Janusz Strychalski

Deletion/insertion polymorphism of the prion protein gene (PRNP) in Polish Holstein-Friesian cattle

The aim of the present study was to identify the deletion/insertion polymorphism of the bovine prion protein gene (PRNP) within the promoter sequence (23 bp), intron 1 (12 bp) and 3’ untranslated region (14 bp). DNA was isolated from blood of 234 randomly tested Polish Holstein-Friesian cows and from semen of 47 sires used for artificial insemination (AI) in 2004. No statistically significant differences were found in the frequency of genotypes and alleles between cows and breeding bulls in the 3 analysed polymorphic sites within thePRNP gene. Only 3 haplotypes were identified in sires and 4 haplotypes in cows.

Nutrient digestibility in Arctic fox (Vulpes lagopus) fed diets containing animal meals

Three digestibility experiments on Arctic foxes were carried out. Control groups were fed standard diets (C1 and C2) composed of fresh or frozen animal by-products and steamed ground grain. Dry experimental diets (E1 and E2) contained animal meals, extracted meals and fat, were mixed with water prior to administration. In a preliminary experiment, the digestibility of dry diet E1 moistened with water for 15min and 24h was compared to determine the optimum moistening time during the experimental period proper. The preliminary experiment showed that moistening time had no significant effect on digestibility. In the main experiment, two independent digestibility trials were performed to compare the digestibility of diets fed to foxes during growth (C1 vs. E1) and fur development (C2 vs. E2). Better nutrient digestibility was noted for control diets, compared to experimental. The greatest differences were reported for total protein digestibility. Protein contained in meals undergoes denaturation during heat treatment, which reduces digestibility. It was found that the retention of nitrogen in relation to nitrogen digestion was higher in foxes fed experimental diets (E1 and E2).

Deletion/insertion polymorphism of the prion protein gene (PRNP) in Polish Red cattle, Polish White-backed cattle and European bison (Bison bonasus L., 1758)

The aim of the present study was to identify deletion/insertion polymorphism of the bovine prion protein (PRNP) gene within the promoter sequence (23 bp indel), intron 1 (12 bp indel) and the 3′ end untranslated region (14 bp indel). The experiment was performed on three groups of animals protected under a genetic resources conservation program: 139 Polish Red (PR) cows, 79 Polish White-backed cows and 50 European bison (Bison bonasus L., 1758). White-backed cattle were characterized by a higher frequency of ins/del heterozygotes and a relatively lower frequency of ins/ins homozygotes within the promoter sequence region (23 bp indel), compared to Polish Red cattle. At the polymorphic locus of intron 1 (12 bp indel) the genetic structure of both cattle populations was similar. Monomorphism, expressed by the occurrence of one genotype variant in each of the analyzed sequence regions, was observed in European bison. Five haplotypes were found in Polish White-backed cows, four haplotypes in Polish Red cows and only one in analyzed group of bison. Differences between the observed and expected number of PRNP haplotypes were recorded in Polish Red cattle.

Usability of rapeseed cake and wheat-dried distillers' grains with solubles in the feeding of growing Californian rabbits.

By-products of biofuels production such as rapeseed cake and dried distillers’ grains with solubles (DDGS) may constitute valuable feedstuffs for livestock. The objectives of the study were to determine the usability of these components in the feeding of growing rabbits and to assess their impact on physiological changes in the gastrointestinal tract of the animals. Sixty-four rabbits were divided into four feeding groups: Control (5% soyabean meal [SBM] in the diet), R (5% rapeseed cake [RSC]), DDGS (5% wheat DDGS), and R/DDGS (2.5% RSC and 2.5% wheat DDGS). The study included a production experiment, a digestibility-balance experiment and physiological assessment of the functioning of animals’ gastrointestinal tract (small intestine, caecum and colon). No statistically significant differences were determined in production results of the rabbits. Digestibility of nutrients and energy and nitrogen retention were the highest in the Control and the lowest in Group DDGS. Group DDGS was characterised by the highest relative weight of small intestine and digesta. In turn, Group R was characterised by the highest degree of caecal digesta hydration and bulking and by the highest pH value and the lowest concentration of VFA in caecum. The activity of selected bacterial enzymes released to the caecal environment was similar in all groups; however, the activity of α-arabinopyranosidase was significantly increased in Groups R and DDGS. Worthy of notice is the enhanced enzymatic activity of colonic microbiota in the R/DDGS group which has a positive effect upon increased utilisation of dietary nutrients compared to the DDGS group. The obtained results indicate that SBM from rabbit diets may be successfully replaced by 5% RSC as well as by 2.5% RSC + 2.5% wheat DDGS.

A comparison of selected performance indicators, nutrient digestibility and nitrogen balance parameters in Californian and Flemish Giant rabbits

Medium rabbit breeds such as Californian (CAL) are generally regarded as most suitable for meat production on commercial farms. Despite the increasing scale of production, commercial rabbit breeding has not replaced traditional and organic small-scale farming systems which use various rabbit breeds and hybrids. The Flemish Giant (FG), the largest rabbit breed in the world, is widely used in small household farms. According to researchers, the progeny of FG does have a relatively high weaning weight, and bucks are deemed good paternal components in commercial crossing. The aim of this study was to compare rearing rate, body weight, daily gains, carcass dressing percentage and the percentage of primal cuts in the carcass in CAL and FG rabbits. Nutrient digestibility, nitrogen balance and nitrogen retention parameters were also compared in the studied breeds. In our study, CAL rabbits were characterised by better reproductive performance in comparison with FG rabbits. Despite the above, the observed daily gain values, daily nitrogen balance and retention parameters and carcass dressing percentages of the compared breeds suggest that FGs may be a good alternative to medium breeds such as CAL rabbits.

Comparative Analysis of Nutrient Digestibility and Nitrogen Retention in Wild and Farmed Canids

Abstract The aim of this study, conducted in November 2012, was to determine whether farming of common foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) leads to changes in nutrient digestibility and nitrogen retention in comparison with their wild counterparts. Wild and farmed animals were compared within and between species. Each group consisted of five males and five females aged around eight months. Farmed silver foxes - a variety of the common red fox (group FSF) and farmed raccoon dogs (group FRD) were purchased from a breeding farm in southeastern Poland. Wild red foxes (group WRF) and wild raccoon dogs (group WRD) were trapped in the hunting grounds of the Polish Hunting Association (Olsztyn Division). The animals were placed in metabolism cages. The coefficients of nutrient and energy digestibility, and daily nitrogen balance and retention values were compared between groups. Farmed animals tended to have higher digestibility coefficients than their wild counterparts. No significant differences were noted within species. The coefficients of dry matter (P≤0.01), organic matter (P≤0.05, P≤0.05) and protein (only FSF vs. WRD - P≤0.05) digestibility were higher in foxes. Raccoon dogs were characterized by higher digestibility of carbohydrates - N-free extracts (P≤0.01). Nitrogen retention was higher in farmed animals. The highest and lowest levels of retained nitrogen were observed in groups FSF and WRD, respectively

Nutrient digestibility and colonic fermentation processes in species of the families Mustelidae and Canidae fed the same diet.

Nutrient digestibility was compared and the influence of colonic fermentation processes on nutrient digestibility was determined in the American mink (Neovison vison) and the silver fox (Vulpes vulpes). It was hypothesized that gut microbiota exert varied effects on digestion processes in the analyzed species. The experiment was performed in December, on a group of 10 male mink and 10 male foxes. All animals were fed identical diets for fur-bearing carnivores, with the following chemical composition (%): dry matter (DM)-33.12, total protein (TP)-12.01, ether extract (EE)-8.64, crude fiber (CF)-12.01, N-free extracts (N-FE)-9.32, and gross energy (GE)-7.313 MJ/kg(-1) . The coefficients of DM, OM, TP and EE digestibility were significantly higher in foxes than in mink. Mink were characterized by significantly higher utilization of N-FE. In foxes, as compared with mink, fermentation rates were higher in the final section of the gastrointestinal tract, which improved nutrient digestibility. In mink, characterized by lower fermentation rates in the colon, increased enzyme secretion by bacterial cells is one of the physiological mechanisms that enable to optimize nutrient absorption in the large intestine.

The effect of substitution of soybean meal with a mixture of rapeseed meal, white lupin grain, and pea grain on performance indicators, nutrient digestibility, and nitrogen retention in Popielno White rabbits

ABSTRACT Rabbits, bred under large-scale farming conditions, are fed pelleted complete feed containing extracted soybean meal (SBM), which is the protein source. In recent years, in certain areas of the world, a trend has emerged for the elimination of soybean meal from feed rations. The objective of the study was to determine the effect of the substitution of extracted SBM with a mixture of extracted rapeseed meal (RSM; 5–10%), white lupin (WL) grain (4–8%), and pea grain (3–6%) on production results, as well as nutrient digestibility and nitrogen retention in Popielno White rabbits. The ration for the control group (C) contained 15% extracted SBM, while the ration for the experimental group (E1) contained 7.5% extracted SBM, which was partially substituted with a mixture of extracted RSM, and WL and pea grains. In the experimental group (E2) diet, soybean meal was completely substituted. The obtained results indicated that the partial or complete substitution of extracted SBM with extracted RSM, pea, and WL did not have a negative effect on production results, digestibility of nutrients, and nitrogen retention.

Productivity results and physiological response of the gastrointestinal tract of rabbits fed diets containing rapeseed cake and wheat distillers dried grains with solubles

This study was aimed at determining the possibility of applying rapeseed cake (RC) and wheat distillers dried grains with solubles (DDGS) in diets for HYPLUS meat-type rabbits (n = 64, aged 35–84 days). Control diet (SC) contained 5% of extracted soybean meal. In RC diet, the soybean meal was replaced by RC, in DG diet – by wheat DDGS, whereas in RC–DG diet – by a mixture of RC and wheat DDGS (2.5% each). The study included production analyses, digestibility-balance experiment and physiological assessment of gut response to experimental factors hence data was collected on daily bodyweight gains, feed intake and slaughter performance, nutrients digestibility, nitrogen retention and gut response. The latter included assessment of parameters describing the small intestinal, cecal, and colonic environment of rabbits (e.g. digesta viscosity, ammonia concentration, bacterial enzymes activity, short-chain fatty acid concentration). The highest productivity results were reported for SC group and the lowest ones for DG group. The RC and RC–DG groups were characterised by intermediate productivity. Dressing percentage and contents of carcass elements did not differ among the groups (except for the hind part). Nutrients digestibility and nitrogen retention were the highest in the SC group and the lowest in DG group. The dietary incorporation of DDGS resulted in undesired responses of the gastrointestinal tract including excessively watery digesta in the small intestine, increased concentration of cecal and colonic ammonia, enhanced activity of potentially harmful bacterial β-glucuronidase in cecal digesta, and increased cecal concentration of putrefactive short-chain fatty acids. These negative effects were not due to RC and RC–DG dietary treatments, apart from decreased dry matter concentration in the small intestine in the RC–DG group. In general, the results of our study demonstrated that 5% rape cake can be successfully incorporated into rabbit dietary regimen as a substitute of dietary soybean meal. Considering that the productivity of rabbits fed 2.5% of DDGS (with 2.5% rape cake) and these receiving 5% rape cake was comparable, optional seems also dietary inclusion of up to 2.5% wheat DDGS The higher content of DDGS (5%) in the diet deteriorated most of the growth parameters of rabbits.

A novel AAT-deletion mutation in the coding sequence of the BCO2 gene in yellow-fat rabbits

The carcasses of yellow-fat rabbits may be attractive to modern consumers, because they have a relatively high content of biologically active compounds. One of the main candidate genes associated with the yellow-fat trait is β-carotene 9′,10′-oxygenase (BCO2). This study is the first report of the novel AAT-deletion mutation at codon 248 of the BCO2 gene, which has been found in homozygous yellow-fat rabbits. The deletion mutation, located at the beginning of exon 6, results in the absence of asparagine in protein. We also developed a PCR-RFLP test that supports intravital genotyping of indel polymorphism based on genomic DNA.