Pedigree analysis of selected lines of Merino sheep. 1. Inbreeding

2002 ◽  
Vol 53 (7) ◽  
pp. 771
Author(s):  
E. Safari ◽  
J. W. James
Keyword(s):  
Confidence Interval ◽  
Agricultural Research ◽  
Pedigree Analysis ◽  
Early Years ◽  
Research Centre ◽  
Mass Selection ◽  
Pedigree Data ◽  
Selected Lines ◽  
Merino Sheep ◽  
Inbreeding Coefficients

Four pairs of selection lines of Merino sheep consisting of 100 ewes and 5 rams were established at the Trangie Agricultural Research Centre in 1951. Each line was selected (mass selection) for the appropriate character and direction (Plus or Minus) for a period of 18 years (5 generations). The characters subjected to selection were clean fleece weight, crimp frequency, weaning weight, and skin folds. The average inbreeding coefficients calculated from the pedigree data of the those selected lines ranged from 3.79% in the Fleece Plus line to 9.09% in the Folds Plus line, corresponding to average annual inbreeding rates of 0.211% and 0.505%, respectively. Generally, there were similar fluctuating patterns in the means of inbreeding coefficients across years, with higher variation in the early years, and different rates of inbreeding in different flocks. The only exception was the Fleece Plus flock with a trend to increased variation across years, higher fluctuations in average inbreeding coefficient in final years, and inbreeding, which was not located in the 95% confidence interval of the inbreeding in flocks simulated for an infinitesimal model. Although the Folds Plus line showed inbreeding within the 95% confidence interval of simulation inbreeding, it was located at the higher end of the confidence interval, due to natural selection. Excellent agreement was found between the simulated flocks inbreeding (6.54%) and predicted inbreeding from an adaptation of the formula of JA Woolliams, NR Wray, and R Thompson (1993) (6.44%).

Pedigree analysis of selected lines of Merino sheep. 2. Gene contributions

2002 ◽  
Vol 53 (8) ◽  
pp. 955
Author(s):  
E. Safari ◽  
J. W. James
Keyword(s):  
Agricultural Research ◽  
Pedigree Analysis ◽  
Consistent Pattern ◽  
Research Centre ◽  
Mass Selection ◽  
Selected Lines ◽  
Male And Female ◽  
Merino Sheep ◽  
Coefficients Of Variation ◽  
Standard Deviations

Four pairs of selection lines of Merino sheep consisting of 100 ewes and 5 rams were established at the Trangie Agricultural Research centre in 1951. Each line was selected (mass selection) for the appropriate character and direction (Plus or Minus) for a period of 18 years (5 generations). Pedigree analysis of these selected lines in terms of gene contributions revealed different patterns in means and standard deviations of gene contributions of male and female founders. Female founders showed a consistent pattern in all of the selected lines, with an increasing trend for the first 5-6 years in both parameters, and then stabilised. Fleece Plus showed the smallest variation, with an average coefficient of variation of 163%, whereas Folds Plus showed the highest variation with 213%. In the mean contributions, male founders showed a declining pattern for the first 5-6 years and finally stabilised. In the standard deviations, Weight and Folds flocks showed an increasing pattern in the first 1-2 years, whereas Fleece and Crimp flocks showed a declining pattern for the first 3-6 years before stabilising. Male founders showed smaller variation in mean contribution than female founders. In the Weight and Folds flocks, coefficients of variation were in the range of 55-88%, whereas in the Fleece and Crimp flocks they ranged from 98% to 156%. On average, 71% of genes were contributed by female founders and 29% by male founders. A good agreement (>90%) was found between observed and estimated inbreeding from Wray and Thompson (1990) expression in all flocks except Weight Plus and Fleece Minus lines. Effective numbers of male, female, and both male and female founders showed a consistent pattern of early fluctuation, with a trend towards increasing, and eventually stabilised in all the lines. Fleece Plus and Folds Plus lines showed the smallest and highest effective numbers for male, female, and both male and female founders, respectively, which is consistent with the pattern of observed inbreeding. During the first and second year there was a major reduction in the effective number of female founders, which is an indication of marked decrease in the genetic variability at the beginning.

Fleece rot in Merino sheep. 1. The heritability of fleece rot in unselected flocks of medium-wool Peppin Merinos

1984 ◽  
Vol 35 (3) ◽  
pp. 423 ◽  
Author(s):  
BJ McGuirk ◽  
KD Atkins
Keyword(s):  
Agricultural Research ◽  
Heritability Estimate ◽  
Visual Assessment ◽  
Research Centre ◽  
Data Sets ◽  
Data Set ◽  
Merino Sheep ◽  
Two Measures ◽  
Heritability Estimates ◽  
Birth Type

Fleece rot was observed on hogget ewes and rams in unselected medium-wool Peppin Merino flocks over a 15-year period at Trangie Agricultural Research Centre, N.S.W. Each sheep was given a score of from 0 (no fleece rot) to 5 (very severe fleece rot) following a subjective visual assessment along the backline prior to shearing. Data were analysed as two measures of susceptibility to fleece rot: a score as defined above; and incidence, where fleece rot was treated as an all-or-none trait. The average incidence of fleece rot over 23 flock x year combinations was 36%, but this varied widely, from 8 to 90%. Other environmental factors (sex, birth type and age of dam) generally had small and non-significant effects on fleece rot. After adjusting for significant environmental effects, the half-sib heritability estimates for sires:with at least three progeny were 0.36 (�0.07) for score and 0.23 (�0.07) for incidence. Separate anaiyses were conducted for flock x year data sets of low, intermediate and high incidences. The highest heritability estimate for incidence was, as expectedly theoretically, obtained in the data set of intermediate incidence. Offspring-dam heritability estimates ( � s.e.) for fleece rot score and incidence were respectively 0.21 (� 0 0 5 ) and 0.14(�0.04). Corresponding offspring-sire estimates for score and incidence were 0.20 (�0.06) and 0.17 (�0.05). It is concluded that a realistic estimate of the heritability of the underlying liability to fleece rat is of the order of 40%.

Genetic evaluation of production traits between and within flocks of Merino sheep. II. Component traits of the Hogget fleece

1993 ◽  
Vol 44 (7) ◽  
pp. 1523 ◽  
Author(s):  
SI Mortimer ◽  
KD Atkins
Keyword(s):  
Agricultural Research ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Matter Content ◽  
Research Centre ◽  
Production Traits ◽  
Merino Sheep ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight

Components of the fleece and wool quality traits were measured or assessed on Merino hogget ewes in an unselected multiple-bloodline flock over a 7-year period at Trangie Agricultural Research Centre, N.S.W. The traits recorded were face cover score (FC), leg cover score (LC), neck fold score (NF), body fold score (BF), wax content (W), suint content (S), vegetable matter content (VM), dust penetration (D), follicle density (N) and follicle ratio (RA). Genetic differences within and between flocks of Merino sheep were examined for the traits, and estimates of heritability and within-flock genetic and phenotypic correlations and between-flock genetic correlations among the traits were obtained. Genetic and phenotypic correlations were also estimated between these traits and the major wool production traits: greasy fleece weight (GFW), clean fleece weight (CFW), fibre diameter (FD), body weight (BWT) and staple length (SL). Significant strain. flock within strain and flock effects were wresent for all traits. The influence of environmental effects (birth-rearing type, age at measurement and age of dam) on the traits was estimated, with the birth-rearing type being significant and the largest effect for most traits. Paternal half-sib heritability estimates were 0.44� 0.06 for FC, 0.35� 0.06 for LC, 0.24�0.05 for NF, 0.23�0.05 for BF, 0.38�0.07 for W, 0.42�0.07 for S, 0.06�0.04 for VM, 0.22�0.06 for D, 0.20� 0.07 for N and 0.21�0.07 for RA. Estimates of within-flock phenotypic and genetic correlations were in broad agreement with available published estimates. The implications of the results for Merino breeding programs are discussed.

AC Saltlander green wheatgrass

2006 ◽  
Vol 86 (4) ◽  
pp. 1161-1164 ◽  
Author(s):  
H. Steppuhn ◽  
P. G. Jefferson ◽  
A. D. Iwaasa ◽  
J. G. McLeod
Keyword(s):  
Seed Set ◽  
Root Zone ◽  
Agricultural Research ◽  
Plant Morphology ◽  
Research Centre ◽  
Mass Selection ◽  
United States Department ◽  
Collaborative Project ◽  
Agricultural Research Service ◽  
Tolerance Testing

AC Saltlander originated from seeds collected in Turkey by United States Department of Agricultural (USDA) scientists. Plants from these seeds were grown in a nursery near Logan, UT, where researchers at the USDA Forage and Range Research Laboratory selected desirable parents to obtain caespitose growth. In a collaborative project, selected germplasm of this natural hybrid was made available to the Semiarid Prairie Agricultural Research Centre (SPARC), Agriculture and Agri-Food Canada (AAFC) for salt-tolerance testing and improvement. A series of mass selection breeding cycles was conducted at Swift Current, where the resulting plants were evaluated for resistence to root-zone salinity, winter hardiness, and desirable plant morphology, including uniform plant colour, vegetative vigour, leafiness, seed-set, and freedom from plant pests. The progenies from each cycle were cloned, half of which were transported to the Agricultural Research Service Laboratory in Utah, and half intercrossed to develop AC Saltlander, a palatable forage with salinity tolerance equal to that of tall wheatgrass [Thinopyrum ponticum (Podp.) Lui & Wang]. Key words: Green wheatgrass, salt-tolerant forage, salinity, Elymus hoffmannii, perennial forage, reclamation grass

Genetic Variability of Bharat Merino Sheep Derived from Pedigree Information

2020 ◽  
Author(s):  
P. K. Mallick ◽  
I. Chauhan ◽  
S. M.K. Thirumaran ◽  
R. Pourouchttamane ◽  
Arun Kumar
Keyword(s):  
Genetic Diversity ◽  
Body Weight ◽  
Genetic Variability ◽  
Pedigree Analysis ◽  
Inbreeding Coefficient ◽  
Production Performance ◽  
Effective Number ◽  
Pedigree Data ◽  
Breeding Values ◽  
Merino Sheep

Background: The genetic variability in a population is the raw material for selection, because the estimation of genetic parameters depends on the variability present within the population. The pedigree analysis is a method to assess population genetic variability. An increase in the level of inbreeding disturbs the production performance of the animals. Hence, it is essential to assess the effect of inbreeding on production performance of the animals at regular intervals. The present study was conducted on data of Bharat Merino (BM) sheep with twin objectives of evaluating the population structure by pedigree analysis and possible effect of inbreeding on lamb growth and heritability estimates. Methods: The study was conducted on data consisting of a total of 9688 pedigree records of BM sheep born from 1975 to 2018 (43 years), out of which 9050 formed population reference (with both the parents known). ENDOG ver 4.8 program was used to generate different measures of genetic diversity. General Linear Model of SPSS 25.0 was used to ascertain the effect of inbreeding (Fi) or change in inbreeding (ÄFi) on the lamb live weights. Using animal model with software WOMBAT, single trait linear mixed model analyses were performed. The heritability estimates and breeding values were obtained by including or excluding the inbreeding coefficient in the model to observe how the estimates of heritability varied with inclusion or exclusion of the inbreeding coefficient. Result: Effective number of founders (fe) was 56, constituting 11.39% founders in the population reference, while the effective number of ancestors (fa) was 43.The genetic contribution of the 15 most influent ancestors explained 50% of the genetic variability in the dataset. The ratio fe/fa, representing the effect of population bottleneck, was 1.302. The average inbreeding coefficients for the whole pedigree was 2.36%, while it was 3.84% for inbred animals. It was found that the inbreeding coefficient (Fi) increased with the addition of each generation to the pedigree. The average relatedness coefficient was 4.53% between members of the population.The effect of individual inbreeding (Fi) or the change in inbreeding (DFi) was not significant on the lamb live weights, except the effect of individual inbreeding (Fi) on three-month body weight and average daily gain (0-3month) and of change in inbreeding (DFi) on three-month body weight. From the analysis of the pedigree data of Bharat Merino sheep, it was found that the most of the measures of genetic diversity were within acceptable limits and the pedigree data was reasonably well maintained. When inbreeding was accounted for in the model, there were reductions in h2 estimates as well as the estimates of breeding values for both 3WT and ADG1 and consequently there were changes in ranking of animals for both 3WT and ADG1.

Genetic evaluation of production traits between and within flocks of Merino sheep. I. Hogget fleece weights, body weight and wool quality

1989 ◽  
Vol 40 (2) ◽  
pp. 433 ◽  
Author(s):  
SI Mortimer ◽  
KD Atkins
Keyword(s):  
Body Weight ◽  
Environmental Effects ◽  
Genetic Variance ◽  
Research Centre ◽  
Production Traits ◽  
Merino Sheep ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight

Wool production traits were measured on Merino hogget ewes in an unselected multiple-bloodline flock over a 7-year period at Trangie Agricultural Research Centre, N.S.W. The traits measured were greasy fleece weight (GFW), skirted fleece weight (SKFW), yield (Y), clean fleece weight (CFW), fibre diameter (FD), body weight (BWT) and staple length (SL). These measurements were used to examine genetic differences between and within flocks of Merino sheep, and to estimate heritability of and genetic and phenotypic correlations among these traits. Significant strain, flock within strain and flock effects were present for all traits. Interactions between these effects and year were non-significant. Within-flock genetic variance was always larger than between-flock within strain genetic variance for each trait. The influence of environmental effects on these traits was also examined. The environmental effects of birth-rearing type, age at observation and age of dam together accounted for about 7-10% of the total within-flock variation in fleece weights and body weight.After adjusting for significant environmental effects, paternal half-sib heritability estimates were 0.29 �. 0.06 for GFW, 0.22 � 0.05 for SKFW, 0.35 � 0.05 for Y, 0.30 �0.06 for CFW, 0.48 �0.07 for FD, 0.34 �. 0.06 for BWT and 0.44 �0.07 for SL. Estimates for genetic and phenotypic correlations were in agreement with published estimates except for the genetic correlation between CFW and FD (0.40 �. 0.11), and the genetic correlations involving BWT, which were essentially zero. The implications of the results of this study for the genetic improvement of Merino sheep for wool production are discussed.

Effect of foliar application of chelated copper and manganese on yield components and fibre properties of Egyptian cotton (Gossypium barbadense)

1993 ◽  
Vol 121 (2) ◽  
pp. 193-198 ◽  
Author(s):  
Z. M. Sawan ◽  
M. H. Mahmoud ◽  
B. R. Gregg
Keyword(s):  
Yield Components ◽  
Agricultural Research ◽  
Foliar Application ◽  
Field Studies ◽  
Gossypium Barbadense ◽  
Research Centre ◽  
Fibre Properties ◽  
Foliar Sprays ◽  
Egyptian Cotton ◽  
Cotton Cultivar

SUMMARYA decline in supplies of organic manures and the increased use of chemical fertilizers has led to a decrease in the micronutrient content of the soil, with attendant effects on yield.Field studies were conducted in 1986 and 1987 at the Giza Agricultural Research Centre, Egypt, to determine the effect of Cu-EDTA and Mn-EDTA foliar sprays on growth, mineral content, yield components and fibre properties of the Egyptian cotton cultivar Giza 75 (Gossypium barbadense L.).All combinations used significantly increased the uptake of Cu and Mn and the dry matter yield. The earliness of harvest and the value of yield components were all increased by the application of Cu or Mn; 25 mg/1 of both Cu and Mn gave the highest values. Lint percentage and fibre properties were not significantly affected.This study indicated that the yield of cotton, grown under otherwise standard conditions, may be increased by foliar sprays of Cu-EDTA and Mn-EDTA combined.

scholarly journals Tuber yield and nutrient balance of potato (Solanum tuberosum L.) Cultivation as influenced by different nutrients management under AEZ-28

2015 ◽  
Vol 39 (4) ◽  
pp. 641-659
Author(s):  
MAHS Jahan ◽  
MAR Sarkar ◽  
NCD Barma ◽  
MNA Mondal ◽  
MNS Ferdousi
Keyword(s):  
Nutrient Management ◽  
Tuber Yield ◽  
Agricultural Research ◽  
Management Practice ◽  
Solanum Tuberosum L ◽  
Block Design ◽  
Nutrient Balance ◽  
Research Centre ◽  
Gross Margin ◽  
Randomized Complete Block Design

A field experiment was conducted at Regional Wheat Research Centre of the Bangladesh Agricultural Research Institute, Joydebpur, Gazipur for 2 consecutive years during 2006-07 and 2007-08. The objectives were to find out the optimum nutrient management practice on tuber yield, nutrient balance and economics of potato cultivation. Twelve nutrient management treatments were tested in a randomized complete block design with 3 replications. Treatments were T1=HYG (0-198-44-194-24-6-1.2), T2=MYG (0-140-34-138-18-4.5-0.9), T3=IPNS (10000-168-38-170-18-6-1.2), T4=STB (0-171-40-164-22-5-1), T5=FP (0-97-16-91-0-0-0), T6=CON (0-0-0-0-0-0-0), T7=HYG+CRI, T8=MYG+CRI, T9=IPNS+CRI, T10=STB+CRI, T11=FP+CRI, T12=CON+CRI kg ha-1 CDNPKSZnB for potato. The highest tuber yield of potato was obtained from STB+CRI (27.64 t ha-1) followed by IPNS+CRI (27.35 t ha-1), STB (27.10 t ha-1), IPNS (26.83 t ha-1), HYG+CRI (26.52 t ha-1) and HYG (26.10 t ha-1) in 2006- 07. Similar trend was found in 2007-08. The highest tuber yield and yield contributing parameters were noticed in CRI plots than without CRI. Except N, remaining nutrient balance like P K S Zn and B were found positive in case of HYG, MYG, IPNS and STB along with or without CRI nutrient managements. The balance was found almost negative in case of FP and CON. The highest BCR was observed in STB+CRI (3.96) followed by STB (3.93), IPNS+CRI (3.76), and IPNS (3.74). The higher gross return (Tk. 283331 ha-1) and also gross margin (Tk. 211761 ha-1) was observed from the same treatment. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22544 Bangladesh J. Agril. Res. 39(4): 641-659, December 2014

scholarly journals Reviewer Acknowledgements for Vol. 5, No. 2, June 2017

2017 ◽  
Vol 5 (2) ◽  
pp. 204
Author(s):  
Richard Williams
Keyword(s):  
Agricultural Research ◽  
Ohio State University ◽  
Research Centre ◽  
State University ◽  
Clemson University ◽  
Agricultural Research Council ◽  
University Of Wisconsin ◽  
National University ◽  
The Ohio State University

Journal of Agricultural Studies would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether JAS publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issueReviewers for Volume 5, Number 2 Abhishek A. Cukkemane, Bijasu Agri Research Laboratory LLP, IndiaAshit Kumar Paul, Patuakhali Science and Technology University, BangladeshChenlin Hu, The Ohio State University, USA,Eliana Mariela Werbin, National University of Cordoba, ArgentinianErnest Baafi, CSIR-Crops Research Institute, GhanaGerardo Ojeda , Universidad Nacional de Colombia, ColombiaGulzar Ahmad Nayik, SLIET Punjab, IndiaJiban Shrestha, Nepal Agricultural Research Council, NepalMing-Chi Wei, Department and Graduate Institute of Pharmacology, TaiwanReham Ibrahim Abo-Shnaf, Agricultural Research Center, EgyptSahar Bahmani, University of Wisconsin at Parkside, USASait Engindeniz, Ege University Faculty of Agriculture, TurkeySelmi Houc, University of Jandouba, TunisiaSoto Caro Ariel Reinaldo, Universidad de Concepción, ChileZakaria Fouad Abdallah, National Research Centre, EgyptZhao Chen, Clemson University, US Richard Williams,EditorJournal of Agricultural Studies-------------------------------------------Macrothink Institute5348 Vegas Dr.#825Las Vegas, Nevada 89108United StatesPhone: 1-702-953-1852 ext.521Fax: 1-702-420-2900Email: [email protected]: http://jas.macrothink.org

PLASMA CONCENTRATIONS OF LUTEINIZING HORMONE, TESTOSTERONE AND ANDROSTENEDIONE IN CASTRATED AND ADRENALECTOMIZED BULL CALVES

1978 ◽  
Vol 79 (1) ◽  
pp. 137-138 ◽  
Author(s):  
J. J. BASS ◽  
A. J. PETERSON ◽  
E. PAYNE
Keyword(s):  
New Zealand ◽  
Plasma Concentration ◽  
Luteinizing Hormone ◽  
Agricultural Research ◽  
Plasma Concentrations ◽  
Young Male ◽  
Research Centre ◽  
Similar Magnitude ◽  
Research Division ◽  
Bull Calves

Ministry of Agriculture and Fisheries, Research Division, Ruakura Agricultural Research Centre, Hamilton, New Zealand (Received 17 April 1978) An increase in the plasma concentration of luteinizing hormone (LH) occurs in response to castration in bull calves aged 1–4 months; this response is of similar magnitude to that seen in cattle castrated as adults (Odell, Hescox & Kiddy, 1970). In bull calves castrated at birth, however, there is no increase in the plasma concentration of LH until after 28 days of age (Bass, Peterson, Payne & Jarnet, 1977). In other species a range of responses to castration has been reported. Gonadectomy of male guinea-pigs 0–35 days after birth produces an increase in the plasma concentration of LH similar to that observed in guineapigs castrated as adults (Donovan, ter Haar, Lockhart, MacKinnon, Mattock & Peddie, 1975). In contrast, the castration of young male macaques does not cause an immediate increase in the

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