Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

1 Medycyna Weterynaryjna

1 2007

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Zmiany w zawartosci tluszczu i bialka w mleku krow wysoko wydajnych

100%

Tomaszewski A. , Hibner A. , Zachwieja A. , Tesyna E. , Chladek G.

tom 63

nr 07

850-853

The aim of the analysis was the assessment of some milk yield features of heifer cows starting milk production within the space of the last twenty years. Research material consisted of information about milk yield of 3357 heifer cows of Black-White breed with lactations no shorter than 260 days of milking from one of the high yield cattle herds in South-West Poland. Assessed features like the percentage of protein content and the index of protein building turned out to be significantly higher in a group of pure black-white breed cows. The content of protein in a group of crossbreed animals from the final stages of displaced crossbreeding (87.6-100% HF) was lower by 0.16%. Similarly, the index of protein building (IPB) was significantly lower (p = 0.01) in a group of crossbreed cows in comparison to pure-breed Black-White animals. The calculated coefficient of the correlation between fat and protein content in milk was r = 0.546 (p = 0.01). However, this value does not authorize the use of the selection for only one feature (percentage of fat), since it would not lead fully to the increase of the second one (percentage of fat). For this reason, the authors express the opinion that obtaining the optimal difference in fat to protein content in milk (RTB = 1:1) on a level of 3.5% is possible; however, it will require a multigenerational improvement of animals toward this goal.