Digestibility and digestive organ development in indigenous and improved chickens and ducks fed diets with increasing inclusion levels of cassava leaf meal.

Growing indigenous Cambodian chickens and ducks, and broiler chickens and White Pekin ducks were fed diets containing 0%, 7%, 14% and 20% of cassava leaf meal (CLM) to study the effects of CLM level on diet digestibility and gastrointestinal tract (GIT) and organ development. The coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM) and intake of digestible DM decreased with increased dietary CLM. DM and digestible DM intake was higher for local breeds than for the corresponding exotic breeds, and higher for ducks than for chickens (p < 0.001), although there were no species or breed effects on CTTAD of DM (p > 0.05). Weight of small intestine, caeca, gizzard and pancreas, expressed as per kg body weight, increased with increased CLM in the diet (p < 0.001). There was no consistent diet effect on liver weight. Length of small intestine and caeca, expressed on a mass-specific basis, increased with dietary CLM content (p < 0.001). When expressed as per kg body weight small intestine, proventriculus, gizzard, pancreas and liver weights, and small intestine length, were higher in ducks than in chickens (p < 0.001), and were higher in the indigenous than in the improved breeds (p < 0.01), except for small intestine weights, which were similar. However chickens had higher weight of caeca (p < 0.001) and colon (p < 0.01) in absolute units and per kg body weight.

An evaluation of brewery waste as a replacement for concentrates in diets for growing crossbred common ducks.

An experiment was carried out to determine the effect of feeding brewery waste that replaced different levels of concentrate in diets for growing crossbred common ducks. A total of 300 ducks at 3 weeks of age were allocated in a 2 x 5 factorial experiment. Two feeding systems were compared, with the brewery waste provided separately (S) or mixed (M) with a concentrate. For the first feeding system the concentrate was fed alone (C100M), or replaced successively by brewery waste at ratios of concentrate to brewery waste: 75:25 (C75M), 50:50 (C50M) and 25:75 (C25M) on a dry matter basis, and fed ad libitum. For the second system concentrate and brewery waste were fed separately, with the same levels as in the first system. Total feed intakes for both feeding systems and intakes of brewery waste, total dry matter, crude protein, calcium and phosphorus increased significantly as concentrate was reduced (p <0.05). Daily weight gains were not significantly different between the two feeding systems, but were significantly lower for the C25 and C0 diets (p <0.05). Replacement of 50% of the concentrate by brewery waste resulted in the best growth performance. The highest net profits were from the separate feeding system, and for ducks fed brewery waste only (C0). It is concluded that brewery waste can replace traditional diets for crossbred common ducks based on concentrate.