QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ahlstrøm, O. Articles by Hove, K. Search for Related Content PubMed PubMed Citation Articles by Ahlstrøm, O. Articles by Hove, K.

---

Supplement: The WALTHAM International Sciences Symposia Innovations in Companion Animal Nutrition: Poster Presentations

Effect of Exercise on Nutrient Digestibility in Trained Hunting Dogs Fed a Fixed Amount of Food^1–3,

Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway

⁴ To whom correspondence should be addressed. E-mail: oystein.ahlstrom{at}umb.no.

KEY WORDS: • dogs • exercise • digestibility • yttrium oxide

Dogs used for bird hunting have a high energy requirement during working seasons because they get prolonged heavy exercise over several days. Thus, intake of sufficient energy is essential for body weight maintenance and endurance. Consideration of food amount and feeding time in relation to physical activity is important for feeding hunting dogs. Common practice is to feed the dog after the daily hunt and to avoid large meals immediately before and during physical activity, as this may conflict with digestive processes. From practical observations, hunting dogs may experience digestive problems such as diarrhea or frequent defecations at performance onset, indicating nervous anticipation. Vomiting may also occur, demonstrating that the physical effort of running might be the triggering factor. In some cases these signs may be related to a sudden increase in food intake or change in diet composition necessary for satisfying the increased energy expenditure. This points out the importance of gradually increasing exercise and food intake levels before the hunting season to ensure a smoother adaptation to larger energy intakes.

Studies with untrained and trained dogs reveal that exercise has an impact on intestinal functions. Changes in intestinal functions related to exercise after a meal appear as interruptions of intestinal motility in untrained dogs (1) and decreases in gastric acid secretion and in the bicarbonate content of pancreatic juice in trained dogs (2). These findings may indicate that nutrient digestibility is affected by exercise. In sled dogs performing prolonged extremely hard work (Iditarod), intestinal permeability increased in dogs that had completed the 10-d race (3). However, the latter authors did not discuss whether the increased permeability affected nutrient uptake negatively or positively.

To our knowledge, no published study has reported whether intestinal changes induced by exercise affects nutrient digestibility in dogs. The present study was conducted to investigate the effect of moderate exercise (30 km/d) on a treadmill vs. low activity (minimum exercise on leash) on digestibility in trained hunting dogs.

	MATERIALS AND METHODS

TOP MATERIALS AND METHODS RESULTS AND DISCUSSION LITERATURE CITED

 
Animals and experimental conditions

The experiment was performed at Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway. The experimental dogs comprised 4 intact privately owned pedigree dogs, 1 Brittany Spaniel (female, 3 y), 2 Gordon Setters (one male, 8 y and one female, 1 y), and 1 English Setter (male, 6 y). The body scores of the dogs on a scale of 1 to 5 (4) were 2, 3, 2, and 2, respectively, and all dogs had a highly satisfactory health status. The dogs were well trained and generally exercised 1–2 h/d, partly free running and partly walking on a leash. The dogs were fed the experimental food 7 d before experiment onset for feed adaptation. During the food adaptation period they were also adapted to the treadmill by gradually increasing running distance and duration in the laboratory. The first phase of the experimental period was a 4-d period of exercise, and the final phase a 4-d period of low activity. The exercise period consisted of a 30 km/d run on a treadmill constructed for horses (Haico 4000). Exercise periods were divided into four 7.5-km runs of 10 km/h. The laboratory durations were 6 h/d including breaks of 30 min between runs. The dogs were kept in private homes when not participating in the treadmill exercise and during low-activity periods. The exercise in the low-activity period was limited to 30 min/d walking with leash.

The dogs were fed their approximate maintenance requirements, 523 kJ/(BW^0.75 · d)⁵ (5), during the exercise period and slightly less during the low-activity period. During the exercise period, 25% of their daily ration was consumed in the morning before exercise onset, and 25% between the 7.5-km runs. The remaining daily ration (50%) was consumed postexercise. The food was offered dry with access to drinking water. The dogs had free access to water between the 7.5-km runs. Feces were collected in the final phase of each of the 2 sessions on days 3 and 4. Mean temperature in the laboratory during the treadmill running was 12°C. Body weights were recorded at the start and at the end of the treadmill exercise period. Food was provided twice daily during the low-activity period. Use of live animals in experiments at the Department of Animal and Aquacultural Sciences is supervised by the Norwegian National Animal Research Authority

Food composition

The food (150 kg) was produced by extrusion technology at Center for Feed Technology, Ås, Norway. The diet composition was (g/kg): fish meal, 32; poultry meal, 141; corn gluten meal, 120; wheat meal, 292; corn meal, 227; rice meal, 30; beet pulp, 20; poultry fat, 78; soybean oil, 18; calcium carbonate, 15; monocalcium phosphate, 7; sodium chloride, 7; sodium bicarbonate, 7; vitamin-mineral mixture, 3; L-lysine, 1; L-threonine, 1; betaine, 1. Before extrusion the ingredients were ground in a hammer mill and mixed in a paddle mixer. The vitamin and mineral premix was weighed to 0.1 g accuracy. Yttrium oxide (Ida Chemi AS), 0.1 g/kg food, was mixed manually in the premix and then added in the paddle mixer. The ingredients were reground after the first mixing, followed by a second mixing. Fat was added to the food in a vacuum coater before cooling. The food was stored at –20°C until used. Dry matter, crude protein (Kjeldahl-N x 6.25), and ash in food and feces were analyzed according to AOAC (6). Crude fat was determined by acid hydrolysis and petroleum ether extraction (7), whereas the analysis of starch followed the procedure described by McCleary et al. (8). Carbohydrate content in feed and feces was calculated by difference: dry matter – (crude protein + crude fat + ash). The analyzed chemical contents of the food were (g/kg): dry matter, 947; crude protein, 253; crude fat, 147; carbohydrate, 484; starch, 392; ash, 63. Calculated metabolizable energy (ME) content was 16 MJ/kg, the applied ME contents protein, fat, and carbohydrates in the calculation were 14.64, 35.39, and 14.64 kJ/g, respectively. Yttrium in food and in freeze-dried feces was solubilized according to the following procedure: Samples of 100 mg were combusted at 500–550°C for 4–5 h and subsequently mixed with 0.75 mL phosphoric acid (850 g/L) and 1 mL potassium bromate (45 g/L) and boiled for 10 min. The samples were cooled for 2–5 min at 20°C and then mixed with 5 mL of 5 g/L calcium chloride solution. Yttrium was analyzed by inductivity-coupled plasma mass spectrometry (ICP-AES analysis, Perkin Elmer Optia 3000 DV) at 371 nm. The recovery of yttrium added to the food (n = 3) was 92% (SEM ± 0.5). This concentration of yttrium was used in the digestibility calculations. The validation of yttrium as an inert marker in digestibility studies with dogs has been reported in Vhile et al. (9).

Apparent total tract digestibility (%) was calculated as:

where a₁ = analyzed concentration of nutrient in the diet, a₂ = analyzed concentration of marker in the diet, b₁ = analyzed concentration of nutrient in feces, and b₂ = analyzed concentration of marker in feces.

Statistics

The GLM procedure of SAS (10) was applied to test differences in digestibility. Effect of dog was not significant in the model and was therefore excluded. Differences in digestibility between exercise levels were tested in the model:

Y_ij is the ij observation, µ is the general mean, _i is the fixed-effect exercise level, and _ij is a random effect.

	RESULTS AND DISCUSSION

TOP MATERIALS AND METHODS RESULTS AND DISCUSSION LITERATURE CITED

 
Digestibility values were similar in the high-activity period and the low-activity period for all nutrients (Table 1). In other digestibility studies where trained but sedentary Greyhounds were used, digestibility values of >80% for dry matter (DM) and protein and >90% for fat have been reported (11). Our digestibility values were similar to those values, although digestibility values are highly dependent on the characteristics of the food used. There were no clinical signs among the dogs during exercise, indicating that they had no digestive disorders. Usually the dogs consumed the food willingly at every meal. During some of the breaks between the 45-min runs, 1 or 2 dogs did not consume the food offered, but food remnants from one break were often consumed during the next break. The mean body weights of the dogs were 19.6 (SEM ± 2.2) at the start of the exercise period and 19.5 kg (SEM ± 2.1) afterwards. After the 4-d low-activity period, the mean body weight had increased to 19.9 (SEM ± 2.3), thus indicating that the level of exercise was quite moderate for these dogs. Burger (12) divided severity of exercise in dogs into 3 categories relative to duration of exercise: low, <1 h/d; moderate, 1–3 h/d; and high, 3–6 h/d. The dogs in the present study performed moderate exercise according to this classification. A pilot study has indicated that treadmill running is considerably less energy demanding than free running (13). All the experimental dogs trotted at the speed applied in the present experiment (10 km/h), indicating that their maximum running speed capacities were higher. Thus, an increase in the severity of exercise or an increase in food consumption during running above the level used in the present study might have affected digestibility.

	FOOTNOTES

 
¹ Published in a supplement to The Journal of Nutrition. Presented as part of The WALTHAM International Nutritional Sciences Symposium: Innovations in Companion Animal Nutrition held in Washington, DC, September 15–18, 2005. This conference was supported by The WALTHAM Centre for Pet Nutrition and organized in collaboration with the University of California, Davis, and Cornell University. This publication was supported by The WALTHAM Centre for Pet Nutrition. Guest editors for this symposium were D'Ann Finley, Francis A. Kallfelz, James G. Morris, and Quinton R. Rogers. Guest editor disclosure: expenses for the editors to travel to the symposium and honoraria were paid by The WALTHAM Centre for Pet Nutrition.

² Author disclosure: no relationships to disclose.

³ This study was financed by the Norwegian Research Council project 145607.

⁵ Abbreviations used: BW, body weight; ME, metabolizable energy; MMC, migrating myoelectric complex.

	LITERATURE CITED

TOP MATERIALS AND METHODS RESULTS AND DISCUSSION LITERATURE CITED

 

1. Kondo T, Naruse S, Hayakawa T, Shibata T. Effect of exercise on gastro duodenal functions in untrained dogs. Int J Sports Med. 1994;15:186–91.[Medline]

2. Tasler J, Obtulowicz W, Cieszkowski M, Konturek S. Gastrointestinal secretory function during physical exercise. Acta Physiol Pol. 1974;25:215–26.[Medline]

3. Davis MS, Willard MD, Williamson KK, Steiner JM, Williams DA. Sustained strenuous exercise increases intestinal permeability in racing Alaskan sled dogs. J Vet Intern Med. 2005;19:34–9.[Medline]

4. Wills J, Simpson K., editors. The Waltham book of clinical nutrition of the dog and cat. Oxford, UK: Pergamon Press; 1994.

5. Burger IH, editor. The Waltham book of companion animal nutrition. Oxford, UK: Pergamon Press; 1993.

6. Association of Official Analytical Chemists. Official methods of analysis, 15th edition. Washington, DC: AOAC; 1990.

7. European Community Directive. Commission directive 98/64/EC, 1998.

8. McCleary BV, Solah V, Gibson TS. Quantitative measurements of total starch in cereal flours and products. J Cereal Sci. 1984;20:51–8.

9. Vhile SG, Skrede A, Ahlstrøm Ø, Hove K. Yttrium oxide (Y₂O₃) as an inert marker in digestibility studies with dogs, blue foxes and mink fed diets containing different protein sources. J Anim Physiol Anim Nutr. In press 2006.

10. Statistical Analysis Systems Institute. SAS users's guide online, GLM Varcomp, version 7. Cary, NC: SAS Insitute Inc.; 2000.

11. Hill RC, Bloomberg MS, Legrand-Defretin V, Burger IH, Hillock SM, Sundstrom DA, Jones GL. Maintenance energy requirements and the effect of diet on performance in racing Greyhounds. Am J Vet Res. 2000;61:1566–73.[Medline]

12. Burger IH. Energy needs of companion animals: matching the food intakes to requirements throughout the life cycle. J Nutr. 1994;124:2584S–93S.[Abstract/Free Full Text]

13. Ahlstrøm Ø, Skrede A, Speakman J, Redman P, Vhile SG, Hove K. Energy expenditure and water turnover in hunting dogs: A pilot study. J Nutr. 2006;136:2063S–5S.[Free Full Text]

14. De Wever I, Eeckhout C, Vantrappen G, Hellemans J. Disruptive effect of test meals on interdigestive motor complex in dogs. Am J Physiol. 1978;235:E661–5.

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ahlstrøm, O. Articles by Hove, K. Search for Related Content PubMed PubMed Citation Articles by Ahlstrøm, O. Articles by Hove, K.