Natural rubber serum protein as a potential feed ingredient for growing broiler chickens

Natural Rubber Serum (NRS), the aqueous portion of natural rubber (NR) latex contains proteins that can be extracted to be used in animal feed although, in the conventional rubber processing scenario, it is discarded in the effluent. The NRS protein has strong potential as an alternative protein source for animal feeds. However, studies on its palatability in the animal diet and its effect on growth performance remain scarce. This study aimed to explore the feasibility of adding NRS protein to the broiler chicken basal diet with a focus on nutritional composition and its growth performance using 160 day-0 broiler (Ross) chickens. The study observed that when NRS protein was included at varying levels in the basal diet, changes were observed in all nutritional contents (crude protein, carbohydrate, crude fat and energy). The live body weight of broiler chicken fed with different levels of NRS protein increased when the chickens reached 35 days old and achieved the live weight of market standard of more than 2000 g per chicken on the 42nd day. The highest mortality among treatments recorded was 1.25%; lower than the commercial mortality standard of 5 to 7%. The broiler chicken treated with the addition of 2.0% NRS protein showed better feed conversion ratio (FCR) values compared with that of the control chicken. Similarly, the chickens also showed increased digestive tract development and nutrient capacity. The composition percentage of E. coli over total caecal bacteria was also lower in broiler chickens fed with diets supplemented with NRS protein when compared to the control diet. In general, dietary supplementation with 4.0% NRS protein in chicken feed was optimal for growth performance with no deteriorating effect on intestinal morphology and caecal bacteria. The results demonstrated that NRS protein is a viable substitute as a feed ingredient for broiler chickens and may be a worthwhile avenue to pursue in sourcing local ingredients for the Malaysian feed industry.