scholarly journals Comparison of mathematical and comparative slaughter methodologies for determination of heat production and energy retention in broilers

2020 ◽  
Vol 99 (6) ◽  
pp. 3237-3250 ◽  
Author(s):  
S.A.S. van der Klein ◽  
J.A. More-Bayona ◽  
D.R. Barreda ◽  
L.F. Romero ◽  
M.J. Zuidhof
Keyword(s):  
Heat Production ◽  
Energy Retention ◽  
Comparative Slaughter

The utilization of the energy of artificially dried grass prepared in different ways

1972 ◽  
Vol 78 (3) ◽  
pp. 441-447 ◽  
Author(s):  
F. W. Wainman ◽  
K. L. Blaxter ◽  
J. S. Smith
Keyword(s):  
Heat Production ◽  
Metabolizable Energy ◽  
Feed Consumption ◽  
Approximate Methods ◽  
Long Form ◽  
Energy Retention ◽  
Gross Energy ◽  
The Mean ◽  
Exact And Approximate Methods

SUMMARYSheep were given artificially dried grass either in the long form or as pellets, and their energy retention measured. Experiments were made both at the maintenance level of feeding and when feed was offered ad libitum. An analysis of the effects of preceding and current daily feed consumption on heat production was made and both exact and approximate methods of estimating the mean food intake to which a determination of heat production should be referred, are given. Pelleting the dried grass increased voluntary intake of dry matter by 27%, and the intake above maintenance by 59% The metabolizable energy of the grass was depressed by pelleting but the net availability of metabolizable energy for production was 52% for pellets and 40% for long material. The percentage of the gross energy supplied above maintenance which was retained was 28% greater for pellets than for long dried grass. The results show that energy retention of the sheep was almost doubled when the grass was pelleted.

scholarly journals Technical note: Assessment of the oxygen pulse and heart rate method using respiration chambers and comparative slaughter for measuring heat production of cattle

2016 ◽  
Vol 99 (11) ◽  
pp. 8885-8890 ◽  
Author(s):  
D.B. Oss ◽  
M.I. Marcondes ◽  
F.S. Machado ◽  
T.R. Tomich ◽  
M.L. Chizzotti ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heat Production ◽  
Technical Note ◽  
Oxygen Pulse ◽  
Rate Method ◽  
Comparative Slaughter

Hypothalamic obesity, brown adipose tissue, and sympathoadrenal activity in rats

1985 ◽  
Vol 248 (5) ◽  
pp. E607-E617 ◽  
Author(s):  
J. G. Vander Tuig ◽  
J. Kerner ◽  
D. R. Romsos
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Heat Production ◽  
Adult Rats ◽  
Guanosine Diphosphate ◽  
Bat Mitochondria ◽  
Sympathoadrenal Activity ◽  
Brown Adipose ◽  
Energy Retention ◽  
Ad Libitum

Obesity-producing, hypothalamic knife cuts and ventromedial hypothalamic (VMH) lesions in ad libitum-fed adult rats increased intake of a high-fat diet (123 and 130%) and energy retention (880 and 1,099%) during the 4-wk period postsurgery; even when pair fed to control rats, energy retention of the knife-cut and lesioned rats was still elevated (105 and 155%). Thermogenic capacity of brown adipose tissue (BAT), estimated from guanosine diphosphate (GDP) binding to BAT mitochondria, was unchanged in hyperphagic knife-cut and VMH-lesioned rats and was reduced approximately 50% when these rats were pair fed to controls. Urinary excretion of norepinephrine (NE) was approximately twofold higher in ad libitum-fed, knife-cut, and lesioned rats than in control rats; restriction of energy intake decreased NE excretion to control values. Rates of NE turnover in heart paralleled urinary NE excretion, whereas NE turnover in BAT was generally not increased in the hyperphagic rats. Urinary epinephrine excretion, an index of adrenal medullary activity, was depressed in all knife-cut and VMH-lesioned rats. Hyperphagia coupled with a lack of increased heat production in BAT causes gross obesity in ad libitum-fed, knife-cut, and VMH-lesioned rats, whereas obesity in pair-fed rats develops in part at least as a result of reduced heat production by BAT.

Energy exchanges of pregnant and lactating ewes

1964 ◽  
Vol 15 (1) ◽  
pp. 127 ◽  
Author(s):  
N McCGraham
Keyword(s):  
Heat Production ◽  
Nitrogen Loss ◽  
Metabolizable Energy ◽  
Energy Utilization ◽  
Carbon And Nitrogen ◽  
Direct Measurements ◽  
Heat Increment ◽  
Energy Retention ◽  
Energy Exchanges ◽  
Pregnant Ewe

At intervals throughout gestation, the energy, carbon, and nitrogen exchanges of four Merino ewes were determined with the aid of closed-circuit indirect calorimetry. Six similar but non-pregnant animals were studied at the same time. The food consisted of equal parts of lucerne and wheaten hay; half the sheep in each group were given a constant 600 g/day and half 900 g/day, and the non-pregnant ewes were fasted on one occasion. Free fatty acids, glucose, and ketones in the blood were also determined during the final stages of pregnancy. Balance measurements were continued during lactation, the ewes being given 1200 g food/day for the first month and 900 g for the second. The digestibility of the food was not affected by pregnancy or lactation, but urinary nitrogen loss decreased as pregnancy advanced and was least during lactation. Although a constant amount of food was eaten, the heat production of each pregnant animal increased throughout gestation. The heat increment of pregnancy at term was 90 kca1/24 hr/kg foetal tissue. The most direct measurements of oxygen uptake by the foetus in utero indicate much lower levels of heat production per kilogram of tissue; it is concluded that these are underestimates. The metabolic rate was unusually high immediately before parturition, and in two cases decreased to near non-pregnant levels 24 hr after lambing. The total energy retention of the ewes became smaller as pregnancy advanced, and in two cases was negative at term. Metabolizable energy was used for reproduction with a gross efficiency of 15–22% and a net efficiency of 13%. The metabolizable energy used per kilogram of foetus was approximately 10% of the maintenance requirement of the ewe herself. Daily energy utilization by the conceptus at term probably accounted for 70% of the glucogenic substances available from the food. There was no evidence of increased gluconeogenesis from protein by the pregnant ewe. The nutrition of the ewe during gestation affected lactation mainly in the first week or two. The data indicate that nitrogen intake rather than energy intake limited milk production. Irrespective of the amount of energy in the milk, the heat increment due to feeding was 20% smaller for lactating than for dry fatteningewes. It is suggested that efficient use of acetate by the mammary gland permits more efficient lipogenesis by other tissues.

The effect of method of conservation of grass and supplementation on energy and nitrogen utilization by lambs

1999 ◽  
Vol 133 (4) ◽  
pp. 409-417
Author(s):  
D. E. KIRKPATRICK ◽  
R. W. J. STEEN
Keyword(s):  
Energy Intake ◽  
Heat Production ◽  
Dry Matter ◽  
Agricultural Research ◽  
Nitrogen Retention ◽  
Linear Increase ◽  
Nitrogen Utilization ◽  
Metabolizable Energy ◽  
Agricultural Research Council ◽  
Energy Retention

An experiment was carried out in 1994 to examine energy and nitrogen utilization of lambs offered two contrasting grass-based diets. The two forages, which were from the same parent herbage, were grass silage and grass which was conserved by freezing. They were offered as sole diets or supplemented with either 250 or 500 g concentrates per kg total dry matter intake (DMI) to give a total of six experimental treatments. Seventy-two Dutch Texel × Greyface (Border Leicester × Blackface) lambs, consisting of 36 males which were initially 36 (S.D. 4·9) kg liveweight and 36 females which were initially 34 (S.D. 2·5) kg liveweight were used. Ensiling significantly increased apparent digestibility of dry matter, energy and nitrogen (P<0·001), but had no significant effect on methane energy loss as a proportion of gross energy intake, metabolizable energy intake (MEI), heat production, energy retained, efficiency of utilization of energy for growth (kg) or nitrogen retention. Supplementation of forage with concentrates resulted in a curvilinear decrease in heat production expressed as a proportion of MEI (P<0·05) and a linear increase in energy retention, expressed as an absolute value or as a proportion of MEI (P<0·05). Supplementation of forage tended to increase kg when calculated using Agricultural Research Council estimates of maintenance energy requirements, but had no significant effect when alternative estimates of maintenance were used. It is concluded that ensiling had no effect on efficiency of utilization of energy or nitrogen as measured by indirect calorimetry.

Energy exchanges of veal calves in relation to body weight, food intake and air temperature

1976 ◽  
Vol 23 (1) ◽  
pp. 35-42 ◽  
Author(s):  
A. J. F. Webster ◽  
J. G. Gordon ◽  
J. S. Smith
Keyword(s):  
Body Weight ◽  
Heat Loss ◽  
Heat Production ◽  
Live Weight ◽  
Milk Replacer ◽  
Total Heat Loss ◽  
Direct Calorimetry ◽  
Veal Calves ◽  
Air Temperatures ◽  
Energy Retention

SUMMARY1. Two series of energy balance trials were conducted with British Friesian veal calves. In the first, calves were given a milk replacer diet at three different planes of nutrition. In the second, calves were raised from about 80 to 180 kg at four air temperatures, 5°, 10°, 15° and 20°.2. The net efficiency of utilization of the milk replacer diet for growth was 0·72. The effect of body size on heat production in growing calves was best expressed by an exponent of body weight slightly but not significantly below W0·75.3. Measurements of heat production estimated from respiratory exchange and heat loss measured by direct calorimetry agreed exactly at all planes of nutrition. Heat production at zero energy retention was 675 kJ/kg W0·75 per 24 hr.4. Average daily live-weight gain and total heat loss were the same at all air temperatures. Changes during growth in the partition of heat loss into its sensible and evaporative components indicated that calves acclimated progressively to the air temperatures to which they were exposed.

scholarly journals Efficiency of utilization of volatile fatty acids for maintenance and energy retention by sheep

1979 ◽  
Vol 41 (3) ◽  
pp. 541-551 ◽  
Author(s):  
E. R. ØRskov ◽  
D. A. Grubb ◽  
J. S. Smith ◽  
A. J. F. Webster ◽  
W. Corrigall
Keyword(s):  
Fatty Acids ◽  
Butyric Acid ◽  
Heat Production ◽  
Volatile Fatty Acids ◽  
Latin Square ◽  
Nitrogen Retention ◽  
Live Weight ◽  
N Retention ◽  
N Utilization ◽  
Energy Retention

1. Two experiments were conducted with lambs sustained entirely by intragastric infusion of volatile fatty acids (VFA), protein, minerals and vitamins.2. In the first experiment to determine the effects of VFA on nitrogen retention four mixtures of VFA (B, C, D and E) were used containing acetic, propionic and butyric acid in the following molar proportions respectively: 45,45 and 10; 55,35 and 10; 65,25 and 10; 75, 15 and 10.The level of infusion was 836 kJ/live weight0.75 per d and the design was a 4 × 4 Latin square with 14 d periods. There were no significant differences in the N balance between the different mixtures of VFA though mixture B tended to give the highest N retention.3. Thirty-two lambs were used in the second experiment for measurements of heat production in closed- circuit respiration chambers. Six mixtures of VFA were used. These included mixtures B-E from Expt I and in addition two mixtures (A and F) containing acetic, propionic and butyric acid in the following molar proportions respectively: 35, 55 and 10; 85, 5 and 10. The heat production was measured both at 450 and 900 kJ/W0.75 per d, except for mixture F, where it was not possible to achieve a rate of infusion in excess of 675 kJ/W0.75 per d.4. The energy required for maintenance was determined to be 0.45±0.02 MJ/kg live weight0.75 per d regardless of the mixture used.5. The efficiency of utilization for fattening (kf) values for the six mixtures were 0.78, 0.64, 057, 0.61, 0.61 and 0.59 for mixtures A, B, C, D, E and F respectively. Only mixture A was significantly better utilized than the other mixtures. This mixture also gave the most efficient N utilization.6. It is concluded from this evidence that differences in k, for diets normally given to ruminants cannot be attributed to differences in utilization of volatile fatty acids.

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