The ever-increasing cost and scarcity of conventional feed ingredients in developing countries like India has driven the search alternative feed ingredients for poultry feeding, explain B.N. Suresh and colleagues at the Bangalore Veterinary College and Jawaharlal Nehru Centre for Advanced Scientific Research in the introduction to their papers in International Journal of Poultry Science.

They continue that sugarcane press residue (SPR), a by-product of the sugarcane industry, is one such potential feed ingredient. Other researchers have included SPR at up to four per cent in broiler rations, or 10 per cent in layer diets without any adverse effects.

In recent years, the Bangalore group explains that there has been trends towards formulating high-energy diets for broiler chickens by including fats and oils and new feed ingredients with a high content of non-starch polysaccharides (NSP). However, the immature digestive system of young birds in particular secretes insufficient digestive enzymes for optimum utilisation of the nutrients. There is much research to demonstrate that this can be improved by supplementing the diet with feed enzyme products. Suresh and co-workers added what they describe as 'biotechnological tools' to the diets: lipid-utilising agents (lipase at 0.2 g and lecithin 2 g/kg) and/or an NSP-degrading enzyme product(0.5 g/kg).

The Bangalore researchers included SPR in the maize/soy-based diets of broilers and layers at levels of 0 (control), five or 10 per cent. The feeding trials lasted 42 days for broilers, and 84 days (three periods of 28 days) for the hens. Live production parameters were not measured in these experiments.

Carcass Characteristics of Broilers Fed SPR

At the end of the experiment (day 42), there were no significant differences (P>0.05) in dressing percentage, meat to bone ratio or relative weights of different organs (liver, heart, proventriculus or spleen) relating to the level of SPR in the diet. There were some significant differences between the treatments in terms of the relative weight of the bursa but these were not clearly related to either the level of SPR or enzyme addition.

The main factor significantly affected (P<0.01) by SPR was the relative weight of the abdominal fat: 27.79, 22.60 and 19.13 g/bird or 1.81, 1.47 and 1.33 per cent of live weight for the groups fed 0, 5 and 10 per cent, respectively.

The Bangalore group state that the relative length of different segments of small intestine, i.e. duodenum, jejunum and ileum, of birds under different treatments and main factors were statistically (P>0.05) similar. However, the relative lengths of the jejunum and of the whole small intestine were statistically longer (P=0.01 and P=0.006, respectively) for the birds fed 10 per cent SPR than those on the five per cent SPR diet, with the controls intermediate. The authors were unable to explain this effect.

Suresh and colleagues concluded from their results: "The inclusion of SPR up to 10 per cent in broiler diets has no influence on carcass characteristic parameters namely dressing percentage, and meat to bone ratio besides substantially decreasing the abdominal fat deposition."

Egg Quality Traits in Layers Fed SPR

Suresh and co-authors working on the use of SPR for laying hens found no differences in egg quality characteristics such as egg shape index, albumen index, Haugh unit scores, yolk index and yolk colour between the different treatment groups.

However, they did find an influence of different treatments on egg shell thickness that reached statistical significance (P<0.01): SPR level had an effect on day 28, and the biotechnological tools did so on days 28 and 56 of the trial.

The Bangalore group commented: "SPR can be incorporated up to 10 per cent in layer rations effectively as a source of minerals substituting the expensive conventional feed grains without affecting egg quality."

References

Suresh B.N., B.S.V. Reddy, Manjunatha Prabhu B.H. and N. Jaishankar. 2009. Carcass characteristics of broilers fed sugarcane press residue with biotechnological agents. International Journal of Poultry Science 8 (7): 671-676. [click here for full report]

Suresh B.N., B.S.V. Reddy, Manjunatha Prabhu B.H. and N. Suma1. 2009. Egg quality traits of layers fed sugarcane press residue with biotechnological agents. International Journal of Poultry Science 8 (7): 677-683. [click here for full report]

July 2009