Individual intake was recorded daily. However, only the
measurements collected during the last week of each experimental
period were used for statistical analysis. During each
experimental period, representative samples of hay, maize
grain, flattened wheat and concentrates were composited
daily and stored at 2208C. Chemical composition of feed
ingredients was determined using standard procedures(21).
Milk yields of individual goats were recorded three times per
week. However, only the measurements collected during
the last week of each experimental period were analysed statistically.
Samples of milk were collected from all goats over
four consecutive milkings starting at 08.00 hours on day 19 of
each experimental period for fat, crude protein and lactose
analysis. Milk fat, crude protein and lactose were determined
in samples treated with preservative (potassium bichromate;
Merck, Fontenay-Sous-Bois, France) by mid-infrared spectroscopy
(21). Unpreserved samples of milk were also collected
over two consecutive milkings starting at 08.00 hours on day
20 of each experimental period, stored at 2208C, composited
according to yield and analysed for the determination of FA
composition(22). The live weight of each experimental animal
was measured at the start and end of each experimental period.
Blood samples were collected on day 20 of each experimental
period at 07.30 hours. Samples from the jugular vein were
collected into evacuated collection tubes (Venoject; C.M.L.,
Nemours, France) containing potassium ethylene diamine
tetra-acetic acid. Once collected, blood samples were centrifuged
(1500 g for 15 min at 48C, stored at 2208C), and plasma
was analysed for insulin and metabolite concentrations(12