A study of protein utilization by weaned lambs

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.

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 75 (2) ◽  
pp. 287-292 ◽  
Author(s):  
B. W. Norton ◽  
K. T. Jagusch ◽  
D. M. Walker

SUMMARYNineteen male cross-bred lambs, aged between 2 and 5 days, were allotted to each of three dietary treatments. The protein contents of the diets (on a dry-matter basis) were 12·0% (diet A), 28·5% (diet B) and 45·5% (diet C). The energy intakes of groups of lambs within each dietary treatment varied from below maintenance to ad lib.The experimental period was of 3 weeks and the composition of the live-weight gain was estimated by the comparative slaughter method.Body composition within each dietary treatment was highly correlated with empty body weight, but not with the previous energy intake. The fat content of the gain decreased, and the water and protein contents increased, as the dietary-protein concentration increased.When compared at the same empty body weight, the protein content of the fat-free body of lambs given diet C was significantly higher than that of lambs given diet A. This effect of dietary-protein concentration could not be explained by differences in the amounts of protein stored as wool.


Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 783-794 ◽  
Author(s):  
S Freret ◽  
B Grimard ◽  
A A Ponter ◽  
C Joly ◽  
C Ponsart ◽  
...  

The aim of our study was to test whether a reduction in dietary intake could improve in vitro embryo production in superovulated overfed dairy heifers. Cumulus–oocyte complexes of 16 Prim’ Holstein heifers (14 ± 1 months old) were collected by ovum pick-up (OPU), every 2 weeks following superovulation treatment with 250 μg FSH, before being matured and fertilized in vitro. Embryos were cultured in Synthetic Oviduct Fluid medium for 7 days. Heifers were fed with hay, soybean meal, barley, minerals and vitamins. From OPU 1 to 4 (period 1), all heifers received individually for 8 weeks a diet formulated for a 1000 g/day live-weight gain. From OPU 5 to 8 (period 2), the heifers were allocated to one of two diets (1000 or 600 g/day) for 8 weeks. Heifers’ growth rates were monitored and plasma concentrations of metabolites, metabolic and reproductive hormones were measured each week. Mean live-weight gain observed during period 1 was 950 ± 80 g/day (n = 16). In period 2 it was 730 ± 70 (n = 8) and 1300 ± 70 g/day (n = 8) for restricted and overfed groups respectively. When comparing period 1 and period 2 within groups, significant differences were found. In the restricted group, a higher blastocyst rate, greater proportions of grade 1–3 and grade 1 embryos, associated with higher estradiol at OPU and lower glucose and β-hydroxybutyrate, were observed in period 2 compared with period 1. Moreover, after 6 weeks of dietary restriction (OPU 7), numbers of day 7 total embryos, blastocysts and grade 1–3 embryos had significantly increased. On the contrary, in the overfed group, we observed more <8 mm follicles 2 days before superovulation treatment, higher insulin and IGF-I and lower nonesterified fatty acids in period 2 compared with period 1 (no significant difference between periods for embryo production). After 6 weeks of 1300 g/day live-weight gain (OPU 7), embryo production began to decrease. Whatever the group, oocyte collection did not differ between period 1 and 2. These data suggest that following a period of overfeeding, a short-term dietary intake restriction (6 weeks in our study) may improve blastocyst production and embryo quality when they are low. However, nutritional recommendations aiming to optimize both follicular growth and embryonic development may be different.


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.


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.


1984 ◽  
Vol 38 (2) ◽  
pp. 233-240 ◽  
Author(s):  
R. G. Campbell ◽  
M. R. Taverner ◽  
D. M. Curic

ABSTRACT1. Eight diets of similar energy content, ranging in crude protein concentration from 95 to 256 g/kg, were given at either 2·5 or 3·2 times the energy level for maintenance to entire male pigs growing from 45 to 90 kg live weight.2. Growth rate improved with increase in feeding level and with increasing dietary crude protein up to 164 g/kg (P < 0·05). The food conversion ratio improved with each increase in dietary CP up to 186 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 0·05). It was also improved with increase in level of feeding of the lower-protein diets but deteriorated with increase in level of intake of the higher-protein diets (P < 005).3. Rate of protein deposition improved with increasing dietary crude protein up to 186 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 005). The results showed that, for pigs given diets deficient in crude protein, rate of protein deposition was linearly related to protein intake (P < 0·001) but independent of energy intake. For pigs given a diet adequate in crude protein, rate of protein deposition was related to energy intake and independent of crude protein intake.4. Body fat content at 90 kg decreased with increasing dietary crude protein up to 210 and 164 g/kg on the lower and higher feeding treatments, respectively (P < 0·05), and was increased by raising the level of intake of the higher-crude protein diets (P < 0·05). However, the influence of feeding level on body fat diminished as dietary crude protein was reduced.


1971 ◽  
Vol 13 (1) ◽  
pp. 201-204
Author(s):  
H. M. Hassan ◽  
A. M. S. Mukhtar

SUMMARYSixty-four young male Sudan desert lambs were group-fed for 87 days on four diets, all containing approximately 10% crude protein. The four diets contained 0, 1·3, 1·7 and 2·7% urea, respectively.Average daily gains were 0·15, 0·14, 0·14 and 0·13 kg; feed conversion ratios (kg of feed required to produce 1 kg live-weight gain) were 7·26, 8·14, 8·92 and 7·92; dressing percentages were 43·6, 42·1, 44·1 and 42·3.Digestibility trials with lambs fed on diets with 0 or 2·7% urea gave higher digestibility coefficients for crude fibre and nitrogen-free extract for the urea-supplemented lambs. Crude protein digestibility and nitrogen retention values were lower for urea-supplemented lambs.


2017 ◽  
Vol 38 (6) ◽  
pp. 3861 ◽  
Author(s):  
Ulysses Cecato ◽  
Josmar Almeida Junior ◽  
Fabíola Cristine de Almeida Rego ◽  
Sandra Galbeiro ◽  
Wagner Paris ◽  
...  

This study aimed to assess forage production, animal performance, and the chemical composition of Tanzania grass pasture fertilized with 50, 100, 200, and 400 kg ha-1 of nitrogen. The variables analyzed were: leaf mass, daily accumulation rate, leaf/stem ratio, average daily gain, stocking rate, live weight gain per unit of area crude protein, neutral detergent fiber, and in vitro dry matter digestibility of leaves. The pasture management maintained the pasture height at 50 cm by using a continuous grazing method with the adjustment of stocking rate. The experimental design was a randomized block with three replicates. The leaf mass increased linearly in response to nitrogen, with an increase of 1003 kg (34%) observed between a nitrogen content of 50 and 400 kg ha-1. Nitrogen did not affect the average daily gain, but increased the stocking rate and live weight gain ha-1. The value of crude protein and neutral detergent fiber were higher with increased nitrogen levels, whereas the leaf digestibility did not affect nitrogen use. The comparison of 50 and 400 kg ha-1 levels indicated that there was an average increase of 19.2% in the leaf crude protein. The increased application of nitrogen fertilizer in Tanzania grass improved the chemical composition and animal performance; with regard to studied variables, the dose of 200 kg ha-1 resulted in the greatest improvement.


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