Effect of sex and reproductive status on sucrose preference, food intake, and body weight of dogs

In a study of preferences for diets containing 1% to 20% sucrose over a bland diet, both female and male dogs preferred the diets containing sucrose over a bland diet, but female dogs had a significantly (P less than 0.05) greater preference for 1% sucrose than did males. Differences between sexes were not observed at the higher concentrations. Mean daily caloric intake was calculated for 12 bitches fed ad libitum during metestrus, estrus, and anestrus, as determined from metachrome-stained vaginal smears. Mean daily caloric intake was lowest during estrus (149 +/- 17 kcal/kg of body weight), was higher during metestrus (159 +/- 8 kcal/kg of body weight), and was highest (175 +/- 9 kcal/kg of body weight) during anestrus. Ovariohysterectomized bitches gained significantly (P less than 0.01) more weight (1.3 +/- 0.3 kg) in the first 10 days after surgery than did sham operated controls (0.3 +/- 0.1 kg). Food intake also was significantly greater ( less than 0.01) in the ovariohysterectomized bitches (1,708 kcal/day) than in the sham operated controls (1,423 kcal/day). Depth of subcutaneous fat in shoulder, rib, and rump areas of ovariohysterectomized bitches was not significantly different from that of intact bitches.     

Resting energy expenditure and body composition of Labrador Retrievers fed high fat and low fat diets

A high dietary fat intake may be an important environmental factor leading to obesity in some animals. The mechanism could be either an increase in caloric intake and/or a decrease in energy expenditure. To test the hypothesis that high fat diets result in decreased resting energy expenditure (REE), we measured REE using indirect calorimetry in 10-adult intact male Labrador Retrievers, eating weight-maintenance high-fat (HF, 41% energy, average daily intake: 8018 +/- 1247 kJ/day, mean +/- SD) and low-fat (LF, 14% energy, average daily intake: 7331 +/- 771 kJ/day) diets for a 30-day period. At the end of each dietary treatment, body composition measurements were performed using dual-energy X-ray absorptiometry. The mean +/- SD REE was not different between diets (4940 +/- 361 vs. 4861 +/- 413 kJ/day on HF and LF diets respectively). Measurements of fat-free mass (FFM) and fat mass (FM) also did not differ between diets (FFM: 26.8 +/- 2.3 kg vs. 26.3 +/- 2.5 kg; FM: 3.0 +/- 2.3 vs. 3.1 +/- 1.5 kg on HF and LF diets respectively). In summary, using a whole body calorimeter, we found no evidence of a decrease in REE or a change in body composition on a HF diet compared with LF diet.     

Energy and fibre intake in a group of captive giraffe (Giraffa camelopardalis) offered increasing amounts of browse

We investigated the effect of diet on intake of energy and fibre in a group of three captive adult giraffe by weighing offered diet items and leftovers for 7 days after an adaptation period of 7 days. Digestion coefficients were calculated using, as internal marker, the acid detergent lignin content of a faecal sample pooled from subsamples taken during the last 5 days of intake measurement. Two lucerne hay-only diets of differing quality (L1, L2) were fed, as well as the regular diet of lucerne hay and concentrates (L2C), and the regular diet supplemented with 3 or 6 kg of edible, fresh browse material (L2CB3, L2CB6). The proportion of roughage in the ingested diets L2CB6 (45 +/- 5% dry matter), L2CB3 (35 +/- 3%) and L2C (37 +/- 10%) did not differ significantly. Digestible energy intake was low on the hay-only diets [L1: 0.28 +/- 0.06 MJ/kg body weight (BW)0.75; L2: 0.33 +/- 0.10 MJ/kg BW0.75] and increased from L2C (0.60 +/- 0.13 MJ/kg BW0.75) to a significant increase with L2CB3 (0.72 +/- 0.17 MJ/kg BW0.75); no further increase was obvious for L2CB6 (0.63 +/- 0.15MJ/kg BW0.75). The results confirm that giraffes are unlikely to meet energy requirements on lucerne hay-only diets. In a feeding scenario where both lucerne hay and the concentrate component of the diet are fed ad libitum, the animals tended to exchange hay for browse when browse was added. Only the higher level of browse supplementation led to a potentially beneficial increase in fibre intake. Whether additional browse supplementation will lead to increased intakes in a feeding scenario with restricted concentrate provision can be suspected but remains to be demonstrated.     

A high-protein, high-fiber diet designed for weight loss improves satiety in dogs

BACKGROUND: Weight-loss programs for dogs are often hampered by increased begging and scavenging behavior that ensues when food intake is restricted. HYPOTHESIS: A diet formulated to contain a high content of both protein and fiber is more satiating than diets that contain only high fiber or high protein. ANIMALS: Six entire female adult dogs (2 Shetland Sheepdogs, 2 Brittany Spaniels, 2 Labrador Retrievers) participated in the satiety studies; 105 adult female dogs of various breeds and ages were used for the palatability studies. METHODS: Three diets (high protein [103 g/1,000 kcal] high fiber [60 g/1,000 kcal] [HPHF]; high protein [104 g/1,000 kcal] moderate fiber [35 g/1,000 kcal] [HP]; moderate protein [86 g/1,000 kcal] high fiber [87 g/1,000 kcal] [HF]) were tested. Voluntary food intake was measured in 5 sequential crossover studies, and palatability was assessed with food preference tests. RESULTS: Protein digestibility was significantly lower for HF (mean +/- SD; 77.7% +/- 2.52%) than for both HPHF (81.1% +/- 0.96%) and HP (81.1% +/- 1.65%) (P < .001). Short-term food intake (food ingested when offered for 15 minutes every hour for 4 hours) was lower for HPHF than for both HP and HF (P = .038). Medium-term intake (food ingested when offered 3 hours after first meal) was lower for both HPHF (27 +/- 22.2 kcal/kg(0.73)) and HF (41 +/- 6.8 kcal/kg(0.73)) than for HP (57 +/- 18.8 kcal/kg(0.73)) (P = .041). Voluntary food intake 3 hours after feeding a restricted meal (25% daily maintenance energy requirements) was significantly lower on the HPHF diet than on either the HP (-51%, P = .0051) or HF (-47%, P = .014) diets. However, there was no significant difference between the energy intake on the HP and HF diets (7%, P = .37). The HPHF and HP diets had equivalent palatability, and both were more palatable than the HF diet (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The HPHF diet had a satiating effect as evidenced by reduced voluntary intake compared with HP and HF diets, and has the potential to lead to greater compliance in weight-loss programs.     

Theoretical evaluation of risk for nutritional deficiency with caloric restriction in dogs

Background: Risk of nutrient deficiency in dogs during caloric restriction is not currently known, while obesity is a growing concern.

Objectives: To determine nutrients that might require further evaluation for the risk of deficiency during caloric restriction.

Animals and methods: Five commercially available canine diets, representing a range of caloric density (2900–4240?kcal/kg metabolizable energy), were assessed for potential nutrient inadequacy if fed to a hypothetical overweight dog. Caloric density and typical nutrient analysis for protein, amino acids, fat, fatty acids, minerals, and vitamins were obtained from the manufacturer. Nutrient intake was calculated using ideal body weight for caloric intakes including 87, 79, 70, 61 and 52?kcal/kg^0.75 and compared with National Research Council recommended nutrient allowances (NRC-RA) for ideal weight.

Results: No diets were less than NRC-RA when compared to NRC-RA (/1000?kcal). The five evaluated diets varied in terms of which nutrients were less than NRC-RA and the degree of restriction required for this to occur. All diets had at least one essential nutrient less than NRC-RA at 79?kcal/kg^0.75/day and multiple nutrients less than NRC-RA at 70?kcal/kg^0.75/day. Choline and selenium were the nutrients most often affected by caloric restriction but others were less than the NRC-RA with caloric restriction.

Conclusions: Further research is needed to determine actual nutrient requirements in overweight dogs, and whether clinical nutrient deficiencies actually arise in vivo.

Clinical importance: Weight loss plans for overweight dogs (particularly those with very low-energy requirements) should include consideration for nutrient adequacy.     

Primary hair growth in dogs depends on dietary selenium concentrations

Selenium (Se) plays an important role in hair growth. The objective of this study was to investigate the effect of dietary selenium concentration on hair growth in dogs. Thirty-six beagles were stratified into six groups based on age, gender and body condition score. The dogs were fed a torula yeast-based canned food for 3 weeks. Then the dogs were fed varying amounts of selenium supplied as selenomethionine for an additional 24 weeks. Analysed selenium concentrations in the experimental foods for the six groups were 0.04, 0.09, 0.12, 0.54, 1.03 and 5.04 mg/kg dry matter respectively. Body weight and food intake were not affected by the selenium treatments. Serum selenium concentration was similar initially but was significantly different at the end of the study among groups. Dietary selenium concentration below 0.12 mg/kg diet may be marginal for an adult dog. Dietary treatment had no effect on serum total thyroxine (TT(4)), free thyroxine (FT(4)), and free 3,3',5-triiodothyronine (FT(3)). There was a significant diet and time interaction (p = 0.038) for total 3,3',5 triiodothyronine (TT(3)). Hair growth was similar among groups initially but significantly reduced in dogs fed diets containing 0.04, 0.09 or 5.04 mg Se/kg when compared with 0.12, 0.54 and 1.03 mg Se/kg at week 11 (p < 0.05) and week 22 (p = 0.061). These results demonstrated that both low and high selenium diets reduce hair growth in adult dogs.     

Feed intake and weight gain of growing goats fed diets of various energy and protein levels

Growing goats, 45 Alpine and 45 Nubian, were used in a 3 x 3 factorial arrangement to quantify the influence of dietary energy and protein levels on daily DM intake and nutrient utilization for growth. Goats had ad libitum access to complete mixed diets containing either 2.46, 2.77 or 3.05 Mcal/kg ME plus 11.2, 12.7 or 15.1% CP for 16 wk. Dry matter intake decreased curvilinearly as dietary ME density increased (P less than .001). Dry matter intake increased linearly (P less than .05) as dietary CP level increased during all growth intervals except wk 25 to 28 of age. Average daily gain was 115, 113 and 99 g/d for goats fed diets containing 2.46, 2.77 and 3.05 Mcal/kg ME, respectively. Average daily gain was 104, 106 and 117 g/d for goats fed diets with 11.2, 12.7 and 15.1% CP, respectively. Dry matter intake was higher (P less than .01) for Alpine than for Nubian goats, whereas ADG was similar between breeds. Intake of ME was 248, 260 and 198 kcal/(kg.75.d) for goats fed the low- medium- and high-energy diets, respectively. Intake of CP was 9.1, 10.7 and 13.2 g/(kg.75.d) for goats fed low-, medium- and high-protein diets, respectively. Average requirements for growth derived from regression analysis of all data points were 4.6 kcal ME and .26 g CP/g ADG. The prediction equation for intake of growing goats of 4 to 8 mo of age was: DMI, g/d = 1,749 - 496 DE, kcal/g + 18 live weight, kg + 3 ADG, g/d; r2 = .73 (Sy.x = 127, P less than .0001, n = 90). The requirement of ME for growth was 33% lower than the value recommended in 1981 by the National Research Council.     

Pigs weaned from the sow at 10 days of age respond to dietary energy source of manufactured liquid diets and exogenous porcine somatotropin

Previous research indicates that the neonatal pig does not alter feed intake in response to changes in the energy density of manufactured liquid diets. Also, the limited response of IGF-I to exogenous porcine ST (pST) previously observed in young pigs may be influenced by the source of dietary energy. Our objectives were to 1) determine the effect of a high-fat (HF; 25% fat and 4,639 kcal/kg ME; DM basis) or low-fat (LF; 2% fat and 3,481 kcal/kg ME; DM basis) manufactured liquid diet on pig performance; and 2) determine whether the limited response to exogenous pST in young pigs depends on the source of dietary energy. Two replicates of 60 pigs (n = 120; barrows and gilts distributed evenly), with an initial BW of 4,207 +/- 51 g, were weaned from the sow at 10 d of age and used in a randomized complete block design. Pigs were assigned by BW to one of six pens. Diets were formulated to provide a constant lysine:ME ratio and were fed on a pen basis for a duration of 9 d. On d 5, barrows and gilts within a pen were assigned randomly to receive either 0 or 120 microg of pST.kg BW(-1).d(-1) for 4 d. Pigs gained 336 +/- 9 g/d, which resulted in an ending BW of 7,228 +/- 120 g, regardless of dietary treatment (P > 0.15). Pigs fed the LF diet consumed 17% more DM per pen daily than pigs fed the HF diet (2,777 +/- 67 vs. 2,376 +/- 67 g/d, P < 0.01), but calculated ME intake did not differ between dietary treatments (P > 0.20). The G:F was 24% greater in HF- than in LF-fed pigs (P < 0.01). Plasma urea N concentrations were higher in the HF-fed pigs (11.0 +/- 0.6 mg/dL) than in pigs fed the LF diet (6.2 +/- 0.6 mg/dL; P < 0.05). Treatment with pST increased circulating IGF-I (P < 0.01) and decreased PUN (P < 0.01) concentration 32 and 25%, respectively, regardless of dietary treatment (P > 0.30). Circulating leptin averaged 1.8 +/- 0.1 ng/mL and was not affected by dietary treatment (P > 0.35) or pST (P > 0.40). These results suggest that the ST/IGF axis is responsive in the young pig and the increase in circulating IGF-I and growth is independent of the source of dietary energy. Also, young pigs respond to a lower energy density liquid diet with increased feed intake, without altering growth performance, apparently utilizing a mechanism other than circulating leptin.     

The relationship of feeding patterns and obesity in dogs

The rates of dog obesity are increasing and a greater understanding of feeding patterns is required to combat the problem. This study examined relationships between dietary patterns and caloric intake, and nutrient content of foods fed as it relates to obesity in dogs in the United States. Sixty‐one owners and their dogs were enrolled, and lifestyle surveys, food frequencies, and 3‐day food records were collected. Significant differences in overall kcal intake per kilogram of body weight were found (p < 0.04). Crude fibre in dog food was positively associated with protein and negatively associated with fat regardless of the dog’s weight (p < 0.001). Lean dogs received significantly more crude fibre in relation to overweight dogs regardless of the number of treats they received (p < 0.01), and their diets had greater micronutrient densities (p < 0.03) suggesting that high fibre influences body condition. Additionally, owners who ate nutrient‐rich, calorie‐poor diets had normal weight dogs, and owners that fed more table scraps had overweight dogs. Regardless of body condition, 59% of dogs received table scraps, which constituted 21% of daily caloric intake. The nutrient density of scraps fed was variable and did not meet National Research Council’s recommendations for micronutrient adequacy.     

Effect of faunation on ruminal solubility and liver content of copper in sheep fed low or high copper diets

Naturally fauna-free crossbred rams approximately 5 mo old, 49.3 +/- 1.88 kg live weight, were allotted to four groups. Two groups remained fauna-free, whereas the other two groups were faunated. A diet based on corn silage-soybean meal containing either a low or a high Cu concentration (7 or 15 micrograms/g dry matter) was fed ad libitum to the two groups for 197 d. The rams were killed at the end of the experiment and livers and ruminal contents were analyzed for Cu. Faunated sheep grew faster (P less than .01) and as a group consumed 1.53 kg diet dry matter daily compared with 1.34 for the fauna-free sheep. Faunated sheep had lower final liver Cu concentrations (P less than .01), total liver Cu per unit of Cu intake and ruminal Cu solubilities (P less than .01) when fed both low and high Cu diets. The relative hepatic Cu uptake was higher by rams fed the low Cu than by those fed the high Cu diet. The results are interpreted to show that faunation decreased the availability of Cu in sheep fed a corn silage-soybean meal diet. The magnitude of the effect was independent of the Cu concentration in the diet.     

Influence of steam-flaked, steamed-whole or whole shelled corn on performance and digestion in beef steers

Three trials were conducted to evaluate finishing diets containing 67% steam-flaked corn (SFC), steamed-whole corn (SWC) or whole corn (WC). In a feeding trial, steers fed SWC consumed more (P less than .05) dry matter per day (7.6 kg) than those fed WC (7.0 kg) or SFC (6.7 kg). Average daily gain was greater (P less than .05) for steers fed SFC (1.33 kg) and SWC (1.31 kg) than for those fed WC (1.25 kg), and feed efficiency was better (P less than .05) for steers fed SFC (5.06 kg dry matter/kg gain) than for those fed WC (5.62) and SWC (5.79). Carcass characteristics were not different among the three groups. In a digestion trial, method of corn processing did not affect digestibility of dry matter and crude protein. Starch digestibility was greater (P less than .05) for SFC (99.1%) than for SWC (93.8%) and WC (93.0%). There were no differences in nitrogen (N) intake or fecal N among the three diets; however, urinary N was less (P less than .05) for SWC (19 g/d) than for SFC (27 g/d) and WC (32 g/d), and N retention was higher (P less than .05) for the SWC diet. In vitro dry matter digestibility of the SFC diet was higher (P less than .05) than for WC at 4 and 8 h of incubation and higher (P less than .05) than the SWC diet at 8, 12 and 24 h of incubation. In vitro gas production after 6 h was greater (P less than .05) for SFC than for SWC grain, which was greater (P less than .05) than WC.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of insoluble and soluble dietary fiber on glycemic control in dogs with naturally occurring insulin-dependent diabetes mellitus

OBJECTIVE: To evaluate the effects of diets differing in type and quantity of fiber on glycemic control in dogs with naturally occurring insulin-dependent diabetes mellitus. DESIGN: Prospective randomized crossover controlled trial. ANIMALS: 7 dogs with well-regulated naturally occurring insulin-dependent diabetes mellitus. PROCEDURE: Dogs were fed 1 of 3 diets for 1 month each in 1 of 6 randomized diet sequences. Diets included a low-fiber diet (LF) and 2 high-fiber diets; 1 contained only insoluble fiber (HIF), and 1 contained soluble fiber in addition to insoluble fiber (HSF). Caloric intake was unchanged throughout the study. Glycemic control was assessed after each feeding trial by measuring serum fructosamine concentration and performing 5 serial measurements of blood glucose concentration every 2 hours after the morning feeding and insulin injection. RESULTS: Significant differences were not detected in body weight, required insulin dosage, or albumin concentration among dogs fed the HIF, HSF, and LF diets. Mean and maximum blood glucose concentrations and area under the blood glucose curve were significantly lower in dogs fed the HIF diet, compared with values in the same dogs fed the HSF or LF diet. Fructosamine concentration was significantly lower in dogs fed the HIF or HSF diet, compared with values in the same dogs fed the LF diet. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs with naturally occurring insulin-dependent diabetes mellitus, a dry, high insoluble-fiber diet may aid in glycemic control.     

不同中性洗涤纤维与非纤维性碳水化合物比值饲粮对肉用绵羊甲烷排放的影响

本试验旨在研究不同中性洗涤纤维(NDF)与非纤维性碳水化合物(NFC)比值(NDF/NFC)饲粮对肉用绵羊甲烷排放的影响。试验采用4×4完全拉丁方试验设计,将16只杜泊×小尾寒羊杂交羯羊随机分成4组,每组4只,按维持水平饲喂NDF/NFC分别为3.02(饲粮1)、2.32(饲粮2)、1.58(饲粮3)、1.04(饲粮4)的全混合颗粒饲粮(玉米秸秆为粗饲料来源)。试验共进行4期,每期18 d,包括3 d的调整期、7 d的预试期和8 d的正试期,在正试期内测定甲烷产量、饲粮总能和营养物质表观消化率。结果表明:饲粮2的甲烷日排放量显著高于饲粮3和4(43.43 L/d vs.38.88和35.98 L/d;P0.05)。与饲粮1相比,饲粮2和3的每千克干物质采食量(DMI)甲烷排放量显著增加(38.00 L/kg DMI vs.42.24、41.69 L/kg DMI;P0.05),但是饲粮2、3和4之间差异不显著(P0.05)。随着NDF/NFC的降低,每千克可消化有机物(DOM)的甲烷排放量逐渐降低,饲粮4的每千克DOM的甲烷排放量显著低于饲粮1、2和3(58.78 L/kg DOM vs.75.00、73.35和64.11 L/kg DOM;P0.05)。随着NDF/NFC的降低,每千克中性洗涤纤维采食量(NDFI)或酸性洗涤纤维采食量(ADFI)的甲烷排放量逐渐增加,且各饲粮之间差异显著(P0.05)。综上所述,结合各营养物质表观消化率和甲烷排放效率,在维持水平下,采用NDF/NFC为1.04的玉米秸秆饲粮作为肉用绵羊甲烷减排的饲粮最合适。     

Intake, digestion, and digestive characteristics of Neotyphodium coenophialum-infected and uninfected fescue by heifers offered hay diets supplemented with Aspergillus oryzae fermentation extract or laidlomycin propionate

Tarentaise heifers fitted with a rumen cannula (539 +/- 7.5 and 487 +/- 15.7 kg avg initial BW in Exp. 1 and 2, respectively) were used in two Latin square metabolism experiments having 2 x 2 factorial treatment arrangements to determine the effects of supplementation with Aspergillus oryzae fermentation extract (AO) or laidlomycin propionate (LP) on intake, digestion, and digestive characteristics of Neotyphodium coenophialum-infected (IF) or uninfected (FF) tall fescue (Festuca arundinacea) hay diets consumed ad libitum. Heifers were housed in individual stanchions in a metabolism facility with ambient temperatures controlled to range between 26.7 and 32.2 degrees C daily. Total feces and urine were collected for 5 d following a 21-d dietary adaptation period. In situ DM and NDF disappearance and ruminal fermentation characteristics were also determined. In Exp. 1, DMI was 24% greater (P < 0.01) by heifers offered FF than by those offered IF (6.7 vs 5.4 kg/d). Heifers fed 2 g/d AO tended (P = 0.09) to consume 4% more DM than those fed a diet without AO. Degradable DM and NDF fractions of IF were greater (P < 0.01) than those of FF, but AO supplementation did not affect situ disappearance (P > or = 0.42). In Exp. 2, DMI was 18.9% greater (P < 0.01) by heifers offered FF than by those offered IF (6.6 vs 5.5 kg/d). Heifers fed LP (50 mg/d) consumed 10.6% less (P < 0.05) DM than those not fed LP (5.7 vs 6/5 kg/d). Digestibility of NDF tended to be greater (P = 0.08) and digestibility of ADF was greater (P < 0.05) from FF than from IF. Conversely, apparent N absorption (%) was greater (P < 0.05) from IF than from FF. Heifers fed LP had lower (P < 0.05) ADF digestibility than those not fed LP. In situ degradable DM and NDF fractions were greater (P < 0.01) from IF than from FF. Diets supplemented with LP had higher (P < 0.01) indigestible DM and NDF fractions than those without LP. Propionic acid and total VFA concentrations were greater (P < 0.05) from heifers offered FF than from those offered IF and from heifers fed LP than from those not fed LP. Therefore, it appears the major effect of N. coenophialum was a reduction in forage intake and total-tract fiber digestibility in certain situations. Response to the feed additives was similar whether heifers were offered IF or FF and no evidence was apparent that either additive would improve performance substantially by animals consuming low-quality fescue hay diets.     

Importance of milk replacer intake and composition in rearing orphan foals

Effects of milk replacer composition and intake on the growth of orphan foals were evaluated. Twenty foals were assigned to four treatments: 1) mare-nursed, 2) commercial foal milk replacer at recommended intakes (standard), 3) commercial foal milk replacer at high intakes (high), and 4) acidified replacer at recommended intakes (acidified). Foals fed milk replacer diets were weaned at 12-24 hours postpartum and fed milk replacer for 50 days. Mare-nursed foals were weaned between 52 and 56 days of age. Foals fed replacer diets gained 12% to 28% less weight than mare-nursed foals up to two weeks of age. However, by four months of age, weights of replacer-fed foals were similar to those of mare-nursed foals and 32 other mare-nursed foals at the farm weaned between three and four months postparium. Foals drank 10 to 12 L/100 kg body weight (BW) in fluid replacer daily over the trial period. During the first week, high intake foals consumed 26% more replacer (p<0.05) than foals fed acidified or standard diets. This higher intake resulted in diarrhea earlier (6-11 days vs 11-22 days) and for a longer time (6.3 days vs 2.5-3.6 days) than in foals fed recommended amounts. Mare-nursed foals developed “foal heat scours” in the second week postpartum. After the first week, foals fed high replacer diet voluntarily consumed the same volume of fluid replacer as foals fed the standard intake. Foals ate less than 1 kg grain mix/100 kg BW daily to one month of age, then increased intake to 1.5-2 kg/ 100 kg BW to weaning. Water intake was 20-40% of daily fluid intake and was correlated (r = 0.85) to dry matter intake. Foals in the high intake group ate less (p<0.05) solid feed and drank less water than foals fed the standard and acidified diets. The foal's stomach capacity appears to limit meal size and thus replacer intake. If recommended feeding intervals are used, replacer intakes by foals are less than 15% BW daily. High volume intakes appeared to prolong diarrhea. Normal growth rates occur when replacer and good-quality feeds are fed concurrently.     

Relationship between dietary protein concentration and serum trypsin-like immunoreactivity in dogs

Serum trypsinogen concentration was studied in 6 adult mixed-breed dogs randomly fed diets containing 6.8, 31.4, or 39.7% protein (dry weight) for 3 weeks each. Blood was collected on days 20, 21, and 22 of each feeding period, and serum trypsinogen concentrations were determined by radioimmunoassay of trypsin-like immunoreactivity (TLI). Mean serum TLI concentrations for each dog fed each diet were compared. A significant (P less than 0.05) positive linear relationship (P less than 0.02) was determined between serum TLI concentrations and the percentage of dietary protein. Mean serum TLI concentrations for each dog fed all diets ranged from 5.7 to 20.2 micrograms/L.     

The effects of dietary crude protein level on rate, efficiency and composition of gain of growing beef bulls

Two experiments were conducted to evaluate the effects of dietary CP level on rate, efficiency and composition of gain of growing beef bulls. In Exp. 1, 59 bulls (333 +/- 15.8 kg) were used. Eleven bulls were slaughtered on d 0 to provide an estimate of initial carcass composition (9-10-11 rib section chemical analyses), and remaining bulls were assigned to treatment diets containing 10, 12 or 14% dietary CP. Bulls fed the 10% CP diet grew slower (P less than .05) than bulls fed the 12 or 14% CP diets, although dry matter intake and feed-to-gain ratio did not differ. Bulls fed the 12% CP diet had fatter carcasses (P less than .05) than bulls fed the 10 or 14% CP diets and had greater daily fat accretion than bulls fed the 10% CP diet. In Exp. 2, 60 bulls (318 +/- 9.0 kg) were used. Bulls were assigned to initial slaughter (n = 6) or to one of three dietary treatments, 10, 12 or 14% CP, and were slaughtered after feeding for 66, 136 or 202 d (n = 6 . treatment -1 . slaughter time -1). Bulls fed 10% CP diets had lower (P less than .05) rates of carcass protein accretion during d 0 to 136 and d 0 to 202. Carcass fat gain was similar among treatments over the entire experiment, although bulls fed the 14% CP diet gained more fat during d 0 to 136 than bulls fed the other treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ileal and total tract nutrient digestibilities and fecal characteristics of dogs as affected by soybean protein inclusion in dry, extruded diets

Plant-based protein sources are generally less variable in chemical composition than animal-based protein sources. However, relatively few data are available on the nutrient digestibilities of plant-based protein sources by companion animals. The effects of including selected soybean protein sources in dog diets on nutrient digestion at the ileum and in the total tract, as well as on fecal characteristics, were evaluated. Six protein sources were used: soybean meal (SBM), Soyafluff 200W (soy flour), Profine F (traditional aqueous-alcohol extracted soy protein concentrate [SPC 1]), Profine E (extruded SPC [SPC 2]), Soyarich I (modified molecular weight SPC [SPC 3]), and poultry meal (PM). All diets were extruded and kibbled. Test ingredients varied in CP and fat contents; however, diets were formulated to be isonitrogenous and isocaloric. Nutrient intakes were similar, except for total dietary fiber (TDF), which was lower (P < 0.01) for dogs fed the PM diet. Apparent ileal digestibilities of DM, OM, fat, and TDF were not different among treatments; however, CP digestibility at the terminal ileum was higher (P < 0.01) for diets containing soy protein sources than for PM. Total tract CP digestibility was greater (P < 0.01) for soy protein-containing diets than for PM. Apparent total tract digestibilities of DM, OM, fat, and TDF were not different among treatments. Apparent amino acid digestibilities at the terminal ileum, excluding methionine, threonine, alanine, and glycine, were higher (P < 0.01) for soy protein-containing diets than for PM. Dogs fed SPC diets had lower (P < 0.01) fecal outputs (g asis feces/g DMI) than dogs fed the SF diet, and dogs fed SBM tended (P < 0.11) to have lower fecal outputs than dogs fed the SF diet. However, dogs fed the PM diet had lower (P < 0.03) fecal outputs than dogs fed SPC-containing diets. Fecal outputs and scores reflected the TDF and nonstructural carbohydrate contents of the soy protein fraction. Soy protein sources are well utilized by the dog prior to the terminal ileum, and SPC offers a viable alternative to PM as a protein source in dry, extruded canine diets.     

Net energy value of ammoniated wheat straw

Eight steers (327 kg average) were fed diets containing either nontreated or anhydrous NH3-treated wheat straw in a two-period crossover design. Intake and digestibilities of dry matter, gross energy, neutral detergent fiber, acid detergent fiber and crude protein were measured by total collection. Energy losses in urine and methane were determined. Heat production was determined by indirect respiration calorimetry on steers fed both diets and after they were fasted. Ammoniation of the straw raised its N content from .49 to 1.59% (P less than .001). Dry matter (DM) intake was increased (P less than .01) by the process from 1.0 to 1.3% of body weight. Digestibility coefficients of dry matter and energy, as well as those for fiber, were increased (P less than .001) by four percentage units or more. Crude protein digestibility, however, was depressed (P less than .001) from 67.8% to 53.5% by ammoniation. Urinary energy as a percentage of gross energy intake (GEI) was reduced (P less than .05) by NH3 treatment from 4.10 to 3.74%. Methane energy was not different (P greater than .10). Metabolizable energy was improved (P less than .001) by ammoniation, increasing from 45.2 to 50.0% of GEI. Daily heat production was higher (P less than .01) for steers consuming the ammoniated straw diet, increasing from 113.7 to 125.3 kcal/wt.75), and was due to higher metabolizable energy intake (MEI) since partial efficiency of MEI used for maintenance did not differ (P greater than .10) between diets. The higher net energy value of the ammoniated wheat straw diet (1.45 vs 1.26 kcal/g DM) was due mainly to decreased fecal loss and a slight decline in urinary loss.     

Influence of dietary composition on gastric emptying and motility in dogs: potential involvement in acute gastric dilatation

Gastric dilatation-volvulus is a dramatic and life-threatening disease of large-breed dogs. The cause is unknown, but ingestion of dry cereal-based food is frequently incriminated as a predisposing factor. The purpose of this study was to examine the effect of commercial diets on gastric motility and emptying in the dog. Four large-breed dogs were fed 3 different diets (diet A = canned meat-based; B = cereal-based with 77% added water; and C = dry cereal-based) in a randomized block design. Each experiment was done in triplicate. Motility was assessed, using 5 AgAgCl electrodes and 2 strain gauges sutured along the serosa of the stomach and proximal duodenum. Dogs were fed at the same time each day and the time to change from the fed to the fasted pattern of gastrointestinal motility (changeover) was measured. Gastric emptying was assessed by recording gastric radioactivity. After feeding a meal mixed with 99mTc-labeled resin, the log of activity was plotted against time, and the half-time of gastric emptying (t1/2 GE) was calculated. Mean (+/- SEM) times from feeding to changeover for the 3 diets were: diet A, 9.7 +/- 0.9; B, 10.5 +/- 0.4; and C, 11.0 +/- 0.8 hours. Diet had minimal influence on the half time of gastric emptying (diet A, 2.2 +/- 0.3; B, 2.6 +/- 0.4; and C, 2.9 +/- 0.3 hours; P greater than 0.05). The data indicate that gastric motility and emptying in healthy large-breed dogs were not affected by dietary composition. Because most large dogs are fed cereal-based food for reasons of cost and ease of use, these diets may have been wrongly incriminated as a predisposing factor in gastric dilatation-volvulus.