A comparison of lactation physiology effects at high and lower yield on components, properties and health state indicators of milk in Czech Fleckvieh
2010
Sojkova, K.,Agrovyzkum Rapotin, Vikyrovice (Czech Republic) | Hanus, O.,Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic) | Riha, J.,Agrovyzkum Rapotin, Vikyrovice (Czech Republic) | Yong, T.,Anhui Agricultural Univ., Hefei (China) | Hulova, I.,Agrovyzkum Rapotin, Vikyrovice (Czech Republic) | Vyletelova, M.,Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic) | Jedelska, R.,Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic) | Kopecky, J.,Agrovyzkum Rapotin, Vikyrovice (Czech Republic)
Differences within milk indicators (MIs) between two Czech Fleckvieh (CF) dairy cow groups with high (CF1; n = 213 individual milk samples (animals)) and lower (CF2; n = 265) milk yield (MY) were tested. The files were balanced in factors of lactation. Group 1 had higher genetical value and even better nutrition according to the MY. Average daily MY was higher by 56% in CF1 than in CF2. Significant differences (P less than 0.001) were determined for fat (FAT), lactose (LAC), solids non fat (SNF), log somatic cell count (log SCC), crude protein (CP), casein (CAS), true protein (TP) and fat/crude protein ratio. CF1 cows had lower milk FAT, LAC, SNF and log SCC than CF2 cows. CF1 cows had higher genetic potential and higher feed intake. There were significant differences between CF1 and CF2 in milk nitrogen fraction for CP, CAS and TP. The two groups showed significant differences in electrical conductivity (CF1 more than CF2), time for enzymatic coagulation (renneting ability; CF1 less than CF2), rennet curds firmness (CF1 less than CF2), whey volume after renneting (CF1 more than CF2), whey protein (CF1 less than CF2) and ratio of urea nitrogen in the non protein nitrogen (CF1 more than CF2). Insignificant differences existed for the next 9 MIs (as acetone, pH, titration acidity, alcohol stability, casein number). Surprisingly, higher milk urea was not linked with higher MY in CF breed. The differences in MIs between CF1 and CF2 do not represent health troubles. High MY which was reached by genetic improvement and more effective nutrition did not lead to aggravated milk quality, but led to its lower technological recovery.
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