Digestive Response of Rainbow Trout, Salmo gairdneri, to Pellet Diets

1969 ◽  
Vol 26 (7) ◽  
pp. 1801-1812 ◽  
Author(s):  
John T. Windell ◽  
David O. Norris ◽  
James F. Kitchell ◽  
James S. Norris

Quantitative data are presented for three laboratory experiments concerning rate of gastric evacuation of pellets (fed in gelatin capsules) and pellet components. Rainbow trout, Salmo gairdneri, acclimated to a constant water temperature of 15 C were killed 12 hr after consuming an experimental meal. Subtraction of amount of dry matter remaining at autopsy from dry matter consumed yielded amount of food digested or evacuated or both, from the stomach per unit time.Meals of encapsulated pellet were evacuated from the stomach more rapidly (65.8% decrease in 12 hr) than encapsulated corn oil (42.6%), gelatin (50.8%), a combination of corn oil and gelatin (47.3%), saturated fat (28.8%), or methyl cellulose (50.3%).Groups of fish consuming five capsules equal to approximately 0.65 % of their body weight evacuated 35.9, 45.1, 64.2, 95.5, and 100% at intervals after killing from 6 to 36 hr, respectively. Similar groups consuming seven capsules equal to approximately 1.0% of their body weight evacuated 23.7, 57.9, 70.5, and 86.6% at intervals after killing from 4 to 20 hr, respectively.Ten groups of trout consuming amounts of dry matter equal to 0.24, 0.40, 0.74, 1.11, 1.31, 1.19, 1.59, 1.56, 1.91, and 2.26% of their body weight evacuated 90.7, 81.3, 64.2, 57.9, 56.6, 52.5, 53.4, 51.3, 58.7, and 50.0% in 12 hr, respectively. Gastric motility remains relatively constant once food has entered the stomach. However, when larger meals are fed a greater quantity is evacuated per unit time. This could only be accomplished by changes in volume of gastric contents pumped per peristaltic stroke or number of strokes per unit time.

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 436-437
Author(s):  
Arquimedes Lima Junior ◽  
Murillo A Meschiatti ◽  
Vinicius N Gouvêa ◽  
Victor Dantas ◽  
Daniel Silva Antonelo ◽  
...  

Abstract The objective of this study was to evaluate the growth performance and carcass traits of finishing bulls fed diets containing, on dietary dry matter basis, different levels of corn wet distillers bran plus solubles (WDBS; 0, 15, 30 or 45%) added with or without corn oil (CO; 0 and 3%). A total of 205 Nellore bulls (390 ± 25 kg initial BW) were blocked by initial body weight, distributed in 40 pens and pens within weight block were randomly assigned to treatments in a 2 × 4 factorial arrangement. Diets were isonitrogenous and contained 8.5% sugarcane bagasse and 91.5% concentrate (ground corn, soybean meal, pelleted citrus pulp, urea, mineral). The WDBS (FlexyDDG®) and the corn oil were from SJC Bioenergia (Quirinópolis, Goiás, Brazil). Data were analyzed using the PROC MIXED procedure of SAS. An interaction between CO × WDBS levels was observed for dry matter intake (DMI; P = 0.032). In diets without CO, increasing levels of WDBS linearly (P = 0.004) reduced the DMI, but in diets containing 3% CO, increasing levels of WDBS quadraticaly affected the DMI (P = 0.002). No effects of CO, WDBSF levels or CO × WDBS levels were observed for final body weight, average daily gain, hot carcass weight and dressing percentage. Feed efficiency tended (P = 0.07) to be greater for bulls fed diets containing CO (0.154 vs. 0.144). Increasing levels of WDBS tended (P = 0.09) to increase the feed efficiency. In summary, increasing levels of WDBS in finishing diets linearly (in diets without CO) or quadratically (in diets with CO) reduces the dry matter intake. Adding CO and WDBS tend to increase feed efficiency.


1990 ◽  
Vol 64 (1) ◽  
pp. 45-58 ◽  
Author(s):  
P. C. Gregory ◽  
M. Mcfadyen ◽  
D. V. Rayner

The aims of the present study were to compare the gastric emptying of dry matter (DM) and liquids during the feeding period with that following meal consumption, to clarify the relationship between feeding and gastric emptying, and to investigate how gastric emptying changes in growing animals. The studies were performed in pigs fitted with a gastric cannula and fed on a normal finely ground solid diet mixed with water containing CrEDTA as liquid marker. Gastric emptying was measured using a gastric evacuation technique. It was observed that between 0.75 and 6 h after feeding the total amounts emptied increased, but the proportion of the meal emptied fell, with increase in meal size; emptying of both DM and liquids with large and small meals followed and exponential pattern. In contrast, while the animals were feeding, there was linear and rapid emptying of both DM and liquids following a very short (approximately 2 min) lag phase before emptying began. The rate of emptying increased linearly with body-;weight (by 0.55 g DM/min and by 0.24 ml/min per kg body-weight over the range 58–200 kg) such that the emptying of digestible energy per kg metabolic body-weight (W0.75) was roughly maintained (between 2.9 and 3.2 kJ/min per kg W0.75). This suggests that the rate of emptying may be linked in some way with the metabolic requirements of the body. The biphasic pattern of gastric emptying observed is probably the intrinsic pattern of emptying of a meal which does not require breakdown of particles before emptying can occur.


1980 ◽  
Vol 37 (9) ◽  
pp. 1421-1425 ◽  
Author(s):  
Larry J. Paulson

Ammonia excretion by brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) was measured in relation to nitrogen consumption, body weight (15–154 g for rainbow trout and 50–360 g for brook trout), and temperature (11.2–21.0 °C) under laboratory conditions. Four natural diets, collected from Castle Lake, California, and a commercial pellet diet were fed to the trout in gelatin capsules at feeding rates from 2.5 to 5% body weight∙d−1. Nitrogen consumption was the most important factor influencing ammonia excretion, followed by body weight and temperature. Testing the models with an independent data set revealed good agreement between measured and predicted rates of excretion. The models seem to estimate adequately ammonia excretion by trout in both natural and artificial aquatic systems.Key words: models, ammonia excretion, nitrogen consumption, body weight, temperature, multiple regression, rainbow trout, brook trout


1981 ◽  
Vol 91 (1) ◽  
pp. 285-292 ◽  
Author(s):  
G. BOGÉ ◽  
A. RIGAL ◽  
G. PÉRES

The effects of 4 and 8 weeks fasting at 16 °C were studied in rainbow trout, Salmo gairdneri Richardson. After 4 and 8 weeks, the wet weights of the intestine of fasted animals are respectively 64% and 69% lower than those of fed animals. These effects especially concern the mucosal tissue. Glycine absorption (0.5 and 10 mm) was studied using an in vivo perfusion technique. After 4 weeks, the absolute amounts of 0.5 mm glycine absorbed by fasted and fed fish are similar. With 10 mm glycine, the absorption is slightly lower in fasted trout (−19%). After 8 weeks these differences are more marked, with glycine concentrations of 10 mm (−42%). Results expressed per 100 g body weight showed that these differences result partly from a weight gain of fed trout. Absorption expressed in terms of weight of dry intestine is higher in 4 and 8 weeks fasted animals, principally for the lower amino acid concentration (+61% and +111%). Larger differences were apparent when the absorptions were expressed in terms of dry weight of mucosal tissue (+122% and +225%).


1962 ◽  
Vol 19 (2) ◽  
pp. 201-270 ◽  
Author(s):  
T. G. Northcote

The marked differences in response to water current, exhibited by juvenile rainbow trout migrating into Loon Lake from its outlet and inlet streams, were studied both in the field and in experimental laboratory apparatus. All available evidence argued against genetically discrete outlet and inlet stocks, each maintaining different innate responses to water current. Difference in water temperature between streams was shown, in field and laboratory experiments, to regulate direction of juvenile trout migration through action on behaviour associated with downstream movement, maintenance of position and upstream movement.In laboratory experiments with cool (5 and 10 °C) flowing water, recently emerged fry rarely made contact with the stream bottom in darkness and exhibited much more downstream movement than in warm (> 14 °C) water. In cool streams of the Loon Lake system (daily mean consistently < 13 °C) large numbers of recently emerged fry moved downstream in darkness. Laboratory experiments indicated that combination of cool water (10 °C) and long day length (16 hours) induced downstream movement of fingerlings. In the field, fingerlings moved downstream largely in late spring and summer in cool streams of the Loon Lake system.In laboratory experiments with warm (15 and 20 °C) flowing water, recently emerged fry made frequent contact with the stream bottom in darkness and exhibited much less downstream movement than in cool (10 °C) water. In the warm outlet stream (daily mean in summer usually > 15 °C) recently emerged fry maintained position in darkness. Laboratory experiments suggested that short day length (8 hours) may facilitate maintenance of position exhibited by fingerlings in streams during late autumn and winter.Upstream movement of fry recorded in the field and tested in the laboratory was most pronounced in warm water (> 14 °C). Fingerlings subjected to rapid 5–degree (C) increases in water temperature in an experimental stream exhibited an immediate increase in upstream movement. Upstream movement in summer of large fry and fingerlings occurred only in the warm outlet stream; daily periodicity of upstream movement was positively correlated with sharp rises in water temperature.Evidence examined from four other widely separated stream systems indicated an environmental control of migration in juvenile rainbow trout similar to that demonstrated in the Loon Lake stream system. Possible mechanisms and interaction of factors controlling migratory patterns between and within streams are discussed. Significance of the predominant role played by temperature is considered.


1975 ◽  
Vol 32 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Patricia G. McNicholl ◽  
W. C. Mackay

Rainbow trout (Salmo gairdneri) were force fed, with and without M.S. 222 anesthesia, pellets containing DDT equivalent to 0, 10, and 100% of the 96 h-LD50 dose of 0.03 mg DDT/g body weight. DDT at the LD50 dose significantly increased learning rate 48 and 72 h after treatment. Although the 10% LD50 group did not learn significantly faster than controls, their slightly improved learning rate indicated a dose-dependent response curve. M.S. 222 did not affect learning rate of a simple conditioned response whether or not the anesthetic was combined with DDT.


1989 ◽  
Vol 2 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Craig W. Hawryshyn ◽  
Margaret G. Arnold ◽  
Duane J. Chaisson ◽  
Patricia C. Martin

AbstractThe present study examines the changes in ultraviolet (UV) photosensitivity that occur during the growth of rainbow trout (Salmo gairdneri). A comparison of the ocular media transmission of small (n = 3) and large (n = 3) trout eyes did not reveal large changes in the transmission of UV radiation through the eye. We used the heart-rate conditioning technique to measure spectral sensitivity in immobilized trout. Four trout, each weighing less than 30 g, exhibited a UV-sensitivity peak at 360 nm while four additional trout weighing more than 60 g each exhibited no evidence of UV sensitivity. Spectral-sensitivity measurements of two trout weighing 44 g and 60 g revealed UV sensitivity, but when measured one month later (after a 25% increase in body weight) both fish exhibited no UV-sensitivity peak. At this time their sensitivity appeared to conform to the known blue-sensitive cone mechanism.


1981 ◽  
Vol 38 (11) ◽  
pp. 1350-1356 ◽  
Author(s):  
A. J. Niimi ◽  
C. Y. Cho

Subadult rainbow trout (Salmo gairdneri) were fed diets containing hexachlorobenzene (HCB) to establish mean body burdens of 225 and 440 μg HCB per fish. They were sampled after 0, 24, 55, and 110 d to estimate the rate of elimination. The biological half-life or T[Formula: see text] of HCB for trout under the prescribed laboratory conditions was estimated to be at least 7 mo, and perhaps as long as several years. T[Formula: see text] was calculated using body burden or μg HCB per fish, and tissue concentrations or μg/kg HCB. Estimates of T[Formula: see text] derived from tissue concentrations ranged from 61 to 117 d, but this was shown to be due to a relative increase in body weight over the study period. The implications of increasing body weight on kinetics measurements are discussed, and an equation is presented that adjusts for changes in body weight where estimates of T[Formula: see text] are calculated using tissue concentrations.The results of this and other studies on HCB were used to examine the kinetics of HCB in salmonids collected from Lake Ontario. Using the information derived from laboratory studies on rainbow trout, good agreement was achieved between the expected level and that monitored in field samples of rainbow trout, but only a fair agreement was suggested for lake trout (Salvelinus namaycush) and coho salmon (Oncorhynchus kisutch). Differences in the HCB kinetics of these species may be attributed to body weight, age, and perhaps feeding habits. Concentrations of HCB reported in field sampling programs generally range from 1 to 100 μg/kg in fish, and it is suggested that these levels are primarily due to the limited availability of HCB in the Lake Ontario environment.Key words: contaminants, hexachlorobenzene (HCB), half-life, elimination, depuration, rainbow trout, Salmo gairdneri; Lake Ontario


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