Effect of Parity on Dynamics of Milk Yield and Composition during Normal Lactation in Dairy Cows

Simona Baul

Abstract


The purpose of the research was to study the effect of lactation order on milk quality and quantity for 125 lactations of Romanian Black and White Spotted cows breed, data were recorded and statistically analyzed by ANOVA / MANOVA method determining the average values and dispersion indices. Based on averages parameters of lactation curves were calculated using the mathematical model proposed by Wood called incomplete gamma function. For the order of lactation there were significant differences (p<0.05) for the evolution of milk daily quantity (parameter a) between 1st and 3rd lactation (-4.39805 kg), for the daily milk growth rate (parameter b) the difference was significant (p<0.05) between lactation 1 and 3 (-0.07683 kg) and for daily milk loss rate (parameter c) there were distinct significant differences (p <0,01) between lactation 1st and lactation 3rd (-0.00254). There were significant differences (p<0.05) for the rate of decrease in the amount of milk between lactation 2 and lactation 3 (-0.00093 kg). Also, there were significant differences (p<0.05) for the growth rate of daily milk between lactation 3 and lactation 5 and above (0.02134 kg) and for daily rate of decrease in the amount of milk the difference being 0.00045 kg.


Keywords


dairy cows, lactation order, Romanian Black and White Spotted breed, milk dry matter, milk quality

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Scientific Papers Animal Science and Biotechnologies publish open access articles under the terms of the Creative Commons Attribution 4.0 Licence (read full legal code).


LUCRARI STIINTIFICE ZOOTEHNIE SI BIOTEHNOLOGII (SCIENTIFIC PAPERS ANIMAL SCIENCE AND BIOTECHNOLOGIES)

ISSN print 1841 - 9364
ISSN online 2344 - 4576
ISSN-L  1841 - 9364
(former ISSN 1221-5287, E-ISSN 1841-9364)

PUBLISHER: AGROPRINT Timisoara, Romania
PAPER ACCESS: Full text articles available for free
FREQUENCY: Semiannual
PUBLICATION LANGUAGE: English
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Banat´s University of Agricultural Sciences and Veterinary Medicine "King Michael I of Romania" from Timisoara
Faculty of Animal Science and Biotechnologies
300645, Timişoara, Calea Aradului 119, Romania

E-mail: spasb [at] animalsci-tm.ro
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