Cecilia Villaverde

Effects of dietary concentration and degree of polyunsaturation of dietary fat on endogenous synthesis and deposition of fatty acids in chickens

1. Two experiments were performed to assess the effect of different amounts of dietary polyunsaturated fatty acids (PUFA) on fatty acid composition of chickens. The contribution of de novo fatty acid synthesis to fatty acid profile was also estimated. 2. In trial 1, different fat sources were blended in different ratios allowing a gradient of dietary PUFA (from 15 to 61 g/kg), keeping added fat constant (9%). In trial 2, PUFA-rich oil was added at increasing inclusion rates (2, 4, 6 and 8%), achieving a dietary PUFA content ranging between 27 and 59 g/kg. 3. Increasing dietary PUFA inclusion resulted in an increase in PUFA deposition, with higher efficiency when dietary fat also provided saturated (SFA) and monounsaturated (MUFA) fatty acids (trial 1). 4. Increasing dietary PUFA in both trials resulted in a decrease in SFA and MUFA concentration in the whole body. 5. The estimated deposition of fatty acids from de novo synthesis was reduced when dietary fat content increased from 0 to 10%, varying between 35·34 and 17·66% for SFA and between 52·70 and 7·01% for MUFA in the whole body. The greater variation range for the MUFA supports the existence of a mechanism maintaining the SFA: (MUFA + PUFA) ratio within a specific range in biological membranes.

Effect of water content in a canned food on voluntary food intake and body weight in cats

OBJECTIVE To determine whether water content in a canned food diet induces decreases in voluntary energy intake (EI) or body weight (BW) in cats fed ad libitum. ANIMALS 16 sexually intact male domestic shorthair cats. PROCEDURES Maintenance EI was determined for 2 months in 10 weight-stable cats consuming a control diet (typical colony diet). Cats were allocated into 2 groups of equal BW and fed a canned diet (with-water [WW] diet) or a freeze-dried version of the canned diet (low-water [LW] diet) twice daily. Diets were identical in nutrient profile on a dry-matter basis. Each dietary treatment period of the crossover experiment lasted 3 weeks, with a 3-week washout period between diets. Body composition measurements were determined by use of deuterium oxide at the end of each dietary treatment. Daily food intake was measured for determination of dry-matter intake and EI. Six other cats were used in preference tests for the 3 diets. RESULTS EI was significantly decreased for the WW diet (mean ± SD, 1,053.0 ± 274.9 kJ/d), compared with EI for the LW diet (1,413.8 ± 345.8 kJ/d). Cats had a significant decrease in BW during consumption of the WW diet. Body composition was unaltered by diet. In short-term preference tests, cats ate significantly more of the WW than the LW diet. CONCLUSIONS AND CLINICAL RELEVANCE Bulk water in the WW diet stimulated decreases in EI and BW in cats. The impact of water content on energy density and food consumption may help promote weight loss in cats.

High Levels of Dietary Unsaturated Fat Decrease α-Tocopherol Content of Whole Body, Liver, and Plasma of Chickens Without Variations in Intestinal Apparent Absorption

An experiment was designed to assess the effect of dietary unsaturated fat inclusion level on alpha-tocopherol apparent absorption and deposition in broiler chickens at 2 ages (20 and 39 d). The dietary fat was a mixture of linseed and fish oil, rich in polyunsaturated fatty acids (PUFA). The experimental treatments were the result of 4 levels of supplementation with alpha-tocopheryl acetate (0, 100, 200, and 400 mg/kg; E0, E100, E200, and E400 treatments, respectively) and 4 dietary oil inclusion levels (2, 4, 6, and 8%; O2, O4, O6, and O8 treatments respectively). Almond husk was used as an energy dilutor in the high-fat diets. Apparent absorption of total fatty acids was high in all treatments averaging 88% and was higher with high fat dietary inclusion level. alpha-Tocopheryl acetate hydrolysis and apparent absorption of alpha-tocopherol were similar in both ages and were not affected by fat inclusion level, except for a reduction of the absorption in the low-fat diet (O2) in the E100 treatment at 20 d of age. Despite this lack of differences in hydrolysis and absorption, higher-fat PUFA diets induced lower concentrations of free alpha-tocopherol in the excreta, at high alpha-tocopherol doses, suggesting an increase in the destruction of alpha-tocopherol by lipid oxidation in the gastrointestinal tract. Similarly, total and hepatic alpha-tocopherol deposition was lower in the birds fed high-PUFA diets in the E200- and E400-supplemented birds, possibly due to a destruction of vitamin E when protecting these PUFA from lipid peroxidation. alpha-Tocopherol concentration in liver and, to a lesser extent, in plasma was a useful indicator of the degree of response of this vitamin to different factors that can affect its bioavailability; however, in the present experiment, CV were too high to use liver and plasma concentrations as estimators of total body vitamin E.

Chemical composition and energy content of chickens in response to different levels of dietary polyunsaturated fatty acids

Abstract Two experiments were performed to study the effect of dietary polyunsaturated fatty acids (PUFA) on abdominal fat pad weight and chemical composition of broilers. In Experiment 1, different fat sources were blended in different ratios keeping added fat level constant (9%). In Experiment 2, PUFA gradient was obtained by increasing the level of inclusion (2, 4, 6 and 8%) of PUFA-rich oil. The treatments had 15, 34, 45 and 61 and 28, 38, 48 and 59 g PUFA/kg diet, respectively. Apparent metabolizable energy intake was similar in both experiments, except for the more saturated diet in Experiment 1 (15 g PUFA/kg), where it was lower. In Experiment 1, abdominal fat pad weight, total body fat and body energy were lower in the animals on the high PUFA diets (p < 0.05) compared to the animals on the saturated-rich ones, meanwhile in Experiment 2 there were no differences on chemical and energy composition by increasing added PUFA-rich oil inclusion level. In conclusion, PUFA-rich chicken diets, compared to saturated-rich ones, cause a lower body fat deposition, but not compared to low-PUFA low-fat diets.

Scope of the Problem and Perception by Owners and Veterinarians

Obesity is a common disease of modern dogs and cats. Dog and cat owners often do not realize their animal is affected. Some pet owners are skeptical of the diagnosis or rationalize the overweight condition of their pets. Animal-related factors associated with obesity in dogs and cats include breed, neuter status, age, and gender, whereas owner-related factors include diet choice, feeding method, and provision of exercise. Owner characteristics, such as age and income, are also potential risk factors for pet obesity. Identifying such risk factors for both animals and owners may help provide targets for prevention or interventional tools.

Macronutrients in Feline Health

Dietary macronutrients include protein, fat, and carbohydrates. Current nutritional recommendations establish minimums but not maximums for protein and fat but not for carbohydrates; thus, commercial feline maintenance diets have a wide range of macronutrient distribution depending on manufacturer, ingredients, and processing. There is growing interest and discussion, however, in defining the ideal macronutrient composition of feline diets to maximize longevity and health. Current recommendations should be tailored to each patient based on age, body condition, presence of muscle mass atrophy, and the presence of disease.

Prevalence of and risk factors for intraoperative gastroesophageal reflux and postanesthetic vomiting and diarrhea in dogs undergoing general anesthesia

OBJECTIVE To determine the prevalence of intraoperative gastroesophageal reflux (GER) and postanesthetic vomiting and diarrhea, and to evaluate risk factors associated with these gastrointestinal disorders (GID) in dogs undergoing general anesthesia. DESIGN Prospective observational study. SETTING University teaching hospital. ANIMALS Two hundred thirty-seven client-owned dogs undergoing general inhalant anesthesia for diagnostic or surgical purposes. INTERVENTIONS None MEASUREMENTS AND MAIN RESULTS: Patient, surgical, and anesthetic variables, and postanesthetic treatments administered in the immediate postanesthesia period were evaluated in relation to GID using univariate and multivariate logistic regression analysis (P < 0.05). Seventy-nine of the 237 (33.4%) dogs developed GID during the perianesthetic period. The prevalences of GER, vomiting, and diarrhea were 17.3%, 5.5%, and 10.5%, respectively. Intraabdominal surgery (P = 0.016; odds ratio [OR] 2.82, 95% confidence interval [CI]: 1.21-6.62), changes in body position (P = 0.003; OR 3.17, 95% CI: 1.47-6.85), and length of anesthesia (P = 0.052; OR 1.006, 95% CI: 1.000-1.013) were associated with GER. Changes in the ventilation mode during surgery (P = 0.011; OR 6.54, 95% CI: 1.8-23.8), length of anesthesia (P = 0.024; OR 1.001, 95% CI: 1.001-1.020), and rescue synthetic colloid support due to hypotension (P = 0.005; OR 6.9, 95% CI: 1.82-26.3) were positively associated with postanesthetic vomiting. On the contrary, dogs that received acepromazine as premedication were significantly less likely (P < 0.019; OR 12.3, 95% CI: 1.52-100) to vomit. Finally, length of anesthesia, changes in body position, changes in ventilation mode, or hypoxemia during the procedure tended to increase the risk (univariate model) of diarrhea during the recovery phase. CONCLUSIONS GID are common in dogs undergoing general anesthesia. Duration and characteristics of the procedure, anesthetic management, and changes in certain patient variables are significant risk factors for the presence of GID in the perioperative period.Objective To determine the prevalence of intraoperative gastroesophageal reflux (GER) and postanesthetic vomiting and diarrhea, and to evaluate risk factors associated with these gastrointestinal disorders (GID) in dogs undergoing general anesthesia. Design Prospective observational study. Setting University teaching hospital. Animals Two hundred thirty-seven client-owned dogs undergoing general inhalant anesthesia for diagnostic or surgical purposes. Interventions None Measurements and Main Results Patient, surgical, and anesthetic variables, and postanesthetic treatments administered in the immediate postanesthesia period were evaluated in relation to GID using univariate and multivariate logistic regression analysis (P < 0.05). Seventy-nine of the 237 (33.4%) dogs developed GID during the perianesthetic period. The prevalences of GER, vomiting, and diarrhea were 17.3%, 5.5%, and 10.5%, respectively. Intraabdominal surgery (P = 0.016; odds ratio [OR] 2.82, 95% confidence interval [CI]: 1.21–6.62), changes in body position (P = 0.003; OR 3.17, 95% CI: 1.47–6.85), and length of anesthesia (P = 0.052; OR 1.006, 95% CI: 1.000–1.013) were associated with GER. Changes in the ventilation mode during surgery (P = 0.011; OR 6.54, 95% CI: 1.8–23.8), length of anesthesia (P = 0.024; OR 1.001, 95% CI: 1.001–1.020), and rescue synthetic colloid support due to hypotension (P = 0.005; OR 6.9, 95% CI: 1.82–26.3) were positively associated with postanesthetic vomiting. On the contrary, dogs that received acepromazine as premedication were significantly less likely (P < 0.019; OR 12.3, 95% CI: 1.52–100) to vomit. Finally, length of anesthesia, changes in body position, changes in ventilation mode, or hypoxemia during the procedure tended to increase the risk (univariate model) of diarrhea during the recovery phase. Conclusions GID are common in dogs undergoing general anesthesia. Duration and characteristics of the procedure, anesthetic management, and changes in certain patient variables are significant risk factors for the presence of GID in the perioperative period.

Evaluation of the use of esterified fatty acid oils enriched in medium-chain fatty acids in weight loss diets for dogs.

Esterified fatty acid oils (EAOs) are obtained from esterification of vegetable acid oils with glycerol. These fat sources have the same fatty acid (FA) composition as their respective native oils but new chemical properties. Several studies have confirmed the potential of medium-chain fatty acids (MCFA) to reduce fat mass (FM) in humans and rodents. This study investigates the use of EAOs with different MCFA proportions on food preferences, digestibility and weight loss management in dogs. A basal diet was supplemented with 8% of three different fat sources: C0: soya bean-canola EAO, C20: soya bean-canola (80%) coconut (20%) EAO and C40: soya bean-canola (60%) coconut (40%) EAO. Food preference of these EAOs was tested using a two-pan preference test. Dogs presented a higher daily food intake of C20 and C40 compared to C0 (C20: 155 ± 18.6 g vs. C0: 17 ± 7.0 g, p < 0.001; C40: 117 ± 13.9 g vs. C0: 28 ± 10.5 g, p < 0.05 respectively). Also, the digestibility of the three experimental diets was tested. C20 and C40 showed higher ether extract, total FA and saturated FA digestibilities (p < 0.05) than C0 diet. Lastly, the three diets were investigated in a 14-week weight loss study, following 16 weeks of ad libitum feeding to induce overweight condition. Body weight (BW) reduction was lower (C0: 20.1 ± 2.32%, C20: 14.6 ± 1.43% and C40: 15.7 ± 1.23%, p < 0.05) and FM was higher (FM, 18.7 ± 3.42%, 27.9 ± 3.90% and 28.2 ± 2.88% for C0, C20 and C40, respectively, p < 0.05) for diets C20 and C40 than for C0. Feeding diets with MCFA at these inclusion levels to experimentally overweight dogs during 14 weeks do not result in faster weight loss compared to unsaturated long-chain FA.

Preliminary study: voluntary food intake in dogs during tryptophan supplementation.

Tryptophan, a precursor of important molecules such as serotonin, melatonin and niacin, is an essential amino acid for dogs. In pigs, tryptophan supplementation has been shown to induce a significant increase in food intake. The aim of the present study was to assess whether long-term tryptophan supplementation increases voluntary food intake in dogs and to observe whether this was accompanied by a change in serum ghrelin. In the present study, sixteen adult Beagle dogs were used, with four male and four female dogs fed diets supplemented with tryptophan (1 g/dog per d) during 81 d (Trp) and four male and four female dogs that were not supplemented (control). A voluntary food intake test was performed during 5 d following the supplementation period. The Trp group tended to show a higher food intake during the voluntary food intake test (58.0 (SE 5.37) v. 77.5 (SE 3.65) g/kg metabolic weight per d; P = 0.074). No significant differences were found for serum ghrelin concentrations.

Preliminary study: fibre content in pet rabbit diets, crude fibre versus total dietary fibre

Fibre is an important nutrient for rabbit health, and, on commercial pet rabbit packaging, it is labelled as crude fibre (CF). In several species, it is considered that CF is not an accurate representation of the fibre content in feedstuffs. The objective of this study was to compare the CF stated on the label (CFL) with laboratory analysis of CF (CFA) and the analysed content of total dietary fibre (TDF) in different commercial pet rabbit feeds. We selected 15 commercial diets and analysed CF and TDF. A mixed model was used to evaluate differences between CFL, CFA and TDF, and linear regression was performed to study the correlation between CFL and CFA with TDF. CFA and CFL were not significantly different (p = 0.836) in the feeds studied, and both were lower than TDF (p < 0.001). The correlations between TDF and both CFA and CFL were significant (p < 0.001 and p = 0.02, respectively), but the correlation was better with CFA (R = 0.86) than with CFL (R = 0.53). As expected, TDF content was higher than CF content, an average of two times. These results suggest that the CF content in rabbit diets reported on the label is not an appropriate indicator of their total fibre content, although further work with a larger sample size is required to confirm these results.