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Variation in the activity of stearoyl-CoA desaturase enzyme and endogenous precursors of unsaturated fatty acids in cow's milk during grazing season

100%
Kuczynska B., Puppel K., Nalecz-Tarwacka T., Czub M.
Annals of Warsaw University of Life Sciences - SGGW. Animal Science
|
2015
|
tom 54[1]
Variation in the activity of stearoyl-CoA desaturase enzyme and endogenous precursors of unsaturated fatty acids in cow's milk during grazing season. The aim of this study was to determine variation in the activity of stearoyl-CoA desaturase enzyme and endogenous precursors of unsaturated fatty acids in cow's milk during the grazing season. The study was carried out in 10 certified organic farms The major criterions of choosing organic farms to the experiment were as follows: obtaining certificate for at least 5 years and abidance of the organic farming standards, possessing a herd of Black and White Polish Holstein-Friesian cows (numbering more than 30 cow. The highest concentrations of CLA cis9, trans11 isomer, TVA and LA in milk fat has been reported in June, slightly lower in July and August. While the lowest level has been recorded in May, at the beginning of grazing period. Significant correlations between MUFA and SCD (r2= 0.828 p<0.01) has been recorded. We concluded, that monitoring of SCD activity can be used as a tool to achieve high unsaturation of milk fat, during grazing period.
2

Effectiveness of magnesium added to diets fed to cows at the beginning of the grazing season

84%
Pysera B., Purwin C.
Polish Journal of Natural Sciences. Supplement
|
2006
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tom 03
227-233
3

The immune response against gastrointestinal nematodes in naturally infected Polish Wrzosowka sheep. I. The serum IgG response to Haemonchus contortus in ewes over three grazing seasons

67%
Moskwa B.
Acta Parasitologica
|
1999
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tom 44
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nr 4
Faecal nematode egg counts and IgG activity to Haemonchus contortus were followed in naturally infected Polish Wrzosówka ewes. The egg counts were overdis- persed; most individuals had relatively low egg counts but a small proportion had high counts. Egg production followed a different pattern each grazing season. Larvae cultured from eggs in 1996 were predominantly H. contortus and Trichostrongylus spp. In 1997 the recoveries were largely Trichostrongylus spp. In 1998, larval recoveries were mainly Trichostrongylus spp. and Teladorsagia spp. There were no discernible patterns in the composition of the nematode population within each grazing season. Egg counts in different months were moderately repeatable, indicating that animals tended to maintain their rankings over time. The repeatabilities rose during the grazing season but declined with increasing intervals between sample dates. IgG activity against a somatic extract of adult H. contortus was higher than activity against a preparation from excretory/secretory antigens but the two responses were very strongly correlated. The repeatability of IgG activity at monthly intervals was higher than the repeatability of faecal egg counts. Animals with higher than average IgG activity had significantly lower than average egg counts but only in the last two years of the study. A combination of egg counts and antibody responses may be better at identifying resistant animals than either method used in isolation, but more research is necessary to determine why the association between antibody and egg counts varies in different years.
4

The mean, distribution and repeatability of faecal egg counts in Polish Wrzosowka ewes following natural gastrointestinal nematode infection during two pasture seasons

67%
Moskwa B., Charon K. M., Cabaj W., Rutkowski R.
Acta Parasitologica
|
1998
|
tom 43
|
nr 2
Faecal egg counts per gram of faeces (EPGs) were measured over a period of two years (1995-1996) in Polish Wrzosówka ewes. Measurements were made at monthly intervals. The first examination in each years was conducted before the start of the grazing season, while the rest of the samples were collected during grazing season. The animals were drenched in May 1996 but not in 1995. EPG were estimated by modified McMaster method and were transformed by log (EPG+1) prior to analyses. Infective larvae of nematode species were identified according to the method described in Anonymous (1986). Meteorological data were collected to evaluate the influence of rainfall and temperature on the faecal egg counts. The MINITAB programme was used to calculate the correlation coefficient between EPGs in different sampling. There was substantial variation among individuals in their EPG. Several nematode species were present; however two nematode genera were dominant: Haemonchus contortus and Trichostrongylus sp. The mean count and the composition of the nematode population was influenced by the weather conditions. H. contortus was the main egg producer during the period of high mean counts when the temperature and rainfall were highest. The correlations between EPG on successive sampling were positive and nearly always significant.
5

The immune response against gastrointestinal nematodes in naturally infected Polish Wrzosowka sheep. II. The serum IgG response to nematode somatic antigens in young ewes over three grazing seasons

67%
Moskwa B.
Acta Parasitologica
|
1999
|
tom 44
|
nr 4
A longitudinal study in young Polish Wrzosówka ewes, naturally infected with gastrointestinal nematodes, was carried out to examine the association between parasite-specific IgG antibody and faecal egg counts. IgG activity varied among the young ewes in each sampling month. The highest individual values were measured in the second half of the each season, when the overall means were highest. The distribution of IgG activity among individuals was unimodal with a positive skew. This study appears the first to examine the distribution, among animals and over time, of IgG responses to natural mixed infection. Serum IgG responses were repeatable and significantly associated with reduced nematode faecal egg counts. A combination of faecal egg counts and IgG responses can be used to identify animals with increased resistance to nematode infection in this breed of sheep.
6

Stability of nematode parasite communities of sheep in a Polish flock in relation to years, seasons and resistance status of hosts

59%
Gruner L., Malczewski A., Gawor J., Nowosad B., Krupinski J., Bouix J.
Acta Parasitologica
|
1998
|
tom 43
|
nr 3
The infection of sheep with gastrointestinal nematodes was studied during 4 consecutive years in a flock from southern Poland in which ewes were grazed from May to October and lambs from June to October. Each month during the grazing season, 1 ewe and 2 lambs were necropsied and their worm burdens established at the species level. At the end of the grazing season in 1993 and 1994, 12 lambs selected from the progeny of 2 resistant sires (as established by ranking the faecal egg counts of all their progeny) and 12 from 2 susceptible sires (plus 12 from intermediate sires in 1994), were sampled for individual egg counts and faecal culture. Subsequently they were necropsied to verify if resistance was specific. Teladorsagia circumcincta and Haemonchus contortus were the predominant species present; Trichostrongylus vitrinus, Trichostrongylus axei, Nematodirus filicollis and Cooperia curticei were also present but less abundant. Trichostrongylus colubriformis, Nematodirus helvetianus, Strongyloides papillosus, Chabertia ovina, and Trichuris ovis were present in low numbers except in the last year when S. papillosus was more common. Nematodirus spp. was more common in worm burdens of the lambs than in ewes (25% of <2%). Male lambs were more commonly infected with T. circumcincta and S. papillosus than females but less commonly infected with N. filicollis and C. curticei. Lambs of resistant sires had around half as many worms as those from susceptible sires; although the species composition was essentially similar, except for a somewhat lower proportion of T. circumcincta in 1994 in lambs of resistant sires. The diversity of nematodes present was assessed in terms of species richness, the Shannon index and the equitability index of Pielou. Except for higher richness values in 1992, these indices were not affected by the month of the grazing season, the year, the type of host (ewe or lamb), the sex or the resistance status of the lambs, despite minor differences in species composition. This indicated a high stability of the species diversity in this flock through time as well as between host characteristics.
7

The repeatability of haematological and parasitological parameters in Polish Wrzosowka hoggets naturally infected with trichostrongylid nematodes

51%
Moskwa B., Doligalska M., Cabaj W.
Acta Parasitologica
|
1998
|
tom 43
|
nr 3
Relationship between faecal egg counts and haematological parameters: PCVs, peripheral eosinophil counts, total white blood cell counts (TWBCs) and white cells composition in blood of Polish Wrzosówka breed of sheep were estimated in 1995 and 1996. Hoggets were naturally infected with gastrointestinal nematodes. Anthelmintics were not used. Among Teladorsagia circumcincta, Cooperia spp., Chabertia ovina, Nematodirus spp. (mainly N. spathiger) two species: Trichostrongylus spp. and Haemonchus contortus dominated. High repeatability of EPGs, PVCs and peripheral eosinophil counts were observed over two grazing seasons. There were no significant changes in TWBCs, in percentage of lymphocytes and neutrophils in blood smears. Marked differences in percentage of eosinophils in blood smears were confirmed in peripheral eosinophil counts. Additionally, the eosinophil counts in most sampling data correlated negatively with EPGs. The lowest level of haematocrit correlated negatively with EPGs when the highest percentage of L3 H. contortus larvae were found in the faecal culture. The results reveal that EPGs, PVCs and peripheral eosinophil counts could be considered in terms of phenotypic markers for identification of Wrzosówka sheep with different level of acquired immunity to natural trichostrongylid infection.
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