| Summary: | Growth trials, a digestibility and N-retention trial were conducted using broiler chicks to compare the nutritional value of broiler starter rations based on barley, corn, wheat or combinations of two cereals.
When barley replaced wheat to a maximum level of 50% of the total diet with adjustments to keep diets iso-nitrogenous, feed consumption increased with increasing barley, weight gain fell when barley was used at levels beyond 30% of the diet and feed efficiency fell with increasing barley. However, differences in these parameters were not significant. Feed intakes were 1274, 1292, 1323, 1304, 1311 and 1308 g/bird, weight gains 806.25, 817.50, 826.00, 817.25, 802.75 and 797.50 g/bird and feed/gain ratios 1.58, 1.58, 1.60, 1.60, 1.63 and 1.64 for 0, 10, 20, 30, 40 and 50% barley diets respectively.
When corn replaced wheat to a maximum level of 48.6% of the total diet, feed intake significantly (P <.01) decreased while feed efficiency significantly (P <.005) improved with increased corn. High wheat diets gave slightly better weight gains than diets high in corn, however best weight gains were achieved when the two cereals were used in a combination of approximate equal proportions. Differences in weight gains were not significant. Feed intakes were 1466, 1440, 1433, 1426, 1386 and 1386 g/bird. Weight gains were 913.00, 912.75, 921.75, 936.25, 902.00 and 901.75 g/bird and feed/gain ratios were 1.61, 1.58, 1.56, 1.52, 1.54 and 1.54 for the 0, 10, 20, 30, 40 and 48.6% corn diets respectively. When barley replaced corn up to a maximum level of 47% of the diet with adjustments in soybean meal and animal tallow to maintain diets iso-nitrogenous and iso-caloric, there was no significant difference between diets in feed intake, weight gain or feed efficiency although a decline in feed efficiency appeared to occur at 47% barley. Feed intakes were 1349, 1395, 1299, 1404, 1375 and 1394 g/bird, weight gains were 856.62, 885.72, 836.28, 895.25, 863.42 and 874.00 g/bird and feed/ gain ratios were 1.58, 1.58, 1.56, 1.57, 1.59 and 1.60 for the 0, 10, 20, 30, 40 and 47% barley diets respectively.
Corn had significantly (P <.005) higher digestible dry matter (91.40%) than wheat (88.25%) and barley (87.49%), and barley had significantly (P <.05) lower nitrogen retention (71.43%) than corn (77.67%) and wheat (74.03%). No significant difference occurred in the digestible dry matter of diets based on the three cereals but a barley-based diet gave significantly (P <.005) lower nitrogen retention (74.03%) than diets based on corn (84.86%) and wheat (83.74%).
It was concluded that no significant difference occurs in weight gain when broilers are fed corn or wheat based diets but corn-based diets give better feed efficiency. Barley-based diets are not practical in broiler feeding due to low metabolizable energy in barley, however, barley in combination with corn or wheat can be successfully used in practical broiler ratios to a level of 30% of the total ration without a significant effect on weight gain and feed efficiency. === Land and Food Systems, Faculty of === Graduate
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