An estimate of the energy required for maintenance and live-weight gain by young grazing sheep

1966 ◽  
Vol 66 (2) ◽  
pp. 211-215 ◽  
Author(s):  
R. C. Grimes

1. The intake of grazing wethers was estimated from the in vitro organic matter digestibility of herbage samples collected from sheep with oesophageal fistulae, and total faecal collections.2. Body water, estimated by isotope dilution, was used to estimate total body energy from estab-lished regressions relating body water to body composition.3. Total body energy was then related to live weight by regression analysis, giving a value of 2044 kcal. per lb. over the range 68-90 lb. empty body weight. From this it was estimated that 2.41 lb. D.O.M. was required per lb. live-weight gain within this range.4. Energy for maintenance was calculated by deducting D.O.M. required for gain from D.O.M. intake. These values were related to live weight by regression analysis to give a value of 1.31 lb. D.O.M./day for the maintenance of a 100 lb. sheep.

1978 ◽  
Vol 40 (2) ◽  
pp. 377-386 ◽  
Author(s):  
R. B. Williams ◽  
I. McDonald ◽  
I. Bremner

1. The amounts of copper and zinc in the foetuses of ewes carrying from one to four lambs were measured at different stages of gestation and estimates were made of the amounts of these metals in their livers.2. The accretion of Cu and Zn could be described by growth equations of the Gompertz form, from which could be derived estimates of the instantaneous and fractional rates of deposition of these metals in the foetal body.3. Between the 80th and 144th day of gestation the instantaneous rates of deposition of the metals increased exponentially, and at the end of pregnancy were calculated to be 0.24 and 2.0 mg Cu and Zn/d respectively in the triplet lamb foetus. The corresponding total accretions were estimated to be 10 and 69 mg respectively.4. The fractional rates of live-weight gain and of deposition of Cu were similar and decreased at similar rates; that of Zn deposition decreased much more slowly.5. The proportion of whole-body Cu estimated to be in the liver was always greater than 50 %. The amount of Zn in the liver remained constant and contributed 72 % of the total body Zn at 80 d but only 8 % at 144d.6. The relative amounts of Cu and of Zn accrued per unit body-weight gain were not constant during the development of the foetus. As foetal numbers increased the amounts of each metal deposited in the foetus decreased more rapidly than did foetal weight.7. The results are discussed in relation to the demands for Cu and Zn during pregnancy in sheep.


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.


1967 ◽  
Vol 21 (2) ◽  
pp. 275-287 ◽  
Author(s):  
D. M. Walker ◽  
L. J. Cook ◽  
K. T. Jagusch

1. Thirty-three cross-bred lambs were given reconstituted dried whole cow's milk from 1 week of age at different levels of intake and at different frequencies of feeding.2. Feeding frequency had no effect on live-weight gain, N retention or total body composition.3. Lambs given two feeds daily had significantly heavier abomasums than pair-fed lambs given six feeds daily.4. The weights of fat, protein (N x 6.25) and water in the body were closely related to empty body weight; body composition (% of empty body) was not significantly affected by the level of milk intake or by the rate of growth.5. Live-weight gain was closely related to energy intake (r = +0.99) and to N retention (r = +0.97). A live-weight gain of 100 g was associated with an intake of 511 kcal and a N retention of 2.28 g N.


2008 ◽  
Vol 146 (3) ◽  
pp. 251-265 ◽  
Author(s):  
F. GARCIA ◽  
J. AGABRIEL

SUMMARYCull cows account for a large part of beef consumption in France and are a significant proportion of farm income for dairy (0·10) and beef systems (up to 0·30). On-farm observations highlight considerable variations in cull cow phenotypes in terms of age, frame size, health, physiological status and body condition. Consequently, an important issue for producers of cull cows is the management of feed supply during the finishing period to obtain a satisfactory condition score and conformation prior to slaughter.New feeding recommendations for cull cows should consider live weight and live weight gain, age, frame size and body condition score (BCS) to estimate the energy requirements. A predictive model, called CompoCow, was developed for this purpose. The present paper describes the CompoCow model by summarizing developments from previous modelling approaches and outlining the assumptions and equations used in the model. CompoCow combines a growth model for the cow during its productive period (3–8 years old) and a model for the finishing period (in days) and was parameterized for Charolais, Limousine and Holstein breeds. Sensitivity analysis highlighted that the outputs of the model were mainly sensitive to initial body weight and expected body weight gain of the animal. The proportion of lipid in live weight gain was related to body weight, BCS and frame size of the animal. The model also accounts for the higher proportion of lipid in live weight gain in Holstein than in Charolais cows. The model was applied to data from Charolais cows. It showed that the proportion of variability explained by CompoCow for energy requirements was higher than the proportion obtained with previous INRA recommendations, 0·78 and 0·67, respectively. CompoCow does not rely on mechanistic relationships, but it appears robust as it accounts correctly for the effects of age and BCS on the requirements.


1988 ◽  
Vol 47 (3) ◽  
pp. 435-445 ◽  
Author(s):  
F. R. Dunshea ◽  
A. W. Bell ◽  
K. D. Chandler ◽  
T. E. Trigg

ABSTRACTA two-pool model of tritiated water kinetics was investigated as a means of partitioning total body water into empty body water and gut water in 17 lactating goats. Empty body water, gut water and total body water were of a similar magnitude to, and highly correlated with, a rapidly equilibrating tritiated water pool, a more slowly equilibrating pool and the sum of these two pools, respectively.Empty body fat was poorly correlated with both live weight and empty body weight (R2 = 0·42 and 0·51, respectively). However, there was a strong inverse relationship between the water and fat contents of the empty body. Consequently, empty body fat was accurately predicted by a multiple regression equation which included both empty body weight and empty body water as independent variables (R2 = 0·97). Substitution of these variables with estimates derived from tritiated water kinetics still resulted in a high correlation (R2 = 0·88). Tritiated water kinetics offered little improvement over live weight alone in the prediction of empty body protein, empty body ash or fat-free empty body.


1997 ◽  
Vol 64 (3) ◽  
pp. 541-546 ◽  
Author(s):  
A. J. Hanlon ◽  
S. M. Rhind ◽  
H. W. Reid ◽  
C. Burrells ◽  
A. B. Lawrence

AbstractAt weaning at 3 months of age (week 1), 30 red deer hind calves were housed in six groups of five animals at a stocking density of 1·5 m2 per head and maintained in these groups for 4 weeks. At the start of week 5, all calves were immunized with ovalbumin (OVA). Fifteen calves, from three groups, selected at random, were transferred to individual pens which restricted visual and tactile contact with others (ISO) while the remaining animals were kept in their groups (GP). The behaviour, food intake, live-weight gain, antibody and lymphocyte responses in vitro to OVA and lymphocyte responses in vitro to the non-specific mitogen, concanavalin A (ConA), of all calves were assessed in each of weeks 5 to 9. Isolated calves had a lower mean live-weight gain than GP calves (P < 0·001), although there were no differences in food intake. Significantly more time was spent lying (P < 0·001) but less time feeding (P < 0·05) and self-grooming (P < 0·001) by ISO than by GP calves. There was no significant difference between ISO and GP calves in the cortisol response to an ACTH challenge test (10 i.u.) at week 11. Lymphocyte responses and antibody titres to OVA were lower in GP than in ISO calves at weeks 7 (P < 0·05) and 8 (P < 0·05), respectively. In contrast, GP calves had greater lymphocyte responses to the non-specific mitogen, ConA, in weeks 7 (P < 0·05) and 10 (P < 0·001) but not in week 9 compared with ISO calves. Differences in lymphocyte stimulation were attributed to the non-specific mitogenic nature of ConA. Factors such as agonistic interactions evident in group housing may have compromised the antibody and lymphocyte responses to OVA by GP calves but conversely the lack of social contact may have also suppressed behavioural activity in ISO calves.


1969 ◽  
Vol 73 (2) ◽  
pp. 189-196 ◽  
Author(s):  
A. J. Mudd ◽  
W. C. Smith ◽  
D. G. Armstrong

SUMMARYThree gilts and three castrated males weighing 23 kg live weight were given four semi-synthetic diets containing increasing amounts of Ca and P. The Ca and P contents (% dry basis) and Ca:P ratios for the four diets were A, 0·30, 0·38, 1:1·27; B, 0·58, 0·68, 1:1·17; C, 0·94, 1·13, l:l·20; D, 1·16, 1·47, 1:1·27. Each animal was slaughtered at 41 kg live weight and the whole body contents of Ca and P determined. Six pigs were slaughtered at 23 kg live weight and their bodies also analysed for Ca and P contents. Dietary concentration of Ca and P did not influence rate or efficiency of live weight gain nor carcass characteristics. Net retention of Ca and P increased with increasing dietary concentration of these elements. Analyses of isolated femurs suggested that optimal mineralization of the bone was associated with a net retention of 8·2 g Ca/kg live weight gain. The data were used to calculate a value of 32·9 mg/kg live weight/day for the endogenous loss of Ca in pigs of 23–41 kg body weight. The values have been used to compute a mineral requirement of dietary calcium which is in excellent agreement with that derived from estimates in the literature.


1974 ◽  
Vol 19 (2) ◽  
pp. 193-200 ◽  
Author(s):  
R. M. Tetlow ◽  
R. J. Wilkins

SUMMARYCobs and pellets which differed in particle size (modulus of fineness, MF) were prepared from dried perennial ryegrass and tall fescue and given to sheep. The MF values of the feeds were 2·45,1·09,0·81 and 0·74 for perennial ryegrass and 2·28,0·84,0·67 and 0·57 for tall fescue. Organic matter digestibility was similar for the two grass species when measured in vivo, but when measured in vitro values for perennial ryegrass were about 3 units higher than those for tall fescue. Voluntary intake and live-weight gain were higher for sheep given tall fescue, the difference in live-weight gain being just significant at P < 0·05. The response to change in particle size was similar for the two grass species. Intake was lowest and digestibility highest for the feeds with the highest MF, but differences between the three finely-ground forms of each species were not significant. There was a tendency for the intake of digestible organic matter to be lower for the feeds with lowest MF than for those with intermediate values for MF. The rate of passage of undigested particles was slower for cobs with the highest MF than for the other feeds, which did not differ significantly one from another.


1961 ◽  
Vol 41 (1) ◽  
pp. 63-70
Author(s):  
Vern Miles ◽  
V. S. Logan ◽  
W. J. Pigden

Thirty-five Holstein heifer calves were assigned at birth to three ration schedules: moderate m; control c; high h. These three groups were weaned from whole milk during the 2nd, 7th and 9th weeks respectively with m and h calves receiving skim milk to 7 and 16 weeks of age respectively. m and c calves were allowed 4 pounds and h calves up to 6 pounds of meal daily with no limit on hay consumption. Moderate and high rationed calves were further sub-divided into three birth groups and were abruptly switched from the above feeding schedules and placed on pasture without supplementation at 56, 112, and 168 days. Treatment comparisons included live weight gain, withers height and heart girth measurements.High rationed calves made greater growth increases than m or c calves during the barn feeding period. These differences were greater for weight than for heart girth or withers increases. Pastured calves made smaller body gains during the first 28-day pasture period than barn-fed controls. This trend was reversed by the third pasture period with some pastured calves gaining over 2 pounds daily, h calves placed on pasture at 2 months of age made greater body weight gains and appeared to be thriftier than calves previously moderately rationed.


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