INFLUENCE OF THE CALVING SEASON ON THE MILK YIELD GIVEN BY A FRIESIAN POPULATION, IMPORTED FROM THE NETHERLANDS

V. Maciuc

Abstract
The individual milk production at cows is influenced by several factors, which taken by their nature, may be genetic factors and environmental factors. The calving season has an influence on the milk production per lactation, through ratio structure and nutrition level and by climatic factors, as well. In this study the research was focused on the influence of the specified factor on the milk production in Frisian cows from Netherlands exploited in the eastern parts of Romania. The ascendance of cows was valuable, including mothers who had an average production of 7,923.4 kg milk, 4.23% fat and 287.97 kilograms pure fat. Paternal grandmother have achieved more superior yields then maternal mothers with average values of 8960.29 kg milk, 4.37% fat and 371.25 kilograms pure fat. The best milk production from the descendants was registered during winter season, 7,798.51 ± 204.07 kg of milk per total lactation and 7,379.31±132.79 Kg of milk per normal lactation, the differences between seasons being statistically significant p>0.05.

Key words: Frisian, cows, milk production, calving season, influenced

INFLUENTA SEZONULUI DE FATARE ASUPRA PRODUCTIEI DE LAPTE LA O POPULATIE DE TIP FRIZA IMPORTATA DIN OLANDA

V. Maciuc

Rezumat
La vaci, productia individuala de lapte este influentata de o serie de factori care, dupa natura lor, se pot grupa în factori genetici si factori de mediu. Sezonul fatarii influenteaza productia de lapte pe lactatie, atât prin structura ratiei si nivelul de furajare cât si prin factorii climatici. În lucrare, s-a urmarit influenta factorului mentionat asupra productiei de lapte la o populatie de tip Friza din Olanda exploatata în conditiile pedoclimatice din estul României. Ascendenta efectivului analizat este valoroasa cu mame care au avut o productie medie de 7923,4 kg lapte, 4,23% grasime si 287,97 kg grasime pura. Bunicile dupa tata (MT) au realizat productii superioare mamelor (MM) având valori medii de 8960,29 kg lapte, 4,37 % grasime si 371,25 kg grasime pura.
Cea mai buna productie de lapte obtinuta de la descendenta s-a înregistrat în sezonul de iarna, pe lactatie totala 7798,51 ± 204,07 Kg iar pe lactatie normala 7379,31 ± 132,79 Kg, diferentele între sezoane fiind statistic semnificative p > 0.05.

Cuvinte cheie: Friza, vaci, lapte, sezonul fatarii, influenta