Selection Of

Abstract: The objective of this work was to evaluate the oil content and characters related to fiber quality and yield in cotton lines (Gossypium hirsutum), in order to select genotypes with high oil content and acceptable levels of the other characters. Twenty-two F6 lines and three checks were cultivated in three field trials - two in the municipality of Apodi, in the state of Rio Grande do Norte, and one in the municipality of Barbalha, in the state of Ceará, both in Brazil. The genetic parameters and the genetic gain from selecting 20% of the lines were estimated according to their means in each environment and in the group of environments. Regarding oil content, there is genetic variability, and the selection based on the overall mean is indicated, since this character showed high heritability, with 4.58% expected gain. The lines selected with this criterion have oil contents between 23.52 and 24.51%, which are higher than those of the Brazilian cultivar BRS Aroeira with the highest grain oil content (22.04%).

Selection for rate and efficiency of lean gain in Hereford cattle 1. Selection pressure applied and direct responses

1990 ◽  
Vol 51 (1) ◽  
pp. 23-34 ◽  
Author(s):  
R. A. Mrode ◽  
C. Smith ◽  
R. Thompson
Keyword(s):  
Genetic Parameters ◽  
Control Line ◽  
Correlated Responses ◽  
Direct Response ◽  
Lean Growth ◽  
Hereford Cattle ◽  
Frozen Semen ◽  
Phenotypic Standard Deviation ◽  
Selection For ◽  
Selection Of

ABSTRACTSelection of bulls for rate and efficiency of lean gain was studied in a herd of Hereford cattle. There were two selection lines, one selected for lean growth rate (LGR) from birth to 400 days and the other for lean food conversion ratio (LFCR) from 200 to 400 days of age, for a period of 8 years. A control line bred by frozen semen from foundation bulls was also maintained. Generation interval was about 2·4 years and average male selection differentials, per generation were 1·2 and — 1·1 phenotypic standard deviation units for LGR and LFCR respectively.Genetic parameters and responses to selection were estimated from the deviation of the selected lines from a control line and by restricted maximum likelihood (REML) techniques on the same material. Realized heritabilities were 0·40 (s.e. 0·12) for LGR and 0·40 (s.e. 0·13) for LFCR using the control line. Corresponding estimates from REML were 0·42 (s.e. 0·10) and 0·37 (s.e. 0·14). The estimate of the genetic correlation between LGR and LFCR was about — 0·69 (s.e. 0·12) using REML.The estimates of direct annual genetic change using deviations from the control were 3·6 (s.e. 1·3) g/day for LGR and — 0·14 (s.e. 0·07) kg food per kg lean gain for LFCR. Corrsponding estimates from REML were similar but more precisely estimated. The correlated responses for LFCR in the LGR line was higher than the direct response for LFCR.

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