Genetic Improvement of Weaning Weight in Barki Sheep Using Nucleus Breeding Scheme

2014 ◽  
Vol 9 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Manal El Sayed ◽  
Salwa I. El-Wakil ◽  
A. M. Ahmed
Keyword(s):  
Genetic Improvement ◽  
Breeding Scheme ◽  
Weaning Weight ◽  
Nucleus Breeding

scholarly journals Open Nucleus Breeding Strategy for Fogera Cattle Breed in Ethiopia: Achievements and Lessons Learnt

2021 ◽  
Author(s):  
Assemu Tesfa Sendeku ◽  
Mekonnen Tilahun ◽  
Zelalem Asmare ◽  
Demelash Kassahun ◽  
Tewodross Bimerew ◽  
...  
Keyword(s):  
Milk Yield ◽  
Maximum Yield ◽  
Cattle Breed ◽  
Breeding Strategy ◽  
Breeding Scheme ◽  
Productivity Improvement ◽  
Grazing Land ◽  
Weaning Weight ◽  
Nucleus Breeding ◽  
Open Nucleus

Abstract Fogera cattle are one of the promising indigenous milk type local breed of Ethiopia. The objective of this paper was to evaluate the performance of Fogera breed under open nucleus breeding scheme. The work was done in two purposively selected districts (Gondar Zuria and Fogera) with community-based breed productivity improvement (CBBPI) as an approach. The collected data was analysed by GLM procedure of SAS for fixed factors estimation. Genetic parameters estimate was made by ASREML software for heritability and correlation. The overall milk yield of the nucleus herd was 2.26 ± 0.794 litter. From the total herd, best 10% and 25% of them give a respective milk yield of 3.31 and 2.87 litter; and some elite cows give an average of 5.45 ± 0.73 litter with a maximum yield of eight litters per day. The overall birth and weaning weight of nucleus herd calves was 21.30 ± 0.06 and 103.66 ± 0.59kg, respectively. Heritability for birth and weaning weight was 0.24 ± 0.09 and 0.18 ± 0.05, respectively. The phenotypic and genotypic correlation with their respective standard error between birth and weaning weight was 0.0613 ± 0.0075 and 0.0712 ± 0.0343, respectively. For CBBPI program, 17 pure Fogera bulls were distributed to the two districts. The birth and weaning weight of the village calves was 23.77 ± 0.21 and 85.89 ± 1.07, respectively. Through the program, above 1000 households were benefiting through the breeding program, health, forage development and grazing land management. To share the achievements of the results in CBBPI program, popularization through filed days and innovation platforms; and documentation of each step via publications, videos and pictures was done. From the result, it can be concluded that the strategy implemented for the breed conservation “open nucleus breeding scheme” had shown progressive results and improvement was recorded. To widen the result and improve the livelihood of the farmer, scaling up of the activity should better be planned with stakeholders.

Genetic improvement of meat sheep. 1. A comparison of different methods of correcting weaning weight for age of lamb

1976 ◽  
Vol 16 (80) ◽  
pp. 325 ◽  
Author(s):  
IP Gregory ◽  
EM Roberts ◽  
JW James
Keyword(s):  
Birth Weight ◽  
Genetic Improvement ◽  
Average Daily Gain ◽  
Weaning Weight ◽  
Significant Difference ◽  
Meat Sheep ◽  
Daily Gain ◽  
Weight For Age

Several methods of correcting lamb weaning weight for age were compared. Lambs were weighed at birth, at 90 � 1 day of age, when the oldest and when the youngest lamb was 90 days and when the average age of lambs was 90 days. Weights were adjusted to 90 days by the methods of regression, regression pooled within sire groups, average daily gain with and without a standard birth weight and weight per day of age. All the correction methods examined gave similar results and there was no significant difference between methods. The correlations between the actual 90-day weight and the adjusted weights ranged from 0.922 to 0.960 and were highest when the weights taken when the average age of lambs was 90 days were used as the basis for adjustment. All adjusted weights were significantly biased as estimates of actual 90-day weight, but the bias was least for weights when average age was 90 days.

scholarly journals The relevance of milk protein polymorphisms for dairy cattle breeding.

1993 ◽  
Vol 1993 ◽  
pp. 46-46
Author(s):  
Henk Bovenhuis
Keyword(s):  
Genetic Variants ◽  
Milk Protein ◽  
Production Traits ◽  
Milk Production Traits ◽  
Breeding Scheme ◽  
Cattle Breeding ◽  
Dairy Cattle Breeding ◽  
Nucleus Breeding ◽  
Selection For ◽  
Β Lactoglobulin

Several studies have shown milk protein genetic variants to be associated with manufacturing properties of milk. The main findings were that κ-casein genetic variants affect renneting time of milk and βlactoglobulin genetic variants are associated with casein number (reviewed by Grosclaude, 1988). There are reports also of associations between milk protein genetic variants and milk production traits. Results from these studies indicate that κ-casein genotypes are associated with protein content and βlactoglobulin genotypes are related to fat content (reviewed by Bovenhuis et al., 1992). Therefore, κ-casein and βlactoglobulin genotypes might be of value as selection criteria. The aim of the present study was to quantify the potential effects of selection for κ-casein and β-lactoglobulin genotypes by using stochastic simulation of a closed adult MOET nucleus breeding scheme.

Genetic improvement of meat sheep. 4. Effect of age of dam on productivity of Dorset and Border Leicester sheep

1977 ◽  
Vol 17 (88) ◽  
pp. 735 ◽  
Author(s):  
IP Gregory ◽  
EM Roberts ◽  
JW James
Keyword(s):  
Genetic Improvement ◽  
Weaning Weight ◽  
Maximum Productivity ◽  
Clear Association ◽  
Meat Sheep ◽  
Effect Of Age ◽  
Age Structures

The effect of age of the dam on the number of lambs born (LBL) and weaned (LwL) and the weight of lambs weaned (WLWL) per ewe lambing and on the number of lambs weaned per lamb born (LwB) and lamb weaning weight (WWT) has been estimated for Dorset and Border Leicester sheep. In both breeds, LBL, LWL and WLWL showed a clear association with age of the dam, rising to a peak at a dam age of five years in the Dorsets and at between four and six years in the Border Leicester. The association between age of dam and WWT and LWB was less marked. WWT rose to a peak in both breeds at a dam age of five years and LWB rose to a peak at four and three years in the Dorsets and Border Leicester respectively. The estimates of ewe productivity were used to calculate the productivity of Dorset flocks of differing age structures. It was found that maximum productivity would be achieved with a flock aged from two to six years.

Genetic gain in open nucleus breeding scheme to improve milk production in Egyptian Buffalo

2010 ◽  
Vol 131 (2-3) ◽  
pp. 162-167 ◽  
Author(s):  
S.A. Abdel-Salam ◽  
A.I. Sayed ◽  
Manal Elsayed ◽  
S. Abou-Bakr
Keyword(s):  
Milk Production ◽  
Genetic Gain ◽  
Breeding Scheme ◽  
Nucleus Breeding ◽  
Egyptian Buffalo ◽  
Open Nucleus

Genetic Response from Marker Assisted Selection in an Outbred Population for Differing Marker Bracket Sizes and with Two Identified Quantitative Trait Loci

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1389-1396 ◽  
Author(s):  
Richard Spelman ◽  
Henk Bovenhuis
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Marker Assisted Selection ◽  
Phenotypic Variance ◽  
Genetic Response ◽  
Breeding Scheme ◽  
Outbred Population ◽  
Trait Loci ◽  
Polygenic Component ◽  
Nucleus Breeding

AbstractEffect of flanking quantitative trait loci (QTL)-marker bracket size on genetic response to marker assisted selection in an outbred population was studied by simulation of a nucleus breeding scheme. In addition, genetic response with marker assisted selection (MAS) from two quantitative trait loci on the same and different chromosome(s) was investigated. QTL that explained either 5% or 10% of phenotypic variance were simulated. A polygenic component was simulated in addition to the quantitative trait loci. In total, 35% of the phenotypic variance was due to genetic factors. The trait was measured on females only. Having smaller marker brackets flanking the QTL increased the genetic response from MAS selection. This was due to the greater ability to trace the QTL transmission from one generation to the next with the smaller flanking QTL-marker bracket, which increased the accuracy of estimation of the QTL allelic effects. Greater negative covariance between effects at both QTL was observed when two QTL were located on the same chromosome compared to different chromosomes. Genetic response with MAS was greater when the QTL were on the same chromosome in the early generations and greater when they were on different chromosomes in the later generations of MAS.

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