Feeding preferences of ostriches towards the inclusion of full-fat canola seed in grower diets
The largest expense of an intensive ostrich production unit is feed cost (ca.75%). Protein makes up a great portion of feed for monogastric animals and this expense can be lowered by utilizing locally produced feedstuffs such as full-fat canola, although it is not clear whether ostriches will readily consume full-fat canola because of its anti-nutritional and other known factors. To evaluate the feeding preference of ostriches towards full-fat canola, 60 South African Black ostriches (82.2 ± 1.06 kg in live weight) were placed in 10 camps of six birds per camp. Each camp had five identical feed troughs containing diets in which full-fat canola seed (FFCS) incrementally (0, 25, 50, 75 and 100% of protein source) replaced the soybean oilcake meal (9.8% of the total diet composition in control diet was soybean oilcake meal and full-fat canola was included up to 27.5% of the total diet) as protein source. Dry matter intake (DMI) was measured daily and feed colour characteristics were measured, based on L*, a* and b* colour attributes. Only the 25%FFCS showed a higher DMI (817.38 ± 81.98 g/bird/day) and percentage DMI (~29.53%) than the other diets, with an average DMI of 488.8 g/bird/day) and percentage DMI of 17.62%. Although the 0%FFCS, 50%FFCS and 75%FFCS had a lighter colour than the 25%FFCS and 100%FFCS and the b* colour parameter for 100%FFCS was lower than the rest, it is believed that these differences had no effect on DMI. Based on the results of this study, diets with up to 27.5% full-fat canola seeds had no detrimental effect on feed intake of finishing ostriches. Birds prefer diets with a combination of 6.9% full-fat canola seed and 7.4% soybean oilcake meal.
Keywords: Anti-nutrients, dry matter intake, feed colour, feed palatability, glucosinolates, ostrich