Data from 662 litters and 221 samples (two replicates per each sample) of rabbit milk were collected
from three different genetic groups [Gabali (G), V-line (V) and G×V (F1)] to study the effect of line and of some
non-genetic factors affecting production and milk composition traits. The studied traits were: number born
alive (LSBA); litter size at weaning (LSW); litter weight born alive (LWBA); litter weight at weaning (LWW); total
milk yield (TMY) and protein, fat, total solids (TS), ash, phosphorus (P), potassium (K), sodium (Na), calcium
(Ca) and magnesium (Mg) milk content. The genetic group effect was significant for LSBA [V (7.3) and F1(7.3)
were superior to G (6.6)); LWBA (higher values for V (416 g) and F1 (405 g) than for G (382 g)]; TMY [G (3497
g) and F1(3486 g) higher than V (3042 g)]; milk fat [F1 (26%) and G (25%) superior to V (23%)] and milkTS
[F1(42%) superior to G (40%) and V (39%)]. The estimates of the heterosis effect ranged between 1.6% and
12.8% for production and milk gross chemical traits, being significant only for milk fat content (9.1%). The
positive values of the heterosis estimates for those traits and the complementarity between the G breed and
the V line, the G superior in milk related traits but the V superior in prolificacy, show the interest of their cross
and of the synthetic lines derived from them. The heterosis was non-significant for milk mineral content traits.
The parity effects were significant for LSBA, fat, TS, ash and K (the maxima were reached at 6th or 5th parity).
The effect of week of lactation was significant for fat, ash and TS, corresponding the maximum values of fat
and TS to the 3rd and 4th week. The year-season or the year-month effects were significant for all traits
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