According to recent archeological evidence, turkey (Meleagris gallopavo gallopavo) domestication may have occurred in Mexico around 2000 years ago. However, little is known about the phylogenetic and genealogical background underlying domestic turkey populations. This study aimed to further understand the domestication process and identify inter- or intraspecific connections between turkey populations to determine their origins, trace their global expansion, and define the species’ genetic value. Ninety-three domestic turkeys (local breeds) were sampled from populations in Brazil, Mexico, USA, Spain, Italy, Iran, and Egypt. Publicly available sequences from previous studies were also included. Standard mitochondrial DNA, genetic diversity, and haplotype network analyses were performed. Seventy-six polymorphic sites were identified. Turkeys from Mexico showed the greatest number of polymorphic sites (40), while turkeys from Italy and Brazil reported only one site each. Nucleotide diversity was also highest in Mexico and the USA (π = 0.0175 and 0.0102, respectively) and lowest in Brazil and Italy. Of the six major haplogroups defined, the Mexican and USA populations appeared to have remained more stable and diverse than the other populations. This may be due to conservative husbandry policies in the rural areas of other populations, which have prevented the introduction of commercial turkey lines.

Growth and meat production are the most relevant targets for animal breeders, there are strong relationships between animal growth regulation, body composition and meat quality. Therefore, it is essential to identify the genetic factors that are controlling growth, carcass, and meat quality traits and to explore the correlations between identified genes of those traits. Identification of candidate genes may shift rabbit breeding from classical to modern approaches, which offer great potential to accelerate genetic improvement plans, especially in developing countries. The current work reviews several genes and mutations affecting growth, carcass and meat quality traits. These candidate genes and mutations can be incorporated into MAS programs to improve rabbit breeds especially local breeds, provided that a reasonable proportion of trait additive genetic variance is explained by the significant marker. Furthermore, we highlighted the indispensable need for more researches investigating candidate genes for different traits.

There is still a wide gap between meat demand and meat production in Egypt. This gap is becoming larger due to the direct and indirect impacts of global warming that negatively influence the grazing area and the performance of livestock. In this context, rabbits are considered as an alternative source for animal-origin meat. In the Southern Mediterranean region, the most obvious problem encountering rabbit production is the hot waves during the summer, especially during the last decades. The narrow thermo-neutral zone of rabbits makes the high temperature hinder the success of commercial production. Different strategies may assist rabbits in coping with heat stress, which are reviewed in the current study, including the improved management practices, development of new breeds, and implementation of different nutritional strategies.

This study aimed to investigate the characteristic differences between the white and brown-feathered Japanese quails, by evaluating the carcass traits and egg fat content, blood parameters, and intestinal histopathological features. A total of 1200 1-day-old Japanese quail chicks of two varieties (brown and white-feathered) were used in this study. Live body weight and feed intake were reordered every week. At the 4^th week of age, 80 birds from each variety were slaughtered and carcass quality measurements and histopathological changes were recorded. After 6 weeks of age, eggs were collected, and egg quality was assessed. The results revealed that white-feathered quails had significantly heavier body weights and higher growth rates. At 4 weeks of age, females of the white-feather quail had significantly heavier slaughter, after de-feathering, and carcass weights. Remarkable variations between the studied quail varieties, with significant dominance of females in both varieties, at the level of water holding capacity, pH, and meat tenderness ascertained an obvious superiority of white-feathered quails compared to brown ones and indicated the higher tendency of the white quails for meat production. These results were linked with significant changes in biochemical profiles including lipids biomarkers, total protein, and Ca and phosphorus levels along with variations in the intestinal morphometry. It can be concluded that white-feathered quails had, in general, higher values of productivity compared with the brown-feathered ones during growing and laying periods.

Candidate gene is a powerful approach to study gene-trait association and offers valuable information for genetic improvement using marker-assisted selection. The current work aimed to study the polymorphisms of four single nucleotide polymorphism (SNPs) at located growth hormone (GH), insulin-like growth factor-II (IGF-II), fat mass and obesity-associated (FTO), and insulin receptor substrate-1 (IRS-1) genes, and their association with the carcass, and meat quality traits in rabbits. The SNPs were genotyped using RFLP-PCR in New Zealand White and local Baladi rabbits. The results revealed that the heterozygous genotype was the most frequent in all cases, except for the FTO SNP in LB rabbits. There was a significant effect for GH genotypes on meat lightness after slaughter and hind-part weight. While, IGF-II mutation significantly affected slaughter, hot carcass, commercial carcass, and hind-part weights. The FTO SNP was associated with cooking loss and intramuscular fat weight, and the IRS-1 SNP was significantly associated with drip loss and intramuscular fat. Specific-breed effects were obtained for IGF-II SNP on cooking loss, and for the intramuscular fat. Although the results suggested that these mutations are useful candidate genes for selection, more research for detecting more variants associated with carcass and meat quality traits in rabbits are recommended.