The effects of fiber source on extrusion processing parameters and kibble characteristics of dry cat foods

Abstract

Cellulose and beet pulp have been commonly used in the pet food industry to increase dietary fiber content of cat foods. However, pet food companies seek alternatives to these so-called byproducts. Miscanthus grass is grown for its fiber content and may serve as an alternative to traditional fibrous ingredients. The objectives of this study were to determine the effects of fiber sources on extrusion processing and kibble structure of cat foods. Three replicate batches of adult maintenance complete and balanced cat foods each containing 10% of Miscanthus grass, cellulose, or beet pulp was mixed and kibbles were produced on a single screw extruder. Feed rate, preconditioner water and steam, extruder screw speed, extruder water and steam addition, and knife speed were adjusted to achieve a wet bulk density of 330 g*L -1. After extrusion, kibbles were dried at 115.5ºC to less than 10% moisture. Dried kibbles were coated with chicken fat and flavor enhancer. No effects due to fiber source were reported for extrusion parameters or kibble measurements (P > 0.05) with the exception of compression energy; wherein, kibbles produced with cellulose required more energy to compress than those containing beet pulp (6917 N*mm vs. 3591 N*mm, respectively). In conclusion, tested fiber sources had no impact on extrusion parameters and most kibble characteristics. Kibbles containing cellulose required more energy to compress than kibbles containing beet pulp. Miscanthus grass could be used as an alternative to traditional fiber sources used to produce cat foods.

Miscanthus Grass as a Nutritional Fiber Source for Monogastric Animals

“…As the structure is altered due to differences in expansion, Miscanthus grass kibbles required more energy to compress compared to beet pulp kibbles; however, hardness was similar [4]. For the cat foods addition of Miscanthus grass had no effects on tested extrusion parameters or kibble traits [6] compared to cellulose and beet pulp. Conversely, dog foods with Miscanthus grass required less mechanical energy to process compared to beet pulp supplementation [4].…”

“…Relative to the current options, the grasses would certainly qualify as less processed and could even be considered as a purpose grown, sustainable, low environmental impact ingredient in diets for man and animal. Miscanthus grass is one such novel grass that has been evaluated as a fiber source for broiler chickens, dogs, and cats [1][2][3][4][5][6]. Other authors have also evaluated this fiber for companion animal applications [7].…”

Insights to Study, Understand and Manage Extruded Dry Pet Food Palatability

“…In 2013, De Godoy et al [130] stated that dietary fibers gained increasing interest in the pet food industry for their beneficial effect on digestive health, but limited scientific information was available, especially in terms of palatability. Beet pulp and cellulose have been commonly used in pet food [130][131][132][133][134], and new sources of dietary fiber are considered for their nutritional benefits, but their palatability interest remains to be determined. To explore new sources of fiber, researchers and manufacturers have focused on discarded byproducts to develop sustainable and value-added ingredients for pet food [55,131,132,135,136].…”

“…Regarding cats, Donadelli et al [133,137] and Finet et al [138] studied the inclusion of Miscanthus grass as a dietary fiber source. Contrary to the previous ingredients presented, Miscanthus grass is produced for its fiber content and hence is not labeled a "byproduct", which may be favored by pet owners.…”