Multiple linear regression equations for the prediction of food intake in the laying fowl

Leeson, S.; Lewis, D.; Shrimpton, D. H.

doi:10.1080/00071667308416069

Cited by 33 publications

(8 citation statements)

References 21 publications

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“…The larger variation of BWCH in the second period (Table 1), as already found for EM output, seemed to be the cause for the smaller amount of feed explained by this trait in older hens. Leeson et al (1973) also reported larger values of similar size for young hens. Bentsen (1983a) found an average additional intake of 1.2 g feed/g BWCH when combining data over several strains and several periods.…”

Section: Influences On Feed Intakementioning

confidence: 67%

“…The periods were between 21 and 40 wk (Period 1) and between 41 and 60 wk (Period 2). This approach was used in similar investigations by Leeson et al (1973) and Hagger and Abplanalp (1978) among others, as well as in genetic investigations of residual feed consumption (Bentsen, 1983a) or residual feed efficiency (Bordas and Merat, 1981).…”

Section: Methodsmentioning

confidence: 99%

“…Estimates from an intercept model for additional feed consumption due to deviations in EM output given in the literature are variable. For brown egg layers, Leeson et al (1973) reported distinctly larger regression coefficients, but also smaller ones, depending on amount of data and age of hens. A slightly higher value than given in Table 2 was found by Bentsen (1983a).…”

Section: Influences On Feed Intakementioning

confidence: 99%

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Phenotypic and Genetic Effects on Feed Intake of Laying Hens in Different Years

Hagger

1991

Poultry Science

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Feed intake from 21 to 40 wk and from 41 to 60 wk of age of brown egg layers was analyzed. The full model contained BW, egg mass (EM) output, BW change (BWCH), and age at first egg as covariates in addition to effects of plumage condition class, sire, and dam. A reduced model contained the covariates only. Between 90S and 1,161, and 880 and 1,119 hens were available in the first and second periods, respectively. Averaged over 6 yr the full model explained 84 and 77%, the reduced model 73 and 63%, respectively, of the variance in feed consumption in the two periods. Regression coefficients for BW showed only a small variation between years as well as between periods. Variation was larger for the coefficients of EM and of BWCH. Larger coefficients were observed in the first period for both traits. The sequence of entering the reduced equation in a stepwise procedure was always BW, EM output, then BWCH. Averaged over 6 yr, the relative contribution of BW by its own to the accuracy of the regression model, was 68 and 60% in the two periods. Egg mass output then added 25 and 39%, and BWCH 7 and 2% in the first and second periods, respectively. The predictive value of the covariates changed with increasing age of the hens. A high average heritability of .48 could be estimated for the residual feed intake in both periods. This suggested enhanced selection response for efficiency.

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Section: Influences On Feed Intakementioning

confidence: 67%

Section: Methodsmentioning

confidence: 99%

Section: Influences On Feed Intakementioning

confidence: 99%

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Phenotypic and Genetic Effects on Feed Intake of Laying Hens in Different Years

Hagger

1991

Poultry Science

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“…Leeson et al (1973) fitted two separate multiple linear regression equations to data from a light hybrid stock and from two heavy hybrid stocks. When these equations were used to predict the feed consumption of other stocks of similar body weight, systematic deviations from realized feed consumption of 9.3-11.4% were observed.…”

Section: Residual Feed Consumptionmentioning

confidence: 99%

Genetic variation of energy partitioning in laying hens: causes of variation in residual feed consumption

Luiting

1990

World's Poultry Science Journal

111

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When multiple linear regression of feed consumption on metabolic body weight (MBW), body weight gain (BWG) and egg mass production (EM) is calculated between or within strains of laying hens, a standard deviation of 47-180 kJ metabolizable energy (ME) per day remains unexplained by these effects. This unexplained fraction, called residual feed consumption (RFC), has a heritability of O-8O0/o. A survey of the literature was performed to quantify this unexplained variation between strains and among individuals within strains of laying hens with respect to some energy metabolism parameters independent of MBW, BWG and EM. Genetic differences in ability to metabolize gross feed energy are found to be of limited magnitude; the coefficient of variation is 1-3%. From calorimetric experiments, the ran e of heat production (HP) between strains is found to be 44-118 kJ kg-' s7' d-' ; variation among individuals within strains is of the same magnitude (standard deviation: 16-125 kJ kg-0.75 d-I). The range of maintenance requirements (ME,) is reported to be 41-113 kJ kg-0,75 d-'; standard deviation among individuals is 23-80 kJ kg-0.75 d-'. Variation of heat increment of production (constituting the difference between HP and ME,) seems to be small. The range of fasting heat roduction (FHP) between strains of laying hens appears to be 18-130 kJ kg-'qR d-l, whereas the standard deviation among individuals has again the same magnitude (22-51 kJ kg-0+75 d-' 1. It is concluded that variation of heat increment of maintenance (ME, -FHP) is small. The main component of HP variation and of RFC variation seems to be the variation of ME, : differences in physical activity, feathering density, basal metabolic rate, area of nude skin (comb, wattles, legs), body temperature and body composition. Net energy per g EM does not play an important role in variation of RFC.

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“…5671 of the Maryland Agricultural Experiment Station (Department of Poultry Science). Leeson et al (1973) found that the Byerly (1941) equation predicts feed intake about 15% higher than observed feed intake for many currently used commercial hybrid laying strains. They reported a partition equation describing feed intake.…”

mentioning

confidence: 93%

Feed Requirements for Egg Production

et al. 1980

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Data for individual feed intake, liveweight, and egg production were recorded for five genetically different groups of 40 pullets each during 10 test periods of 28-days each. Average ambient temperature at cage level varied from 6.7 C during January to 21.1 C during June. A 2890 kcal/kg metabolizable energy (ME) diet with 16% crude protein (CP) was fed ad lib. Average egg production for the Small Leghorns (SL) was about 60%, for white-egg hybrids (WL) about 75%, for brown-egg hybrids (BL) about 72%, for female line broiler breeders (BB) about 48%, and for broiler-cross pullets (B) about 51%. Average grams liveweight and grams feed intake per hen day were: SL, 1426 and 83.7; WL, 1809 and 104.9; BL, 2610 and 122.9: BB, 4197 and 156.2; and B, 4158 and 167.7.Partition equations which describe the data for SL, WL, BL, and BB, assuming 70% efficiency of use of feed ME for maintenance, tissue formation, and egg formation were: F = (.534 -.004T)W .653 + 2.76AW + .80EM and F = (.259 -.00259T)W-75 + 2.76AW + .80EM. Similar equations for B, assuming 65% efficiency use of ME, are: F = (.589 -.0044T)W°5 3 + 2.9AW + .85EM and F = (.275 -.00275T)W-75 + 2.9AW + .85EM. The terms are: F = grams feed/hen day; T = ambient temperature in °C; W = grams liveweight; AW = grams daily change in liveweight; EM = grams egg mass per hen day.Equations which assume 70% efficiency of use of ME are shown to predict feed intake of a diet containing 2890 kcal of apparent ME per kilogram for white and brown-egg layers and broilerbreeder pullets varying in individual body weights from about 1 to 5 kg. Equations, assuming 65% energetic efficiency, describe feed intake for a group of broiler-cross pullets. (

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Multiple linear regression equations for the prediction of food intake in the laying fowl

Cited by 33 publications

References 21 publications

Phenotypic and Genetic Effects on Feed Intake of Laying Hens in Different Years

Phenotypic and Genetic Effects on Feed Intake of Laying Hens in Different Years

Genetic variation of energy partitioning in laying hens: causes of variation in residual feed consumption

Feed Requirements for Egg Production

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