ACCOUNTING FOR COVARIANCES AMONG TEST DAY MILK YIELDS IN DAIRY COWS

1987 ◽  
Vol 67 (3) ◽  
pp. 637-644 ◽  
Author(s):  
T. E. ALI ◽  
L. R. SCHAEFFER
Keyword(s):  
Regression Model ◽  
Gamma Function ◽  
Polynomial Function ◽  
Genetic Correlations ◽  
Quadratic Polynomial ◽  
Holstein Friesian ◽  
Lactation Curve ◽  
Observation Vector ◽  
Daily Milk ◽  
Friesian Cows

Daily milk weights from 1006 lactations on 775 Holstein-Friesian cows in 42 herds and monthly test-day weights from 102 540 lactations on 73 717 cows in 17 481 herd-year-seasons were used to study the influence of covariances among milk weighings within a lactation on three models for describing the shape of the lactation curve for individual cows. The models included a gamma function, an inverse quadratic polynomial function, and a regression model of yields on day in lactation (linear and quadratic) and on log of 305 divided by day in lactation (linear and quadratic). For each model, several variance-covariance matrices of the observation vector were used. Models were compared on the basis of squared deviations of predicted versus actual milk weights and on the correlation between predicted and actual weights through the lactation averaged over cows. Better predictions were observed when covariances among test-day yields were ignored while models could be ranked regression model, gamma function, and inverse quadratic polynomial function in order of best to worst. Heritability estimates for the parameters of the various models and for 305-d milk yield ranged from 0.11 to 0.30. Genetic correlations were estimated and predictions of correlated responses in 305-d yield from selecting on various combinations of parameters from each method were computed. The best combination of parameters of the gamma function gave a relative efficiency of 74.7% as compared to selection for 305-d yield alone. Key words: Lactation curves, covariances, Holsteins

scholarly journals Genetic and non genetic effects for lactation curve traits in Holstein-Friesian cows

2012 ◽  
Vol 55 (5) ◽  
pp. 450-457 ◽  
Author(s):  
I. Boujenane ◽  
B. Hilal
Keyword(s):  
Milk Yield ◽  
Genetic Correlations ◽  
Genetic Effects ◽  
Peak Time ◽  
Holstein Friesian ◽  
Lactation Curve ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Calving Season ◽  
Friesian Cows

Abstract. The objective of this study was to determine the genetic and non genetic effects on lactation curve traits determined by the incomplete gamma function of Wood (1967) for Holstein-Friesian cows in Morocco. Data analysed included 49262 monthly records of the test-day milk yield from 4888 lactations of 3932 cows at their 1st, 2nd or 3rd parity collected during 1990 and 1999 in 232 herds enrolled in the official milk recording. In general, lactation curve traits (A, B, C, peak time [Tmax], peak milk yield [Ymax], persistency and 305 day milk yield [MY305]) were affected by herd, parity, age at calving, season of calving and year of calving. Heritability estimates were low and varied from 0.01 for parameter A to 0.10 for Ymax. Genetic and phenotypic correlations among traits varied from −0.79 to 1.00 and from −0.80 to 0.96, respectively. Genetic correlations between MY305 and parameter C were negative, but those between MY305 and all the other lactation curve traits were positive. It was concluded that selection for high peak milk yield and persistency will result in higher 305 day milk yield.

scholarly journals A Study on Milk Yield, Fertility and Milk Quality Characteristics of Primiparous Red-Holstein and Holstein-Friesian Cows

2020 ◽  
Vol 8 (12) ◽  
pp. 2562-2569
Author(s):  
Atakan Koç ◽  
Ramazan Gürses
Keyword(s):  
Milk Yield ◽  
Milk Quality ◽  
Gestation Length ◽  
Holstein Friesian ◽  
Significant Difference ◽  
Days Open ◽  
Daily Milk Yield ◽  
Daily Milk ◽  
Friesian Cows

The aim of this study was to determine the reproductive characteristics, milk yield and milk quality of Primiparous Red-Holstein (RH) and Holstein-Friesian (HF) cows. For this aim, records and monthly taken milk samples of 83 RH and 14 HF raised on a farm in Aydın, Turkey were used. The averages of the first calving age (FCA), gestation length (GL), days open (DO), calving interval (CI), daily milk yield (DMY), 305-day milk yield (305-dMY), solid non-fat (SNF) and Log10 somatic cell count (Log10SCC) of milk were found to be 27.6±0.24 mo, 278.4±1.09 d, 144.0±7.12 d, 421.4±7.66 d, 22.7±0.21 kg, 6981±137.0 kg, 9.8±0.04% and 4.59±0.024 (38905 cells/ml), respectively. Except for DMY, the differences between the breeds were statistically insignificant for FCA, GL, DO, CI, 305-dMY, SNF and Log10SCC. DMY averages for RH and HF were 21.8±0.21 kg and 24.3±0.49 kg, respectively. The effect of season on FCA and the effect of lactation month on SNF and Log10SCC were also found to be statistically significant. Apart from DMY, not any significant difference was observed between RH and HF breeds in terms of the characteristics emphasized.

scholarly journals Estimation of heritability and genetic correlations between milk yield and linear type traits in primiparous Holstein-Friesian cows

2021 ◽  
Vol 50 ◽  
Author(s):  
Hasan Ismael ◽  
Dobrila Janković ◽  
Dragan Stanojević ◽  
Vladan Bogdanović ◽  
Snežana Trivunović ◽  
...  
Keyword(s):  
Milk Yield ◽  
Genetic Correlations ◽  
Linear Type ◽  
Holstein Friesian ◽  
Type Traits ◽  
Friesian Cows

Calculation of lifetime net income per year (LTNI/year) of Australian Holstein cows to validate the Australian profit ranking of their sires. 1. Genetic analyses and prediction of LTNI/year for cows still in the herd

2010 ◽  
Vol 50 (8) ◽  
pp. 757 ◽  
Author(s):  
M. Haile-Mariam ◽  
P. J. Bowman ◽  
M. E. Goddard
Keyword(s):  
Genetic Correlation ◽  
Genetic Correlations ◽  
Net Income ◽  
Productive Life ◽  
Holstein Friesian ◽  
Average Maximum ◽  
Relative Production ◽  
Fat Yield ◽  
Residual Correlations ◽  
Friesian Cows

Birth, calving, milk yield, somatic cell count (SCC) and culling data of 274 000 AI-bred Holstein Friesian cows that were born between 1990 and 1998 from ~3400 herds were used to calculate lifetime net income per cow per year (LTNI/year). The main objective of this study was to identify an early measure of LTNI/year so that data of cows that are still in the herd can be used for predicting LTNI/year of cows. LTNI/year of cows that are still in the herd was predicted from net income per year (NI/year) assuming cows are culled at the end of each lactation and other traits that are measured early in the life of cows. LTNI/year is defined as NI up to the end of parity 9 or culling or death of cows per year of productive life. On average maximum LTNI/year was attained by cows that completed seven lactations and LTNI/year of cows was the lowest if cows completed only one lactation. For cows that at least survived to second lactation LTNI/year increased with their NI/year at the end of the first parity and their relative production compared with their herdmates but decreased with the increase in average lactation SCC. The heritability of LTNI/year was 0.09 and had a genetic and residual correlation of 0.62 and 0.71, respectively, with productive life. The genetic correlation of LTNI/year with first-parity lactation protein and fat yield was high (~0.7 or above) but near zero with calving interval and lactation SCC. The genetic correlations between LTNI/year and NI/year up to the end of parity 1, 2, 3 and 4 were 0.84, 0.96, 0.99 and 1.0, respectively. The corresponding residual correlations were 0.55, 0.89, 0.96 and 0.98. The genetic correlation between actual and predicted LTNI/year based only on cows that did not complete their lifetime (cows still in the herd) were 0.93, 0.96, 0.98 and 0.99 by the end of the first, second, third and fourth parity, respectively. The corresponding residual correlations were lower at 0.54, 0.70, 0.80 and 0.86, respectively. Estimates of genetic correlations between LTNI/year and NI/year based on calvings that happened 1 (1.0) to 4 (0.98) years earlier were unity. The corresponding residual correlations were slightly lower at 0.92 if the calvings that occurred 4 years ago and before were used, and near unity (0.98) if calvings that happened 1 year ago and before were used. In conclusion, the high genetic correlation (0.9 or above) between LTNI/year of cows and measures of lifetime NI/year based on cows that had a shorter opportunity to complete their lifetime suggests that genetic evaluation for LTNI/year is feasible even if some of the cows have incomplete lifetime data.

scholarly journals Genetic and environmental parameters estimation for milk traits in Slovenian dairy sheep using random regression model

2013 ◽  
Vol 58 (No. 3) ◽  
pp. 125-135 ◽  
Author(s):  
A. Komprej ◽  
Š. Malovrh ◽  
G. Gorjanc ◽  
D. Kon ◽  
M. Kovač
Keyword(s):  
Regression Model ◽  
Protein Content ◽  
Milk Yield ◽  
Random Regression ◽  
Dairy Sheep ◽  
Milk Traits ◽  
Random Regression Model ◽  
Lactation Curve ◽  
Daily Milk Yield ◽  
Daily Milk

(Co)variance components for daily milk yield, fat, and protein content in Slovenian dairy sheep were estimated with random regression model. Test-day records were collected by the ICAR A4 method. Analysis was done for 38 983 test-day records of 3068 ewes in 36 flocks. Common flock environment, additive genetic effect, permanent environment effect over lactations, and permanent environment effect within lactation were included into the random part of the model and modelled with Legendre polynomials on the standardized time scale of days in lactation. Estimation of (co)variance components was done with REML. The eigenvalues of covariance functions for random regression coefficients were calculated to quantify the sufficient order of Legendre polynomial for the (co)variance component estimation of milk traits. The existing 13 to 24% of additive genetic variability for the individual lactation curve indicated that the use of random regression model is justified for selection on the level and shape of lactation curve in dairy sheep. Four eigenvalues sufficiently explained variability during lactation in all three milk traits. Heritability estimate for daily milk yield was the highest in mid lactation (0.17) and lower in the early (0.11) and late (0.08) lactation. In fat content, the heritability was increasing throughout lactation (0.08–0.13). Values in protein content varied from the beginning toward mid lactation (0.15–0.19), while they rapidly increased at the end of lactation (0.28). Common flock environment explained the highest percentage of phenotypic variability: 27–41% in daily milk yield, 31–41% in fat content, and 41–49% in protein content. Variance ratios for the two permanent environment effects were the highest in daily milk yield (0.10–0.27), and lower in fat (0.04–0.08) and protein (0.01–0.10) contents. Additive genetic correlations during the selected test-days were high between the adjacent ones and they tended to decrease at the extremes of the lactation trajectory.

scholarly journals Heritabilities and genetic correlations of lactational and daily somatic cell score with conformation traits in Polish Holstein cattle

2011 ◽  
Vol 56 (No. 5) ◽  
pp. 205-212 ◽  
Author(s):  
E. Ptak ◽  
W. Jagusiak ◽  
A. Żarnecki ◽  
A. Otwinowska-Mindur
Keyword(s):  
Somatic Cell ◽  
Variance Components ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Direct Selection ◽  
Linear Type ◽  
Holstein Friesian ◽  
Type Traits ◽  
Selection For ◽  
Friesian Cows

The objective of this study was to estimate heritabilities and genetic correlations of lactational and daily somatic cell scores with descriptive and linear type traits in Polish Holstein-Friesian cows. Data were: test-day somatic cell scores and conformation evaluations of 24 599 primiparous cows, daughters of 802 sires. Cows calved from 2006 to 2007. The lactational somatic cell score was calculated as the average of four test-day somatic cell scores at least. The daily somatic cell score was the test-day somatic cell score closest to the date of type evaluation. A multi-trait animal model was used to estimate genetic parameters. (Co)variance components were estimated by a Bayesian algorithm via Gibbs sampling. The heritability of lactational somatic cell score was 0.20 and it was much higher than that of daily somatic cell score (0.13). Heritabilities of type traits were high to moderate for height at rump (0.46), size (0.39), overall conformation score (0.30), two linear rump traits (0.28–0.29) and three linear teat traits (0.26–0.29). The genetic correlation between lactational and daily somatic cell scores was 0.84. In many cases, daily somatic cell score showed higher genetic correlations with type traits than lactational somatic cell score. Descriptive udder and feet and legs scores were genetically correlated negatively with both lactational (–0.22 and –0.20) and daily somatic cell scores (–0.28 and –0.33). Somatic cell traits were genetically correlated positively with rump angle (0.21 and 0.19) and negatively with fore udder height (–0.26 and –0.29), udder depth (–0.23 and –0.17) and central ligament (–0.14 and –0.16). Due to higher heritability, direct selection for lower lactational somatic cell score would be more effective than selection for lower daily somatic cell score. The magnitude of obtained heritabilities and the favourable genetic correlations indicate that the selection utilizing some type traits could improve the resistance to mastitis.

Short-term response in solids-not-fat to grain fed in addition to molasses for dairy cows grazing tropical pastures

1991 ◽  
Vol 31 (2) ◽  
pp. 191 ◽  
Author(s):  
BP McLachlan ◽  
WN Orr ◽  
BA Silver
Keyword(s):  
Dairy Cows ◽  
Experimental Period ◽  
Short Term ◽  
Tropical Pastures ◽  
Additional Energy ◽  
Holstein Friesian ◽  
Term Response ◽  
Tropical Grass ◽  
Daily Milk ◽  
Friesian Cows

Holstein-Friesian cows in mid to late lactation grazed tropical grass-legume pastures with no supplement (C); 2.7 kg DM molasses/cow.day (M); or 2.6 kg DM molasses + 2.5 kg DM grain/cow.day (MG). Daily milk yields over the 8 week experimental period were 10.4, 11.2 and 12.9 kg/cow for C, M and MG. The MG supplementation increased solids-not-fat (SNF), protein and lactose percentages in milk, with average SNF values of 8.02, 8.10 and 8.24% (P<0.05), and lactose values 4.46,4.50 and 4.58% (P<0.057), for weeks 5-8; and average protein values for weeks 1-8 of 2.96, 3.02 and 3.10% (P<0.05) for C, M and MG, respectively. Molasses alone did not substantially increase the protein and lactose content of milk, but additional energy in the form of maize increased these values. If SNF percentages in milk were low, maize plus molasses feeding did not improve the quality to the legal minimum of 8.5% in 8 weeks.

The influence of shade on milk production of Holstein-Friesian cows in a tropical upland environment

1988 ◽  
Vol 28 (2) ◽  
pp. 149 ◽  
Author(s):  
TM Davison ◽  
BA Silver ◽  
AT Lisle ◽  
WN Orr
Keyword(s):  
Milk Yield ◽  
Rectal Temperature ◽  
Somatic Cell Count ◽  
Experimental Period ◽  
Milk Composition ◽  
Holstein Friesian ◽  
Average Maximum ◽  
Fat Yield ◽  
Daily Milk ◽  
Friesian Cows

Sixteen Holstein-Friesian animals, comprising 8 multiparous cows and 8 first-lactation heifers, were divided into 2 equal groups which had access to either tree shade or no shade. All animals were in the first third of lactation and were subjected to treatment for 8 weeks in summer 1985. Average maximum monthly temperatures ranged from 26.2 to 28.22� over the experimental period. The provision of shade increased (P< 0.01) milk yield; however, there was a significant (P<0.05) interaction between response to shade and cow parity. Mean daily milk yields for multiparous cows were 19.2 and 17.2 kg/cow (P< 0.01) and 16.3 and 15.9 kg/cow (P> 0.05) for heifers in the shade and no shade groups respectively. Cows without shade incurred a significant decrease (P< 0.05) in solids-not fat yield, lactose percentage and lactose yield, and a significant increase ( P < 0.05) in somatic cell count. The composition of milk from heifers without shade was no different from that from heifers with shade. Rectal temperature was higher (P < 0.01) in animals without shade (mean 40.0�C) than in animals with shade (mean 39.4�C). The highest mean maximum rectal temperature of 41.6�C was recorded in the noshade group. It was concluded that shade is essential if milk yield and milk composition are to be maximised in this environment.

Estimates of genetic parameters for fertility traits of Australian Holstein-Friesian cattle

2003 ◽  
Vol 76 (1) ◽  
pp. 35-42 ◽  
Author(s):  
M. Haile-Mariam ◽  
J.M. Morton ◽  
M.E. Goddard
Keyword(s):  
Genetic Correlation ◽  
Genetic Correlations ◽  
Dairy Herds ◽  
Environmental Correlations ◽  
Holstein Friesian ◽  
Fertility Data ◽  
National Selection ◽  
Fertility Traits ◽  
Friesian Cattle ◽  
Friesian Cows

AbstractFertility data collected on 17131 Holstein-Friesian cows from 158 dairy herds in Australia were used to estimate heritabilities for and correlations among several fertility traits using a sire model. Pregnancy rate (PR), survival (Surv), calving interval (CI), calving to first service interval (CFS), insemination rate (coded as 1 if a cow received a service or 0 otherwise) (InsemR) and first service non-return rate (FNRR) were the main traits analysed in a six-trait model. Among the traits, CFS had the highest h2 (0·13) and FNRR had the lowest h2 (0·01). Genetic correlations among the traits were higher than environmental correlations in all cases. The genetic correlations of PR with InsemR, FNRR, CFS, CI and Surv were 0·74, 0·79 and -0·84, -0·57, and 0·67, respectively. The genetic correlation between InsemR and CFS was high (-0·95) indicating that they almost measure the same trait. Analysis of data from cows that did not return to service after the first service despite not being pregnant (so-called ‘phantom’ cow syndrome) showed that the syndrome is not heritable. The relatively high genetic correlation of PR with traits such as CI and Surv that can be extracted from milk recording data and CFS, FNRR and InsemR that can be obtained from mating data suggests that routine genetic evaluation of sires for daughter fertility based on these traits can be implemented in national selection programs.

Sign in / Sign up

Export Citation Format

Share Document