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.

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 development of an automatic system for rearing lambs artificially

1971 ◽  
Vol 6 (5) ◽  
pp. 227-231 ◽  
Author(s):  
T. T. Treacher ◽  
P. D. Penning
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Automatic System ◽  
Meat Production ◽  
Feed Conversion ◽  
Artificial Rearing ◽  
The Past

The efficiency of meat production in sheep can be increased by achieving a larger litter size or by increasing the frequency of breeding to give, say, three litters in two years. The former approach demands the use of some method of artificial rearing which, in the past, has been a labour intensive operation. The authors describe and discuss a system which makes minimal demands on labour and appears to ensure both a satisfactory growth rate and efficient feed conversion.

On the behaviour in the field of small grain obtained by premature harvesting

1945 ◽  
Vol 35 (3) ◽  
pp. 177-183 ◽  
Author(s):  
E. S. J. Hatcher ◽  
O. N. Purvis
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Field Trial ◽  
High Growth ◽  
High Growth Rate ◽  
Field Conditions ◽  
Final Size ◽  
Percentage Survival ◽  
Rate Characteristic ◽  
Final Yield

1. By premature harvesting, as early as 5 days after fertilization, dwarf grains are obtained which will germinate readily and produce normal plants, even though grain size may be only 10% that of fully developed grain. Such plants tend to attain the same final size as those from mature grain. This paper deals with the growth under field conditions of dwarf grain with regard to survival during the winter, and final yield.2. Pot cultures with vernalized winter and spring varieties of rye, wheat, and barley have shown that the high growth rate characteristic of dwarf grain is not confined to the vegetative phase of growth, but is also manifested after the ear has developed. The fact emerges that dwarf grain can be successfully vernalized.3. A field trial is described using three size classes of grain (mature, medium, dwarf) with mean grain weights of 33·93, 23·56 and 10·23 mg. respectively. These were sown (i) at sowing rates of 2 and 3 bushels per acre, and (ii) at uniform spacings of approximately 200 and 300 grains per 9 ft. row. A subsidiary experiment with spacing of 1 ft. was also carried out.4. All classes of grain germinated well and survival during the winter was uniformly high in the equally spaced plots; with the close spacing of the dwarf grain at 2 and 3 bushels per acre (plots 11 and 12) percentage survival was somewhat reduced.5. The effect of grain size and spacing on time of flowering was negligible.

scholarly journals Implanting melatonin at lambing enhances lamb growth and maintains high fat content in milk

2021 ◽  
Author(s):  
José Alfonso Abecia ◽  
Silvia Luis ◽  
Francisco Canto
Keyword(s):  
Growth Rate ◽  
Milk Fat ◽  
High Growth ◽  
Total Solid ◽  
Fat Content ◽  
High Growth Rate ◽  
Solid Content ◽  
Artificial Rearing ◽  
Melatonin Treatment ◽  
Total Solid Content

Abstract Three experiments were designed to study the effects of melatonin implantation of ewes and lambs after lambing on the growth of lambs and milk quality throughout lactation. In experiment 1, 53 lambs either did (n = 28) or did not (n = 25) receive a subcutaneous 18-mg melatonin implant. In experiment 2, 55 lambs and their mothers either did (lambs: n = 28; ewes: n = 15) or did not (lambs: n = 27; ewes: n = 16) receive a melatonin implant. Milk samples were collected at 15, 30, and 45 d after lambing. In experiment 3, 16 lambs were separated from their mothers 24 h after birth, moved to an artificial rearing unit, and either did (n = 9) or did not (n = 7) receive a melatonin implant. In the three experiments, implants were inserted 24 h after lambing, and lambs were weighed (LW) weekly until weaning. Average daily gains (ADG) from birth to weaning were calculated. Melatonin treatment of lambs did not have a significant effect on LW at weaning or ADG, but lambs reared by implanted ewes in experiment 2 presented higher (P < 0.05) LW (± S.E.M.) at weaning and ADG than did lambs reared by control ewes. At day 45 of lactation, milk fat and total solid content were higher (P < 0.05) in implanted ewes than in control ewes. In conclusion, melatonin treatment of ewes at lambing induced a high growth rate of their lambs and increased the fat content of the milk; however, the direct treatment with melatonin of the lambs at birth did not have an effect in their growth rate.

Cattle temperaments in extensive beef herds in northern Queensland. 1. Factors affecting temperament

1988 ◽  
Vol 28 (6) ◽  
pp. 683 ◽  
Author(s):  
G Fordyce ◽  
RM Dodt ◽  
JR Wythes
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
High Growth Rate ◽  
Factors Affecting ◽  
Pregnancy Status ◽  
Beef Herds ◽  
Selection For

The temperaments of 170 bullocks and 240 cows from 2 commercial properties in northern Queensland were scored by rating their behaviours, especially movement, while they were handled in a crush and pound. High scores indicate poor temperaments. Brahman cross cattle had higher temperament scores than did Shorthorns (P< 0.05). The heaviest cattle tended to have the lowest scores, suggesting that selection for high growth rate may not result in poorer temperament. Horned cattle tended to have lower temperament scores than hornless cattle (P> 0.05), though it is suggested that any advantage to horned cattle may be outweighed by the production and husbandry advantages of the latter. There was no relationship between temperament scores and age, fatness and, in cows, pregnancy status.

Exploring SiC Growth Limitation of Vapor-Liquid-Solid Mechanism when Using Two Different Carbon Precursors

2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
High Growth Rate ◽  
Carbon Precursor ◽  
Growth Limitation ◽  
Vapor Liquid Solid ◽  
Partial Pressures ◽  
Vapor Liquid Solid Mechanism ◽  
Vls Growth ◽  
Vapor Liquid

Abstract. In this paper, conditions for obtaining high growth rate during epitaxial growth of SiC by vapor-liquid-solid mechanism are investigated. The alloys studied were Ge-Si, Al-Si and Al-Ge-Si with various compositions. Temperature was varied between 1100 and 1300°C and the carbon precursor was either propane or methane. The variation of layers thickness was studied at low and high precursor partial pressure. It was found that growth rates obtained with both methane and propane are rather similar at low precursor partial pressures. However, when using Ge based melts, the use of high propane flux leads to the formation of a SiC crust on top of the liquid, which limits the growth by VLS. But when methane is used, even at extremely high flux (up to 100 sccm), no crust could be detected on top of the liquid while the deposit thickness was still rather small (between 1.12 μm and 1.30 μm). When using Al-Si alloys, no crust was also observed under 100 sccm methane but the thickness was as high as 11.5 µm after 30 min growth. It is proposed that the upper limitation of VLS growth rate depends mainly on C solubility of the liquid phase.

Very High Growth Rate of 4H-SiC Using MTS as Chloride-Based Precursor

2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Dependence ◽  
Growth Rates ◽  
Molar Fraction ◽  
High Growth ◽  
High Growth Rate ◽  
Epitaxial Layers ◽  
Single Precursor ◽  
Very High

The chlorinated precursor methyltrichlorosilane (MTS), CH3SiCl3, has been used to grow epitaxial layers of 4H-SiC in a hot wall CVD reactor, with growth rates as high as 170 µm/h at 1600°C. Since MTS contains both silicon and carbon, with the C/Si ratio 1, MTS was used both as single precursor and mixed with silane or ethylene to study the effect of the C/Si and Cl/Si ratios on growth rate and doping of the epitaxial layers. When using only MTS as precursor, the growth rate showed a linear dependence on the MTS molar fraction in the reactor up to about 100 µm/h. The growth rate dropped for C/Si < 1 but was constant for C/Si > 1. Further, the growth rate decreased with lower Cl/Si ratio.

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