Calcium and phosphorus retention by the milk-fed lamb, with estimates of the endogenous losses

1972 ◽  
Vol 79 (2) ◽  
pp. 171-179 ◽  
Author(s):  
D. M. Walker

SUMMARYThe total body content of calcium and phosphorus of twenty-seven male cross-bred lambs was determined, after the lambs had suckled ewes at pasture for between 2 and 5d. The relationships between empty body weight and Ca and P content were described by linear regression equations. The comparative slaughter method was used with thirty-seven lambs, and the balance method with twenty lambs, to determine the retention of Ca and P from cow's milk by lambs given intakes of milk ranging from maintenance (or below) toad lib. The availability of Ca, calculated as true digestibility, was 88–1 %, and for P, 98–2 %. Estimates of net availability, calculated from the slopes of the regressions relating mineral intake to mineral apparently absorbed, were somewhat higher and close to 100%. The net efficiencies of Ca and P retention, as estimated from the slopes of the regressions relating mineral intake to mineral retention, were also close to 100%. The balance method gave higher estimates of Ca and P retention than the comparative slaughter method. Multiple regression equations were used to describe the dependence of P retention on N and Ca retention. A low-calcium diet was given to two lambs for 20 d and the endogenous losses of Ca (and P) in the faeces and urine were determined. The total endogenous losses were 9–5 + 0–9 mg Ca (and 30–3 ± 1–4 mg P) per kg live weight d, of which the urinary losses were 0–5 mg Ca (and 27–9 mg P). Requirements for Ca, calculated for the milk-fed lamb at live weights of 5 and 10 kg, were somewhat lower than those recommended by the Agricultural Research Council (1965), but P requirements were in close agreement.

1969 ◽  
Vol 73 (3) ◽  
pp. 507-509 ◽  
Author(s):  
A. C. Field ◽  
N. F. Suttle

SummaryEstimates of endogenous loss of calcium have been obtained from balance studies with growing lambs and adult sheep given diets containing deficient and adequate amounts of calcium and phosphorus. The values were generally lower than those obtained for sheep by methods employing radioactive calcium and it was concluded that the endogenous loss by sheep is considerably less than the figure used by the Agricultural Research Council (1965) and is probably of the same order as that of cattle (16 mg/day kg live weight).


1984 ◽  
Vol 102 (1) ◽  
pp. 135-139 ◽  
Author(s):  
G. D. Braithwaite

SummaryThe effect on phosphorus and calcium metabolism of a high rate of Ca infused directly into the blood of 10-month-old sheep, already receiving an adequate Ca and P intake, has been studied by a combination of balance and radioisotope techniques. Ca retention was significantly increased during the infusion and most of the extra Ca was retained in bone. Urinary Ca excretion also showed a small but significant increase and the efficiency of Ca absorption a small but significant decrease. Because of the close association of Ca and P in bone, the increased skeletal retention of Ca resulted in an increased skeletal P retention and hence an increased demand for P. This increased P demand was met partly by a decrease in the rate of endogenous faecal loss of P and partly by an increase in the rate and efficiency of P absorption. Because the increase in P demand was relatively small, it was not possible to decide whether the endogenous faecal loss of P can be reduced in response to increased demands to the level found at zero P intake as suggested by the Agricultural Research Council (1980) or whether higher losses at normal P intakes are inevitable.


1988 ◽  
Vol 46 (2) ◽  
pp. 169-179 ◽  
Author(s):  
H. D. St C. Neal ◽  
M. Gill ◽  
J. France ◽  
A. Spedding ◽  
S. Marsden

AbstractEquations for the prediction of forage dry-matter intake, metabolizable energy (ME), rumen degradable protein and undegraded protein, based on those in the current Agricultural Research Council system, were incorporated into a computer program designed to be used by livestock advisors for on-farm rationing of beef cattle. The predictions of silage intake and live-weight gain are compared with experimental data.Voluntary intake of grass silage was generally over-estimated by the program by proportionately at least 0·06, with a root mean square error of ±0·18 of the mean observed silage intake for the all-silage rations. The prediction of ME requirement for observed production had an error of +0·15 of average ME intake but the calculations of ME intake were themselves dependent on the predictions of the ME concentrations of the silages and supplements. Similarly the comparison of protein supply with requirement was highly dependent on the value assigned to N-degradability. However, the program can be used to assess how changes in the input values would affect ration formulation.The mathematical basis of the program is described in the Appendix.


1972 ◽  
Vol 15 (2) ◽  
pp. 117-125 ◽  
Author(s):  
J. L. Davies ◽  
I. A. M. Lucas

SUMMARYAllowances of about 1·4M, 1·8M, 2·2M, 2·6M, 3·OM, and 3·4M (M = feed required for maintenance) were compared for pigs growing over the live-weight ranges 20·40, 40·60, 60·80, and 80·100 kg, with feed conversion efficiency (FCE) as the main response criterion.Response to increased digestible energy (DE) allowance was curvilinear; FCE improved rapidly up to 2·2M-2·6M, and changed much less with intakes above 2·6M. It is concluded that optimum FCE occurs at about 2·7M for pigs of 30 kg and at about 3·OM for pigs of 50, 70 and 90 kg.Allowances of dietary DE suggested by the Agricultural Research Council correspond to 2·56M, 2·95M, 3·04M and 3·08M for pigs of 30, 50, 70 and 90 kg live weight, respectively. It appears that these are near to the optima in promoting the best FCE.Changes of −25%, −15%, −5%, +5% and +15% in daily intake around the optimum levels caused FCE to deteriorate by averages of about 13%, 4·5%, <1%, <1% and 4·5% respectively. Daily weight gains would then change by about −34%, −18%, −5%, +4% and +10%, respectively.


1970 ◽  
Vol 75 (1) ◽  
pp. 11-18 ◽  
Author(s):  
R. P. Andrews ◽  
E. R. Ørskov

SUMMARYThe live-weight gains of male and female lambs were measured during growth from 16 to 40 kg live weight when five cereal-based diets varying in dietary crude protein concentration (from 10 to 20%) were given at three levels in a 5×3×2 factorial design.Males grew faster than females by about 15% (P < 0·001); this difference increased with age and with the amount of feed given (P < 0·05). Growth rate responded linearly to increase in feeding level (P < 0·001) and curvilinearly to increase in dietary protein concentration (P < 0·01). A significant interaction (P < 0·01) occurred whereby growth increased with higher protein concentrations as feeding level increased.At the highest feeding level (near ad libitum) the results suggest that the optimum dietary crude protein concentration for growth was about 17·5, 15·0, 12·5 and 12·5% at body weights of 20, 25, 30 and 35 kg respectively. The overall optimum dietary crude protein concentration for growth between 16 and 40 kg body weight was about 17·0, 15·0 and 11·0% when the mean digestible energy intake was 3·0, 2·6 and 2·1 Mcal/day.The results agree reasonably well with estimates of protein requirements for lambs given by the Agricultural Research Council (1965).


1978 ◽  
Vol 18 (95) ◽  
pp. 781
Author(s):  
EB Greer ◽  
CE Lewis

A 2 x 2 x 3 x 3 factorial experiment with 72 growing pigs examined the effect of adding salt, calcium and phosphorus (Ca + P) and trace minerals (TM-manganese, zinc, iron and copper) to a wheat/soybean meal diet. Gilts and barrows were individually fed at restricted intakes from 20 kg liveweight. Pigs required both salt and Ca + P to reach slaughter at 73 kg. Without these minerals they stopped growing; lameness and broken bones were also common. All pigs fed salt plus the higher level of Ca + P (0.84 and 0.57 per cent, respectively) completed the experiment but only half those fed salt plus the lower level (0.42 and 0.29 per cent Ca + P, respectively) did so. There was a response to salt within three weeks. In the first four weeks, 0.125 per cent added salt improved growth by 26.5 per cent and feed conversion ratio by 21 per cent. The results indicated that growing pigs require less sodium than currently estimated (Agricultural Research Council). A response to both levels of supplementary Ca + P was seen after about seven weeks with salt and nine weeks without salt. In the first eight weeks of the experiment there were no differences in performance between the two levels of added Ca + P when salt was also used. Between 8 and 12 weeks, pigs fed the higher level grew 17 per cent faster. Although 0.84 + 0.57 per cent Ca + P increased rib Ca and P levels, foot and joint abnormalities showed that these levels were insufficient for normal bone development. This suggests that the Agricultural Research Council estimates of Ca and P requirements for restrictively fed growing pigs are low. TM supplementation did not affect performance when both salt and Ca + P were added to the diet.


1983 ◽  
Vol 50 (3) ◽  
pp. 723-736 ◽  
Author(s):  
G. D. Braithwaite

1. Mineral balance and radioisotope studies have been carried out to test the adequacyof the recent Agricultural Research Council (1980) recommendations for calcium and phosphorus for pregnant and lactating ewes. At the same time, P metabolism was compared throughout pregnancy and lactation in ewes fed according to these recommendations and in ewes fed a plentiful supply of dietary Ca and P.2. Bone mineral stores were mobilized in late pregnancy and early lactation, irrespective of the rate of P absorption. These stores were then replaced in mid- to late lactation in ewes given the plentiful Ca and P intake but not in the ewes given the restricted intake.3. Results suggest that these changes in bone stores occurred as a result of changes in Ca requirements rather than in P requirements, and that accretion of P into bone or resorption of P from bone occurred merely as a conseqence of this change in Ca requirements.Immediate demands for P for maintenance and fetal or milk production do not reflect net Pdemands, which also take into account changes in bone P metabolism.4. The rate of P absorption was directly related to net demands and the rate of endogenous excretion was inversely related to net demands.5. Absorption and endogenous faecal loss of P were also both directly related to P intake.6. A lack of dietary Ca, particularly in mid- to late lactation, makes it impossible to draw conclusions on the adequacy of the Agricultural Research Council (1980) recommendations for P. Results do suggest, however, that P requirements ought to be calculated according to net demands for P rather than immediate demands.


1988 ◽  
Vol 46 (2) ◽  
pp. 181-193 ◽  
Author(s):  
J. R. Newbold ◽  
P. C. Garnsworthy ◽  
P. J. Buttery ◽  
D. J. A. Cole ◽  
W. Haresign

AbstractThe ability of the protein nutrition scheme proposed by the Agricultural Research Council (ARC, 1980, 1984) to predict responses to protein supply was examined in two experiments. In experiment 1, groups of nine British Friesian steers implanted with oestradiol-17β and nine non-implanted steers were fed from 133 to 300 kg live weight on each of four all-concentrate diets (metabolizable energy (ME) = 12 MJ/kg dry matter (DM)) containing ratios of soya-bean meal and formaldehyde-treated soya-bean meal such that undegradable protein (UDP) concentration was 19, 25, 32 or 42 g/kg DM. Rumen degradable protein (RDP) concentration was relatively constant (111 to 116 g/kg DM). Implantation did not affect DM intake (DMI, g/kg M0·75). Both live-weight gain (LWG) and food conversion efficiency (FCE) (LWG/DMI) were greater (P < 0·05) for the implanted cattle (LWG = 1·41 (s.e. 0·04) kg/day; FCE = 0·24 (s.e. 0·02)) than for the non-implanted cattle (LWG = 1·23 (s.e. 0·05) kg/day; FCE = 0·22 (s.e. 0·02)). There were no dietary effects on either DMI or FCE. In the non-implanted steers, UDP did not affect LWG but, for the implanted steers, there were positive, linear responses in LWG to both UDP concentration (P = 0·048) and UDP intake (P = 0·026). In experiment 2, groups of eight implanted steers were fed from 132 to 300 kg live weight on each of six diets (ME = 12 MJ/kg DM, soya-bean meal and formaldehyde-treated soya-bean meal as chief protein sources) supplying 17, 26, 34, 39, 54 and 82 g UDP per kg DM and concentrations of RDP up to 1·5 times ARC recommendations. There was no effect of UDP on either DMI or FCE but positive, linear responses in LWG to both UDP concentration (P = 0·019) and UDP intake (P = 0·010). In both experiments, mean DMI exceeded that predicted by ARC (1980) (P < 0·05). LWG predicted by the ME system and the ARC protein scheme was not significantly different from observed LWG for non-implanted steers, but was an underestimate of observed LWG for implanted steers (P = 0·002 in experiment 1, P < 0·001 in experiment 2). Observed responses in LWG to UDP concentration were also poorly predicted (regressions of observed on predicted LWG: experiment 1, r2 = 0·12, residual s.d. = 0·126; experiment 2, r2 = 0·004, residual s.d. = 0·119). It was concluded that oestradiol-17p has significant effects on responses in LWG to UDP, which are not predicted by the current ARC (1980, 1984) protein nutrition scheme.


2009 ◽  
Vol 33 (6) ◽  
pp. 1637-1642 ◽  
Author(s):  
Rodrigo Palomo de Oliveira ◽  
Juan Rámon Olalquiaga Perez ◽  
Joel Augusto Muniz ◽  
Antonio Ricardo Evangelista ◽  
José Camisão de Souza ◽  
...  

The experiment was carried out in the sheep division of Universidade Federal de Lavras, aiming to evaluate the effect of different concentrate : voluminous ratio on the performance of Santa Inês lamb after wean. 40 lambs, male uncastrated, were used and fed with four different diets: diet A (100% concentrate), diet B (75:25 concentrate : voluminous) , diet C (50:50 concentrate : voluminous) , diet D (25:75 concentrate : voluminous). The experimental diets were isoproteic, differing only on its levels of concentrate : voluminous and balanced to meet the nutritional demands according to the recommendation of the Agricultural Research Council (1980). The experimental period was not pre-established, because it corresponded to the necessary period for the last lamb to reach the live weight of 35kg. The dry matter consumption (DMC), crude protein consumption (CPC), fiber in neutral detergent consumption (FNDC) and fiber in acid detergent consumption (FADC), were affected by the different concentrate : voluminous ratio, in which, the animals that received diets with higher concentrate inclusion presenting better results for the variables related to the development. The lambs fed with the diet containing higher inclusion of voluminous did not present weight gain, on the contrary, presented weight loss, since none of the animals reached slaughter weight and the mortality rate was extremely high (80%).


1985 ◽  
Vol 41 (3) ◽  
pp. 309-321 ◽  
Author(s):  
R. D. Baker ◽  
N. E. Young ◽  
J. A. Laws

AbstractFriesian steer calves born in August were reared from 3 to 7 months of age on either a low (OL) or high (OH) plane of nutrition. A further group born in October (YH) was also reared on a high plane. At grazing, the performance of calves of the same age but different weights (OL v. OH) or the same weight but different ages (OL v. YH) were compared at two levels of herbage allowance, either 30 or 60 kg dry matter per kg live weight. During the winter, the H groups received silage and concentrate and the L group was given silage only. The OL group had a higher concentration of fat and a lower concentration of water in the empty body at the end of the winter than did the OH and YH groups respectively.Compensatory growth was exhibited by the OL group at both herbage allowances. Differences in the live-weight and empty body-weight gains of OL and OH cattle could be explained almost entirely by differences in the energy content of the gains whereas this was only partially so when the OL and YH groups were compared. The results indicate that YH cattle had lower herbage intakes even though they were of similar weight to OL cattle.It was concluded that silage nitrogen is used less efficiently by cattle than is generally assumed and that the levels of gut fill and energy content of the live-weight gains in this experiment were not consistent with the general values suggested by the Agricultural Research Council (1980).


Sign in / Sign up

Export Citation Format

Share Document