The effect of time of weaning on the biological efficiency of meat production in sheep

1975 ◽  
Vol 20 (2) ◽  
pp. 233-241 ◽  
Author(s):  
J. M. Walsingham ◽  
R. V. Large ◽  
J. E. Newton
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Post Partum ◽  
Biological Efficiency ◽  
Meat Production ◽  
Digestible Organic Matter ◽  
Breed Crosses

SummaryThe value of E, defined as the weight of carcass produced per 100 units of digestible organic matter (DOM) consumed, was used to assess the biological efficiency of meat production in housed sheep. The effect on E of weaning lambs at 4, 6, 8, 10, 12, 14 and 16 weeks post partum was studied for a number of different breed crosses. The age at which lambs were weaned was found to have little effect on the growth rate of lambs and no significant effect on the biological efficiency with which sheep produce meat.

The biological efficiency of meat production in sheep

1970 ◽  
Vol 12 (3) ◽  
pp. 393-401 ◽  
Author(s):  
R. V. Large
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
High Growth ◽  
High Growth Rate ◽  
Biological Efficiency ◽  
Meat Production ◽  
Final Size ◽  
Artificial Rearing ◽  
Factors Affecting ◽  
Digestible Organic Matter

SUMMARYThe biological efficiency of meat production (E) is defined as the weight of carcass produced per 100 units of digestible organic matter (DOM) consumed. The factors affecting this relationship, for ewes and lambs, are discussed and the results of experiments are used to demonstrate the effect of number of lambs per year and size of ewe on the value of E. Calculations are made to show the effect on E of other factors such as the growth rate of the lambs and the weight at which the lambs are slaughtered. The general conclusions are that the highest values for E will be obtained from small breeds of ewes producing large litters and crossed with a large breed of ram, leading to a high growth rate and final size in the lamb. A relatively small increase in litter size in the small breeds of ewe (i.e. from one to two lambs) may result in a level of efficiency as high as that achieved by a larger breed with a large litter size (i.e. three to four lambs) without having to resort to techniques such as the artificial rearing of lambs.

scholarly journals The intake, digestion and protein degradation of grazed herbage by early-weaned lambs

1992 ◽  
Vol 68 (2) ◽  
pp. 349-364 ◽  
Author(s):  
G. J. Cruickshank ◽  
D. P. Poppi ◽  
A. R. Sykes
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Organic Matter ◽  
Species Difference ◽  
Similar Rate ◽  
Ammonia Nitrogen ◽  
Grass Species ◽  
Pure Species ◽  
Prairie Grass ◽  
Digestible Organic Matter

Sixty-four intact lambs and twenty-four lambs fitted with a duodenal cannula were weaned at 6 weeks of age and grazed pure species swards of either lucerne (Medicago sativa), white clover (Trifolium repens), ryegrass (Lolium perenne) or prairie grass (Bromus catharticus) for 6 weeks. Intake and duodenal digesta flow were estimated when lambs were 8 and 12 weeks of age. Lambs grazing the two legume species grew at a similar rate, as did lambs grazing the two grass species. Legumes promoted a 38% higher growth rate than grasses. The higher growth rate of lambs grazing legumes was associated with a 36% higher digestible organic matter intake (DOMI; 29.5 and 21.7 g/kg body-weight per d for legume and grass respectively) and a 33% higher duodenal non-ammonia-nitrogen (NAN) flow (1.22 and 0.92 g/kg body-weight per d respectively). There was no species difference in the site of organic matter digestion; on average 0.56 of DOMI was apparently digested in the rumen and 0.77 of DOMI was truly digested in the rumen. There was no difference in duodenal NAN flow, relative to DOMI (average, 43 g/kg) or to organic matter apparently digested in the rumen (80 g/kg). Similarly, there was no difference in microbial N flow relative to duodenal NAN (0.50 g/g) and organic matter apparently (41 g/kg) or truly (29 g/kg) digested in the rumen. It was concluded that the higher growth rates achieved by lambs grazing legumes were due to higher intakes which increased the total quantity of nutrients supplied despite more protein being lost in the rumen of lambs consuming legumes.

The food conversion efficiency in lambs of two crosses of sheep

1967 ◽  
Vol 7 (26) ◽  
pp. 199 ◽  
Author(s):  
ME Bourke
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Conversion Efficiency ◽  
Animal Tissue ◽  
Food Conversion ◽  
Factors Associated ◽  
Digestible Organic Matter ◽  
High Level ◽  
Food Conversion Efficiency

The experiment investigated factors associated with differences in growth rate from birth to seven weeks, by two crossbreeds of lamb. The Dorset Horn x Border Leicester-Merino grew at 0.18 kg per day, and the Dorset Horn x Merino grew at 0.14 kg per day (P<0.001) although both crosses consumed the same digestible organic matter intake. Thus the second cross was significantly more efficient (P<0.05) than the first cross. Two levels of milk were also fed to both crosses and, although the high level improved growth rate (P <0.001), it did not effect the efficiency of conversion of food to animal tissue.

The effect of herbage allowance on herbage intake and performance of lambs grazing perennial ryegrass and red clover swards

1976 ◽  
Vol 86 (2) ◽  
pp. 355-365 ◽  
Author(s):  
M. J. Gibb ◽  
T. T. Treacher
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Perennial Ryegrass ◽  
Nitrogen Fertilizer ◽  
Daily Intake ◽  
Live Weight ◽  
Red Clover ◽  
Asymptotic Curves ◽  
Digestible Organic Matter ◽  
The Relationship

SummaryThe effect of daily herbage allowance on herbage intakes and growth rates lambs grazing perennial ryegrass and red clover was investigated in two experiments. Herbage allowances defined as g herbage D.M./kg live weight (LW)/day were controlled by varying the areas of plots grazed for 2 days by groups of six lambs.In the first experiment five herbage allowances in the range 20–120 g D.M./kg LW/day were offered on two areas of a perennial ryegrass (cv. S. 23) sward that received nitrogen fertilizer applications of 39 or 78 kg N/ha/28 days. In the second experiment five herbage allowances in the range 30–160 g D.M./kg LW/day were offered on perennial ryegrass (cv. S. 23) and red clover (cv. Hungaropoly) swards.Asymptotic curves were fitted to describe the relationship between herbage allowance and daily intake of herbage. In Expt 1 nitrogen fertilizer rates did not affect the yield of herbage or animal performance. In Expt 2 intakes were higher on the clover sward than on the ryegrass sward at the higher herbage allowances.The asymptotic curves to describe the relationship between herbage allowance and growth rate of lambs differed widely between periods. Growth rate of the lambs increased linearly with increase in digestible organic matter intake. Live-weight gain per unit of digestible organic matter intake was higher on the red clover than on the ryegrass.The conclusion is drawn that if the herbage present to ground level is not more than three times the daily intake of the animals, intake of herbage of the animals may bo restricted.

The feed intake of grazing cattle III. The influence of level of milk yield

1965 ◽  
Vol 7 (2) ◽  
pp. 141-151 ◽  
Author(s):  
J. G. W. Jones ◽  
R. M. Drake-Brockman ◽  
W. Holmes
Keyword(s):  
Organic Matter ◽  
Milk Production ◽  
Post Partum ◽  
Live Weight ◽  
Milk Composition ◽  
High Yield ◽  
Meadow Fescue ◽  
Lactating Cows ◽  
Digestible Organic Matter ◽  
The Mean

SUMMARY1. The feed intakes of 18 Ayrshire cows continuously grazing a timothy-meadow fescue-white clover sward were estimated by the chromic oxide-faecal nitrogen method for two 6-weekly periods, one in 1960 and one in 1961. The cows consisted of (1) 6 lactating cows, 6–7 months post partum (Low yield), (2) 6 lactating cows, 2 months post partum (High yield) and (3) 6 dry cows; their live-weights, milk yields and milk composition were recorded.2. The mean organic matter digestibility of the herbage consumed in the two experiments was 78·2 and 76·2%. The mean digestible organic matter intakes (DOMI) were 23·3, 24·7 and 17·6 Ib./day for low yield, high yield and dry cows respectively.3. The mean daily fat-corrected milk (FCM) yields of the low and high yield cows were 29·1 and 34·3 lb. in the first experiment, and 26·8 and 42·8 lb. in the second. The mean live-weights of the lactating groups were 1036 lb. and 1106 lb. in the two experiments and did not differ between yield levels.4. DOMI was partitioned between maintenance, live-weight gain and FCM yield by regression analysis. Significant partial regression coefficients of DOMI on FCM varying between 0·221 and 0·272 were obtained. It was concluded that milk production accounted for about 0·24 lb. DOMI per lb. FCM.5. The results are discussed with particular regard to other estimates of the effect of milk production on the DOMI of the grazing cow and to the estimation of the maintenance requirement for DOM by the grazing animal.

Efficiency of growth and wool production of young Merino ewes from a flock selected for fertility

1976 ◽  
Vol 16 (80) ◽  
pp. 315 ◽  
Author(s):  
KD Atkins ◽  
GE Robards
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Reproductive Rate ◽  
Feed Conversion ◽  
Or Efficiency ◽  
Net Reproductive Rate ◽  
Wool Production ◽  
Significant Difference ◽  
Digestible Organic Matter ◽  
Conversion Efficiencies

A handfeeding experiment was conducted with weaner ewe lambs from two Merino flocks. One flock had been selected for high net reproductive rate, growth rate and wool production (fertility flock) ; the other flock was a randomly selected control flock (random flock). Single and twin born lambs from each flock were used in the experiment. Lambs were randomized into four treatment groups and offered the diet either ad libitum or at one of three levels estimated to restrict growth rate to 50, 100 and 150 g day-1. At each level of feeding, fertility flock lambs grew faster and were more efficient in converting feed to liveweight gain. Over the whole experiment the feed conversion efficiencies in g gain per kg digestible organic matter intake per day were 218 and 185 (P < 0.05) for the fertility and random flocks respectively. There were no significant differences in growth rate or efficiency of conversion of feed to liveweight gain between single-born and twin-born lambs. Random flock lambs had a significantly higher wool growth rate and were more efficient converters of feed to wool than fertility flock lambs. Gross efficiencies were 10.8 and 9.1 g clean wool per kg digestible organic matter intake per day (P < 0.05) for random and fertility flock lambs respectively. Single-born lambs grew significantly more wool than twin-born lambs but there was no significant difference between birth types in the efficiency of conversion of feed to wool.

scholarly journals Population improvement and synthetic cultivar production in forage kale (Brassica oleracea L.)

Euphytica ◽  
2021 ◽  
Vol 217 (7) ◽  
Author(s):  
John E. Bradshaw
Keyword(s):  
Organic Matter ◽  
Annual Cycle ◽  
Dry Matter ◽  
No Reduction ◽  
Optimum Number ◽  
Breeding Method ◽  
Thiocyanate Ion ◽  
Digestible Organic Matter ◽  
Population Improvement ◽  
Field Transplant

AbstractExperimental results are brought together to demonstrate that forage kale population improvement involving full-sib and selfed families can be done on an annual cycle, followed by production of a synthetic cultivar. Furthermore, this new breeding method compares favourably with the two successful methods used to date, namely triple-cross hybrid cultivars from inbreeding and crossbreeding programmes and open-pollinated cultivars from population improvement programmes. The key findings were that natural vernalization of kale in south east Scotland occurred by mid-December so that plants could be pollinated in a glasshouse with heating and lighting by the end of February and seed harvested by the end of May. The resulting full-sib or selfed families could be assessed in a field transplant trial in the same year, from June to November, thus completing an annual cycle. Self-pollination resulted in shorter plants with lower fresh-weight, dry-matter and digestible organic-matter yields, and undesirably higher contents of S-methylcysteine sulphoxide, the haemolytic anaemia factor, and the goitrogenic thiocyanate ion. As a consequence of digestible organic-matter yield being reduced by as much as 22%, the estimated optimum number of selfed parents in a synthetic cultivar was four to eight. Synthetic cultivars are expected to yield as well as triple-cross hybrids as there was no reduction in yield when the latter were open-pollinated.

Effect of age, abomasal cannulation and rumen catheterization on intake and site of digestion by early-weaned lambs

1990 ◽  
Vol 114 (1) ◽  
pp. 49-54 ◽  
Author(s):  
G. J. Cruickshank ◽  
D. P. Poppi ◽  
A. R. Sykes ◽  
A. S. Familton
Keyword(s):  
Organic Matter ◽  
Live Weight ◽  
Experimental Period ◽  
Nutrient Digestion ◽  
Digestible Organic Matter ◽  
Outflow Rate ◽  
Ram Lambs ◽  
Effect Of Age ◽  
Cumulative Intake

SUMMARYThe voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.

Effect of starch on the utilization by sheep of a straw diet supplemented with urea and minerals

1976 ◽  
Vol 27 (1) ◽  
pp. 139 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
WR McManus
Keyword(s):  
Organic Matter ◽  
Nitrogen Retention ◽  
Nitrogen Excretion ◽  
Digestible Organic Matter ◽  
Cellulose Digestibility ◽  
Oat Straw ◽  
Total Body ◽  
Body Energy ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Individually penned Border Leicester x Merino wethers, aged 11 months, were fed ad lib. for 16 weeks on a basal ration of ground, pelleted oat straw, urea and minerals, supplemented with 0, 5, 10, 15, 20, 30 or 40% starch. The diets contained equal percentages of nitrogen and minerals. Dry matter intake reached a maximum of 2000 g/day with 30% starch; above this starch level, digestive disturbances were observed. Organic matter digestibility was increased by the addition of starch, but cellulose digestibility was depressed by as much as 18 units with the addition of 30% starch. Up to 10% the starch level had little effect on cellulose digestibility. Liveweight change was significantly correlated with digestible organic matter intake, mean daily weight gains varying from 22 g with no starch to 104 g with 30% starch. However, a large percentage of the liveweight gain was as total body water, and body energy storage increased appreciably only when the diet contained at least 20% starch. The inclusion of 5% starch slightly depressed both intake and liveweight gain. Daily clean wool production was significantly increased at starch levels higher than 20% and ranged from 5.3 to 7.5 g/day with 0 and 40% starch respectively. Increasing levels of starch had little effect on apparent nitrogen digestibility, but resulted in a substantial increase in nitrogen retention through a reduction in urinary nitrogen excretion. Serum urea levels fell from a mean of 42 mg/100 ml during the first week to 31 mg/100 ml during subsequent periods, with no significant differences between diets. With the general exception of potassium, mineral balances were positive or close to zero throughout the experiment.

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