The objective of this paper is to review selection of poultry genotypes in humid tropics for meat quality traits, the challenges, and opportunities including selection of poultry genotypes, breeds of broilers kept by the farmers, selection criteria, and trait preference for meat quality in humid tropics.
The indigenous village chicken is the most prominent class of livestock in the country and constitutes about 60-80% of the total poultry population, their productivity levels are low because of low genetic potential and poor nutrition. To overcome the problem of low productivity in local chickens, high-yielding exotic breeds have been introduced through cockerel exchange program by the government. This intervention is bedeviled with many challenges; prominent among them is the birds’ inability to adapt to the humid and hot environment, resulting in reduced feed intake and retarded growth.
A number of major heat-tolerant genes or gene complexes like naked-neck, ptylopody, polydactyly and frizzle have been identified in the genome of Ghanaian local chicken populations. These unique genes have been reported to ameliorate tropical heat stress and enhance the performance of chickens under hot and humid environments. The existence of the naked-neck gene results in 20-30% less feather coverage overall, with the lower neck of the bird appearing almost naked while the frizzle gene but is reported to reduce the insulating properties of the feather cover (reduce featherweight) and make it easier for the bird to radiate heat from the body.
Table of Contents
1. INTRODUCTION
2.2 Genetic selection
2.3 Genomic prediction
2.4 Main selection criteria
2.4.1 Carcass traits
2.4.2 Carcass components of poultry meat
2.4.3 Meat Type Chickens
2.4.4 Major genes affecting heat tolerance
2.4.5 Meat traits
2.4.6 Effect of High Temperature on Meat Quality
2.4.7 Effect of High Temperature on heat production
2.4.8 Opportunity of Genetic Selection on the Welfare of Chickens
2.4.9 Challenges of Genetic Selection on the welfare of chickens
2.4.10 Genetic selection methods
2.4.11 Selection Strategies
3. Summary
4. Recommendation
Research Objectives and Core Themes
This paper aims to review the selection of poultry genotypes in humid tropical environments, focusing specifically on meat quality traits, the inherent challenges of these climates, and the available opportunities for genetic improvement. The research addresses the critical need to balance productive adaptability with animal welfare in regions where heat stress significantly impacts output.
- Genetic adaptation of poultry genotypes in hot and humid climates.
- Evaluation of selection criteria and meat quality preferences.
- Impact of major heat-tolerant genes on production and welfare.
- Strategies to mitigate the negative effects of climate-induced heat stress.
Excerpt from the Publication
2.4.4 Major genes affecting heat tolerance
There are specific genes which play crucial role in heat tolerance.
These genes are:
Naked neck gene (Na)
Sex-linked dwarfism gene (dw)
Sex-linked slow feathering gene (KS)
Frizzle feather gene (F)
Summary of Chapters
1. INTRODUCTION: This chapter outlines the prominence of indigenous village chickens and the challenges they face regarding low productivity due to environmental heat stress and poor nutrition.
2.2 Genetic selection: This section discusses the importance of choosing appropriate breeding goals and the use of pedigree and multiplication level selection to maximize genetic gain.
2.3 Genomic prediction: This chapter covers the use of relationship matrices based on genomic information to perform more accurate evaluations of additive genetic merit.
2.4 Main selection criteria: This segment details the various physiological and structural traits—such as skeletal integrity and heart function—that are prioritized in breeding programs.
2.4.1 Carcass traits: An analysis of how body weight and muscular tissue growth are influenced by genetic and environmental factors in different poultry species.
2.4.2 Carcass components of poultry meat: An overview of the primary commercial meat components and the distinction between white and dark meat in poultry.
2.4.3 Meat Type Chickens: This chapter explains the selection of modern fast-growing broilers and their susceptibility to physiological problems when kept in non-ideal tropical conditions.
2.4.4 Major genes affecting heat tolerance: An examination of specific genetic complexes that provide innate resistance to high temperatures in poultry.
2.4.5 Meat traits: A review of how rearing systems and genotypes influence meat quality parameters such as color, pH, and oxidative stability.
2.4.6 Effect of High Temperature on Meat Quality: This section explores how heat exposure affects fat accumulation, chemical composition, and physical meat quality post-slaughter.
2.4.7 Effect of High Temperature on heat production: A discussion on the relationship between high metabolic rates, feed intake, and the birds' ability to maintain a thermo-neutral zone.
2.4.8 Opportunity of Genetic Selection on the Welfare of Chickens: This chapter addresses how heat stress reduces feed conversion efficiency and the potential for improving welfare through selective breeding.
2.4.9 Challenges of Genetic Selection on the welfare of chickens: An evaluation of how genetic predisposition, management, and environmental factors intersect to cause welfare issues like tibial dyschondroplasia.
2.4.10 Genetic selection methods: A description of the processes like "broilerisation" and the use of independent culling to identify successful breeders at different levels of the pyramid.
2.4.11 Selection Strategies: This final section emphasizes that successful breeding requires a clear balance between individual trait goals and long-term market objectives.
3. Summary: This chapter synthesizes the main findings, highlighting the conflict between climate change and productivity and emphasizing the need for continued research.
4. Recommendation: The author suggests the development of strong national breeding policies and improved healthcare management to support the productivity of crossbred poultry in the tropics.
Keywords
Poultry breeding, Humid tropics, Heat stress, Meat quality, Genetic selection, Naked-neck gene, Genomic prediction, Broiler production, Animal welfare, Thermo-neutral zone, Carcass traits, Climate adaptation, Genotype, Selective breeding, Feed conversion efficiency.
Frequently Asked Questions
What is the primary focus of this paper?
The paper focuses on reviewing the selection of poultry genotypes in humid tropical environments, specifically examining how to balance meat quality traits with the challenges posed by heat stress.
What are the central thematic areas covered?
The central themes include genetic selection methods, the identification of heat-tolerant genes, the impact of climate change on broiler production, and the welfare of parent stocks.
What is the main objective of the research?
The general objective is to review the opportunities and challenges of selecting poultry genotypes that are suited for meat production in humid tropical climates.
Which scientific methods are primarily discussed?
The paper discusses genomic prediction, the use of relationship matrices (G), and standard selective breeding techniques such as independent culling and the use of estimated breeding values.
What topics are analyzed in the main part of the work?
The main body covers carcass composition, the influence of high temperatures on meat quality and production, and the application of genetic selection to improve both productivity and animal welfare.
Which keywords best characterize the work?
Key terms include poultry breeding, heat stress, humid tropics, meat quality, and genetic selection.
How does the "naked-neck" gene help poultry in the tropics?
The naked-neck gene reduces feather coverage by 20-40%, allowing birds to radiate heat more effectively, which is highly advantageous in hot and humid climates.
What is "broilerisation" as described in the text?
Broilerisation is a process used in pedigree and multiplication flocks where selected chicks are reared for six weeks as if they were commercial broilers to identify those without genetic predispositions to welfare problems.
How does chronic heat stress affect meat quality?
Chronic heat stress can lead to paler meat, increased fat deposition, and a decrease in the proportion of breast muscle in broilers.
- Arbeit zitieren
- Anonym (Autor:in), 2018, Selection of Poultry Genotypes in Humid Tropics for Meat Quality Traits, Challenges and Opportunities Ahead, München, GRIN Verlag, https://www.grin.com/document/1005551
