Experiments on the nutrition of the dairy heifer IV. Protein requirements of 2-year-old heifers

1963 ◽  
Vol 60 (3) ◽  
pp. 393-398 ◽  
Author(s):  
W. H. Broster ◽  
Valerie J. Tuck ◽  
C. C. Balch

1. In the winters of 1959–61 three randomized block experiments were carried out to study protein requirements of heifers of 800–1000 lb. live weight. 24 animals were used in each experiment. Half the animals were kept indoors; the remainder stayed out of doors except for 1 hr. per day when they came into covered yards to receive their concenrates ration.2. Rations were based on straw, cereals and roots. The intake of crude protein was varied by replacing cereals by decorticated ground nut meal. The estimated level of energy intake varied from 7·2–8·2 lb. starch equivalent/day between experiments, but the level was constant for all treatments within an experiment.3. At the end of each feeding trial the nitrogen balance was measured for 2 animals from each treatment. The results confirmed the estimated levels of digestible crude protein intakes upon which the experiments were based.4. An increase in intake of digestible crude protein (as determined in the metabolism trials) from 0·35 lb./day to 0·72 lb./day gave a marked response of 0·45 lb./day in the rate of live-weight gain. Further increases in protein intake gave little response in live-weight gain. It was concluded that for heifers of 800–900 lb. live weight the protein requirement for maintenance and a live-weight gain of 1·2 lb./day was 0·70 lb. digestible crude protein/day.5. Comparison of the estimated starch equivalent intakes in the three experiments showed that in heifers receiving 0·52 lb. digestible crude protein per day the rate of gain increased from 0·25 to 0·90 lb./day as the level of energy intake increased from 0·78 lb. starch equivalent/100 lb. live weight per day to 1·01 lb./100 lb. live weight.6. Biological value of the dietary nitrogen decreased as level of protein intake increased. The values for individual animals ranged from 61·3 to 82·4. The mean value was 69·5.7. The weather during these experiments was typical of winters in south-east England with mean minimum ground temperatures about 30° F. and mean maximum and minimum air temperatures of about 50° F. and 35° F., respectively. Snow fell occasionally only; 3½–5½ in. of rain fell in the period 1 January to 31 March. In 2 years out of 3 the outdoor group grew slightly faster than the indoor groups. In the third year this trend was reversed.

1971 ◽  
Vol 13 (4) ◽  
pp. 643-651 ◽  
Author(s):  
T. H. McClelland ◽  
T. J. Forbes

SUMMARYIn-lamb ewes were given 38, 58 and 82 g of digestible crude protein daily at a constant energy intake of 1600 kcal ME per head daily during the last 6 weeks of gestation. There were no significant differences between treatments in live-weight gain of the ewes, lamb birth weight or ewe net body-weight change (the difference between live-weight gain over the experimental period and live-weight loss at lambing).Digestibility coefficients for the diet components and nitrogen balances were determined on three ewes per treatment during weeks 15-16 and 19·20 of gestation. No differences in the apparent digestibility of the diet components were observed between the two periods. The apparent digestibility of crude protein increased significantly (P > 0·001) with increase in crude protein intake. A significant linear relationship (P<0·01) was found between digestible crude protein intake and nitrogen retention; daily N retention increased by 0·19 g per kg W0·73 for every 1 g per kg W0·73 of apparent digested nitrogen intake per day.


1970 ◽  
Vol 12 (1) ◽  
pp. 95-105 ◽  
Author(s):  
J. J. Robinson ◽  
T. J. Forbes

SUMMARYFifty weaned store lambs approximately 7-month-old were used in an experiment designed to assess their protein requirements and utilization. At the beginning of the experiment a random sample of 10 animals were slaughtered and their loin joints analysed. The remaining 40 were allocated at random to four dietary treatments (T1, T2, T3, T4) comprising four crude protein intakes at a constant energy intake. The experiment was divided into two periods. During period 1 (48 days) the dietary crude protein intakes were 58 (T1), 111 (T2), 170 (T3), and 198 (T4) g/day with a mean digestible organic matter intake (DOMI) of 578 g/day. During period 2 (55 days) the corresponding crude protein intakes were 89, 157, 215, 251 and the DOMI was 678 g/day.Digestibility and nitrogen balance trials were carried out on two animals from each treatment in period 1 and on six animals on each treatment in period 2. At slaughter the loin joints from five animals on each dietary treatment were chemically analysed.The only significant effect on live-weight gain of varying protein intake was a lower gain on the lowest protein intake (T1) in period 1. It was estimated that the optimum ratio of digestible protein intake (g) to digestible energy intake (meals) for live-weight gain in period 1 was approximately 30 : 1 and in period 2 approximately 21 : 1. There was a significant increase in killing-out percentage with increasing crude protein intake. The digestibility of dry matter and nitrogen increased with increasing crude protein intake. There was a significant quadratic relationship between the apparently digested nitrogen intake in g/day (X) and nitrogen retained in g/day (Y). The regression equation wasY= −0·008X2+ 0·537X+ 0·682Liver copper levels decreased with increasing crude protein con-centration in the diets.


2021 ◽  
Vol 28 (2) ◽  
pp. 187-192
Author(s):  
F. OLALERU ◽  
T. A. ADEGBOLA

The effects of cotton seed cake (CSC) or urea in supplying either 12% or 16% crude protein on sorghum stover utilization by Yankasa rams was studied for twelve weeks, using a 2 x 2 factorially designed experiment. Nutrient intake, digestibility, weight gain and feed conversion ratio (FCR) were monitored. In vitro volatile fatty acid (VFA) and ammonia-nitrogen (NH,-N) concentrations were also determined. The result of the study indicated that the source and/or level of nitrogen (or crude protein) significantly (P<0.05) affected crude protein intake (CPI), digestible crude protein intake (DCPI) and in vitro NH,-N concentration. Total feed intake, live weight gain (LWG), FCR and DCPI were significantly (P<0.05) affected by source x level interaction. Acid detergent fibre (A DF) and neutral detergent fibre (NDF) intakes, CP, ADF and NDF digestibilities, digestible ADF and NDF intakes, stover intake and in vitro VFA concentration were not significantly (P>0.05) affected by either main effects of CP source and level or their interaction. The rams on the 16% CSC and 12% urea ration gained more weight and had lower FCR than those on the 12% CSC and 16% urea. The 16% CSC ration gave the best result in terms of sorghum stover supplementation. The 12% urea treatment which also had a good result in terms of weight gain and FCR could also be recommended for use.


1933 ◽  
Vol 4 (2) ◽  
pp. 177-196 ◽  
Author(s):  
Samuel Morris ◽  
Norman C. Wright

The protein requirements for maintenance and milk production are based on the well-known investigations of Kellner, Armsby, Haecker, Savage and others, who recommend feeding standards varying from 0·5 to 0·;8 lb. digestible crude protein per 1000 lb. live weight for maintenance, and from 0·52 to 0·63 lb. digestible crude protein per 10 lb. milk for milk production. A detailed study of the work of these investigations shows that in many instances nitrogen equilibrium has been obtained on considerably lower planes of protein intake: but the figures have been arbitrarily raised, partly to provide a sufficient safeguard against underfeeding, and partly on the assumption that the excess food protein could exert a stimulating effect on mammary secretion. Recent investigations, particularly those of Hills and his associates (l), Perkins (2), Buschmann(3) and Savage and Harrison (4) indicate that the existing protein standards could, in fact, be considerably reduced. The above investigations have, however, been limited to a study of the quantity of protein required for maintenance and milk production, and no account has been taken of the possible effect of variations in the quality of proteins on their utilisation.


1971 ◽  
Vol 13 (4) ◽  
pp. 653-660 ◽  
Author(s):  
J. J. Robinson ◽  
C. Fraser ◽  
Elizabeth L. Corse ◽  
J. C. Gill

SUMMARYTwenty-one Finnish Landrace × Polled Dorset Horn female sheep approximating 8 months old were individually penned from 3 to 4 weeks after mating until parturition. They were allocated to one of three diets containing either 12·3, 14·1 or 16·5% crude protein and 2·1 Meal metabolizable energy per kg dry matter, offered at a level of 85 g/kg W0·75 per day. A series of nitrogen balance trials was carried out on all lambs during the last 100 days of gestation.The mean age at parturition was 382 days and the mean litter size 1·52. The live-weight gain (mean value 152 g/day) was not significantly affected by the level of protein intake. There was a tendency (005 < P < 0·10 for singletons) for lamb birth weight to decrease and the body-weight change of the dam to increase with increasing protein concentration in the diet. There was a significant linear increase in nitrogen retention both with stage of gestation and level of protein intake.The partition of nitrogen between the foetal and maternal body is discussed in relation to the estimated nitrogen content of the maternal live-weight gain.


1969 ◽  
Vol 72 (1) ◽  
pp. 13-30 ◽  
Author(s):  
W. H. Broster ◽  
Valerie J. Tuck ◽  
T. Smith ◽  
V. W. Johnson

SUMMARYEight feeding trials on cattle showed that the response in live-weight gain was curvilinear when protein or energy level was varied independently in rations based on poor quality roughages to which cereals and groundnut were variously added to give a range of protein and energy intakes. Live-weight gain was increased by 0·12 lb/day for each 0·1 lb additional digestible crude protein/day at levels of intake below 0·7 lb/day and by 0·03 lb/day at higher levels. It was increased by 0·4 lb/day for each additional 0·1 lb starch equivalent daily/100 lb live weight at total intakes below 0·9 lb daily/ 100 lb and by 0·2 lb/day at higher levels. Over the range 0·5–2·0 lb digestible crude protein daily and 0·7–1·2 lb starch equivalent daily/100 lb live weight the effects of these nutrients were additive.A Latin square nitrogen balance trial demonstrated that a portion of the nitrogen from a protein supplement was retained in the body despite the excretion of the greater part of it in the urine and a further part in the faeces. Nitrogen retention was increased by a supplement of readily available energy through a decrease in urinary nitrogen loss. Nitrogen balance was not increased by a supplement of a fibrous energy source because this induced an increase in faecal nitrogen loss.In a further feeding trial milk yield was found to be affected in a similar manner to growth. At a yield of 30 lb/day the response per lb starch equivalent added to the diet was 0·5 lb milk including 0·05 lb solids not fat and to an increase of 0·1 lb digestible crude protein daily it was 0·25 lb milk including 0·025 lb solids not fat.


1968 ◽  
Vol 10 (1) ◽  
pp. 37-42 ◽  
Author(s):  
M. Kay ◽  
H. B. Bowers ◽  
G. McKiddie

1. Two growth trials and digestibility trials were carried out with 54 steers given diets containing either 11%, 14% or 17% crude protein in the dry matter and the same concentration of metabolisable energy.2. There were no significant differences in either dry-matter intake or live-weight gain by the steers given the diets containing 14% or 17% crude protein. Dry-matter intake was lower for the steers given the diet containing 11% crude protein and their live-weight gain was lower up to 250 kg live weight. Beyond 250 kg live weight their live-weight gain was similar to that of the steers on the two other treatments.3. Both dry-matter digestibility and apparent nitrogen digestibility were lowest for those steers given the diet containing 11% crude protein.


1957 ◽  
Vol 49 (4) ◽  
pp. 435-445 ◽  
Author(s):  
G. L. Bailey ◽  
W. H. Broster

The literature on the protein requirements of young dairy heifers has been discussed and the wide variations noted, both in quantities estimated for particular live-weight ranges and in the suggested trends of requirements with live weight.Short-term trials have been conducted in which the effect of variation in protein intake on rate of live-weight gain of dairy heifers of various ages was studied.The response to increments of protein in the ration was found to be curvilinear with a rapid decline in response above critical levels of intake. This level varied with the live weight of the animal, being 0·8 lb. crude protein at 300 lb. live weight and 1·0 lb. at 400 and 500 lb. when rations based on hay, decorticated ground-nut meal and flaked maize were fed.These levels are somewhat lower than estimates of protein requirements quoted in the literature, though the trend indicated in them agrees with some of the published data.No marked difference was observed between the values of decorticated ground-nut meal and white fish meal as protein supplements. Urea was inferior to decorticated ground-nut meal.The overall depressant effect of straw on rate of live-weight gain is demonstrated and discussed.


1982 ◽  
Vol 34 (2) ◽  
pp. 179-190 ◽  
Author(s):  
A. G. Kaiser ◽  
D. F. Osbourn ◽  
P. England ◽  
M. S. Dhanoa

ABSTRACTFour silages were prepared from whole crop maize, each receiving additives of 21 1 formic acid per t fresh crop, and 0, 14, 27 or 53 g formaldehyde per kg crude protein in the crop. These silages, together with 19·6 g urea per kg dry matter, were offered ad libitum for 83 days to 60 British Friesian steer calves, initially 99 kg live weight, either alone or with groundnut or fish meal to raise the dietary crude protein content by 27 g/kg dry matter.Formaldehyde treatment restricted silage fermentation, increased silage and dry-matter intake and live-weight gain, but reduced digestibility, so digestible organic matter and digestible energy intakes were unaffected. Much of the increase in live-weight gain appeared to be due to an increase in gut fill, as carcass weight was not significantly affected by formaldehyde treatment. There was no improvement in the utilization of dietary nitrogen, but there was some evidence that formaldehyde treatment may have increased the proportion of muscle in the carcass.Supplementation with protein improved intake, nitrogen retention, feed conversion ratio, live-weight gain and carcass weight. The improvement in intake and food conversion ratio occurred mainly on the control silage, there being little effect on the formaldehyde-treated silages. Fish meal supplementation increased the digestibility of organic matter, cellulose and energy, and was more effective in improving food conversion ratio than groundnut meal. There were no significant differences between diets in the proportion of dietary nitrogen retained.It was concluded that the scope for the use of formaldehyde, when ensiling maize for use in diets for young calves, appears to be limited.


1975 ◽  
Vol 84 (2) ◽  
pp. 353-364 ◽  
Author(s):  
C. Thomas ◽  
J. M. Wilkinson ◽  
J. C. Tayler

SUMMARYFifty-four British Friesian castrated male calves, initially 3, 6 or 9 months of age (107, 180 and 249 kg initial live weight, respectively), were individually fed for 83 days on maize silage (27·9% dry matter (D.M.), 10·7% crude protein in D.M.), offeredad libitum. Silage was offered either alone or supplemented with cobs of dried lucerne (21% of total D.M. intake). Three levels of urea (0, 1 and 2% of silage D.M.) were added to the silage before feeding.Total D.M. intakes averaged 23·0, 23·4 and 21·6 g/kg live weight (LW) for the 3-, 6- and 9-month-old animals, respectively. Addition of urea increased silage intake by 11% in the 6-month-old group but there was little effect in the 3- and 9-month-old groups. Lucerne supplementation reduced silage D.M. intake from 22·0 to 18·4 g/kg LW (P< 0·001) and increased total D.M. intake by 1·4 g/kg LW (P< 0·001).Live-weight gain (LWG) of the cattle fed on silage alone increased (P< 0·001) with increasing age of animal. The main effect of urea was to elevate (P< 0·001) LWG from an average of 0·79 (no urea) to 0·94 kg/head/day (2% urea). However, it appeared that most of this effect was confined to the 6-month-old group. The effect of lucerne on LWG decreased with increasing age of animal (P< 0·001). Inclusion of lucerne in the diet significantly reduced the response to urea (P< 0·05).Feed conversion efficiency (LWG/100 Mcal DE intake) decreased (P< 0·01) with increasing age of animal but increased with urea addition from an average of 4·7 (no urea) to 5·3 kg LWG/100 Meal DE intake (2% urea). The response to lucerne supplementation in terms of efficiency was greatest in the 3-month-old group and thereafter declined markedly with increasing age of animal.The results of this experiment indicated that cattle older than 6 months of age (180 kg LW) could achieve a rate of growth of 1·0 kg/head/day on maize silage supplemented solely with urea, but that younger animals required supplementary lucerne to support a high rate of live-weight gain.


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