Fiber in Animal Nutrition

Fiber in Dog and Cat Food 64 maintains optimum feces consistency, but lowers fecal volume in dogs. Ludolph (2007) used diets containing either wheat bran or lignocellullose in the form of fibrillated fibers (Arbocel RC). Wheat bran contains about 8% cellulose, 28% hemicel- lulose and 5% lignin. Arbocel RC contains about 46% cellulose, 16% hemicellulose and 24% lignin. To formulate the test food, 15% wheat bran in the dry control diet was replaced by 2.7% Arbocel RC, 9.3%wheat flour and 3% greaves. The lignocellulose preparation increased apparent dry matter digestibility by 2.3%units and reduced fresh feces weight by 25%. Average fecal scores for the two diets 2.3 and 2.2 on a 1-4 scale where score 2 is optimally formed. In another experiment (Shiva Kumar et al., 2012), the dry test contained 3% Arbocel RC. It was prepared by adding the lignocel- lulose preparation at the expense of part of the wheat bran in the control diet. The two diets had identical contents of protein, energy and crude fiber. The apparent digestibility of dry matter was increased by 4.2% units when the dogs were fed the test diet, whereas fresh feces output was lowered by about 12%. Dried beet pulp contains about 20%soluble pectin fiber and 12–18% crude fiber. Kröger et al. (2011) used a control diet containing 12% beet pulp and replaced it by 2.7% Ar- bocel RC plus rice flour to make the test diet. The crude fiber contents of the diets were 3.1 and 2.4%. The dogs’ fecal scores were similar for the control and test diet. Arbocel RC had reduced the amount of fresh feces by 44% and dry fecal mass by 20% and raised the apparent digestibility of dietary organic matter by 3.7%. The percentage of fecal water was lowered by beet pulp, which is explained by its high fermentability (Barry et al., 2011; Sunvold et al., 1995a,b). 5.4 Low-calorie diets 5.4.1 Low-calorie diets for dogs When comparing commercial foods, the im- pact of a high versus low crude fiber content in itself cannot be interpreted. This relates to the variable and unknown composition of the crude fiber fraction and the fact that incorporating more fiber into food replaces carbohydrates, fats and/or proteins. Effects of a high versus low-fiber diet may be caused by both the addition of fiber and the omis- sion of macronutrients. Furthermore, high intakes of fiber impair the digestion of the dietary organic matter. Cellulose can be used to dilute the calo- ric content of food. Janowitz and Grossman (1949) fed dogs excess amounts of a com- mercial wet food for a fixed period of 45 mi- nutes per day.Then, the food was mixed with cellulose and water so that moisture content was kept constant at 70% and the amount of cellulose was 12.5% (about 25% crude fiber in the dry matter). The dogs increased the quantity of food eaten, but four out of the six animals lost 15%body weight after 10 weeks. Time-limited access to a high-fiber dry diet once or for a 10-days period lowered dry matter intake (Jackson et al., 1997; Weber et al., 2007). However, time-limited feeding for two or three weeks raised food intake, but lowered energy intake (Jewell and Toll, 1996, 2000). When dogs had 45–60 minutes/day access to commercial dry foods containing 22 or 2% crude fiber for six months, the high-fiber diet had raised food intake by 17%, but it lowered energy consumption and body weight by 8 and 5% (Jewell et al., 2007). Two fiber-enhanced dry foods, which were available for 45 minutes per day for four months, each increased food intake, but induced a 10%-decrease in body weight (Yamka and Riesen, 2008a). © ERLING Verlag