Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets

The objectives of this study were to determine differences in apparent total tract energy and macronutrient digestibility, fecal and urine characteristics, and serum chemistry of domestic cats fed raw and cooked meat-based diets and extruded diet. Nine adult female domestic shorthair cats were utilized in a replicated 3 × 3 Latin square design. Dietary treatments included a high-protein extruded diet (EX; 57% CP), a raw beef-based diet (RB; 53% CP), and a cooked beef-based diet (CB; 52% CP). Cats were housed individually in metabolic cages and fed to maintain BW. The study consisted of three 21-d periods. Each period included diet adaptation during d 0 to 16; fecal and urine sample collections during d 17 to 20; and blood sample collection at d 21. Food intake was measured daily. Total feces and urine were collected for determination of nutrient digestibility. In addition, a fresh urine sample was collected from each cat for urinalysis, and a fresh fecal sample was collected from each cat for determination of DM percentage and ammonia, short-chain fatty acid (SCFA), and branched-chain fatty acid (BCFA) concentrations. All feces were scored after collection using a scale ranging from 1 (hard, dry pellets) to 5 (watery, liquid that can be poured). Blood was analyzed for serum metabolites. Apparent total tract DM, OM, CP, fat, and GE digestibilities were greater (P ≤ 0.05) in cats fed RB and CB than those fed EX. Total fecal SCFA concentrations did not differ among dietary treatments; however, molar ratios of SCFA were modified by diet, with cats fed RB and CB having an increased (P ≤ 0.05) proportion of fecal propionate and decreased (P ≤ 0.05) proportion of fecal butyrate compared with cats fed EX. Fecal concentrations of ammonia, isobutyrate, valerate, isovalerate, and total BCFA were greater (P ≤ 0.05) in cats fed EX compared with cats fed RB and CB. Our results indicated that cooking a raw meat diet does not alter apparent total tract energy and macronutrient digestibility and may also minimize risk of microbial contamination. Given the increasing popularity of feeding raw diets and the metabolic differences noted in this experiment, further research focused on the adequacy and safety of raw beef-based diets in domestic cats is justified.     

Toxoplasma gondii antibodies in exotic wild felids from Brazilian zoos.

Serum samples from 37 captive exotic felids in 12 zoos from six Brazilian states were assayed for antibodies to Toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. Titers greater than or equal to 1:20 were considered positive. Antibodies to T. gondii were found in 24 of 37 (64.9%) felids, including one European lynx (Lynx lynx), two jungle cats (Felis chaus), two servals (Leptailurus serval), two tigers (Panthera tigris), three leopards (Panthera pardus), and 14 of 27 lions (Panthera leo). This is the first serologic analysis for T. gondii infection in exotic wild felids from Brazilian zoos.     

Septicemic salmonellosis in two cats fed a raw-meat diet

Salmonella gastroenteritis and septicemia were diagnosed in two cats presented for necropsy. Both cats resided in the same household and were fed a home-prepared, raw meat-based diet. Salmonella was isolated from multiple organs in both cats and from samples of raw beef incorporated into the diet fed to one of the cats. Subtyping of the bacterial isolates yielded Salmonella newport from one cat and from the diet it had been fed. This report provides evidence that the practice of feeding raw meat-based diets to domestic cats may result in clinical salmonellosis.     

Positive effects of diet change on shedding of Salmonella spp. in the feces of captive felids.

A high prevalence of fecal Salmonella shedding in a collection of healthy exotic felids precipitated a change to two new commercially available feline diets. One year after initiation of the new diets, 18 fecal samples from individual felines, their exhibits, and representative samples of the diets were cultured for Salmonella spp. Only one culture grew a Salmonella sp. Salmonella uganda was cultured from the feces of one snow leopard (Felis uncia). Feeding a diet with minimal to no Salmonella contamination lowered Salmonella shedding rates in this collection of captive exotic felids.     

Evaluation of methods to reduce bacteria concentrations in spray-dried animal plasma and its effects on nursery pig performance

Four experiments with 1,040 weanling pigs (17 +/- 2 d of age at weaning) were conducted to evaluate the effects of spray-dried animal plasma source, drying technique, and methods of bacterial reduction on nursery pig performance. In Exp. 1, 180 barrows and gilts (initial BW 5.9 +/- 1.8 kg) were used to compare effects of animal plasma, animal plasma source, drying technique (spray-dried or freeze-dried), and plasma irradiation in nursery pig diets. From d 0 to 10, pigs fed diets containing irradiated spray-dried animal plasma had increased ADG and ADFI (P < 0.05) compared with pigs fed diets containing nonirradiated spray-dried animal plasma. Pigs fed irradiated animal plasma Sources 1 and 2 were similar in ADG and ADFI, but pigs fed animal plasma Source 1 had greater ADG (P < 0.05) than pigs fed animal plasma Source 2 and pigs not fed plasma. Pigs fed freeze-dried animal plasma had growth performance similar (P > 0.36) to pigs fed spray-dried animal plasma. Overall (d 0 to 24), pigs fed irradiated spray-dried animal plasma were heavier (P < 0.05) than pigs fed no animal plasma, whereas pigs fed nonirradiated spray-dried plasma were intermediate. In Exp. 2, 325 barrows and gilts (initial BW 5.8 +/- 1.7 kg) were used to compare the effects of irradiation or formaldehyde treatment of animal plasma and formaldehyde treatment of the whole diet. Pigs fed diets containing irradiated animal plasma had greater ADG (P < 0.05) than pigs fed nonirradiated plasma. Pigs fed formaldehyde-treated plasma had greater ADG and ADFI (P < 0.05) than pigs fed diets with either nonirradiated plasma or whole diet treated with formaldehyde. In Exp. 3 (360 barrows and gilts; initial BW 6.3 +/- 2.7 kg) and Exp. 4 (175 barrows and gilts; initial BW 6.1 +/- 1.7 kg), the irradiation of feed (high bacteria) and food-grade (low bacteria) animal plasma in nursery pig diets was examined. Pigs fed irradiated feed-grade plasma Product 2 had increased ADG (P < 0.05) compared with pigs fed nonirradiated plasma Product 2 and pigs fed the control diet without plasma. In Exp. 3 and 4, pigs fed irradiated food-grade plasma had growth performance similar to pigs fed nonirradiated food-grade plasma (P > 0.12). These studies indicate that bacterial reduction of feed-grade, but not food-grade animal plasma, improves nursery pig performance.     

Effect of irradiation of individual feed ingredients and the complete diet on nursery pig performance

A total of 1,210 nursery pigs was used in two experiments to evaluate the effects of irradiation of typical nursery diet ingredients, specialty protein products, and the whole diet on nursery pig performance. In Exp. 1, 880 barrows and gilts (15 +/- 2 d of age at weaning) were used in two growth trials (14 d and 12 d for Trials 1 and 2, respectively) to determine the effects of individual ingredient and whole-diet irradiation on nursery pig performance. Overall (d 0 to 14 of Trial 1 and d 0 to 12 of Trial 2), ADG was greater (P < 0.05) for pigs fed irradiated animal plasma compared with pigs fed the control, the diet containing irradiated microingredients, and the diet that was manufactured and irradiated. Also, pigs fed irradiated soybean meal had greater (P < 0.05) ADFI compared with pigs fed the manufactured diet that was irradiated. Pigs fed the diet containing irradiated animal plasma had improved feed efficiency (G:F; P < 0.05) compared with those fed the diet with irradiated microingredients and when all ingredients were irradiated before manufacturing of complete feed. Finally, pigs fed irradiated corn, whey, fishmeal, soybean oil, microingredients, or if all ingredients or the whole diet were irradiated, had similar ADG, ADFI, and G:F (P > 0.12) to control pigs. In Exp. 2, 330 nursery pigs (20 +/- 2 d of age at weaning) were used to determine the effects of irradiation of commercially available specialty protein products in diets for nursery pigs. Overall, ADG was greater (P < 0.05) when pigs were fed diets containing nonirradiated spray-dried animal plasma and egg combination (SDAPE) and dried porcine digest (DPD) compared with pigs fed the control diet containing no specialty protein products. In addition, G:F was improved (P < 0.05) when pigs were fed diets containing nonirradiated SDAPE, DPD, spray-dried beef muscle (SDBM), and spray-dried whole egg (SDWE) compared with pigs fed the control diet. Pigs fed irradiated SDAPE and SDBM had greater (P < 0.05) ADG than pigs fed the nonirradiated forms. Pigs fed irradiated SDBM had improved (P < 0.05) G:F compared with pigs fed the nonirradiated form. In Exp. 1 and 2, an irradiation treatment level of 8.5 kGy was effective in reducing the total bacterial concentration of all ingredients evaluated, as well as the whole diet in Exp.1. Irradiation of certain ingredients, but not the complete diet, increased growth performance of nursery pigs.     

Fiber fermentability effects on energy and macronutrient digestibility, fecal traits, postprandial metabolite responses, and colon histology of overweight cats

Considering the different potential benefits of divergent fiber ingredients, the effect of 3 fiber sources on energy and macronutrient digestibility, fermentation product formation, postprandial metabolite responses, and colon histology of overweight cats (Felis catus) fed kibble diets was compared. Twenty-four healthy adult cats were assigned in a complete randomized block design to 2 groups of 12 animals, and 3 animals from each group were fed 1 of 4 of the following kibble diets: control (CO; 11.5% dietary fiber), beet pulp (BP; 26% dietary fiber), wheat bran (WB; 24% dietary fiber), and sugarcane fiber (SF; 28% dietary fiber). Digestibility was measured by the total collection of feces. After 16 d of diet adaptation and an overnight period without food, blood glucose, cholesterol, and triglyceride postprandial responses were evaluated for 16 h after continued exposure to food. On d 20, colon biopsies of the cats were collected under general anesthesia. Fiber addition reduced food energy and nutrient digestibility. Of all the fiber sources, SF had the least dietary fiber digestibility (P < 0.05), causing the largest reduction of dietary energy digestibility (P < 0.05). The greater fermentability of BP resulted in reduced fecal DM and pH, greater fecal production [g/(cat × d); as-is], and greater fecal concentration of acetate, propionate, and lactate (P < 0.05). For most fecal variables, WB was intermediate between BP and SF, and SF was similar to the control diet except for an increased fecal DM and firmer feces production for the SF diet (P < 0.05). Postprandial evaluations indicated reduced mean glucose concentration and area under the glucose curve in cats fed the SF diet (P < 0.05). Colon mucosa thickness, crypt area, lamina propria area, goblet cell area, crypt mean size, and crypt in bifurcation did not vary among the diets. According to the fiber solubility and fermentation rates, fiber sources can induce different physiological responses in cats, reduce energy digestibility, and favor glucose metabolism (SF), or improve gut health (BP).     

Disseminated coccidioidomycosis in a captive Indochinese tiger (Panthera tigris corbetti) with chronic renal disease.

A 19-yr-old, 78.2-kg captive female Indochinese tiger (Panthera tigris corbetti) from the El Paso Zoo (El Paso, Texas, USA) with chronic renal disease was euthanized after a 10-day course of anorexia, depression, progressive rear limb weakness, muscle fasciculations, and head tremors. Postmortem findings included pericardial effusion, generalized lymphadenopathy, glomerulosclerosis, glomerular atrophy with membranous glomerulonephropathy, and pancreatic adenocarcinoma. Pyogranulomatous pneumonia, pericarditis, and lymphadenitis were associated with fungal spherules histomorphologically consistent with Coccidioides immitis. Rising antibodies to C. immitis were detected on samples obtained perimortem and 2 mo before euthanasia. Retrospective serology was negative for two additional Indochinese tigers, two Iranian leopards (Panthera pardus saxicolor), two jaguars (Panthera onca), two bobcats (Lynx rufus texensis), two ocelots (Leopardus pardalis), and three Amur leopards (Panthera pardus orientalis) housed at the zoo over an 8-yr period. Despite being located within the endemic region for C. immitis, this is only the second case of coccidioidomycosis reported from this institution.     

Effect of a novel animal milk oligosaccharide biosimilar on macronutrient digestibility and gastrointestinal tolerance,fecal metabolites,and fecal microbiota of healthy adult cats

GNU100 is a novel animal milk oligosaccharide (AMO) biosimilar. In a recent in vitro fermentation study, GNU100 was shown to be fermentable by feline gastrointestinal microbiota and lead to increased short-chain fatty acid production. Our objectives herein were to evaluate the palatability, safety, and gastrointestinal tolerance of GNU100 in healthy adult cats. Exploratory end-points were measured to assess utility. In study 1, 20 adult cats were used to test the palatability of diets containing 0% or 1% GNU100. In study 2, 32 (mean age = 1.9 yr; mean body weight = 4.6 kg) male (n = 12) and female (n = 20) adult cats were used in a completely randomized design. After a 2-wk baseline, cats were assigned to one of the following treatment groups and fed for 26 wk: control (CT, no GNU100), low dose (LD, 0.5% GNU100), medium dose (MD, 1.0% GNU100), and high dose (HD, 1.5% GNU100). On weeks 2, 4, and 26, fresh fecal samples were collected for the measurement of stool quality and immune and inflammatory markers and on weeks 2 and 4 for microbiota and metabolites. On week 4, total feces were collected to measure apparent total tract macronutrient digestibility. On weeks 2, 4, and 26, blood samples were collected for serum chemistry, hematology, and inflammatory marker measurement. The palatability test showed that 1% GNU100 was strongly preferred (P < 0.05), with GNU100 having a 17.6:1 consumption ratio compared with control. In the long-term study, all cats remained healthy, without any signs of gastrointestinal intolerance or illness. All diets were well accepted, resulting in similar (P > 0.05) food intake, fecal characteristics, immunoglobulin A, and calprotectin, and dry matter, organic matter, fat, and crude protein digestibilities. Fecal butyrate was greater (P = 0.02) in cats fed HD than cats fed LD or MD. Fecal indole was lower (P = 0.02) in cats fed HD than cats fed LD. Cats fed CT had a higher (P = 0.003) relative abundance of Actinobacteria than cats fed LD. The relative abundance of Peptococcus was impacted by diet and time. At 4 wk, Campylobacter was lower in fecal samples of cats fed HD. Overall, the data suggest that dietary GNU100 supplementation was highly palatable, well tolerated, did not cause detrimental effects on fecal quality or nutrient digestibility, increased fecal butyrate concentrations, and reduced fecal indole concentrations, supporting the safety of GNU100 for inclusion in feline diets and suggesting potential benefits on gastrointestinal health of cats.     

Clostridium perfringens enterotoxicosis in two Amur leopards (Panthera pardus orientalis).

Two 6-yr-old male sibling Amur leopards (Panthera pardus orientalis) housed together at the Pittsburgh Zoo presented for acute onset of diarrhea with no changes in appetite or behavior. Heat-fixed modified Wright-stained and Gram-stained fecal smears revealed a mixed bacterial population with a large number of gram-positive Clostridium perfringens-like spores (>20 per high-power oil immersion field). In addition, C. perfringens enterotoxin was isolated from one leopard at 1:256, confirming the presence of C. perfringens enterotoxicosis. Treatment with oral metronidazole, tylosin tartrate, and psyllium fiber was prescribed, with return of more normal stool by the third day of treatment. Fecal consistency steadily improved and was considered normal by the time all prescribed treatments were complete. Diarrhea has not recurred. Partially thawed meat in the leopards' diet may have precipitated the production of an endogenous clostridial enterotoxicosis by disrupting digestive tract flora with resultant clostridial overgrowth and sporulation.     

Blood thiamine values in captive adult African lions (Panthera leo).

Heparinized whole-blood samples from 22 adult African lions (Panthera leo) fed diets considered nutritionally adequate in 10 American Zoo and Aquarium Association member zoos in North America were provided for this study. Blood thiamine values were estimated using a standard microbiological assay method. The mean +/- standard deviation for blood thiamine values was 249.3 +/- 43.5 nmol/L with a range in values from 160 to 350 nmol/L after exclusion of one outlier. There were no differences (P > 0.05) in the mean blood thiamine values of male and female lions, or of lions that were over and under 10 yr of age. This range (160 to 350 nmol/L) is proposed as a reasonable estimate of the expected range in blood thiamine values for captive adult African lions as currently fed in North American zoos.     

Effects of short-chain fructooligosaccharides and galactooligosaccharides, individually and in combination, on nutrient digestibility, fecal fermentative metabolite concentrations, and large bowel microbial ecology of healthy adults cats

Short-chain fructooligosaccharides (scFOS) and galactooligosaccharides (GOS) are nondigestible oligosaccharides that result in a prebiotic effect in some animal species; however, the cat has not been well studied in this regard. This experiment evaluated scFOS and GOS supplementation on nutrient digestibility, fermentative end product production, and fecal microbial ecology of cats. Eight healthy adult cats were fed diets containing no prebiotic, 0.5% scFOS, 0.5% GOS, or 0.5% scFOS + 0.5% GOS (scFOS + GOS) in a replicated 4 × 4 Latin square design. Apparent total tract CP digestibility was decreased (P < 0.05) when cats were fed a diet containing scFOS + GOS compared with the other treatments. Dry matter, OM, acid hydrolyzed fat, and GE digestibilities were not different (P > 0.05) among treatments. Cats fed scFOS-, GOS-, and scFOS + GOS-supplemented diets had greater (P < 0.05) fecal Bifidobacterium spp. populations compared with cats fed the control diet. Fecal pH was less (P < 0.05) for cats fed the scFOS + GOS-supplemented diet compared with the control. Butyrate (P = 0.05) and valerate (P < 0.05) concentrations were greater when cats consumed the scFOS + GOS diet. Acetate tended (P = 0.10) to be greater when cats were fed the scFOS + GOS diet. Total short-chain fatty acid (P = 0.06) and total branched-chain fatty acid (P = 0.06) concentrations also tended to be greater when cats consumed the scFOS + GOS treatment. Fecal protein catabolites, including ammonia, 4-methylphenol, indole, and biogenic amines, blood lymphocytes, neutrophils, total white blood cell counts, or fecal DM concentration and output did not differ (P > 0.05) among treatments. Low level supplementation of scFOS, GOS, and their combination exert positive effects on select indices of gut health in cats.     

Nutrient digestibilities,microbial populations,and protein catabolites as affected by fructan supplementation of dog diets

Fructans are fermentable carbohydrates and include short-chain fructooligosaccharides (scFOS), inulin, and hydrolyzed inulin (oligofructose, OF). Two studies with dogs were designed to examine the effects of low concentrations of fructans on nutrient digestibilities, fecal microbial populations, and endproducts of protein fermentation, and fecal characteristics. In Exp. 1, 11 adult male beagles were fed corn-based, kibbled diets supplemented with or without OF to provide 1.9 +/- 0.6 g/d. Dietary inclusion of OF decreased (P < 0.05) nutrient digestibilities, but did not affect fecal characteristics. Increasing OF concentration tended (P < 0.06) to linearly decrease fecal ammonia concentrations, but not those of branched-chain fatty acids (BCFA), amines, indole, or phenols. Fecal concentrations of total short-chain fatty acids (SCFA) and butyrate tended to be higher in OF-supplemented dogs (P < 0.10), as was the ratio of bifidobacteria to total anaerobes (P = 0.15). In Exp. 2, ileally cannulated adult female hounds were fed a meat-based kibbled diet and were assigned to four scFOS treatments (0, 1, 2, or 3 g/d) in a 4 x 4 Latin square design. Ileal nutrient digestibilities tended to increase (P < 0.15) with increasing concentrations of scFOS. On a DMI basis, fecal output tended to decrease linearly (P < 0.10) in response to increasing scFOS supplementation, whereas fecal score tended to exhibit a quadratic response (P = 0.12). In general, fecal concentrations of SCFA, BCFA, ammonia, phenols, and indoles were not altered by supplemental scFOS. Supplementation of scFOS increased fecal concentrations of total aerobes (P < 0.05) and decreased concentrations of Clostridium perfringens (P < 0.05). From these data, it seems that low levels of supplemental fructans have divergent effects on nutrient digestibility and fermentative endproducts, but do not adversely affect nutrient digestibility or fecal characteristics and may improve colonic microbial ecology in dogs.     

Effect of diet on the feces quality in javan langur (Trachypithecus auratus auratus).

A high intake of easily fermentable carbohydrates and a low intake of fiber material are generally regarded as major factors affecting the health of captive langurs. The effect on fecal consistency of excluding fruits and vegetables from the diet was evaluated in Javan langurs (Trachypithecus auratus auratus). Cross-over trials were carried out at Rotterdam Zoo and at the Apenheul Zoo, The Netherlands. During the first and third dietary period, the langurs were fed their usual diet, which contained fruits, vegetables, langur pellets, and browse. During the second period, the vegetables and fruits were excluded from the diet and the diet essentially consisted of pellets and browse. Feces consistency was scored using a fecal score chart developed for langurs. During the second feeding period the feces consistency improved significantly in animals at both zoos. Across all trials, a firmer feces consistency was correlated with an increase in dietary cell wall (measured as neutral detergent fiber) and a decrease in dietary water. It is suggested that the combined decrease in the intake of soluble sugars, the increase of fiber intake, and a lower amount of dietary water in the diet resulted in more solid stools. The results indicate that a dietary neutral detergent fiber content of approximately 46% in dry matter will result in a feces consistency indicative of undisturbed gut function.     

Effect of irradiation on the viability of Toxoplasma gondii cysts in tissues of mice and pigs

Muscles from tongue, heart, and limbs of 14 pigs inoculated orally with Toxoplasma gondii oocysts were irradiated with 10, 20, 25, and 30 krad of gamma (cesium-137 and cobalt-60) irradiation. Viability of T gondii cysts was assayed by feeding porcine muscles to T gondii-free cats and/or by inoculation of sediment from acid-pepsin digested porcine muscle into mice. Cats fed 500-g samples of muscles irradiated with up to 20 krad shed T gondii oocysts. Cats fed muscles irradiated with 25 or 30 krad did not shed oocysts. Mice were inoculated with 8 isolates of T gondii, and tissue cysts in their brains irradiated with up to 40 krad were infective to mice; however, there was a 10,000-fold reduction in the viability of organisms in tissue cysts irradiated with 40 krad, compared with that in nonirradiated cysts. At 50 krad of gamma irradiation, there were no detectable infective organisms in infected mouse brains.     

Refinement of a commercial bench-top relaxin assay for pregnancy diagnosis using urine from domestic and nondomestic felids

Relaxin, a 6-kDa polypeptide hormone, is excreted in the urine during pregnancy in several mammalian species. A recent study showed that detection of urinary relaxin using a bench-top serum assay (Witness relaxin kit, Synbiotics Corp., San Diego, California 92127, USA) can be diagnostic for pregnancy in domestic cats (Felis silvestris catus), but it is unknown whether the bench-top kit is applicable with urine across felid species. Our objectives were to 1) examine modifications in urine processing to improve kit reliability in pregnant cats, 2) evaluate the impact of concentrating urine via filtration on relaxin detection, 3) assess the effect of sample freezing on relaxin concentrations, and 4) begin quantifying urinary relaxin levels in nondomestic felids. Urine and serum were collected from domestic cats and nondomestic cat species (Pallas' cat, Otocolobus manul; sand cat, Felis margarita; cheetah, Acinonyx jubatus; and lion, Panthera leo) at several times after breeding. Urine samples, subjected to various processing methods, were tested using the bench-top kit, and relaxin levels were later quantified via radioimmunoassay. For domestic cat urine samples, filtration and addition of protein/phosphate buffer improved the consistency of the relaxin kit for early pregnancy diagnosis. Urine freezing caused a slight (approximately 13%) but significant decrease in relaxin concentrations, but frozen-thawed samples still tested positive with the bench-top kit. In nondomestic felids, urinary relaxin immunoreactivity during pregnancy was similar to or higher than that of pregnant domestic cats, suggesting that relaxin is a reliable cross-species marker of pregnancy. Urinary relaxin was detectable using the bench-top kit in pregnant Pallas' cats, but urine samples from other species tested negative, regardless of processing methods. Findings suggest that measurement of urinary relaxin is a promising approach for noninvasive pregnancy diagnosis in exotic felids, but further assessment of urinary relaxin profiles among cat species and modification of the bench-top relaxin kit are warranted to improve cross-species utility.     

Effects of blood meal pH and irradiation on nursery pig performance

A total of 720 nursery pigs in three experiments were used to evaluate the effects of blood meal with different pH (a result of predrying storage time) and irradiation of spray-dried blood meal in nursery pig diets. In Exp. 1, 240 barrows and gilts (17 +/- 2 d of age at weaning) were used to determine the effects of blood meal pH (7.4 to 5.9) in diets fed from d 10 to 31 postweaning (7.0 to 16.3 kg of BW). Different lots of dried blood meal were sampled to provide a range in pH. Overall (d 0 to 21), pigs fed diets containing blood meal had greater ADG (P < 0.05) and ADFI (P < 0.05) than pigs fed diets without blood meal. Ammonia concentrations in blood meal rose as pH decreased. However, blood meal pH did not influence (P > 0.16) ADG, ADFI, or gain:feed (G:F). In Exp. 2, 180 barrows (17 +/- 2 d of age at weaning) were used to determine the effects of post drying pH (7.6 to 5.9) and irradiation (gamma ray, 9.5 kGy) of blood meal on growth performance of nursery pigs from d 5 to 19 postweaning (6.8 to 10.1 kg of BW). One lot of whole blood was isolated with 25% of the total lot dried on d 0, 3, 8, and 12 after collection to create a range in pH. Overall, pigs fed blood meal had improved G:F (P < 0.01) compared to pigs fed the control diet. Similar to Exp. 1, the ammonia concentration of blood meal increased with decreasing pH. Blood meal pH did not influence ADG, ADFI, or G:F (P > 0.21), but pigs fed irradiated blood meal (pH 5.9) had greater ADG and G:F (P < 0.05) than pigs fed nonirradiated blood meal (pH 5.9). In Exp. 3, 300 barrows (17 +/- 6 d of age at weaning) were used to determine the effects of blood meal irradiation source (gamma ray vs. electron beam) and dosage (2.5 to 20.0 kGy) on growth performance of nursery pigs from d 4 to 18 postweaning (8.7 to 13.2 kg of BW). Overall, the mean of all pigs fed blood meal did not differ in ADG, ADFI, or G:F (P > 0.26) compared to pigs fed the control diet without blood meal. Pigs fed irradiated blood meal had a tendency (P < 0.10) for increased G:F compared with pigs fed nonirradiated blood meal. No differences in growth performance were detected between pigs fed blood meal irradiated by either gamma ray or electron beam sources (P > 0.26) or dosage levels (P > 0.11). These studies suggest that pH alone as an indicator of blood meal quality is not effective and irradiation of blood meal improved growth performance in nursery pigs.     

Effect of different starch sources in a raw meat-based diet on fecal microbiome in dogs housed in a shelter

A dietary intervention study was assessed to determine if different sources of starch in homemade diets could significantly modify fecal microbiome of dogs. Twenty-seven adult dogs were enrolled and fed a diet based on a mixture of rice and pasta with fresh raw meat (CD). After 90 d, 8 dogs continued to receive CD diet, 10 dogs received a diet made of a raw meat and a complementary food with rice as the main source of starch (B1), and 9 dogs were fed a diet with the same raw meat and a complementary food with potato as the main source of starch (B2). Samples of feces were collected from each dog in the mornings at the beginning of the study and after 15 d and analyzed for pH, ammonia N (N–NH₃) and total N, short chain fatty acids (SCFA) and lactic acid. Relative abundance of fecal microbiota was assessed by sequencing and annotating the V3–V4 regions of the 16S rRNA. Total starch intake was similar between diets but differed in the in vitro rate digestion and in the resistant starch, which was higher in B2 than in B1 and CD diets. Dogs fed B2 diet showed lower (P < 0.05) N–NH₃ and pH but higher (P < 0.05) molar proportion of lactic acid. Linear discriminant analysis of the genera relative abundances indicated a significant (P < 0.01) increase of SMB53 genus at the end of the study in B1 diet and of Megamonas genus in B1 and B2 diets in comparison to CD diet. These results suggest that changes of starch source in a raw meat-based diet have limited effects on fecal microbiome in healthy dogs, but underline a high variability of microbiota among dogs.     

Effects of diet on fecal occult blood testing in healthy dogs.

Six dogs were fed each of nine diets to evaluate the effects of diet on fecal occult blood test results. The diets represented a range of different type (i.e. canned, dry or semi-moist), protein and vegetable constituents, and fiber contents. Each diet was fed twice daily for five consecutive days; fecal samples were collected twice daily on days 4 and 5. An o-tolidine test kit and a guaiac paper test kit for fecal occult blood were used. Two hundred and sixteen fecal samples were analyzed (24 samples/diet). When using the guaiac test the following positive results were obtained from fecal samples from dogs consuming a canned meat- and vegetable-based diet (24/24 samples); a canned meat-based diet (24/24 samples); a dry corn and poultry-based diet (9/24 samples); a dry corn, wheat, and meat meal diet (4/24 samples), a canned poultry-based diet (1/24 sample) and a semi-moist soybean meal-based diet (2/24 samples). A total of 64 samples were positive using the guaiac test. Using the o-tolidine test, no samples were positive. The difference between the number of positive results with each test kit was highly significant (p < 0.001). Results indicate that 1) diet affects the specificity of guaiac test fecal occult blood results in the dog and 2) positive o-tolidine test results were not caused by diets fed in the study.     

Fructooligosaccharide supplementation in the yearling horse: effects on fecal pH, microbial content, and volatile fatty acid concentrations

Short-chain fructooligosaccharides (FOS) were supplemented to the diets of nine quarter horses ranging in age from 489 to 539 d with initial BW averaging 400.6 +/- 21.2 kg. The objectives of this study were to determine the effects of dietary FOS on the fecal responses in terms of pH, the microbial population, and VFA concentrations. The horses were used in a 3 x 3 replicated Latin square design, fed according to NRC requirements, and their individual diets were supplemented with no FOS (CON), 8 g of FOS/d (LOW), or 24 g of FOS/d (HIGH) over three 10-d feeding periods. On the last 3 d of each 10-d feeding period, a single fecal sample was collected between 0730 and 0930. Fecal pH decreased linearly (P = 0.01) from 6.48 with the CON diet to 6.38 with the HIGH diet, but there was no change (P = 0.19 for linear effect) in fecal consistency among treatments. A quadratic effect (P < 0.01) was observed for fecal Escherichia coli population, but no difference (P = 0.88 for linear effect) was found in fecal Lactobacilli enumeration among treatments. The presence of fecal Bifidobacteria was unable to be confirmed and was therefore not reported. Fecal acetate concentrations increased linearly (P = 0.03), with means of 2.13, 2.18, and 2.52 mg/g of wet feces for CON, LOW, and HIGH treatments, respectively. Similarly, fecal propionate concentrations increased linearly (P = 0.01), with means of 0.58, 0.64, and 0.73 mg/g for CON, LOW, and HIGH treatments, respectively. Fecal butyrate concentrations also increased linearly (P = 0.02), with means of 0.40, 0.46, and 0.54 mg/g for CON, LOW, and HIGH treatments, respectively. Total VFA (P = 0.01) and lactate (P = 0.02) concentrations increased linearly, with total VFA means of 3.47, 3.69, and 4.25 mg/g for CON, LOW, and HIGH treatments, respectively, and lactate means of 0.36, 0.41, and 0.47 mg/g for CON, LOW, and HIGH treatments, respectively. Supplementing FOS in diets fed to yearling horses altered fecal microbial populations, fecal VFA concentrations, and pH.