Author/Authors :
Tiantong, Attapol Faculty of Animal Sciences and Agricultural Technology - Silpakorn University, Phetchaburi IT Campus, Phetchaburi, Thailand , Augustino Mwabena, Danford Faculty of Animal Sciences and Agricultural Technology - Silpakorn University, Phetchaburi IT Campus, Phetchaburi, Thailand
Abstract :
Several factors affect milk production in cows, including parity which can affect milk quality and health of
cows. One of the essential process that occurs in the mammary gland at the drying stage is known as Involution which
removes the milk-producing epithelial cells when they become redundant. In this stage, also, the γ-globulin (Ig), lactoferrin (Lf ), and bovine serum albumin (BSA) levels which are the major protective proteins in the mammary secretion
increased strongly. Matrix metalloproteinase-2 and -9 (MMP-2, -9) are enzymes secreted by leukocytes that play an
important role in the remodeling mechanisms of the mammary gland during involution. Therefore, the objective of
this study was to compare the protective protein components and the proteolytic capacity of the mammary secretion
in primiparous and multiparous cows during the first 2 weeks after drying off. Six crossbred Holstein dairy cows with
differential parity, including the 1st, 2nd, and 3rd parities, were used in this study. Mammary secretions were collected
from the four quarters on d 0, 3, 7, and 14 of drying off and analyzed for protective protein components and the proteolytic capacity. Results showed that the total protein concentration and the proteinous component bands, including
Ig, Lf, and BSA, were significantly higher in multiparous cows than in primiparous cows (P < 0.05) on d 7 and 14 of
drying off. In contrast, the casein protein level decreased in multiparous cows compared to primiparous cows on d 7
and 14 of drying off. The level of MMP-9 in the mammary secretion of primiparous cows increased temporarily only
on d 3, whereas that of multiparous cows gradually increased up to d 7. It can be concluded that the mammary glands
in the multiparous cows underwent significant changes during the dry period. These changes most probably indicate
the need of the mammary glands to deal with the characteristics of the involution.
Keywords :
Parity , Proteolytic activity , Mammary secretion , Involution , Dairy cow
