Diet mixing in an aquatic carnivore, the harbour seal

2005 ◽  
Vol 83 (6) ◽  
pp. 851-859 ◽  
Author(s):  
Stephen J Trumble ◽  
Michael A Castellini
Keyword(s):  
Dry Matter ◽  
Single Species ◽  
Pacific Herring ◽  
Mixed Diet ◽  
Feeding Frequency ◽  
Digestible Energy ◽  
Diet Mixing ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Harbour Seals ◽  
The Mean

To determine the effects of diet mixing on digestive performance, harbour seals (Phoca vitulina L., 1758) were offered either pure diets of Pacific herring (Clupea pallasii Valenciennes, 1847) or walleye pollock (Theragra chalcogramma (Pallas, 1814)) or a 1:1 mix of herring and pollock. Regardless of diet, retention time decreased approximately 40% as intake quadrupled. The mean apparent digestible dry matter (ADDM) was greatest on mixed diets during low feeding frequency trials; ADDM during high feeding frequency trials was significantly reduced as intake increased for animals on the single-species (pollock or herring) diets. As intake increased, up to 45% more digestible energy was assimilated from the mixed diet than from either single-species diet. The findings of this study suggest that a mixed diet consisting of prey differing in lipid and protein amounts increased digestible energy intake in harbour seals. Our measures of intake and ADDM in harbour seals revealed digestive flexibility and indicated that digestion in harbour seals was more efficient on a mixed diet.

Studies on the metabolism of fowls: III. The determination of the comparative nett energy of Sussex ground oats and white maize meal for fattening cockerels

1940 ◽  
Vol 30 (3) ◽  
pp. 463-484 ◽  
Author(s):  
T. Deighton ◽  
J. C. D. Hutchinson
Keyword(s):  
Dry Matter ◽  
Metabolizable Energy ◽  
Mean Values ◽  
Digestible Energy ◽  
Significant Difference ◽  
Maize Meal ◽  
The Mean ◽  
Image Position

1. The comparative nett energy for fattening of Sussex ground oats and white maize meal have been determined on Light Sussex cockerels by difference experiments with a direct calorimeter.2. The mean values for nett energy per gram dry matter, nett energy/ metabolizable energy, metabolizable energy per gross feed energy and digestible energy per gross feed energy were as follows:3. There was no significant difference in the utilization of metabolizable energy from the two cereals. The higher nett energy of the white maize meal was due to its higher digestibility.We again welcome the opportunity of expressing our indebtedness to Mr G. A. Childs for his assistance in carrying out the experiments.

scholarly journals The effect of feeding frequency and meal size on amounts of total and parotid saliva secreted by sheep

1990 ◽  
Vol 63 (2) ◽  
pp. 305-318 ◽  
Author(s):  
Richard R. Carter ◽  
O. Brian Allen ◽  
W. Larry Grovum
Keyword(s):  
Dry Matter ◽  
Feeding Frequency ◽  
Parotid Saliva ◽  
Fixed Amount ◽  
Sham Feeding ◽  
Time Period ◽  
Production Response ◽  
Stem Leaf ◽  
Effect Of Feeding ◽  
Saliva Production

Total and unilateral parotid saliva production during eating were measured in response to offering sheep a fixed amount of lucerne (Medicago sativa) hay as one, two, four or eight meals. Total saliva measurements were obtained using sham-fed oesophageal-fistulated sheep. Unilateral parotid saliva was collected from sheep fitted with reversible re-entrant cannulas. Dry matter intakes and eating times were measured for each meal but were not constrained to particular values. Total and unilateral parotid saliva production during eating increased linearly with the log of the number of meals (p = 0.0001). The amounts corresponding to one, two, four and eight meals of lucerne hay were 1553, 1737, 1851 and 2087 ml during total collections and 209, 248, 307 and 352 ml during unilateral parotid collections. The time-period spent eating and the amount of food consumed both increased as meal number increased. Total saliva collections when lucerne hay was sham-fed as one, two, four or eight meals were associated with eating times of 56.9, 57.4, 70.8 and 86.0 min and intakes of 562, 622, 629 and 638 g dry matter respectively. For unilateral parotid collections, eating times and dry matter intakes were 64.2, 71.3, 78.0, 82.1 min and 515, 579, 614 and 627 g for one, two, four and eight meals of lucerne hay respectively. The saliva production response appeared to be determined through the effects of the time-period spent eating and amounts consumed, but other undetermined effects of feeding frequency contributed to the response. The importance of meal duration on total saliva production was assessed by sham-feeding of 800 g lucerne as stem, leaf, hay, chopped hay or ground and pelleted hay. Increasing meal duration by feeding with stems resulted in the production of 1808 ml saliva, whereas the rapid consumption of pellets resulted in only 442 ml being produced.

scholarly journals Survival analysis of a stochastic delay single-species system in polluted environment with psychological effect and pulse toxicant input

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Xiangjun Dai ◽  
Suli Wang ◽  
Weizhi Xiong ◽  
Ni Li
Keyword(s):  
Sufficient Conditions ◽  
Single Species ◽  
Threshold Value ◽  
Psychological Effect ◽  
Polluted Environment ◽  
Population System ◽  
Stochastic Delay ◽  
Species Population ◽  
The Mean ◽  
Single Species Population

Abstract We propose and study a stochastic delay single-species population system in polluted environment with psychological effect and pulse toxicant input. We establish sufficient conditions for the extinction, nonpersistence in the mean, weak persistence, and strong persistence of the single-species population and obtain the threshold value between extinction and weak persistence. Finally, we confirm the efficiency of the main results by numerical simulations.

The effect of different proportions of hay and fortified rolled barley in the diet on digestible-energy value and urinary-energy excretion by cattle

1972 ◽  
Vol 79 (1) ◽  
pp. 99-103 ◽  
Author(s):  
A. M. Raven
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Rumen Fluid ◽  
Latin Square ◽  
Progressive Increase ◽  
Linear Increase ◽  
Metabolizable Energy ◽  
Digestible Energy ◽  
Gross Energy ◽  
Concentrate Treatment

SUMMARYA 6 x 6 Latin Square balance experiment was carried out using six Friesian steers, each of which initially weighed about 304 kg. The six treatments studied were an all-hay diet and five other diets containing 20,40,60,80 and 100 % of rolled barley fortified with mineral and vitamin supplements, accompanied by correspondingly reduced proportions of hay. Each diet was fed at an estimated maintenance level of feeding.The progressive increase in the proportion of concentrate gave a significantly linear increase (P < 0·001) in both digestible and calculated metabolizable energy. The actual increase in digestible energy was from 2·62Mcal/kg dry matter (59·3% of the gross energy) on the all-hay treatment to 3·42 Mcal/kg dry matter (79·5% of the gross energy) on the all-concentrate treatment. Use of the determined digestible energy values for the all-hay and fortified barley diets to calculate the digestible energy of the four mixed diets gave results in reasonably good agreement with the determined values, the maximum difference being 0·12 Mcal/kg dry matter, which represented 3·83 % of the determined value. The losses of energy in the urine expressed as percentages of the gross energy of the diets showed a small but significantly linear decrease (P < 0·01) with increase in proportion of barley in the diet. The molar proportions of steamvolatile acids in samples of rumen fluid taken from two animals on each treatment indicated that increase in the proportion of concentrate was associated with tendencies for increase in acetic acid, decrease in propionic acid and little change in butyric acid. The mean digestibility of the organic matter was 62·6 % on the all-hay treatment and 81·8 % on the all concentrate treatment. The progressive increase in the proportion of concentrate gave a significantly linear increase (P < 0·001) in digestibility of the organic matter. Although intakes of nitrogen decreased with increase in the proportion of concentrate due to a decrease in the amount of dry matter fed, the weights of nitrogen retained were well maintained and when expressed as percentages of intake showed a significantly linear increase (P < 0·01).

PREDICTION OF DIGESTIBLE ENERGY INTAKE BY SHEEP OF DIETS CONTAINING GROUND ROUGHAGE AND GRAIN

1977 ◽  
Vol 57 (2) ◽  
pp. 279-288 ◽  
Author(s):  
S. O. THORLACIUS
Keyword(s):  
Energy Demand ◽  
Dry Matter ◽  
Organic Matter Content ◽  
Rapeseed Meal ◽  
Regression Equation ◽  
Curvilinear Relationship ◽  
Crested Wheatgrass ◽  
Digestible Energy

Digestibility and intake of diets containing 8, 28, 48 or 68% ground wheat straw plus ground crested wheatgrass and rapeseed meal, and diets containing 33, 48, 63 and 78% ground crested wheatgrass plus barley and rapeseed meal was measured with four yearling wethers per diet. Digestible energy (DE) content ranged from 2.07 to 2.95 kcal/g dry matter (DM) and dry matter digestibility (DMD) (%) from 48.7 to 71.1%. Regression of DE intake y (kcal/w0.75kg/d) on DE content (x) was curvilinear; y = −2,133 + 1,626x − 277.9x2, r = 0.996, P < 0.01, SE = ± 7.3. There was also a curvilinear relationship between diet density, as fed, (x) g (DM)/ml and DMD (%), y = 9.057 + 364.1x − 530.0x2, r = 0.970, P < 0.01, SE = ± 2.4. A linear regression equation was calculated over the DE range (2.07–2.52) for which there was an obvious increase in DE intake with increasing diet DE content; y = −700.6 + 361x, r = 0.994, P < 0.01, SE = ± 9.4, y = DE intake (kcal/w0.75kg/d), x = DE [kcal/g (DM)]. Using this regression equation and assuming a linear increase in DE intake with increase in diet DE content up to a point at which the apparent energy demand of the animal is satisfied gave a more accurate prediction of DE intake than when the curvilinear regression equation, y = −2,133 + 1,626x − 277.9x2, was used empirically. Accuracy of the prediction was further improved by expressing DE/unit ration volume instead of per unit DM. The sheep used in the present experiments had an apparent energy demand of 230 kcal/w0.75kg/day which was met at diet DE contents above 0.48 kcal/ml or 2.6 kcal/g (DM). There was a high correlation between in vivo DE content of the diet, y [kcal/g (DM)] and in vitro (x) digestible organic matter content, x, (%), r = 0.991, P < 0.01, y = 0.38 + 0.037x, SE = ± 0.04.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

THE EFFECT OF INGESTED CHLORTETRACYCLINE ON SOME HYDROLASES AND ORGANS ASSOCIATED WITH THE DIGESTIVE PROCESS IN GROWING PIGS: II. PROTEASE, AMYLASE, AND GELLULASE ACTIVITY OF THE CONTENTS OF THE SMALL INTESTINE AND OF THE CECUM; WEIGHTS OF SMALL INTESTINE AND MUCOSA

1957 ◽  
Vol 35 (3) ◽  
pp. 195-202 ◽  
Author(s):  
M. A. A. Vonk ◽  
L. W. McElroy ◽  
R. T. Berg
Keyword(s):  
Small Intestine ◽  
Dry Matter ◽  
Cellulase Activity ◽  
Dry Weight ◽  
Growing Pigs ◽  
Weanling Pigs ◽  
Intestinal Contents ◽  
Wet Weight ◽  
The Mean ◽  
Ad Libitum

Four treatments, involving differences in method of feeding and interval between last feed and slaughter, were employed in a study of the effect of dietary chlortetracycline on protease, amylase, and cellulase activity in the intestinal and cecal contents of 16 pairs of weanling pigs. Most consistent results were obtained with six pairs which were limited pair-fed except for the final feeding during which feed was available ad libitum for a 4-hour period ending 18 hours before slaughter. The mean total activities of all three hydrolases in the contents of the small intestines and of the ceca of the antibiotic-fed animals of these six pairs were significantly greater than in those of the control animals. Expressed as activity per gram dry matter of intestinal contents, significantly higher values for protease and amylase, but not for cellulase, were observed in the pigs that had received chlortetracycline. When the combined results obtained from all 16 pairs of the experimental animals were analyzed, the results showed that on a basis of activity per gram dry matter of intestinal contents, ingested chlortetracycline was associated with significant increases in amylase and cellulase but not in protease activity. Protease, amylase, and cellulase activities per gram dry matter of cecal contents were higher for pigs fed the antibiotic than for their controls. The mean wet weight of the empty small intestine and the mean dry weight of the mucosa scraped from the anterior 3-meter section of the small intestine were lower for the chlortetracycline-fed animals, but the differences were not statistically significant.

scholarly journals The influence of the method of preservation of forages on the digestion in dairy cows. 1. Composition of the forages and digestibility of dry matter, organic matter and nitrogen.

1975 ◽  
Vol 23 (1) ◽  
pp. 3-9
Author(s):  
S. Tamminga ◽  
C.J. van der Koelen
Keyword(s):  
Organic Matter ◽  
Formic Acid ◽  
Dairy Cows ◽  
Crude Protein ◽  
Dry Matter ◽  
Mixed Diet ◽  
Apparent Digestibility

1. Grass from the same sward was ensiled without additive, with 14.6 g formic acid/100 g crude protein or 10.8 g formic acid and 10.6 g formaldehyde/100 g crude protein. Similar grass was dried and pelleted. Drying or ensiling with the mixture reduced solubility of N in the preserved grass but formic acid increased it, and ensiling without additive increased it even more. Apparent digestibility of N in the rumen of cows tended to decrease with decrease in solubility. Digestibility in vitro of the mixed diet given to the cows, calculated from digestibility of the separate components, agreed well with the values in vivo for diets with silages, but was high for that with dried grass. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals EVALUATION OF NUTRITIONAL VALUE OF GRAIN-HAYLAGE FROM LUPIN, OAT AND SUDAN GRASS

2020 ◽  
Vol 2020 (1) ◽  
pp. 63-69
Author(s):  
Valentina Ruckaya ◽  
Alexander Sorokin ◽  
Elena Afonina ◽  
Natal'ya ZAYCEVA
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Nutritional Value ◽  
Single Species ◽  
Matter Content ◽  
Metabolic Energy ◽  
White Lupin ◽  
Dry Matter Content ◽  
Sudan Grass ◽  
Sowing Period

The average data for 2018–2019 are presented for yield, dry matter content in grain-haylage mass, nutritional value of test grain-haylage samples produced from plant mass of white lupin, oat and Sudan grass from single and mixed cenosis of different sowing times. The grain-haylage mass was harvested in the phase of brilliantly ripening lupin bean, milky-waxy ripeness of oats and the end of flowering of the Sudan grass. It’s revealed that variants of the second sowing date — 2 decade of May — have the best yield of grain-haylage mass and its dry matter content. The yield of grain-haylage mass in the best variants of the second sowing period exceeded by 7–8 t/ha. According to the nutritional value of grain silage samples (the content of metabolic energy, crude protein, crude ash and carotene), the best results were obtained in most variants of the first sowing period. In content of the metabolic energy and crude protein of 1 kg of dry matter of grain-haylage, the best were variants of the single-species cenosis of lupine and its mixture with oats of the first sowing period. Variants of single-species sowing of lupine and Sudan grass were distinguished by the content of carotene.

scholarly journals PRODUCTIVITY OF PERENNIAL GRASSES AND MIXTURES WITH DIFFERENT SOWING DATES IN WESTERN SIBERIA

2020 ◽  
pp. 24-32
Author(s):  
V. A. Petruk
Keyword(s):  
Dry Matter ◽  
Crop Yields ◽  
Growing Season ◽  
Single Species ◽  
Field Studies ◽  
Perennial Grasses ◽  
First Year ◽  
Sowing Dates ◽  
Second Year ◽  
Sowing Period

The results of field studies for 2017 - 2019 are presented. yields of perennial grasses sown at different times of the growing season. Spring, summer, and winter sowing periods were compared. Alfalfa, clover, rump, and also their mixtures were sown in 2017 under the cover of barley. The value of the cover crop yield of spring and summer sowing periods did not differ significantly and amounted to 4-5 t / ha of absolutely dry matter. Winter barley crops have not formed. On average, over 2 years of use, the highest yields were observed in alfalfa-crust grass mixtures - 3.4 t / ha of absolutely dry matter. The lowest yield was obtained in the single-species seeding of the rump. Correspondingly, in the spring, summer and winter periods of sowing, the yield of rump was 1.6; 1.1 and 1.3 t / ha. With a late sowing period, the yield of perennial grasses is significantly lower compared to spring and summer. With winter sowing periods, the yield was the highest for grass stands of alfalfa and alfalfacrust grass mixture - 2.3 and 2.4 t / ha. It should be noted that in the second year of use, the yield by the sowing dates in single-species crops and grass mixtures is leveled. The winter crops of perennial grasses in the first year of use formed a low yield. Only in the second year (third year of life) the productivity of perennial grasses of winter sowing began to increase. Consequently, in the area under perennial grasses of the winter sowing period, during one growing season (the next year after sowing), the crop was not actually formed. Based on the data obtained, production can be recommended for spring and summer planting of perennial grasses under the cover of barley. The winter sowing period provides economically valuable crop yields only by the third year of life.

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