A completely random design of this experiment was conducted to evaluate rocket and onion oils or mixture of these oils in diets of NZW rabbits under climate summer conditions on their productive and reproductive performance traits. Digestibility coefficients and nutritive values, milk yield, some blood serum constitute and economic efficiency, semen characteristics of buck and their offspring performance were estimated.A total number of 48 NZW rabbit does (6 months old) and 12 bucks (6 month old) with nearly similar weights were divided at random into four groups (12 does and 3 bucks in each). Rabbits were fed either basal diets as control diet (G1) or control diet supplemented with either 1 g/kg diet of rocket oil (G2), onion oil (G3) or mixture of these oils (G4). The experiment prolonged during the hot summer conditions started in May to July, 2009. The experimental diet was isonitrogenous (CP=18.5%) and isocaloric (about 2401 kcal/kg DE).
Results showed that percentages of total unsaturated fatty acids, especially linoleic were higher in onion oil than in rocket oil. The percentage of erucic fatty acid was higher in rocket oil than in onion oil. Does fed G2 diet recorded the highest (P<0.05) values of feed intake, final body ,weight, gain, conception rate, number of parturition, litter size, litter weight, litter weight gain at birth and at weaning. Digestibility coefficient of CP and EE and nutritive value expressed as DCP were the highest (P<0.05) with rabbits fed the rocket oil diet. Average daily milk yield during different lactation weeks and feed conversion ratio to milk production were the highest (P<0.05) for does fed rocket oil diet. However, does fed onion oil diet showed the highest (P<0.05) milk contents at most lactation weeks. Weight at weaning, weight gain and relative growth rate of bunnies were the highest (P<0.05) for does fed rocket oil diet. Mortality rate at birth and during the suckling period was the lowest (P<0.05) for bunnies of does fed onion oil diet. Does received rocket oil diet recorded the lowest (P ≤ 0.05) values of blood serum cholesterol, triglycerides and low density lipoprotein cholesterol (LDL) followed by those fed mixture of rocket oil and onion oil. However, control group recorded the highest value. Most physical semen characteristics, including sperm cell concentration, and percentages of motility and dead spermatozoa were the best (P<0.05) for the buck rabbits fed rocket oil diet .Does received rocket oil diet recorded the highest net return and economic efficiency followed by those fed diet supplemented with onion oil or rocket oil plus onion oil.
Results of the experiment showed that addition of 1 g rocket oil /kg diet was more effective than other treatments for improving productive and reproductive performance traits, digestibility coefficients and nutritive values, milk yield of NZW doe and buck rabbits under hot climate of summer season in Egypt.