Development of a Diet for Long-Term Raising of F344 Rats. Relationship between Dietary Digestible Crude Protein Content and Digestible Energy Content.

1. In two continuous digestibility trials carried out in 1960 and 1961, groups of three wether sheep were fed on oven-dried herbage which had been selectively collected from natural pastures during December 1959 to March 1960 and December 1960 to March 1961. The organic matter digestibility and the digestible crude protein content of the herbage and the nitrogen concentration in faeces were measured over periods of 5 days. The fresh faeces of dairy cattle grazing the natural pastures were regularly sampled and analysed. Regressions of organic matter digestibility and digestible crude protein content on faecal nitrogen were evaluated. From these equations and the composition of the dairy cattle faeces the digestibility of the herbage grazed was calculated.2. The herbage consumed by the cattle had a significantly higher organic matter digestibility and digestible crude protein content than the collected material. This difference, which increased as the season progressed, indicates that dairy cattle became increasingly selective in their grazing as the pasture deteriorated in quality.3. There was a marked yearly difference in digestibility-faecal nitrogen relationships and in the quality of the consumed forage. The grass eaten in 1959-60 had a higher digestibility and lower digestible crude protein content than in the following year. These differences may be part attributable to a seasonal difference in rainfall.4. The organic matter digestibility of the grazed herbage ranged from 52·71 to 65·03% and the digestible crude protein content from 3·08 to 7·43% For milk production, the herbage consumed is low in digestible protein in relation to the total amount of digestible nutrients.

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Energy values in pig nutrition:3. The digestible and metabolizable energy content of barley, wheat, maize, oats and rye

The Journal of Agricultural Science ◽

10.1017/s0021859600041149 ◽

1982 ◽

Vol 98 (1) ◽

pp. 89-97 ◽

Cited By ~ 10

Author(s):

J. Wiseman ◽

D. J. A. Cole ◽

D. Lewis

Keyword(s):

Protein Content ◽

Significant Variation ◽

Crude Protein ◽

Energy Content ◽

Nitrogen Retention ◽

Metabolizable Energy ◽

Crude Protein Content ◽

Experimental Conditions ◽

Cereal Species ◽

Commercial Sources

SUMMARYThe digestible energy (DE) and metabolizable energy (ME) content of eight samples of barley, eight of wheat, four of maize and two each of oats and rye were determined using growing gilts. The DE content of barley ranged from 15·35 to 15·89 MJ/kg D.M., from 15·15 to 16·42 MJ/kg D.M. for wheat and from 16·05 to 16·47 MJ/kg D.M. for maize. DE values for the two oat samples were 12·48 and 12·74 MJ/kg D.M. and 15–04 and 15–47 MJ/kg D.M. for the two rye samples. There was a significant correlation between DE and ME:ME (MJ/kg D.M.) = 0·050 + 0·965 DE: r = 0·99; P < 0·001.The ratio ME/DE was significantly influenced by crude-protein content:ME/DE = 100–0·254 CP%: r = –0·77; P < 0·001.ME values were also corrected to zero nitrogen retention (MEno) and to 30% nitrogen retention (MEN30). The effect of such corrections was expressed as MEN0/ME and MEN30/ME. Values thus obtained were 0·98 and 1·00 respectively for the pooled values for all cereals.The data indicated that there was unlikely to be significant variation in the DE content of samples of the same cereal species, selected from commercial sources within the U.K. when evaluated under standardized experimental conditions.

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THE EFFECT OF RELATIVE PROTEIN AND ENERGY CONTENT OF DAIRY RATIONS ON PRODUCTION AND COMPOSITION OF MILK

Canadian Journal of Animal Science ◽

10.4141/cjas59-030 ◽

1959 ◽

Vol 39 (2) ◽

pp. 226-234 ◽

Cited By ~ 12

Author(s):

V. S. Logan ◽

Vern Miles ◽

S. R. Haskell

Keyword(s):

Design Of Experiments ◽

Protein Content ◽

Milk Production ◽

Crude Protein ◽

Dry Matter ◽

Energy Content ◽

Holstein Cows ◽

Early Lactation ◽

Digestible Crude Protein ◽

Effect On Yield

Two trials, each with 12 Holstein cows in early lactation, were conducted to study the effect on yield and composition of milk when the relative protein and energy contents of dairy rations were altered. A change-over design of experiments was used and digestibility of representative rations was determined with steers. A significant increase in fat-corrected milk production was obtained when energy (T.D.N.) intake was raised 5 to 12 per cent above recommended feeding standards. The protein content of the milk was increased (P < 0.05) when digestible crude protein was 20 to 30 per cent in excess of recommended allowances, but increases in milk production, in percentages of butterfat and solids-not-fat were not significant (P > 0.05). When molasses comprised up to 18 per cent of dry matter of a ration, digestion co-efficients for protein and fibre were reduced.

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Effect of Precipitation and Long Term Nitrogen Fertilization on Nitrogen Uptake, Crude Protein Content and Yield of Bromegrass Forage 1

Agronomy Journal ◽

10.2134/agronj1963.00021962005500030002x ◽

1963 ◽

Vol 55 (3) ◽

pp. 215-218 ◽

Cited By ~ 18

Author(s):

W. L. Colville ◽

Leon Chesnin ◽

D. P. McGill

Keyword(s):

Protein Content ◽

Nitrogen Uptake ◽

Nitrogen Fertilization ◽

Crude Protein ◽

Crude Protein Content

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The effect of breed (Large White × Landrace ν. purebred Meishan) on the diets selected by pigs given a choice between two foods that differ in their crude protein contents

Animal Science ◽

10.1017/s0003356100006231 ◽

1993 ◽

Vol 56 (1) ◽

pp. 121-128 ◽

Cited By ~ 24

Author(s):

I. Kyriazakis ◽

K. Leus ◽

G. C. Emmans ◽

C. S. Haley ◽

J. D. Oldham

Keyword(s):

Protein Content ◽

Crude Protein ◽

Live Weight ◽

Energy Concentration ◽

Crude Protein Content ◽

Large White ◽

Protein Food ◽

Digestible Energy ◽

Continuous Access ◽

Better Than

AbstractTwo pig breeds, one improved (Cotswold Fl hybrid Large White × Landrace pigs = LWX) and the other unimproved (Chinese Meishan pigs = CM) were used to test the proposition that the genotype of the pig has an effect on the selection of a diet from two foods that differ in their crude protein content. From 21 to 34 kg live weight, the pigs were given access to either one of three foods or a choice of two foods with similar digestible energy concentration (16 MJ digestible energy per kg) but a different crude protein (CP) concentration. This resulted in four dietary treatments: (i) free and continuous access to low (L) crude protein food alone (130 g CP per kg, no. = 4 of each breed); (ii) free and continous access to high (H) crude protein food alone (252 g CP per kg, no. - 4 of each breed); (Hi) free and continuous access to moderate (M) crude protein food alone (206 g CP per kg, no. = 4 of each breed) and (iv) free and continuous access to both foods L and H as a choice (no. = 6 of each breed). On all treatments the LWX performed significantly better than the CM pigs in terms of live-weight gain and food conversion efficiency (P< 0·001). The LWX and CM pigs given access to a single food contained the same amounts of protein in their bodies at 34 kg live weight, but the CM pigs had a considerably higher lipid (P< 0·001) and a lower water content (P< 0·001). When given a choice, the LWX pigs selected a significantly higher proportion of foodH(521v.226 (s.e.d. 49) g food H per kg for LWX and CM respectively) and therefore, a higher CP content in their diet (194v.144 (s.e.d. 5·4) g CP per kg respectively) than the CM pigs. The performance of pigs given a choice between two foods, in terms of live weight and rate of protein gain, was comparable with the best performance achieved on a single food (M) for the LWX, and better than the best performance on a single food (L) for the CM pigs. Thus, when given a choice between an appropriate pair of foods that differ in their crude protein content, pigs are able to select a diet that meets their requirements and allows them to express the growth characteristics typical for their breed (genotype).

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