Effect of Hen Genotype and Laying Time on Egg Quality and Albumen Lysozyme Content and Activity.

According to research, egg quality and lysozyme content are influenced by a number of factors, which are mostly known in the case of commercial hybrids, while in breeds included in genetic resources conservation programmes, new research results in this regard are emerging. The aim of the study was to determine the effect of egg laying time and genotype of selected Polish native breeds of hens on egg quality and lysozyme content and activity in the albumen. The study material consisted of eggs collected from four strains of laying hens included in the Polish conservation programme, i.e., Green-legged Partridge (Z-11), Yellow-legged Partridge (Z-33), Rhode Island Red (R-11) and Leghorn (H-22). At week 56, 28 eggs were randomly collected at 7:00 and 13:00 h from each breed of hen and assessed for quality. Laying time influenced certain egg quality traits. Eggs laid by hens in the morning were characterised by 1.7 g lower total weight and albumen weight, 2.4 pores/cm2 higher number of shell pores, 0.15 higher albumen pH values and 0.17 lower yolk pH values compared to those laid in the morning. The time of laying did not affect the level and activity of lysozyme in the albumen. A significant negative correlation was found between eggshell traits and albumen height, and between Haugh unit and lysozyme content and activity in the albumen. The studied egg quality traits were more influenced by genotype than by the egg-laying time.

Genetic Diversity and Population Structure of the Native Pulawska and Three Commercial Pig Breeds Based on Microsatellite Markers.

Swine DNA profiling is highly important for animal identification and parentage verification and also increasingly important for meat traceability. This work aimed to analyze the genetic structure and genetic diversity in selected Polish pig breeds. The study used a set of 14 microsatellite (STR) markers recommended by ISAG for parentage verification in the native Pulawska pig (PUL, n = 85) and three commercial pig breeds: Polish Large White (PLW, n = 74), Polish Landrace (PL, n = 85) and foreign breed Duroc (DUR, n = 84). Genetic differentiation among breeds accounted for 18% of the total genetic variability (AMOVA). Bayesian structure analysis (STRUCTURE) indicated that the four distinct genetic clusters obtained corresponded to the four breeds studied. The genetic Reynolds distances (Ɵw) showed a close relationship between PL and PLW breeds and the most distant for DUR and PUL pigs. The genetic differentiation values (FST) were lower between PL and PLW and higher between PUL and DUR. The principal coordinate analysis (PCoA) supported the classification of the populations into four clusters.

Current Analytical Methods and Research Trends Are Used to Identify Domestic Pig and Wild Boar DNA in Meat and Meat Products.

The pig, one of the most important livestock species, is a meaningful source of global meat production. It is necessary, however, to prove whether a food product that a discerning customer selects in a store is actually made from pork or venison, or does not contain it at all. The problem of food authenticity is widespread worldwide, and cases of meat adulteration have accelerated the development of food and the identification methods of feed species. It is worth noting that several different molecular biology techniques can identify a porcine component. However, the precise differentiation between wild boar and a domestic pig in meat products is still challenging. This paper presents the current state of knowledge concerning the species identification of the domestic pig and wild boar DNA in meat and its products.

Qualitative and Quantitative Detection of Mealworm DNA in Raw and Commercial Food Products Using Real-Time PCR.

Considering food safety and an increasing public awareness of the ingredients, production process and origin of foods, the application of insects as food requires the development of tests for the reliable identification of their presence. The aim of the study was (1) the determination of appropriate modifications of the selected method for isolating the DNA of two life stages of mealworm, i.e., larva and adult, from commercial food products; (2) the determination of the method parameters for the qualitative and quantitative analysis of mealworm contents based on the detection of a species-specific mitochondrial DNA fragment, using real-time PCR; (3) the application of a method to test the commercial food products of mealworm. A total of nine species of adult insect were investigated (field cricket, Dubia cockroach, Madagascar cockroach, banded cricket, migratory locust, yellow mealworm, superworm, house fly and lacewing), theirlarvaes (yellow mealworms and superworms) and thirteen commercial food products (dried whole insects, powder and granules) representing various insect species and origins which were purchased from the European market. The obtained results showed that the efficiency of the modification of the DNA extraction method is dependent on the life stage of the mealworm. We proved the high sensitivity of the test, with the range of the method being 0.1-100%; we also proved the biological specificity in this range, and the linearity. The linearity of the test was also statistically verified using the Fisher-Snedecor test. One-way variance analysis showed statistically significant differences between the cT values of the two mealworm life stages studied, and similarly, between the threshold cycle (cT) values of adult forms. In contrast, for the inside group of mealworm larvae, there was no significant difference observed between the results of the cT values. The test is effective for processed food products and may be used to monitor food. The research proved the suitability of the applied method for the analysis of samples that are commercially available as food for exotic animals. The hereby-developed method is based on widely used laboratory techniques, and does not require any additional investment in equipment. The availabilityof such a methodallows for the verification of the accuracy of the declared species component of the food products.

Differentiating Pigs from Wild Boars Based on NR6A1 and MC1R Gene Polymorphisms.

This preliminary study aimed to differentiate domestic pigs from wild boars based on MC1R and NR6A1 polymorphisms and to identify admixture between these genomes. We studied samples obtained from wild boars from two regions of Poland and five pig breeds: Polish Landrace, Polish Large White, Zlotnicka White, Pulawska and Duroc. Along the MC1R gene sequence, we identified four polymorphic loci comprising three codons. The "wild type" allele was primarily found in wild boar but also in the Duroc and Zlotnicka White breeds. Non-wild type alleles were identified in the vast majority of domestic pig samples and in two wild boar samples. Based on MC1R profiles, we conducted a population study, and revealed admixture between both genomes using STRUCTURE and NETWORK Software. Interestingly, an allelic discrimination assay with NR6A1 g.748C > T TaqMan probes revealed a clear separation of samples into two groups: wild boar samples representing the C allele and domestic breeds representing the T allele. Based on the obtained results, we conclude that NR6A1 g.748C > T is an effective marker for differentiating between wild boars and domestic pigs, where this is supported by MC1R data, to identify admixed profiles. We recommend that a larger sample of genomes is studied to verify this method.

Analysis of the effect of vitamin D supplementation and sex on Vdr, Cyp2r1 and Cyp27b1 gene expression in Wistar rats' tissues.

Vitamin D supplementation is widely recommended for animals and humans. However, its effects on extra-skeletal disorders have not been well proven. Our research aimed to analyse the effect of supplementation with standard and increased doses of vitamin D on the health status, biochemical and haematological parameters of blood as well as on the level of expression of genes metabolising vitamin D and the Vdr gene in the kidney, liver, fat and brain of rats of different sexes. 36 Wistars rats (18 males and 18 females) divided into three supplementation groups (I-O vitamin D, II- 1000 U / kg of vitamin D, III - 5000 U / Kg of vitamin D) were analysed. Vitamin D supplementation had little effect on growth traits and biochemical blood indices; slight decrease in a heart size was observed in females supplemented with high doses of vitamin D (p = 0.0075), moreover male rats tended to have increased level of triglyceride (TG) (p = 0.0516)). In our study we observed that vitamin D supplementation did not change the expression of Vdr gene in any of analysed tissue. However, we noticed evident downregulation of Cyp27b1 gene by vitamin D supplementation in the liver and kidney in a dose-dependent manner. Additionally, we observed that in the female's liver, Vdr and Cyp2r1 were upregulated, in the female's kidney Vdr was upregulated while Cyp27b1 was downregulated compared to males. Moreover, in the female's brain and fat Cyp27b1 and Cyp2r1 tended to be upregulated compared to males. Our results confirm that Vdr and vitamin D metabolising genes are regulated by sex in the kidney and several extra-renal tissues.

Microsatellite DNA Analysis for Diversity Study, Individual Identification and Parentage Control in Pig Breeds in Poland.

Swine DNA profiling is of high importance for animal identification and parentage verification. The aim of this study was to test a set of 14 microsatellite (STR) markers recommended by ISAG for parentage verification in Polish Landrace (PL, n = 900), Polish Large White (PLW, n = 482), Pulawska (PUL, n = 127), and Duroc pigs (DU n = 108). The studied breeds showed a medium level of genetic differentiation. The average value of heterozygosity and degree of polymorphism (PIC) were above 0.5 for the studied breeds, except for the DU breed (PIC = 0.477). The population inbreeding coefficient indicates an absence of inbreeding in the studied breeds (an average value of FIS = 0.007). The cumulative power of discrimination for all breeds reached high values close to 1.0, while the probability of identity (PID) was low, with PID values ranging between 10-9 (for DU) and 10-12 (for PLW). The cumulative exclusion probability for PE1 and PE2 showed that the parentage can be confirmed with a probability of from 92.75% to 99.01% and from 99.49% to 99.97%, respectively.

3'quant mRNA-Seq of Porcine Liver Reveals Alterations in UPR, Acute Phase Response, and Cholesterol and Bile Acid Metabolism in Response to Different Dietary Fats.

Animal fats are considered to be unhealthy, in contrast to vegetable fats, which are rich in unsaturated fatty acids. However, the use of some fats, such as coconut oil, is still controversial. In our experiment, we divided experimental animals (domestic pigs) into three groups differing only in the type of fat used in the diet: group R: rapeseed oil (n = 5); group B: beef tallow (n = 5); group C: coconut oil (n = 6). After transcriptomic analysis of liver samples, we identified 188, 93, and 53 DEGs (differentially expressed genes) in R vs. B, R vs. C, and B vs. C comparisons, respectively. Next, we performed a functional analysis of identified DEGs with String and IPA software. We observed the enrichment of genes engaged in the unfolded protein response (UPR) and the acute phase response among genes upregulated in B compared to R. In contrast, cholesterol biosynthesis and cholesterol efflux enrichments were observed among genes downregulated in B when compared to R. Moreover, activation of the UPR and inhibition of the sirtuin signaling pathway were noted in C when compared to R. The most striking difference in liver transcriptomic response between C and B was the activation of the acute phase response and inhibition of bile acid synthesis in the latest group. Our results suggest that excessive consumption of animal fats leads to the activation of a cascade of mutually propelling processes harmful to the liver: inflammation, UPR, and imbalances in the biosynthesis of cholesterol and bile acids via altered organelle membrane composition. Nevertheless, these studies should be extended with analysis at the level of proteins and their function.

Polymorphism of the Myostatin (MSTN) Gene in Landes and Kielecka Geese Breeds.

Myostatin, also known as growth differentiation factor 8 (GDF8), belongs to the TGF-ß superfamily of proteins. MSTN is a highly conserved protein that acts as a negative regulator of skeletal muscle growth. Loss of myostatin functionality causes the phenotype to appear in the form of 'double musculature', among others in cattle, sheep, and house mice. The presented results of the research were carried out on two geese breeds-Landes and Kielecka. The aim of the study was to identify mutations in the MSTN gene and study their impact on body weight in both geese breeds in different periods of life. Analysis of the obtained results showed the existence of polymorphism in exon 3 (c.1231C>T) and suggested a possible association (p < 0.05) between BW and genotype in 12 weeks of life in male Kielecka geese breed. The identified polymorphism may be one of the factors important for improving body weight in the studied Kielecka breed, therefore, it is necessary to conduct further research on a larger population of geese breeds in order to more accurately estimate the effect of the identified SNP c.1231C>T on BW in geese.