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Department of Animal Science: Faculty Publications

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Full-Text Articles in Animal Sciences

Type Appraisal: Ii. Variation In Type Traits Due To Sires, Herds, And Years, H. D. Norman, L. Dale Van Vleck Mar 1971

Type Appraisal: Ii. Variation In Type Traits Due To Sires, Herds, And Years, H. D. Norman, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Variance components were estimated from type appraisal data to determine the importance of year, herd, sire, and herd x sire effects upon 49 body, udder, and management traits. Estimates were based on over 16,000 appraisals on daughters of Holstein artificial insemination sires. The variation explained by these effects never exceeded 34% of the total variance. Year effects were almost nonexistent (-2 to 3%). Herd effects were small for all traits except feeding speed, body weight, intensity and persistency of edema, and ketosis, and never exceeded 25%.

Most appraisal traits had low heritabilities. The estimate for milking speed was .23 while …

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Type Appraisal: I. Effects Of Age And Stage-Of-Lactation On Type Ratings, H. D. Norman Mar 1971

Type Appraisal: I. Effects Of Age And Stage-Of-Lactation On Type Ratings, H. D. Norman

Department of Animal Science: Faculty Publications

Dairy cattle type appraisal data were examined to determine whether body and udder conformation and management ratings were affected by age and period of lactation at appraisal. Data were collected from 1961 to 1968 from 188 herds having over 23,000 Holstein type appraisals. The body and udder traits were scored by scheduled appraisers, and the management traits were coded by each dairyman. Some of the 35 original traits were composed of more than one descriptive characteristic and, as a result, 49 renamed traits were derived from these.

A model was selected that considered years and herds as well as cow …

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Type Appraisal: Iii. Relationships Of First Lactation Production And Type Traits With Lifetime Performance, H. D. Norman, L. Dale Van Vleck Mar 1971

Type Appraisal: Iii. Relationships Of First Lactation Production And Type Traits With Lifetime Performance, H. D. Norman, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Phenotypic and genetic correlations were estimated between 48 type appraisal traits and first lactation milk production to determine the importance of appraisal traits in a breeding program from 5,024 records from the New York type appraisal program. Most phenotypic correlations among the type traits were near zero. Depth of udder was the appraisal trait having the highest correlation with first lactation milk (.27) and fat (.23). Multiple correlations of all appraisal traits with first lactation milk and fat were .44 and .40.

Correlations with lifetime variables were calculated from 2,068 records meeting time qualifications. Of the first lactation variables, milk …

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Genetic And Environmental Aspects Of Udder Infections, J. W. Wilton, L. Dale Van Vleck, R. W. Everett, R. S. Guthrie, S. J. Roberts Jan 1971

Genetic And Environmental Aspects Of Udder Infections, J. W. Wilton, L. Dale Van Vleck, R. W. Everett, R. S. Guthrie, S. J. Roberts

Department of Animal Science: Faculty Publications

Information on the presence or absence of bacterial infections and abnormal secretions in each quarter of cows in their initial survey on the New York State Veterinary College Mastitis Program was used to obtain several criteria of udder infection. Year-season and stage of lactation effects were statistically significant for several criteria of infection in first, second, and later lactation groups but did not explain much of the variation in any infection criterion. Age within first and second lactation group also accounted for little of the variation in infection although age within later lactations accounted for up to 5% of the …

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Selection On Test-Day Fat Percentage And Milk Production, J. F. Keown, L. Dale Van Vleck Aug 1970

Selection On Test-Day Fat Percentage And Milk Production, J. F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Selection procedures which weight equally each test day sample may not be optimum for selection on test days.

Monthly test day data from 63,300 records of artificially sired Holsteins with 305-day lactations were from the New York Dairy Records Processing Laboratory. Heritabilities (h 2) were estimated intraherd-year- season from sire components of variance for monthly test day production within lactations 1, 2, 3, 4, and 5 or greater. Heritability of lactation fat percentage decreased from .60 to .40 from first to fifth lactations whereas heritability for 305-day milk yield increased slightly from .25 to .37 with succeeding lactations. Heritabilities for …

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Misidentification And Sire Evaluation, L. Dale Van Vleck Jun 1970

Misidentification And Sire Evaluation, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Biases in evaluation of sires result from misidentified records in the sire group averages used for sire evaluation. The bias increases as the fraction of misidentified cows increases. Use of variance components estimated from misidentified records also contributes to the bias. Estimates of the correlation between estimated and true genetic value, as well as estimates of genetic progress due to selection, are biased when misidentified records are included in sire group averages.

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Misidentification In Estimating The Paternal Sib Correlation, L. Dale Van Vleck Apr 1970

Misidentification In Estimating The Paternal Sib Correlation, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Misidentification of sires of cows in paternal half-sib analyses of variance biases the estimate of heritability downward. Four models o£ misidentification yield approximately the same reductions in estimated heritability. The reduced estimates are approximately p2 of the actual heritability where p is the fraction of cows whose sire is correctly identified. The reduction in heritability estimates from daughter-dam regression would be to a fraction, p, of the actual heritability where p is the fraction of dams correctly identified. Empirical paternal sib analyses of New York Dairy Herd Improvement Holstein records suggest that misidentification is more common among grade cows …

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Effects Of Age, Herd, And Herd Status On Classification Scores Of Jersey Cattle, H. L. Barr, H. W. Carter, L. Dale Van Vleck Apr 1970

Effects Of Age, Herd, And Herd Status On Classification Scores Of Jersey Cattle, H. L. Barr, H. W. Carter, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Classification was arranged for herds belonging to the official Jersey program concurrently with classification for Jersey research herds. Herds were categorized as official, registered research and grade research. Cattle were also grouped as 2 year olds, 3 to 4 year olds and 5 year olds.

Differences for herd status were significant (P < .05) for all type traits except stature, breed character, feet and legs and fore udder. Research cattle scored higher only in dairy character and udder quality. Differences between registered research and grade research cattle were not significant.

Differences for age were significant for all traits except feet and legs, mammary and rear udder. Five year-olds scored highest in final score, general appearance, stature, breed character, back and rump, and chest and barrel. The traits relating to mammary system were scored higher on younger cows.

For …

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Influence Of Dietary Supplements Of Cholesterol And Vitamin D On Certain Components Of The Blood And Body Of Growing-Finishing Swine, M. H. Jurgens, E. R. Peo, Jr. Jan 1970

Influence Of Dietary Supplements Of Cholesterol And Vitamin D On Certain Components Of The Blood And Body Of Growing-Finishing Swine, M. H. Jurgens, E. R. Peo, Jr.

Department of Animal Science: Faculty Publications

The American public has been made extremely conscious of the concept that saturated fat and cholesterol may be involved in atherosclerosis in man. Likewise, because of their content of cholesterol and saturated fatty acids, animal products have become engrossed in a controversy concerning their role in the atherogenic process. No definite conclusions have been made in this area and until further research advances in the field of atherosclerosis, the animal scientist may have to concern himself with modifying the animal product in such a way that it will be more acceptable to the American public. The degree to which this …

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Effect Of Feeding-Fasting Interval On Finishing Pigs: Weight Gain, Feed Utilization And Physical And Chemical Carcass Measurements, T. L. Veum, W. G. Pond, L. Dale Van Vleck, E. F. Walker Jr., L. Krook Jan 1970

Effect Of Feeding-Fasting Interval On Finishing Pigs: Weight Gain, Feed Utilization And Physical And Chemical Carcass Measurements, T. L. Veum, W. G. Pond, L. Dale Van Vleck, E. F. Walker Jr., L. Krook

Department of Animal Science: Faculty Publications

Thirty-two Yorkshire pigs (49 kg body weight, 108 days of age) were used to determine the effect of feeding-fasting interval on rate of body weight gain, feed utilization and carcass and organ measurements at a slaughter weight of approximately 90 kilograms. Treatments were: (1) Continuous ad libitum feeding,(2) ad libitum 1 day, fasted on alternate days, (3) ad libitum 1 day, fasted 2 days, (4) ad libitum 1 day, fasted 3 days. Average daily gain was reduced progressively as severity of the fasting-feeding interval was increased. Efficiency of feed utilization, likewise, was reduced as the severity of feed restriction increased, …

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Influence Of Dietary Supplements Of Vitamin D3 And Various Fats On Cholesterol And Fatty Acid Composition Of The Blood And Body Of Growing-Finishing Swine, M. H. Jurgens, E. R. Peo, Jr., P. E. Vipperman, Jr., R. W. Mandingo Jan 1970

Influence Of Dietary Supplements Of Vitamin D3 And Various Fats On Cholesterol And Fatty Acid Composition Of The Blood And Body Of Growing-Finishing Swine, M. H. Jurgens, E. R. Peo, Jr., P. E. Vipperman, Jr., R. W. Mandingo

Department of Animal Science: Faculty Publications

Previous work at this station suggested that vitamin D2, when fed with or without dietary cholesterol, depressed blood cholesterol levels of swine (Jurgens, Peo and Vipperman, 1967) and rats (Jurgens, Blunn and Peo, 1968). While not proven to be the cause, blood cholesterol levels have been used as one of the main criteria to estimate the development of atherosclerosis in man (Rabinowitz, Meyerson and Wohl, 1960; Swell, Law and Treadwell, 1962). Several investigators have reported that supplementation of unsaturated fats (Ahrens et al., 1957; Okey and Lyman, 1957; Avigan and Steinberg, 1958; Peifer, 1966) and especially linoleic …

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Diammonium Citrate And Diammonium Phosphate As Sources Of Dietary Nitrogen For Growing-Finishing Swine, G. F. Wehrbein, P. E. Vipperman Jr., E. R. Peo, Jr., P. J. Cunningham Jan 1970

Diammonium Citrate And Diammonium Phosphate As Sources Of Dietary Nitrogen For Growing-Finishing Swine, G. F. Wehrbein, P. E. Vipperman Jr., E. R. Peo, Jr., P. J. Cunningham

Department of Animal Science: Faculty Publications

Many scientists are concerned about the possibility Of a protein shortage in the near future. Since the pig will be placed in direct competition with man for many of the proteins presently used in feeds, it has become increasingly important to determine if other sources of nitrogen can serve as a replacement for some of the non-essential amino acid nitrogen in natural proteins.

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Genetic Aspects Of Calving Ease, James S. Brinks Jan 1970

Genetic Aspects Of Calving Ease, James S. Brinks

Department of Animal Science: Faculty Publications

Several trends in cattle production and marketing are becoming evident. Leaner and perhaps heavier muscled slaughter cattle will be in demand through the chain from consumers back through retailers, packers, feeders and finally the producers. Emphasis on growth in the feedlot will continue. Thus, the feedlot and carcass characteristics desired point towards fairly large, heavier muscled cattle. At the producer level, increased emphasis is being placed on matching cow size, milk level, and overall biological type to available resources. Thus, the trend for maternal herds in the Great Plains point towards an adapted, probably moderate size, and milking cow that …

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Effect Of Feeding-Fasting Interval On Finishing Pigs: Blood Urea And Serum Lipid, Cholesterol And Protein Concentrations, T. L. Veum, W. G. Pond, E. F. Walker Jr., L. Dale Van Vleck Jan 1970

Effect Of Feeding-Fasting Interval On Finishing Pigs: Blood Urea And Serum Lipid, Cholesterol And Protein Concentrations, T. L. Veum, W. G. Pond, E. F. Walker Jr., L. Dale Van Vleck

Department of Animal Science: Faculty Publications

A system of restricted feeding in which feed is entirely withheld for intervals of 24, 48 or 72 hr. following a 24-hr. period of ad libitum feeding in continuous sequence throughout the finishing period depresses weight gain and efficiency of feed utilization in direct relation to duration of the fasting period and has marked associated effects on carcass measurements, gland and organ weights and a small effect on fatty acid composition of the back fat (Veum et al., 1970). Cohn (1963) and Leveille and Hanson (1965, 1966) have shown marked changes in metabolism of nutrients and in body composition associated …

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Sire Effects In Different Housing Systems, G. R. Wiggans, L. Dale Van Vleck Oct 1969

Sire Effects In Different Housing Systems, G. R. Wiggans, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Over 1,000 Holstein herds in New York's Dairy Herd Improvement Cooperative were classified as to housing system. The two housing systems considered were stanchions and free stalls. First-lactation records (21,285) produced in these herds by daughters sired through artificial insemination were analyzed to determine if housing system would affect sire ranking. The study covered records started in 1964 through 1967.

The sire component of variance was estimated for each housing system for deviations of these records from their adjusted herdmate averages. The covariance between the means of daughters in each housing system was computed. The genetic correlation between sire effects …

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Variation Within Herds Under Different Housing Systems, G. R. Wiggans, L. Dale Van Vleck Aug 1969

Variation Within Herds Under Different Housing Systems, G. R. Wiggans, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

New York Holstein herds (1,152) including 75,875 cows were classified by housing system (stanchions, free stalls, and other combinations). Records initiated in these herds from 1964 to 1968 were used to determine the degree to which housing type might affect variance of milk production records in herds with 45 or more cows.

The within-herd variances by lactation for each housing system in each year-season were examined by Bartlett's test for nonhomogeneity among housing systems. Records in the stanchion systems were less variable than those in free-stall systems. This difference was not large enough to require adjustment for type of housing …

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Changes In Body Weight And Composition Of Adult Nongravid Female Rats Deprived Of Dietary Protein, W. G. Pond, L. Dale Van Vleck, E. F. Walker Jr., C. F. Eisenhard, J. R. O'Connor Mar 1969

Changes In Body Weight And Composition Of Adult Nongravid Female Rats Deprived Of Dietary Protein, W. G. Pond, L. Dale Van Vleck, E. F. Walker Jr., C. F. Eisenhard, J. R. O'Connor

Department of Animal Science: Faculty Publications

Seventy-six young adult nongravid female rats of the Carworth strain were used in two experiments to study the effect of dietary protein deprivation on body weight, feed consumption, body composition and serum protein concentration. Semipurified diets containing glucose, corn oil, vitamins and minerals with or without casein (protein-free = PF, 14% casein = C) were fed ad libitum in both experiments to rats caged in individual wire-bottom cages. Feeding the PF diet for up to 26 days resulted in a continuous weight loss over the entire period. The average loss in body weight as a percentage of initial weight of …

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Relationship Between Type Traits And Longevity Of Daughters Of Hew York Holstein Sires, L. Dale Van Vleck, D. B. Filkins, H. W. Carter, C. L. Hart Jan 1969

Relationship Between Type Traits And Longevity Of Daughters Of Hew York Holstein Sires, L. Dale Van Vleck, D. B. Filkins, H. W. Carter, C. L. Hart

Department of Animal Science: Faculty Publications

The percentage of 40 or more daughters having four lactations of 81 New York Holstein artificially insemination sires was correlated with the percentage of daughters in 66 type categories measured in the first lactation and their average first-lactation milk yield. Multiple regression on these type and production traits accounted for 92% of the variation in percentage of daughters having four lactations. A subset of 33 traits accounted for 82% of the variation. Traits with the largest standard partial regressions for longevity were milk production (.41), udder edema (.87 and .71), deep body (.53), medium upstandingness (.41), fore udder attachment (--.86 …

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Levels Of Calcium And Phosphorus For Growing-Finishing Swine, G. W. Libal, E. R. Peo, Jr., R. P. Andrews, P. E. Vipperman, Jr. Jan 1969

Levels Of Calcium And Phosphorus For Growing-Finishing Swine, G. W. Libal, E. R. Peo, Jr., R. P. Andrews, P. E. Vipperman, Jr.

Department of Animal Science: Faculty Publications

The calcium and phosphorus requirements of growing-finishing swine have not been satisfactorily resolved. Recently it was suggested that levels of calcium and phosphorus needed in diets of growing-finishing (G-F) swine for optimum growth and feed conversion may be different from those needed for optimum bone development (Miller et al., 1960; Lloyd et al., 1961; Rutledge et al., 1961; Combs et al., 1966). The problem of determining calcium and phosphorus requirements is further magnified by the observation of Chapman et al. (1955) that G-F swine do not utilize plant phosphorus as efficiently as inorganic phosphorus. In …

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Effects Of Dietary Levels Of Manganese And Magnesium On Performance Of Growing-Finishing Swine Raised In Confinement And On Pasture, A. J. Svajgr, E. R. Peo, Jr., P. E. Vipperman, Jr. Jan 1969

Effects Of Dietary Levels Of Manganese And Magnesium On Performance Of Growing-Finishing Swine Raised In Confinement And On Pasture, A. J. Svajgr, E. R. Peo, Jr., P. E. Vipperman, Jr.

Department of Animal Science: Faculty Publications

Research on the optimum dietary levels of manganese and magnesium for growing swine is limited. Johnson (1940) fed pigs diets containing 0.3 to 100 ppm Mn and observed no difference in growth rate. Similarly, Liebholz, Speer and Hays (1962) found that 0.4 ppm Mn in the diet of baby pigs was sufficient to support maximum growth. A level of 4,000 ppm Mn was not toxic but growth rate of the pigs was reduced.

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Growth Of Yorkshire Suckling Pigs, W. F. Gipp, W. G. Pond, L. Dale Van Vleck, P. D. Miller Jan 1969

Growth Of Yorkshire Suckling Pigs, W. F. Gipp, W. G. Pond, L. Dale Van Vleck, P. D. Miller

Department of Animal Science: Faculty Publications

The birth weights and daily liveweights for 87 male and 99 female pigs reared under drylot conditions were obtained over a 3-week period and used to construct a growth curve for the very young male and female pig. Analysis of variance was used to test litter and sex main effects and the litter x sex interaction effect on liveweight. The daily standard deviations of the 186 pig sample were calculated and are presented in graphic form. No significant difference between the growth of male and female pigs of this young age were found. The average birth and first-, second- and …

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Sire Evaluation For Economic Merit, J. W. Wilton, L. Dale Van Vleck Jan 1969

Sire Evaluation For Economic Merit, J. W. Wilton, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Procedures for selecting sires are compared in terms of making maximum genetic progress in economic merit. A quadratic index, a simplified form of the quadratic index and a linear index to evaluate economic merit, and a restricted index to improve milk as much as possible while holding milk fat percentage constant, all result in nearly equal expected genetic progress in economic merit. Selection for milk production results in less expected genetic progress in economic merit, the extent of the decrease depending on the economic value of milk production at a given base test and on the test differential.

Evaluation of …

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Measuring Milk Flow Of Dairy Cows, G. H. Schmidt, L. Dale Van Vleck Jul 1968

Measuring Milk Flow Of Dairy Cows, G. H. Schmidt, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Milk flow measurements on 124 cows were analyzed to determine how they are affected by vacuum level, pulsation rate, pulsation ratio of the milking machine, and the breed, age, stage of lactation, and milk yield of the cow. Average rate of flow prior to machine stripping, yield during the first minute, and yield during the first 2 rain of milking were highly correlated with maximum rate of milk flow. These measurements were significantly increased by days in milk, vacuum level, pulsation rate, pulsation ratio, and total yield. Age at calving had a slight effect on yield during the first minute …

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Relative Selection Efficiency In Retrospect Of Selected Young Sires, L. Dale Van Vleck Jul 1968

Relative Selection Efficiency In Retrospect Of Selected Young Sires, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The indexes used in retrospect in estimating one-half genetic value (daughter superiority) of progeny of 541 Holstein matings contracted by Eastern Artificial Insemination Cooperative were determined. A set of information on relatives to be complete would include records of paternal sisters, the dam, paternal sisters of the dam, maternal sisters, maternal grandam, and maternal sisters of the dam. The average index of daughter superiority for the 541 progeny was between 406 and 455 kg of milk, depending on which combination of relatives was used. Paternal sisters accounted for 45 to 50% of the total daughter superiority. Records of maternal relatives, …

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Selection Of Dairy Cows For Economic Merit, J. W. Wilton Apr 1968

Selection Of Dairy Cows For Economic Merit, J. W. Wilton

Department of Animal Science: Faculty Publications

Selection of dairy cows for economic merit requires the use of a model for genetic merit that involves the cross-product of the genetic values for milk and milk fat percentage. A linear and a quadratic index are described as procedures for selection of cows, the linear index being b1pm + b2pt and the quadratic index being b1pm + b2pt + b2pm2 + b4pt2 + b5pmpt where pm and pt are the phenotypic deviations …

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Variation Of Milk Records Within Paternal-Sib Groups, L. Dale Van Vleck Mar 1968

Variation Of Milk Records Within Paternal-Sib Groups, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Differences between daughter-dam and paternal sib estimates of heritability of first lactation milk yield have not been explained for New York data. Deviations of first lactation records from herdmate means of 155,070 artificially sired Holsteins were analyzed to examine the effect of unequal within group variances on the paternal sib estimate of heritability. The statistical model used to describe the data was yy = μ + si + eiy with σ 2yi = σ 2s + = σ2ei. Estimates of the within sire-group variances, σ1 2ei, were heterogeneous (P …

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Weight Gain And Carcass Measurements Of Pigs From Gilts Fed Adequate Vs. Protein-Free Diets During Gestation, W. G. Pond, J. A. Dunn, G. H. Wellington, J. R. Stouffer, L. Dale Van Vleck Jan 1968

Weight Gain And Carcass Measurements Of Pigs From Gilts Fed Adequate Vs. Protein-Free Diets During Gestation, W. G. Pond, J. A. Dunn, G. H. Wellington, J. R. Stouffer, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Fifty-two weanling pigs from six litters(Pond et al., 1968) were fed a standard 18% protein corn-soybean meal diet from weaning to slaughter. The six litters were from gilts paired on the basis of parturition date so that one gilt fed the control diet and one fed the “protein-free” diet (0.5% protein) from week 4 of pregnancy to parturition made tip each pair. Each dam was fed the control diet throughout lactation and nursed one-half of her own litter and one-half of a pairmate’s litter resulting from reciprocal transfer of one-half of each litter at birth. Individual bodyweight gains and feed …

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Relationships Among The Parameters Of Milk Production, Constituent Production, And Constituent Percentage, J. W. Wilton, L. Dale Van Vleck Jan 1968

Relationships Among The Parameters Of Milk Production, Constituent Production, And Constituent Percentage, J. W. Wilton, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

A method of finding the parameters pertaining to one of the variables of milk production, constituent production, and constituent percentage when the parameters pertaining to the two other variables are known is presented. The method is based on the expectation of products of random variables. This method and the delta approximation method are compared to sampling estimates from simulated data.

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Effects Of Dietary Safflower Oil Or Hydrogenated Coconut Oil On Growth Rate And On Some Blood And Tissue Components Of Pigs Fed A Fat-Free Diet, G. M. Babatunde, W. G. Pond, L. Krook, L. Dale Van Vleck, E. F. Walker Jr., P. Chapman Jul 1967

Effects Of Dietary Safflower Oil Or Hydrogenated Coconut Oil On Growth Rate And On Some Blood And Tissue Components Of Pigs Fed A Fat-Free Diet, G. M. Babatunde, W. G. Pond, L. Krook, L. Dale Van Vleck, E. F. Walker Jr., P. Chapman

Department of Animal Science: Faculty Publications

The effects of feeding diets containing no fat, 3% hydrogenated coconut oil (HCO) or graded levels (0.1, 0.5, 1.0 or 3%) of safflower oil (SO) on serum cholesterol, lipids and protein level; on total heart and liver cholesterol and lipid level and on growth rate and skin condition were studied in weanling Yorkshire and Yorkshire x Hampshire pigs. Pigs fed the fat-free diet for 21 weeks developed severe skin lesions not observed in pigs fed HCO diets. Highly significant elevation of serum, liver and heart lipid and liver cholesterol, and a highly significant depression of total serum protein were observed …

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First Classification Score And Length Of Herd Life, L. W. Specht, H. W. Carter, L. Dale Van Vleck Apr 1967

First Classification Score And Length Of Herd Life, L. W. Specht, H. W. Carter, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The relationship of first score and length of life in the herd was measured in Holstein females two or three years of age at first classification. The regression of herd life (number of times classified) on the first over-all type score (nearly all values were between 65 and 90 points) was 1.7 months. Correlation between first classification score and herd life was approximately 0.2, indicating that less than 5% of the variation in herd life could be attributed to the relationship between first score and herd life.

Differences among herds accounted for about 10% of the total variance in overall …

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