The objective of this experiment was to determine whether alkaline hydrogen peroxide-treated oat hulls (termed oat fiber; OF) are nutritionally efficacious as a source of dietary fiber in meat-based dog foods. Thirty female English Pointers were assigned in a completely randomized design to isonitrogenous diets. Treatments were 1) control diet, 2) 7.5% added beet pulp (BP), and 3) 2.5, 4) 5.0, and 5) 7.5% added OF. Inclusion of 7.5% BP increased (P less than .05) DM intake and decreased (P less than .05) digestibility of DM and OM compared with the control. Dry matter intake increased (P less than .05) with increasing level of OF and digestibility of DM, OM, and total dietary fiber (TDF) decreased (P less than .05). Digestibility of DM, OM, and TDF were higher for dogs fed the 7.5% BP than for those fed the 7.5% OF treatment. Digestible energy, expressed as a percentage of GE, was greater for the control treatment than for the 7.5% BP treatment. A linear decrease in DE (percentage of GE) was noted as the concentration of OF increased, and the DE value (percentage of GE) for the 7.5% BP treatment was greater (P less than .05) than that for the 7.5% OF treatment. A linear decrease (P less than .05) was noted in ME, expressed as a percentage of GE, as the level of OF increased. Frequency of defecation and mean retention time were unaffected (P greater than .05) by treatment. Oat fiber was an effective substitute for BP in dog diets.

The objectives of this study were to examine widely divergent fiber sources for their efficacy as ingredients in a meat-based dog diet and to determine the effects of these fibers on fecal excretion responses and mean retention time of marked fiber in the gastrointestinal tract of the dog. Fiber sources tested included beet pulp (BP), tomato pomace (TP), peanut hulls (PH), wheat bran (WB) and alkaline hydrogen peroxide-treated wheat straw (AHPWS). Diets were isonitrogenous (5.3% N) and iso-total dietary fiber (TDF; 12.5%). Thirty female English Pointers (five/treatment) were used in the experiment. Intakes of DM and OM were similar among treatments. The highest intakes of ether extract (EE) occurred on the TP, PH and WB treatments. Dogs fed PH ingested the most crude fiber (23.6 g/d), NDF (53.5 g/d), ADF (34.3 g/d) and TDF (59.7 g/d). Digestibilities of DM and OM for all fiber treatments were lower than the control (87.6 vs 81.8% for DM; 90.2 vs 85.4% for OM), but values were similar among fiber sources. The highest EE and N digestibilities occurred on the control and AHPWS treatments. No differences were noted among exogenous fiber-containing treatments in fiber component digestibility. Digestible energy and ME values generally were similar among treatments. Among fiber sources, BP resulted in the greatest amount of wet feces excreted (270 g/d) and the lowest fecal DM (30.3%). No differences among fiber sources were noted in frequency of defecation or mean retention time. Iso-TDF diets (containing, on average, 12.5% TDF) appear to be utilized similarly, regardless of the diversity in sources of fiber tested.

The optimal level of beet pulp (BP) inclusion in a meat-based dog diet and the effects of graded levels of dietary BP on fecal excretion responses and mean retention time of marked fiber in the gastrointestinal tract of the dog were evaluated using 30 female English Pointers assigned to isonitrogenous diets containing 0, 2.5, 5.0, 7.5, 10.0 or 12.5% BP (DM basis). Beet pulp replaced portions of dietary cornstarch. Digestibilities of DM and OM decreased by an average of 6% when comparing diets containing BP to the control diet, and quadratic and cubic responses were noted in digestibilities of fiber constituents (lower values at the 7.5 and 10.0% levels, higher values at the 2.5, 5.0 and 12.5% levels). Digestible energy (DE) and ME intakes (kcal/d) were not affected by treatment, but when expressed as a percentage of GE, values decreased (4.8% for DE; 6.2% for ME) linearly with increasing BP levels. Wet weight of feces increased (from 117 to 374 g/d) linearly as percentage of dietary BP increased. Frequency of defecation was higher (P less than .05) for dogs fed the diet containing 12.5% BP than for dogs fed the other diets (5.2 vs mean value of 2.8/24 h). Mean retention time of marked fiber decreased linearly (high value of 23.4 h for the 2.5% BP treatment, low value of 13.0 h for the 10.0% BP treatment) with increased level of BP. Beet pulp levels up to 7.5% of diet DM appear acceptable as a dietary fiber source in a meat-based canine diet.

Experiments were conducted to determine the effects of a dietary inadequacy of, and to estimate the dietary requirement for magnesium (Mg) in the growing Kitten. In Experiment 1, fourteen Kittens were fed a casein-based diet containing 50 mg/kg Mg without supplemental Mg or supplemented with 700 mg/kg Mg. Muscular weakness, hyperirritability, convulsions, reduced feed intake and poor growth were observed in kittens fed 50mg/kg Mg. Additionally, these animals exhibited reduced serum and bone Mg, and increased soft tissue calcium (Ca) concentrations. Graded levels of dietary Mg were fed in Experiment 2 (100, 400 and 700 mg/kg) and Experiment 3 (400, 550 and 700 mg/kg) to estimate the dietary requirement for Mg in the young kitten. Gross manifestations of a Mg deficiency were not observed. Serum Mg concentration declined within one week after kittens were fed 100mg/kg Mg, but were unchanged by feeding of 400, 550 or 700 mg/kg Mg. Calcium concentration was increased in aorta, liver and skeletal muscle, but not in kidney, and bone Mg concentration was reduced when kittens were fed 100 mg/kg Mg. No significant changes were observed in soft tissue Ca or bone Mg when kittens were fed diets supplemented to 400, 550 or 700 mg/kg Mg. We conclude that 400 mg/kg dietary Mg is adequate for growth, maintenance of blood and tissue Mg and prevention of calcification of soft tissues.

The extracutaneous tissues in pups fed a Zn-deficient diet were examined. Four pups were fed a Zn-deficient diet and 3 littermates were fed a Zn-adequate diet. After 5 weeks, the pups were euthanatized. Lesions found only in pups fed a Zn-deficient diet were located in the buccal mucosa, lymph nodes, spleen, and thymus. In the buccal mucosa, lesions consisted of irregular epithelial hyperplasia and disruption of epithelial cell layers. There was a marked absence of lymphocytes in the thymus and in T-cell areas of the lymph nodes and spleen.

Six-week-old puppies fed a corn-soy based zinc-deficient diet developed lesions of parakeratosis, mild hyperkeratosis, alterations in germinal epithelium, erosions, ulcerations, vesiculation, alopecia, and inflammation of the skin. These changes were prominent in the skin of dependent regions, in areas of stretch and friction, and external contact. The epithelial lesions were reversible by adding zinc to the diet, with complete remission of external lesions by 6 weeks.

Body composition was determined in 24 female Beagle dogs ranging in age from 2 to 4 years (live weight 11.1 +/- 3.3 kg). Subcutaneous fat measurements were made using an ultrasonic probe device on the live animal and direct measurements after death. Measurements were made near the shoulder, mid-rib, last rib, mid-lumbar, and last lumbar areas. The actual fat measurement giving the highest correlation with body fat was the one made directly over the longissimus muscle near the last rib (r2 x 100 = 93.6). Multiple linear regression, using live weight and the last rib fat thickness measurement, estimated body fat with a standard error of 0.27 kg (r2 x 100 = 98.4). Body fat = 2.2 + (0.13 x fat thickness + (0.36 x live weight) where body fat and live weight were measured in kg and fat thickness in mm.

There studies examined the effect of dietary arginine deficiency in the mature dog. Deletion of arginine from the diet resulted in a slight but significant loss of body weight. Severe episodes of emesis were observed in all experiments. Muscle tremors and frothing around the mouth were also observed in the experiments where the arginine-free diet was force fed. Increasing the amount of diet force-fed to mature dogs accentuated the symptoms of emesis, muscle tremors and frothing. Elevated plasma ammonia and orotate were detected in dogs fed an arginine-deficient diet. Urinary citric and orotic acid was also increased in mature dogs fed a diet devoid of arginine. Nitrogen balance was not significantly altered by deletion of arginine from the diet. Based on the occurrence of emesis, loss of body weight and alterations in intermediary metabolism, we concluded that the mature dog does require a dietary source of arginine. Dietary inclusions of 0.28% arginine prevented the symptoms of arginine deficiency.

Journal Article Evaluation of Byproduct Feedstuffs as Dietary Ingredients for Dogs Get access S. E. Allen, S. E. Allen 2University of Illinois, Urbana 61801 Search for other works by this author on: Oxford Academic PubMed Google Scholar G. C. Fahey, Jr., G. C. Fahey, Jr. 2University of Illinois, Urbana 61801 Search for other works by this author on: Oxford Academic PubMed Google Scholar J. E. Corbin, J. E. Corbin 2University of Illinois, Urbana 61801 Search for other works by this author on: Oxford Academic PubMed Google Scholar J. L. Pugh, J. L. Pugh 2University of Illinois, Urbana 61801 Search for other works by this author on: Oxford Academic PubMed Google Scholar R. A. Franklin R. A. Franklin 2University of Illinois, Urbana 61801 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Animal Science, Volume 53, Issue 6, December 1981, Pages 1538–1544, https://doi.org/10.2527/jas1982.5361538x Published: 01 December 1981

Three experiments were conducted to determine the nitrogen (N) requirement of the young kitten. The feline basal diet contained minimal requirement levels of each indispensable amino acid (IAA) to comprise a total dietary N concentration of 2.52% and an IAA N to dispensable amino acid (DAA) N ratio (I/D) of 0.70. In experiments 1 and 2, both the dietary N concentration and I/D ratio were varied through changes in either the DAA level (experiment 1) or IAA level (experiment 2). The results revealed that a reduction in either dietary N or in I/D ratio from basal levels (ie, 2.52% N and I/D ratio of 0.70) depressed (P less than 0.05) kitten weight gain, feed efficiency, and N retention, whereas simultaneous increases in each resulted in no further improvement in these responses. Comparison of this feline basal diet with a commercial ration (experiment 3) revealed no differences (P less than 0.10) in gain, gain/feed, or N retention, although the purified diet showed superiority (P less than 0.01) when gain/N intake was determined (13.3 vs 5.7). Therefore, the feline dietary N requirement has been estimated to be 2.52% (15.75% protein equivalent) or 16% of the calories as protein. In the process of these experiments, creatinine and orotic acid excretion from kittens fed the purified diet were constant, averaging (+/- SEM) 24.7 +/- 0.7 mg/kg of body weight and 9.95 +/- 2.3 micrograms/mg of creatinine, respectively. Urea-N and ammonia-N comprised approximately 83.0% and 3.8% of the total urinary nitrogen.

Ten adult female pointers were used in metabolism trials conducted to evaluate the efficacy of substituting portions of a corn-soybean meal basal diet with 20% tallow, 20% lard or 30% meat and bone meal, and to compare cooked and uncooked high energy feedstuffs (rice, oats and corn). Three metabolism trials were performed in which the corn-soy basal served as the control and the fats and meat and bone meal as the experimental treatments. Three additional metabolism trials compared the utilization of cooked and uncooked rice, oats and corn. Feed and feces were anlayzed for dry matter content, and digestibilities of starch and cellulose were subsequently determined. Fecal moisture and nitrogen balance data were also collected. In all trials, dry matter digestibility was found to be unaffected by treatment. The starch present in all diets was highly digestible. Cooking of oats significantly improved starch digestibility of this energy source over that of the uncooked control (95.8 vs 93.8%). Starch digestibility of rice and corn was unaffected by cooking. Cellulose digestibility was significantly increased when the 20% lard and 30% meat and bone meal diets were fed. Cellulose digestion by dogs fed cooked rice or oats was significantly greater than that by dogs fed uncooked feedstuffs. Fecal moisture was reduced by 25.2% when meat and bone meal was substituted for soybean meal. Dogs fed 20% tallow or 20% lard consumed more nitrogen than did their respective controls. Animals fed cooked rice ingested 6.6% more nitrogen than did those fed the uncooked cereal. More fecal nitrogen was excreted by animals fed uncooked oats then by those fed cooked oats (19.3 vs 15.5 g/5 days, respectively). Although significant treatment differences in absorbed and retained nitrogen were observed, no differences in retained nitrogen expressed as a percentage of nitrogen intake were noted in any of the experiments.

Growth assays and nitrogen balance trials were conducted in an attempt to estimate requirements for threonine, isoleucine, valine and leucine. Weanling kittens were fed a basal purified diet containing 27% crystalline L-amino acids and 4,700 kcal metabolizable energy per kilogram diet. Based upon rate and efficiency of growth, and upon urinary nitrogen excretion, estimated requirements for threonine, isoleucine, valine and leucine were .80%, .30%, .60% and 1.20% of the diet, respectively.

Growth assays were conducted to estimate the minimal dietary requirement levels of histidine, tryptophan, phenylalanine and tyrosine for the young kitten. Dietary concentrations of histidine and tryptophan of .30 and .15%, respectively, were found to support optimal kitten performance. A preliminary study of the total aromatic amino acid (TAAA) requirement indicated that no more than 1.20% TAAA (.60% phenylalanine + .60% tyrosine) is required by the kitten. Subsequent experiments revealed no decrease in growth rate when TAAA were reduced to 1.00% of the diet. At this level of TAAA, tyrosine could supply 50% of the requirement for TAAA.

Domestic kittens were used in four experiments to establish quantitative requirements for lysine and arginine. A purified L-amino acid diet (by calculation, 4,700 kcal metabolizable energy/kg diet) was employed throughout. Weight gain, gain:feed and nitrogen retention data of cats fed dietary lysine levels ranging from 0.48 to 1.92% suggested a requirement not exceeding 0.80%. The dietary arginine requirement for maximal gain was assayed at this level of lysine and found to be not greater than 0.83%. A dietary arginine level of 0.33% resulted in vomiting and extreme lethargy within 4 hours of ingestion.

Four experiments were conducted to determine both the choline requirement and the choline-sparing capacity of methionine for young cats. In the first study turkey fat, a major component of the feline choline-free purified diet, was found to contribute no bioavailable choline activity as determined by chick bioassay, thus assuring that the purified diet was, indeed, choline-free. With dietary methionine present at its minimal physiological requirement, gain and gain to feed ratio increased linearly and liver lipid decreased as dietary choline was increased from 0 to .05% to .10%. In a subsequent study, choline levels of .1% and .3% were evaluated. Maximum growth occurred at .1%, but .3% was required to achieve a lower concentration of liver lipid. A level of methionine (.37%) isomethyl to .1% choline was found capable of completely replacing the dietary need for choline. Dietary inclusion of 2-amino-2-methyl-l-propanol, an inhibitor of choline biosynthesis, increased liver lipid and decreased growth and also negated the choline-sparing activity of methionine. Thus, the primary explanation for the choline-sparing activity of methionine in the feline animal appears to lie in its function in providing methyl groups for endogenous choline biosynthesis rather than in its capacity to replace choline per se.

A 24-week experiment was undertaken to evaluate the essentiality of taurine for the young kitten fed a taurine-free crystalline amino acid diet containing required levels of both methionine and cystine. Kittens fed the taurine-free diet exhibited central retinal degeneration (CRD), but neither growth rate nor food intake was significantly depressed. Taurine concentrations in plasma, heart, liver, retina, lens, olfactory bulb and bile were markedly reduced in cats that received the taurine-free diet. Tissue concentrations of amino acids were also affected by taurine deficiency. Glycine and glutamine both increased in the retina, but only glutamine increased in the lens. Glutamic acid and glutamine increased in the heart. However, the concentrations of all amino acids measured, except histidine, increased in the olfactory bulb due to the fact that olfactory bulbs from taurine-deficient cats weighed only one-half that of the bulbs from taurine-adequate cats. The taurine concentration in queen's milk was determined to be 93.6 ±10.4 µmoles/100 ml, an amount three times that present in human milk.