scholarly journals Measurement and prediction of digestible energy values in feedstuffs for the herbivorous fish tilapia (Oreochromis niloticus Linn.)

1991 ◽  
Vol 66 (1) ◽  
pp. 37-48 ◽  
Author(s):  
J. Anderson ◽  
B. S. Capper ◽  
N. R. Bromage

Digestible energy (DE) values were measured in a selection of feedstuffs for the tilapia (Oreochromis niloticus Linn.) and used to develop equations for predicting DE values of a wider range of feedstuffs from chemical analyses. Preliminary work examined the influences of substitution level in a reference diet and adaptation over time on DE values for soya-bean meal. Length of adaptation period significantly affected DE values (P < 0.01), but substitution level, over the range 200–600 g soya-bean meal/kg reference diet, did not. The DE values of sixteen feedstuffs, thirteen derived from plant sources and three animal by-products, were subsequently determined. DE values for plant-derived feedstuffs were found to be higher than those quoted in the literature for trout (Oncorhynchus mykiss) and catfish (Ictalurus punctatus), whereas DE values for animal-derived feedstuffs were lower than those for trout and pigs. It was concluded that energy values quoted in tables of feed composition for other species are inaccurate when used as proxy values for tilapia. Regression equations were therefore computed using data from the present study to provide a rapid means of predicting DE values of feedstuffs for tilapia. Equations using neutral-detergent fibre as an independent variable were found to predict DE values of plant-derived feedstuffs reliably. Where fibre values were not used as independent variables, available carbohydrate and crude protein (nitrogen × 6.25) were found to be useful predictors of DE values. These equations offer the possibility of reducing the need for time-consuming digestibility trials with tilapia when formulating least-cost production diets for this species.

1979 ◽  
Vol 42 (3) ◽  
pp. 535-545 ◽  
Author(s):  
R. C. Siddons ◽  
R. T. Evans ◽  
D. E. Beever

1. Wilted perennial ryegrass (Lolium perenneL. cv. Endura) was ensiled without additive or after addition of a mixture of equal volumes of formic acid (850 g/kg) and formalin (380 g formaldehyde/kg) applied at a rate of 35 g formaldehyde/kg herbage crude protein (nitrogen × 6.25). The digestion of the two silages and the effect of supplemental N as urea or urea plus soya-bean meal on the digestion of the treated silage was studied using sheep fitted with a rumen cannula and re-entrant cannulas in the proximal duodenum and distal ileum.2. The additive markedly reduced carbohydrate fermentation and protein degradation in the silo.3. There were no significant differences between diets in rumen pH, dilution rate, volatile fatty acid production and the molar proportions of acetate, propionate and butyrate. However, rumen ammonia levels and the apparent digestibility of organic matter (OM), gross energy (GE) and cellulose in the stomach were significantly depressed (P< 0.05) by the additive. It also reduced (P< 0.05) the extent to which the N of the silage was degraded in the rumen and, with the treated silage, more microbial N was synthesized in the rumen than food N degraded, resulting in a net gain of N between mouth and duodenum, as compared to a net loss with the untreated silage.4. Supplementation of the treated silage with urea or urea plus soya-bean meal significantly increased (P< 0.05) the amount of food N degraded in the rumen and rumen ammonia levels but had no effect on the apparent digestibility of OM, GE and cellulose in the stomach or on the amount of microbial N reaching the duodenum.5. The quantity of microbial amino acids entering the small intestine and the apparent digestibility of amino acids in the small intestine were similar for all four diets. However, the quantity of food amino acids reaching the small intestine was significantly higher with the three diets containing the treated silage and consequently the apparent absorption of amino acids from the small intestine was substantially higher with these diets than with the untreated silage.


1981 ◽  
Vol 32 (3) ◽  
pp. 285-295 ◽  
Author(s):  
C. Thomas ◽  
K. Aston ◽  
J. C. Tayler ◽  
S. R. Daley ◽  
D. F. Osbourn

ABSTRACT1. The primary growth and first regrowth of perennial ryegrass were preserved either without additive (NA), or with a mixture consisting of equal volumes of formic acid and formalin at 10·0 and 13·01/t fresh crop for primary growth and regrowth herbage respectively (35 g formaldehyde per kg crude protein) (FF). The silages were given ad libitum to 40 lactating British Friesian heifers and cows, with a supplement of either pelleted ground maize (104 g crude protein per kg dry matter) (LP) or pelleted ground maize and soya bean meal (254 g crude protein per kg dry matter) (HP), at 6·1 and 7·1 kg per head per day for heifers and cows respectively. The primary growth silage was given from weeks 4 to 14 and the regrowth from weeks 15 to 22 of lactation. The silages were supplemented with urea so that the dietary supply of rumen degradable protein exceeded 7·8g/MJ metabolizable energy.2. Silage FF had lower concentrations of both fermentation acids and ammonia-nitrogen than silage NA. The digestibility of the dry matter, energy and crude protein of the diet containing silage FF was significantly less than that of diets containing silage NA when cows were given primary growth material (P < 0·001). But silage treatment had no significant effect on the digestibility of cellulose. When cows were given regrowth silage, silage treatment had no significant effect on the digestibility of dry matter, energy and cellulose, but formic acid/formaldehyde reduced the digestibility of crude protein (P < 0·01). The inclusion of soya bean meal in the supplement significantly increased the digestibility of crude protein, dry matter and energy, but when cows were given the primary growth silage the effect on the digestibility of dry matter and energy was only apparent with silage NA.3. Cows and heifers given silage FF from primary growth consumed 160g/kg more dry matter than those given silage NA (P < 0·01). This effect was not apparent when the animals were given regrowth silage. The effect of formic acid/formaldehyde on the intake of digestible energy was not significant in either period on the trial, but the inclusion of soya bean meal in the pellet significantly increased the intake of digestible energy (P < 0·01).4. Cows and heifers given silage FF from primary growth produced 90g/kg more milk and 50g/kg more solids-corrected milk than those given silage NA, but the differences were not significant and these trends were not apparent when regrowth silage was given. An increase in the crude protein content of supplement increased the milk (P < 0·01) and protein yield (P < 0·05) of cows, but not heifers, when they were given primary growth silage. The effect was less when milk output was expressed in terms of solids-corrected milk since milk fat content tended to fall when cows were given the HP supplement. Treatments had no significant effect on live-weight change.5. It is suggested that the increases in milk output were mediated via changes in the supply of energy rather than of protein.


1986 ◽  
Vol 43 (3) ◽  
pp. 377-384 ◽  
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
V. Samuel ◽  
I. Bruckental

ABSTRACTTwo feeding trails were made and in both all the diets given contained about 11 MJ metabolizable energy (ME) per kg dry matter (DM).In trial 1, diets containing three concentrations of crude protein (CP) were given to a total of 84 Friesian bulls in each of three stages of growth. They were, in stage 1 (150 to 250 kg live weight) 130, 145 and 160 g CP per kg dietary DM; in stage 2 (250 to 350 kg live weight) 110, 130 and 145 g CP per kg dietary DM; in stage 3 (350 kg to slaughter) 95, 110 and 130 g CP per kg dietary DM. In stages 2 and 3, the source of supplementary nitrogen at each CP concentration was either soya-bean meal or non-protein nitrogen (NPN) giving six combinations of concentration and source of dietary CP. Live-weight gains in stage 1 were 1·52, 1·60 and 1·58 kg/day respectively (P > 0·05). In the stages involving both concentrations and source of nitrogen (soya-bean meal in parentheses), the mean daily live-weight gains were (1·40), 1·38, (1·32), 1·34 (1·34) and 1·31 kg for stage 2 (F > 0·05) and (1·14), 1·14, (1.24), 1·16, (1·06) and 1·08 kg for stage 3 (P < 0·05), for the diets of 130, 145 and 160 g CP per kg diet respectively.Trial 2 consisted of six stages of growth, the first five of 45 days duration and the sixth of varying length up to a predicted slaughter weight, and seven dietary treatments. Treatment 1 was a negative control (NC) with a dietary CP concentration of 90 g/kg DM. For the other six treatments two concentrations of dietary CP were given; 120 g/kg and 140 g/kg in stages 1 and 2 and 100 g/kg or 120 g/kg in stages 3 to 6. Dietary CP concentration was increased by the addition of NPN, fish meal or soya-bean meal. A total of 98 Friesian bulls were used with an initial average live weight of 185 kg. Daily gain of the NC group in the six stages of the trial was 0·86, 0·97, 101, 1·13, 1·07 and 1·00 kg for stages 1 to 6 respectively. From the results it was concluded that feeding NPN is not efficient at live weights lower than 250 kg and that there is no advantage to feeding fish meal over soya-bean meal in diets of medium energy concentration at live weights heavier than 250 kg.


1977 ◽  
Vol 89 (3) ◽  
pp. 699-710 ◽  
Author(s):  
G. J. L. Jacobs ◽  
Jane Leibholz

SummarySemi-purified diets containing urea (diet A), uric acid (diet B) or soya-bean meal (diet C) as the sole source of nitrogen were fed to two Friesian bull calves fitted with re-entrant duodenal cannulae. Total collections of digesta leaving the abomasum were made over 24-h periods.The flow of organic matter to the duodenum expressed as a percentage of intake increased from 35·8% (diet A) and 40·6% (diet B) for the non-protein nitrogen diets to 58·3% for diet C. A greater proportion of the apparent digestion of organic matter occurred in the forestomachs of the calves when fed diets A or B than when they were fed diet C.The flow of nitrogen from the abomasum expressed as a percentage of intake showed a significant increase (P< 0·05) from 65·4% for diet A to 84·4% for diet B and 85·1% for diet C. When diets B and C were fed to the calves a greater proportion of the apparent digestion of nitrogen occurred in the hindgut than when they were fed diet A. The synthesis of microbial protein was 13·9 g and 13·0 g for every 100 g of organic matter digested in the stomach when the calves were fed diets B and C and only 10·9 g when the calves were fed diet A.A significantly (P< 0·05) greater proportion of dry matter of the digesta at the duodenum was composed of amino acids on diet C (19·5%) than diet A (16·1%) with the proportion of essential amino acids (especially threonine, lysine, histidine and arginine) also being greater. The amino acid composition of the digesta dry matter on diet B was intermediate (17·2%).From the data presented, it was predicted that cystine and histidine were the first limiting amino acids for growth when the calves were fed the non-protein nitrogen diets (A and B).


1999 ◽  
Vol 1999 ◽  
pp. 104-104
Author(s):  
A. Kamalak ◽  
D.S. Parker ◽  
H.J. Finlayson ◽  
P. Hooper

The introduction of new forage maize hybrids has provided feed raw materials with a range of nutritional characteristics. The objective of this experiment was to investigate the impact of feeding different hybrids of forage maize on the overall digestibility of feed components and rumen degradability of starch in sheep.Four forage maize hybrids from different sites within the UK[NANCIS(A) and EMA(B)] and France[Hybrid 6196 High Oil (C) and Volgata Waxy(D)] were ensiled in sealed drums with no additives. The resultant silages were used as the basis for a digestibility trial using four fistulated Suffolk X wethers in a 4 X 4 factorial design. Sheep were fed twice daily with total intake of 900 g DM of silage plus 150g Soya Bean Meal. After an adaptation period (21d) a 5 day total collection of faeces was carried out followed by a rumen degradability study.


1991 ◽  
Vol 52 (1) ◽  
pp. 215-224 ◽  
Author(s):  
Maria J. Villamide ◽  
Maria J. Fraga ◽  
C. de Blas

ABSTRACTOne hundred and eight New Zealand × Californian growing rabbits (nine per diet) were used to determine the nutritive value (digestible energy (DE), digestible protein (DCP) and digestible acid-detergent fibre (DADF)) of five protein concentrates. In assay 1, the effect of the type of basal diet (BD) (7·6 or 10·0 MJ DE per kg dry matter (DM) for BD1 and BD2 respectively) and the substitution level (150, 300 and 450 g/kg) on nutritive value of soya-bean meal was studied. According to the results of assay 1, one basal diet (BD2) and one substitution level (300 g/kg for sunflower 380, gluten meal and extruded soya-bean meal or 500 g/kg for sunflower 320) were selected in assay 2 to determine their nutritive value.The effect of the basal diet and the substitution level on the nutritive value of soya-bean meal was evident only for the values calculated from BD1 and the lowest level of inclusion. The data obtained by difference at the highest level of inclusion and by extrapolating the linear equations were very similar (16·32 v. 16·35 MJ DE and 387·62 v. 388.58 g DCP per kg DM for BD2), but the standard errors were lower (0·52 v. 0·72 for DE and 6.76 v. 8.95 for DCP) in the former. The DE values obtained for sunflower meal 320 and 380, extruded soya-bean and gluten meal were 10·29, 14·37, 18·58 and 20·57 MJ/kg DM respectively; protein digestibilities were high (with coefficients from 0·80 to 0·90) except in the case of sunflower-320 (0·73). A stepwise regression analysis was made to predict the nutritive value from chemical composition including values from literature. For prediction of DE, the variables selected were: crude fibre, ether extract and ash, obtaining a determination coefficient of 0·935. The protein digestibility was independent of variables employed.


1968 ◽  
Vol 10 (4) ◽  
pp. 381-391 ◽  
Author(s):  
T. Walker ◽  
M. Kay ◽  
T. R. Preston ◽  
I. McDonald ◽  
N. A. MacLeod ◽  
...  

1. Four growth trials were carried out with 297 group-fed steers given diets based on barley, minerals and vitamins, unsupplemented or supplemented with either soya bean meal or various sources of non-protein nitrogen.2. Steers given unsupplemented barley (11% crude protein in dry matter) had inferior growth rates up to 300 kg live weight but thereafter were equal to those given barley supplemented with urea in the drinking water or soya bean meal.3. There were no significant differences in the growth rates of steers given barley supplemented with soya bean meal and those given barley supplemented with ammonium and mineral salts of formic acid or a mixture of acids (predominantly acetic).4. In two out of three trials, tenth-rib joints from steers given barley supplemented with ammonium salts of mixed acids contained less fat and more protein and water than those from steers given barley supplemented with soya bean meal or proprietary protein supplements.5. A number of possible explanations for the apparent carcass differences is discussed.


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