ASSESSMENTS OF THE DRY PERIOD IN DAIRY COWS FROM MOUNTAIN AREA

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 515-520 pp, DOI: 10.5593/sgem2017/61/S25.067

ABSTRACT

The research in dairy cows in mountain aria demonstrated that the arithmetic average of the mammary repose period is about 62 days. This value is very close to the desired value of cow breeders. Very high value of the coefficient of variation (57.28%) shows that we are dealing with an average resulting from compensation. This theory is supported by very large difference of about 13 days between arithmetic and probable average of dry period. Probable average is 49 days to 311 registered cows, preceded by a shorter dry period on 21 days average to other 113 cows, which show that the mammary repose is not respected by most farmers. Standard Deviation (s) has limits between 42.12 days in 2 th lactation and 19.7 days in 8th lactation. The variability of dry period is reduced to lactations with serial number higher coefficient of variation is greatest in 2 th lactation (63.79%) and minimum in lactation 7 th (34.93%). The average standard error (± sx) has maximum 4.52 days at 8th lactation and a minimum of 2.64 days in 3th lactation. The „F” test (Fisher) confirms that the average dry period of 62 days is a consequence of compensation between long and short breast rests, which shows poor management of dry period.

Keywords: dry period, cows, variability, standard error, Fisher test.