Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: pasture season

Sortuj według:

Ogranicz wyniki do:

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Influence of lactation stage on selected blood parameters and biological value of cow milk during pasture season in organic system of production

100%

Sakowski T., Puppel K., Golebiewski M., Kuczynska B., Metera E., Grodkowski G.

Annals of Warsaw University of Life Sciences - SGGW. Animal Science

2015

tom 54[1]

Influence of lactation stage on selected blood parameters and biological value of cow milk during pasture season in organic system of production. The disproportion between the cow's genetically determined ability to produce milk and the limits to improving the energy value of feed may be the cause of the metabolic stress of animals kept at organic farms. Negative energy balance has a major impact on the body's hormonal balance and the function of the organs; it also affects the content of basic components (protein, fat and lactose) in cows' milk. The aim of the study was to investigate changes in the biological value of organic milk obtained from high producing dairy cows at different stages of lactation during pasture season. The study was carried out on 68 Polish Holstein-Friesian primiparous. 272 milk samples were collected from cows which were in one of the following phases: the beginning of lactation (BL): 5-30 days postpartum); peak of lactation (PL): 60-90 days postpartum; full lactation (FL): 120-150 days postpartum); end/final phase of lactation (EL): 250 days postpartum. Stage of lactation had an overriding effect on the majority of analyzed milk constituents including: whey proteins, vitamins soluble in fat, phospholipids and fatty acids. The highest levels of lactoferin were found at the beginning of lactation (BL). At the same time, the β-hydroxybutyrate (BHBA) concentration increased, which confirmed that the fast growing milk yield at the peak of lactation is linked to an increase in energy demand. The lowest alanine aminotransferase and non esterified fatty acids activity was measured during BL. The study has shown a significant influence of lactation stage on the biological value of organic milk obtained from high producing dairy cows during pasture season. In addition, there is evidence that the organic production system has no influence on the metabolic profile of cows as the plasma parameters were within their standard norms. This might be the result of the positive effect of grass antioxidants.

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

80%

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.

Ograniczanie wyników

1 Acta Parasitologica

1 Annals of Warsaw University of Life Sciences - SGGW. Animal Science

1 Cabaj W.

1 Charon K. M.

1 Golebiewski M.

1 Grodkowski G.

1 Kuczynska B.

1 Metera E.

1 Moskwa B.

1 Puppel K.

1 Rutkowski R.

1 Sakowski T.

1 2015

1 1998

Wyniki wyszukiwania

Influence of lactation stage on selected blood parameters and biological value of cow milk during pasture season in organic system of production

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