 |
|
|
|
|
|
 |
New Zealand Journal of Agricultural Research abstractsVariation of lactoferrin and lactoperoxidase in
bovine milk
and the impact of level of pasture intake
S-A. Turner
N. A. Thomson
Dexcel
M. J. Auldist
Department of Primary Industries
Abstract Lactoferrin (Lf) and
lactoperoxidase (LP) are
milk proteins with antimicrobial and immunomodulatory activities. This
study
examined the effect of pasture allowance on the production of Lf and
activity
of LP, as well as the variation in the concentration of Lf and activity
of LP in
the milk of lactating dairy cows during late lactation. Following a
2-week
period where a herd of 20 cows was grazed solely on pasture, two
different
nutritional regimes were imposed upon the cows. For 4 weeks, 10 cows
grazed ad
libitum while the other 10 grazed
a restricted amount of pasture. Milk samples were
collected twice weekly throughout the experiment and were analysed for
Lf
concentration and LP activity, as well as for pH and concentrations of
total
solids, fat, protein, casein, lactose and somatic cells. Cows that had ad
libitum access to pasture had higher milk yields, and higher
concentrations
of crude protein, true protein and casein and higher yields of fat,
protein and
lactose than those that had a restricted pasture allowance. While there
was no
difference in the concentration of Lf in the milk between the two
herds, cows
that had ad libitum access to pasture produced significantly
greater
yields of Lf than those that were restricted (1.45 versus 1.23 g day–1;
P < 0.05). LP activity was greater in the milk of cows that
had ad
libitum access to pasture (6.9 versus 6.1 U ml–1; P
<
0.01). Results for all milk components measured indicated that the
variation
between cows was much greater than the variation within cows. The
quantification of these sources of variation will enhance the design of
future
experiments that examine the concentrations of Lf and the activity of
LP in
milk. They also provide information about the extent to which on-farm
management could be used to manipulate Lf concentration and LP activity
in
milk. Keywords lactoferrin;
lactoperoxidase; late
lactation;
milk; nutrition
PDF file of entire paper: Print-quality (224K) | screen-quality (306K) This year's abstracts | Journal home page | All abstracts | Publishing home page |