521. Normal variations in the rate of machine milking

Dodd, F. H.

doi:10.1017/s0022029900006956

Cited by 31 publications

(14 citation statements)

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“…Yields and rates both declined through lactation. Other researchers (1,3,9) have reported that peak and average rates on a whole udder basis declined throughout lactation.…”

Section: Resultsmentioning

confidence: 93%

“…Variation in total milking time may be an important labor factor in some milking parlors. Rate of flow declines throughout lactation for the whole udder (1,3,10). Smith et al (10) investigated milk flow traits for whole udder and found maximum rate, duration of maximum rate, time to strip, strip time, total time, and average rate were affected by lactation, machine, and interaction of stage of lactation by machine.…”

Section: Introductionmentioning

confidence: 99%

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Sources of Variation in Quarter Milk Flow Measures

Rothschild

Bodoh

Pearson

et al. 1980

Journal of Dairy Science

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An individual quarter milker was used to measure milk yields at staggered 20-s intervals from 198 Holstein cows in the Beltsville Agricultural Research Center herd. Several flow rate variables were calculated. The 2792 quarter samples of milk yield were taken during afternoon milkings. Yields and rates of individual quarters were examined as were effects of lactation, stage of lactation, machine, and cow. Differences between rear and front quarters were .78 kg for yield and .12 kg/min for maximum rate. Differences between left and right quarters were .02 kg/min for maximum rate and .10 kg for yield during the period of maximum rate. Yields departed from front-rear and left-right side patterns. This lack of symmetry, interactions of front-rear by side, for the yield traits may have been from permanent environmental causes such as developmental error, mastitis, or injury. Cow effects were important for all traits as were the effects of lactation, stage of lactation, and machine for many of the traits. Repeatabilities were .63 for maximum rate and .60 for average rate. Designers of milking machines may wish to account for differences between quarters in newer milking machines. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. ABSTRACTAn individual quarter milker was used to measure milk yields at staggered 20-s intervals from 198 Holstein cows in the Beltsville Agricultural Research Center herd. Several flow rate variables were calculated. The 2792 quarter samples of milk yield were taken during afternoon milkings, yields and rates of individual quarters were examined as were effects of lactation, stage of lactation, machine, and cow. Differences between rear and front quarters were .78 kg for yield and .12 kg/min for maximum rate. Differences between left and right quarters were .02 kg/min for maximum rate and .10 kg for yield during the period of maximum rate. Yields departed from front-rear and leftright side patterns. This lack of symmetry, interactions of front-rear by side, for the yield traits may have been from permanent environmental causes such as developmental error, mastitis, or injury. Cow effects were important for all traits as were the effects of lactation, stage of lactation, and machine for many of the traits. Repeatabilities were .63 for maximum rate and .60 for average rate. Designers of milking machines may wish to account

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“…Yields and rates both declined through lactation. Other researchers (1,3,9) have reported that peak and average rates on a whole udder basis declined throughout lactation.…”

Section: Resultsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Sources of Variation in Quarter Milk Flow Measures

Rothschild

Bodoh

Pearson

et al. 1980

Journal of Dairy Science

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“…The rate of milking, as one of the major factors determining the total time of machine-milking (Donald, 1960), has received considerable attention in the herd of the National Institute for Research in Dairying (Dodd and Foot, 1953;Dodd, 1953;Clough and Dodd, 1957). The rate of milking, as one of the major factors determining the total time of machine-milking (Donald, 1960), has received considerable attention in the herd of the National Institute for Research in Dairying (Dodd and Foot, 1953;Dodd, 1953;Clough and Dodd, 1957).…”

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confidence: 99%

“…The independent variables were total milking time, peak-flow rate, machine rate and overall milking rate as defined by Dodd (1953), and lactation length. The independent variables were total milking time, peak-flow rate, machine rate and overall milking rate as defined by Dodd (1953), and lactation length.…”

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confidence: 99%

A note on the relationship between the rate of machine-milking and milk production of Ayrshire heifers

Castle

Henderson

1971

Anim. Sci.

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SUMMARYRecords of milking rate, milk yield and milk composition were collected over 12 yr from 123 Ayrshire heifers in their first lactation in one herd. Three direct measures of milking rate, i.e. peak flow rate, machine rate and overall rate were closely correlated and each was also correlated with total lactation yield of milk. Milking rate accounted for only a very small part of the variation in fat and total solids percentages. The mean yield of milk per milking in early lactation was a better predictor of total lactation yield than was milking rate but, among animals giving the same early lactation yield of milk, the faster milkers gave higher lactation yields than the slower milkers.

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“…Most bull studs rate sire progeny groups according to milking speed to suggest relative ranking of labor and machine costs of milk harvest. Several workers have suggested the economic importance of milking speed in determining dairy profits (Colleau et al, 1971;Dodd, 1953;Johansson, 1961;Lamb, 1970;Politiek, 1968;Smith et al, 1974;and Wagner, 1974). Andrus and McGilliard (1975) (Dodd, 1953;Schmidt and VanVleck, 1969;Touchberry and Markos, 1970;Rothschild et al, 1980).…”

Section: Economicsmentioning

confidence: 99%

The effect of selection for milk yield on milk flow and udder measurements

Magid

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INTRODUCTION 1 REVIEW OF LITERATURE 3 MLlk Flow 3 Economics 3 Measurements of milk flow 4 Heritabilities 7 Repeatabilities 8 Adjustment factors 11 Age 13 Quarter milk flow 14 MLlk flow and udder characteristics 15 Milk flow and lactation yield 17 MLlk flow and mastitis 20 Udder and Teat Measurements Heritabilities Age Udder measurements and milk yield Udder measurements and mastitis Teat-End Shape DESCRIPTION OF DATA 38 Milk Flow 39 Udder and Teat Measurements Teat-End Shape Phenotypic Correlations 45 METHODS OF ANALYSIS 48 Mixed Model and Least-Squares Analyses 48 Repeatabilities 51 Heritabilities 52 Analysis of Teat-End Shape 54 2 Phenotypic Correlations and Maximum R Procedure Analyses 55 iii RESULTS AND DISCUSSION 57 Response in Milk Production Due to Selection 57 Measurements of MLlk Flow 57 Mixed model and least-squares analyses 57 Repea tabilitie s 74 Heritabilities 77 Phenotypic and genetic correlations 81 Udder and Teat Measurements 81 Mixed model and least-squares analyses 81 Repeatabilities 111 Heritabilities 113 Phenotypic and genetic correlations 116 Teat-End Shape 117 Phenotypic Correlations among Milk Flow, Udder Measure ments, Udder Health and Lactation Milk 138 Relationship between milk flow and lactation milk production 138 Relationship between milk flow and udder health 147 Relationship between udder and teat measurements and lactation milk yield Relationship between udder and teat measurements and udder health SUMMARY REFERENCES ACKNOWLEDGMENTS APPENDIX 8 .69 + .08 between peak rate and lactation milk yield, indicating substan tial genetic improvement in milking rate by selecting for milk production. Heritability estimates of 2-mln yield and 2-min yield adjusted for linear and quadratic effects of the total milking yield were found to be .17 and .27, respectively, by Moore et al. (1981). These estimates were found to be in agreement with Sharaby et al. (1979) of .25 and .24, respectively. Adjusting milking rate variables for linear and quadratic effects of lactation number and milk yield for the day of measurement, Tomaszewski and Legates (1972) found that estimates of heritability from 328 daughterdam pairs ranged from .17 to .39 for rate measurements. Genetic cor relations among rate measurements were near unity. Venge (1961) re ported that during the period of 4.5 + 1 month after calving, differences between progeny groups were most pronounced and gave a heritability of .40. Estimates of heritability of milking rate and milking time measure ments obtained by others are in Table 1. Estimates of heritability for measurements of milk flow from litera ture indicate that substantial genetic improvement of these traits can be gained by selection. Repeatabilities Measurements of milk flow were reported to be highly repeatable. Beck et al. (1951a) found very high repeatabilities (.80-.90) for peak flow, average rate of flow, and machine time, not only from one day to the next but also from week to week and between consecutive lactations. Brumby (1956) used thirteen sets of identical twins at simila...

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521. Normal variations in the rate of machine milking

Cited by 31 publications

References 9 publications

Sources of Variation in Quarter Milk Flow Measures

Sources of Variation in Quarter Milk Flow Measures

A note on the relationship between the rate of machine-milking and milk production of Ayrshire heifers

The effect of selection for milk yield on milk flow and udder measurements

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