Polymorphism within IGFBP Genes Affects the Acidity, Colour, and Shear Force of Rabbit Meat.

Rabbits are important livestock animals, popular for their nutritional value. Nowadays, the molecular background of traits influencing the quality of meat and meat products is in high demand. Therefore, in the current study, we analyse the sequences of IGFBP1, IGFBP2, IGFBP4, IGFBP5, and IGFBP6 for possible polymorphisms. Based on a bioinformatics analysis in an association study on 466 animals of different breeds (New Zealand White × Flemish Giant crossbreed (9NZWxFG), Termond White (TW), Popielno White (PW), and Flemish Giant (FG)), we analyse the influence of five polymorphisms within the IGFBP genes. Statistically significant differences were found among the carcass and meat quality traits but not for all of the analysed rabbit breeds. The most promising polymorphism was g.158093018A>T within the IGFBP5 gene. The values of pH24 of m.longissimus lumborum (m.l.l.) and biceps femoris muscles (m.b.f.) were higher for the AT genotypes compared to the AA genotypes for the TW and NZWxFG crossbreeds. Also, for pH24, we found differences in ing.41594308T>C for NZWxFG, where the TT genotype values were higher than the TC values. We found differences in L*24 on m.l.l. for g.41592248A>C for NZWxFG. For m.b.f., significant differences were found in b*45 for g.3431insAC in the FG population and a*45 for g.41592248A>C and g.158093018A>T in the TW population. The shear force statistically differed for g.158093018A>T in TW rabbits and g.41592248A>C for NZWxFG. We conclude that this polymorphism may be promising for better quality rabbit meat and may be implemented in selection processes.

The analysis of chinchilla (Chinchilla lanigera, M.) male reproduction. The case of a leading polish breeding farm.

Research into the chinchilla male fertility concerned mainly semen quality. Little attention has been paid to lifetime reproductive performance, essential from the economical point of view. Thus, the aim of this study was to analyze factors affecting the intensity of breeding use and lifetime performance of male chinchillas. After data transformation, the analysis of variance was performed to evaluate the effect of male birth litter size and age at the first effective mating. Additionally, the correlation coefficients for both litter sizes and litter rearing efficiency were calculated. For all traits, the linear regression on the sire's age at the first effective mating was found non-significant. Litter sizes differed slightly between seasons. The length of sire reproductive use was highly correlated (about 0.8) with the total number of litters and kits born and weaned. The total rearing efficiency was low, and in some cases negatively correlated with other traits, that is, with the total number of litters and kits born and weaned. Most sires were mated up to six dams; they were used in one polygamous set each. In total, the males sired about 60 litters each, hence the conclusion is that they could be extensively used and produce more benefits to chinchilla breeders.

Mutations in Leptin (LEP) Gene Are Associated with Carcass and Meat Quality Traits in Crossbreed Rabbits.

Leptin is a hormone synthesized and secreted primarily in adipose cells that help to regulate energy balance. This study examined the associations of single nucleotide polymorphisms in the rabbit leptin gene with growth traits, slaughter traits and physicochemical parameters of New Zealand White (NZW) and Belgian Giant Grey (BGG) crossbreed rabbits. In total, 320 crossbreed animals were genotyped for polymorphisms within exon 2-g.16081633T>C, intron 1_2-g.16081420C>T, and within UTR-g.16079636C>G for association analysis. Identified polymorphisms within rabbits leptin gene showed significant differences for dissectible fat percentage in carcass and dissectible fat weight in intermediate part (g.16081633T>C). Moreover, meat traits like protein content (g.16081633T>C; g.16079636C>G), intramuscular fat content (g.16081633T>C; g.16079636C>G, g.16081420C>T), dry matter (g.16081420C>T), ash (g.16081420C>T), water (g.16081420C>T), and cohesiveness (g.16081420C>T, g.16079636C>G) were affected by polymorphisms in leptin gene. We conclude that polymorphism in the rabbit leptin gene influences important carcass and meat traits of NZW × BGG crossbreeds. Therefore, polymorphisms identified in this study may be used in selection as a meat trait markers.

Cross Species Amplification of Coat Colour Genes in Nutria (Myocastor coypus Mol).

In this study, nutria-specific DNA fragments were amplified with cross-species primers for parts of coat colour genes (MC1R, ASIP, TYRP-1, c-KIT) conserved across a number of species. Twenty-three nutria-specific DNA fragments were generated using cross-species PCR (26.7% amplification success rate). Certain limitations of this approach were encountered, including strong mismatching in the primer binding sites. Sequences of 12 nutria-specific PCR products aligned in the BLASTx option showed homology with known protein sequences. Obtained sequences were submitted to GenBank with accession number KC758969 for MC1R, KF511655 for ASIP, KF511656 for TYPR-1 and KU831489 for c-KIT. The highest homology for all translated queries was obtained with protein sequences belonging to species of the rodent family. Sequences of proteins encoded by genes involved in environmental adaptation (coat colour genes in rodents) were found to be strongly conserved among species.

[Dynamics of endoparasite infections in rabbits at different rearing regimes]. / Dynamika zarazenia królików endopasozytami w róznych warunkach chowu.

This study was intended to evaluate the occurrence and seasonality of infection of coccidian and helminth parasites, in three rabbit warrens differently managed. Mothers stayed with their offspring on deep litter (farm A, 90 dams), in boxes cleaned weekly (farm B, 30 dams) or on slatted floor (farm C, 10 females), whereas all the young after weaning (1 to 5 months of age) were kept in cages with slatted floor. Animals were fed a complete balanced pelleted feed (warrens A and B) or traditional forage (herd C). Antiparasitic treatment involved coccidiostatic drugs. Robenidine (alternately with Lerbec in farm A) was added to food in the first two farms, whilst Sulfatyf mixed with water was given once after weaning in farm C. A total of 203 individual faecal samples from females of breeding stock, and 133 pooled samples from young animals, were collected on an annual cycle during 2007-2008 (February-January), and analyzed according to a modified concentration McMaster method. Coccidians were identified based on sporulated oocysts. A number of coccidian species (Eimeria perforans, E. media, E. magna, E. irresidua, E. exiqua, E. coecicola, and E. piriformis) were observed in all farms. The most pathogenic species--E. intestinalis was found both in farm A and B, whereas E. flavescens and E. stiedae--only in the former. The level of infection was high, especially in young rabbits, with the prevalence of 94.9 to 100% and mean intensity from 11,161 to 28,871 oocysts per 1 g of faeces (OPG) in a particular warren. The highest intensity of infection was observed in May, when the mean output increased to 29,454, 56,952, and 23,815 OPG in warrens A, B, and C, respectively. A nematode, Passalurus ambiguus, was detected in all searched farms, with the prevalence from 14.1% to 27.5%, depending on a farm. The species was more often seen in the first part of year. The other helminths (Trichostrongylus retortaeformis, Graphidium strigosum, and Trichuris leporis) were found only in rabbits of warren C. In this warren, the forage of farm origin was suggested to be prepared in a proper way in order to protect it from nematode transmission. The presence of coccidia and their specific composition has been continuously monitored in all farms, to estimate the efficiency of prophylactic measures undertaken.

Analysis of associations of PIT1 genotypes with growth, meat quality and carcass composition traits in pigs.

PIT1 was chosen as a candidate gene to investigate its associations with growth, meat quality and carcass composition traits in the pig. PIT1 is known as the pituitary-specific activator of the growth hormone in several mammals. Furthermore, PIT1 is a positive regulatory factor of prolactin and thyroid-stimulating hormone beta. PIT1 is a member of the POU-domain family of genes and is located on porcine chromosome 13. Two informative three-generation families of the University of Hohenheim were used for the presented investigations. The families were based on crosses of the European Wild boar (W) x Pietrain (P) and Meishan (M) x Pietrain (P). Each family included 310 F(2) animals. A RsaI (PCR) RFLP described by Yu et al. (1994) was used for genotyping the animals. Altogether over 50 parameters of growth, meat quality, carcass composition and stress susceptibility were evaluated concerning their associations with RsaI PCR-RFLP. The statistical model of association analyses was used including fixed effects of sex, family, PIT1 genotypes and covariate age at slaughter. Taking the significance level of p < 0.05 as the basis, fourteen traits of growth and carcass composition were associated with PIT1 genotypes in family W x P. Results from this study suggest that there are contributions of PIT1 gene to variations in the analysed performance traits in pigs. The influence of PIT1 genotypes could not be confirmed under the supposition of a genome-wide test limit.