Volume 97, Issue 1, January 2014, Pages 543–551
Abstract
This
study was performed to evaluate α-tocopherol and β-carotene contents of
pasture milk under ordinary Sicilian farming conditions. Fourteen dairy
farms were allocated into 2 balanced groups on the basis of cultivated
(CULT) or spontaneous (SPO) pasture type feeding. Bulk milk per farm was
collected 4 times from February through April at 3-wk intervals.
Pasture botanical and diet composition, diet nutritional quality, milk
yield and composition were estimated each time. Pasture intake levels
were calculated based on feed analyses, hay and concentrate amounts fed,
and milk yield and chemical composition. According to pasture intake,
the farms were split into low pasture intake (LPI; <29.5% of dry
matter) and high pasture intake (HPI; >29.5% of dry matter) groups.
Milk samples per farm were analyzed for α-tocopherol and β-carotene
contents by HPLC. The SPO group had higher levels of α-tocopherol and
β-carotene in milk (0.7 and 0.3 mg/L, respectively) and milk fat (19.0
and 7.5 mg/kg fat, respectively) compared with the CULT group in milk
(0.5 and 0.2 mg/L, respectively) and milk fat (14.6 and 4.9 mg/kg,
respectively). High pasture intake compared with LPI increased
α-tocopherol in milk fat (18.0 and 16.0 mg/kg of fat, respectively).
However, only in the SPO (not in CULT), HPI compared with LPI increased
milk α-tocopherol (0.8 vs. 0.6 mg/L, respectively), milk β-carotene (0.3
vs. 0.2 mg/L, respectively), and milk fat β-carotene (8.4 vs.
6.6 mg/kg, respectively). Results may be related to the different
botanical composition of the respective pasture types and pasture
intake. Spontaneous pasture compared with CULT contained a higher mass
proportion of Asteraceae, Fabaceae, Cruciferae, Euphorbiaceae, and
Malvaceae plants. Milk and milk fat α-tocopherol levels were higher on
test-days (TD)-1, TD-2, and TD-4 compared with TD-3. For HPI farms, milk
fat β-carotene content was higher on the first 2 TD compared with the
last 2 TD. These differences could be related to plant biological stage.
On Sicilian dairy farms, the highest milk α-tocopherol and β-carotene
contents may be obtained feeding high levels of SPO pasture in the
spring.
Key words
- milk;
- α-tocopherol;
- β-carotene;
- pasture
Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
