Abstract:
The objective of the study was to investigate the effects of feeding sprouted sorghum (Sorghum bicolor) diets fortified with exogenous enzymes on egg production by Red and White Amberlink layers. Egg production by 216 Red and White Amberlink layers which were 16 weeks into production was evaluated over a six-week period. The layers were housed in a naturally ventilated battery house, placed in forty-eight 45 cm length × 45 cm width × 42 cm height cages, each stocked at 3 birds/cage. The birds were allocated to treatments in a randomised 3 (diets) X 2 (enzymes) X 2 (strain) factorial arrangement replicated six times. Experimental diets were Meadow Powerlay Late Lay (Product V16418) as a positive control (PC), and iso-nutrient (70 g/kg Crude Fibre, 130 g/kg CP, 5 g/kg Lysine), sprouted, and raw (negative control (NC) sorghum-soybean layer diets. A duplicate mix of each diet was fortified with 500 g/tonne of a custom multi-enzyme cocktail (xylanase Endo-1, 4-Beta-Xylanase (EC-3.2.1.8), 2440 U/kg, Endo-1, 3 (4)-Beta-Glucanase (EC-3.2.1.6), 304 U/kg, and 6-phytase (IUB 3.1.3.26), 1220 U/kg). Layers on the raw sorghum diet had low (P<0.05) feed intake. Interaction (p = 0.0038) of the layer strain, diet and enzyme occurred for the laying rate. Highest (P<0.05) laying rate was attained when the Red Amberlink layers were on the commercial diet with enzymes, and when White Amberlink layers were on the same diet without enzymes, similar (P>0.05) to when both strains were on the enzyme supplemented, sprouted sorghum diet. Lower (P< 0.05) laying rates were observed when both strains were on the raw sorghum, without (P>0.05) enzyme effect compared to other treatments. Laying rate in layers on the sprouted sorghum diet was not different (P> 0.05) from the commercial diet, and significantly higher (P< 0.05) raw sorghum-based diet with or without enzyme fortification. The net effect of treatments on laying rate was in the dietary order commercial feed >sprouted sorghum >raw sorghum (P<0.05). The Red Amberlink strain laid larger (P<0.05) eggs than the White strain. Expressed on both egg number and egg weight basis, the FCR were in the dietary order commercial feed >sprouted sorghum >raw sorghum (P<0.01). Strain*enzyme interaction occurred for egg weight (P<0.05), whereby the enzymes reduced (P<0.05) egg weight in Red Amberlink layers when on the sprouted sorghum diet, which was quantitatively similar on all other treatments, except for opposite, quantitative enzyme effect on White Amberlink layers on the commercial diet. Though inferior to the commercial diet, the comparative egg production and FCR largely supported replacement of the commercial, with sorghum diets, more so when the sorghum is sprouted. Treatment interaction on egg production and size suggested both beneficial and deleterious enzyme action, likely the effects of unique dietary chemical matrices.
