Miscanthus Grass as a Novel Functional Fiber Source in Extruded Feline Diets

Abstract

Although dietary fiber is not considered an essential nutrient in a complete and balanced diet for felines, it provides a substrate for fermentation by gut microbiota, thus promoting gastrointestinal health through the production of fermentative metabolites, as well as improving laxation. The aim of this research was to evaluate the novel fiber source, Miscanthus grass (Miscanthus giganteus), in comparison with traditional fiber sources and their effects on fecal quality, apparent total tract digestibility (ATTD), fecal fermentative end products, and microbiota of healthy adult cats. Four dietary treatments were evaluated, differing in dietary fiber source. The diets were formulated to meet or exceed the AAFCO (2018) nutritional profile for adult cats and contained either cellulose (CO), Miscanthus grass fiber (MF), a blend of Miscanthus fiber and tomato pomace (MF + TP), or beet pulp (BP). The study was conducted using a completely randomized design with 28 neutered adult, domesticated shorthair cats (19 females and 9 males, mean age 2.2 ± 0.03 years; mean body weight 4.6 ± 0.7 kg, mean body condition score 5.6 ± 0.6). The experimental period comprised 21 days, and a fresh fecal and a total fecal collection were performed during the last 4 days of the trial period. Daily food intake (DM basis) was similar across all groups (P > 0.05). Additionally, treatment did not affect fecal output (as-is or DM basis), fecal score, or fecal pH (P > 0.05). Cats fed BP had significantly higher total dietary fiber ATTD than all the other treatments (P < 0.05) and the highest concentrations of total short-chain fatty acid, acetate, and propionate (P < 0.05), while butyrate concentrations were similar for all treatments (P > 0.05). Inclusion of dietary fibers was effective in modulating gut microbiota. Cats fed diets containing Miscanthus grass had greater α-diversity than cats fed BP. As no adverse effects on health, fecal quality, or ATTD of macronutrients were observed with the inclusion of 9% Miscanthus grass fiber or fiber blend, the data suggest that Miscanthus grass fiber and fiber blends are viable alternatives to the traditional dietary fiber sources used in commercial extruded feline diets, being most comparable to cellulose.

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

“…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. The inclusion of Miscanthus grass had a limited impact on the product process and physical characteristics when included at 9% [138] or 10% [137] and did not impact food intake when compared to control products and beet pulp or cellulose-containing products for similar total dietary fiber (TDF) content [138]. In contrast, soybean hulls appeared to have a higher food intake than beet pulp products when included at similar TDF content [139].…”

“…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.…”

The role of carbohydrates in canine and feline nutrition

“…For example, beet pulp, considered to be one of the gold standard fiber sources in the pet food industry, has a fiber profile that includes individual fiber types with both reduced levels of fermentability, solubility, and viscosity such as cellulose, as well as pectin a highly viscous and fermentable fiber ( Fahey et al, 1990 ; de Godoy et al, 2013 ). Recently, researchers have worked to evaluate a vast array of novel fiber ingredients, including avocado meal, soybean hulls, miscanthus grass, coconut fiber, chicory, citrus pulp, and orange fiber, to name a select few ( de Godoy et al, 2015 ; Detweiler et al, 2019 ; Finet et al, 2021 ; Pacheco et al, 2021 ; Dainton et al, 2022 ). The main goal of those research studies was to identify fiber-rich ingredients that are economical, environmentally advantageous, and may otherwise contribute to food waste in the current food system, while describing the potential functionality of these fiber sources and blends in canine and feline nutrition and health.…”

“…In cats, previous reviews have described the effects of age, gastrointestinal disease, environment, and diet on the feline gut microbiome ( Rochus et al, 2014 ; Pilla and Suchodolski, 2021 ). Since then, a few studies have been published evaluating the effects of carbohydrate and dietary fiber sources and their inclusion levels on fecal microbiota of adult healthy cats ( Jackson et al, 2020 ; Finet et al, 2021 ; von Schaumburg et al, 2021 ; Lee et al, 2022 ).…”

MsaH2A.W is identified response to salt tolerance in Miscanthus sacchariflorus

“…There are great differences in lignocellulose components in stems of 179 species of Miscanthus , which indicates that the lignocellulose components of Miscanthus resources in China are rich in genetic diversity (Xu et al, 2020). In addition, Miscanthus has good paper‐making properties (Miao et al, 2021), can be used as high‐quality feed and raw material for edible fungi production (Finet et al, 2021), and has important economic value and ecological significance as an ornamental plant (Mitros et al, 2020). The cultivated land area is increasing to meet the increasing demand for grain (Heaton et al, 2008).…”