R Niznikowski

North European short-tailed breeds of sheep: a review.

The short-tailed sheep, native of an area stretching from Russia to Iceland, are generally considered a primitive type. These robust northern sheep seem to have been spread by Norse vikings to several countries in this area from the late eighth century to the middle of the eleventh century ad. They have several common characteristics in addition to the fluke-shaped and tapered short tail, such as a wide range of colour patterns, dual-coated wool and the ability to thrive under harsh environmental conditions, often in isolated marginal areas. While 34 short-tailed breeds of North European origin can still be identified, it is clear that their population sizes have declined in most cases and several of them are now rare and endangered. Although these breeds have mainly been confined to certain localities, some of them have gained considerable distribution due to their genetic merits, such as prolificacy. Of these, the Finnsheep and the Romanov are best known being exported to several countries in the world where their genetic material has been utilized through crossbreeding with local sheep. This has resulted in the production of some new synthetic breeds. Meat is now generally the main product of the North European short-tailed breeds and their crossbreds, whereas wool, skins and milk are normally regarded as byproducts, yet of considerable economic importance in some cases. Such breeds have clearly a role to play in sustainable grassland-based production systems in the future.

The repeatability of faecal egg counts in Polish Wrzosówka sheep

The number of nematode eggs in the faeces was estimated in Polish Wrzosówka sheep, in the spring and autumn of 1993 and again in 1994. The sheep had been naturally infected. The dominant species were Haemonchus contortus and Teladorsagia circumcincta, but Trichostrongylus spp., Cooperia curticei, Nematodirus spp. and Chabertia ovina were also present. Anthelmintics were not used. Egg counts were skewed, with a range of 0-4100 eggs g-1 (EPG); most sheep had egg counts below 100 EPG. Egg counts were approximately four times higher in spring than in autumn. Repeatability values within a season were all significant and positive. The repeatability of egg counts between seasons was estimated from the correlation between the mean transformed value in spring and in autumn, and was 0.52 in 1993 (P < 0.001) and 0.41 in 1994 (P < 0.05). The results show that animals with higher than average values in spring are likely to have higher than average values in autumn, and suggest that similar mechanisms regulated egg counts in both seasons even though egg counts were much lower in autumn.

EFFECT OF PRNP GENE POLYMORPHISM ON REPRODUCTIVE PERFORMANCE OF MOTHER SHEEP AND THEIR OFFSPRING GROWTH

Abstract The polymorphism of prion protein (PrP) amino acids in codons 136 (A/V), 154 (R/H); and 171 (Q/R/H) was established. Reproductive performance of mother sheep was evaluated analysing the fertility coefficient and litter size, i.e. the number of born and reared lambs. The studies included mothers of synthetic lines BCP - 111 sheep and SCP - 104 sheep born in 2001-2007. In the examined ovine PRNP gene, the following four alleles were identified: ARR, AHQ, ARQ, and VRQ, with the absence of the ARH allele. The highest frequency was determined for the ARR (49.8%) and ARQ (45.8%) alleles. In the studied sheep population, the occurrence of seven different genotypes was reported. It was found that 71.6% of the animals had the genotypes ARR/ARR, ARR/ARQ, and ARR/AHQ, which are regarded as the most resistant to scrapie, while 7.9% of the population had ARR/VRQ-bearing genotypes (low resistance) or ARQ/VRQ ones (high susceptibility to scrapie). The analysis of the obtained results indicates that the PRNP genotype does not affect reproduction efficiency of mothers, or their offspring growth. It was concluded that flock elimination of ewes of genotypes with high and very high susceptibility to scrapie will not reduce the reproduction parameters of ewes or growth of their lambs.

The effect of animal grazing on vegetation and soil and element cycling in nature

Appropriate level of bio-components in blood plasma of animals is associated with their concentration in soil and in green fodder. Cycling of elements in nature and their adequate level in animal organisms result in proper functioning of an organism as a whole (Khan et al. 68:279–284, 2007). Therefore, it is important to analyse soil and green fodder for these components. If some deficits are found, it is important to supplement components responsible for e.g. proper growth and development of a young organism, proper reproduction and, consequently, good quality of obtained product, which may affect human health (Minzanova et al. 134:524–533, 2015). The aim of the presented study was to demonstrate the effect of extensive grazing by sheep on vegetation and soil and to analyse the cycling of some elements important for animal health. The effects of vegetation season on the concentration of potassium in soil and differences in the concentration of some elements in soil, green fodder and animal blood were demonstrated.

A Comparison of the Body Development and Slaughter Value of Polish Wrzosówka Sheep and Their F2 Crossbreeds with Berrichon du Cher Sheep

Background. The study compared the body development and slaughter traits of male and female Polish Wrzosówka lambs and their F2 crossbreeds with Berrichon du Cher rams. Material and methods. The study on male and female Polish Wrzosówka lambs and their F2 crossbreeds with Berrichon du Cher rams was conducted at Prof. Adam Skoczylas Research Farm in Żelazna, Poland between 2012 and 2014. The body development of all the lambs was assessed, but only the rams were slaughtered to assess their carcass quality. The carcasses were assessed according to the EUROP grid. The left half-carcasses were divided into cuts. Results. The F2 crossbreeds were characterised by higher body weights and daily gains. Their carcasses contained less fat, had better fat consistency and higher slaughter value, were heavier and contained more valuable cuts than the Polish Wrzosówka sheep. Conclusion. The findings of the research on the development of a new synthetic line of sheep based on the Polish Wrzosówka sheep for the Central Poland market give grounds to initiate the procedure to register the new synthetic line.

Polymorphism of the PrP prion protein gene in Polish Merino and old-type Polish Merino from Brylewo flock

Abstract The study was conducted on Polish Merino (143♀ and 39♂) and old-type Polish Merino sheep (176♀ and 61♂) in Brylewo flock (Wielkopolskie Province). The examined sheep were at the age of one year. Prion protein (PrP) genotype was determined in all animals. In both breeds four alleles (ARR, ARQ, AHQ, VRQ) were found. Highly significant effect of breed and insignificant impact of gender within breed was observed in regard to the frequency of occurrence of alleles and genotypes susceptible to classical scrapie in the sheep. Eight different PrP genotypes in Polish Merino and nine genotypes in old-type Polish Merino were identified. Very high frequency of ARR/ARR genotype in old-type Polish Merino and high frequency of ARR/ARQ genotype in Polish Merino were found, with relatively significant frequency of occurrence of the genotypes containing VRQ allele. In old-type Polish Merino, three animals (of both genders) had VRQ/VRQ genotype. Breeding work involving elimination of animals encoding valine at codon 136, and introduction of rams with ARR allele to the population increased the frequency of occurrence of ARR/ARR genotype and ARR allele in the population of old-type Polish Merino. To improve the distribution of the genotypes genetically resistant to scrapie in the flock of Polish Merino only rams with ARR/ARR genotype were left. This guarantees an increase in the frequency of occurrence of genotypes genetically resistant to scrapie in the offspring.