Comparing alternative random regression models to analyse first lactation daily milk yield data in Holstein–Friesian cattle

2003 ◽  
Vol 82 (1) ◽  
pp. 81-96 ◽  
Author(s):  
P. López-Romero ◽  
M.J. Carabaño
2005 ◽  
Vol 81 (2) ◽  
pp. 233-238 ◽  
Author(s):  
G. Banos ◽  
G. Arsenos ◽  
Z. Abas ◽  
Z. Basdagianni

AbstractParameters of daily milk yield during the first three lactations of Chios ewes were estimated with random regression models. Data consisted of 42 675 test-day records of 7121 ewes from 75 flocks that had lambed between 1998 and 2000. Models fitted fourth order fixed regressions on Legendre polynomials of the number of days post partum and fourth order random regressions on the individual animal. (Co)variance components were estimated with Gibbs sampling. Lactations were analysed separately. The four eigen values accounted for 0·80 to 0·84, 0·11 to 0·15, 0·04 to 0·05 and about 0·01 of the animal variance, respectively, depending on lactation number. Animal variance estimates, including genetic and, partly, permanent environment effects, were high at the beginning of each lactation and decreased as lactation progressed, suggesting that the animal effect is most important to early daily records. Residual variance was highest in the middle of lactation, suggesting that non-systematic environmental factors play a bigger at that time. Animal correlation estimates between daily yield records ranged from 0·26 to 0·99, were highest for adjacent days and decreased for days further apart. The decline had a different shape in the three lactations and was more evident in the first, suggesting that the three lactations may be biologically distinct traits. Animal correlation estimates between daily and total lactation milk yield ranged from 0·61 to 0·98 and were highest in the middle and lowest towards the end of lactation. Early lactation daily yield had an animal correlation of 0·70 to 0·80 with total lactation milk yield, in all three lactations. Results of this study suggest that daily milk yield records in the early stages of lactation may be useful for selection of ewes with high producing ability and accurate prediction of total lactation milk yield.


2000 ◽  
Vol 70 (3) ◽  
pp. 407-415 ◽  
Author(s):  
S. Brotherstone ◽  
I. M. S. White ◽  
K. Meyer

AbstractRandom regression models have been advocated for the analysis of test day records in dairy cattle. The effectiveness of a random regression analysis depends on the function used to model the data. To investigate functions suitable for the analysis of daily milk yield, test day milk yields of 7860 first lactation Holstein Friesian cows were analysed using random regression models involving three types of curves. Each analysis fitted the same curve to model overall trends through a fixed regression and random deviations due to animals. Curves included orthogonal polynomials, fitted to order 3 (quadratic), 4 (cubic) and 5 (quartic), respectively, a three-parameter parametric curve and a five-parameter parametric curve. Sets of random regression coefficients were fitted to model both animals’ genetic effects and permanent environmental effects. Temporary measurement errors were assumed independently but heterogeneously distributed, and assigned to one of 12 classes. Results showed that the measurement error variances were generally lowest around peak lactation, and higher at the beginning and end of lactation. Parametric curves yielded the highest likelihoods, but produced negative genetic associations between yield in early lactation and later lactation yields, while positive genetic correlations across the entire lactation were estimated with all models involving orthogonal polynomials. The fit of models using orthogonal polynomials to model test day yield was improved by including higher order fixed regressions.


2020 ◽  
Vol 52 (6) ◽  
pp. 2937-2943
Author(s):  
Maximillian Manzi ◽  
Lotta Rydhmer ◽  
Martin Ntawubizi ◽  
Claire D’Andre Hirwa ◽  
Callixte Karege ◽  
...  

Abstract This study assessed daily milk yield (DMY), 100-day (MY100), and 305-day (MY305) milk yield, and lactation length (LL) in purebred Ankole cattle and Ankole crossbreds, and the influence of environmental factors on these traits. Milk yield data were obtained for 865 cows and 1234 lactations and analyzed using a mixed linear model. The overall least squares mean of DMY, MY100, and MY305 across breed groups was 2.7 L (N = 1234, SD = 1.7), 262 L (N = 959, SD = 176), and 759 L (N = 448, SD = 439), respectively, while the average lactation length was 256 days (N = 960, SD = 122). All factors included (breed group, season and year of calving, and parity) were significant for yield traits, except season of calving for MY305. First-parity cows had the lowest milk production, and fourth-parity cows the highest. For all traits, pure Ankole cows had the lowest milk yield. Among the crossbreds, there was no significant difference between Ankole × Friesian, Ankole-Jersey mother × Sahiwal sire, and Ankole-Sahiwal mother × Jersey sire, or between Ankole × Sahiwal and Ankole-Sahiwal mother × Sahiwal sire. It was concluded that Ankole crosses with Friesian or Jersey can be beneficial, even under a management system of limited nutrition as in Rwanda.


2007 ◽  
Vol 2007 ◽  
pp. 98-98
Author(s):  
O. M. Onyiro ◽  
S. Brotherstone

As a major health problem facing dairy farmers worldwide with substantial economic, production and welfare consequences, lameness has attracted much attention over the last two to three decades (Boelling, 1999). Lameness as a linear type trait is measured by locomotion scoring as there is a high genetic correlation between lameness and locomotion score. Studies have included locomotion (as a predictor of lameness) and have associated lameness with no effect, an increase and sometimes a decrease in milk production of cows. Several reasons have been given for these differences and the need still arises for estimates of the effect of lameness on milk yield in herds with current dairy management. The objective of this study was to quantify the effect of lameness on the daily milk yield (DMY) of dairy cows.


1968 ◽  
Vol 70 (2) ◽  
pp. 187-194 ◽  
Author(s):  
J. J. Robinson ◽  
W. H. Foster ◽  
T. J. Forbes

SUMMARYEwo milk yield data obtained by the lamb suckling technique from nutritional experiments were analysed statistically to obtain estimates of the several components of variation. Diurnal variation was studied. The fitting of a sinusoidal curve removed a significant amount of variation.There was a highly significant correlation between successive milk yields obtained at 4 h intervals. Number of lambs suckled and body weight of ewe at parturition had a significant effect on total daily milk yield.The variation within ewes after the removal of diurnal variation and between ewes after the removal of the effects of number of lambs suckled and body weight at parturition were computed. These sources of variation were combined in a general equation which enabled the prediction of the standard errors associated with daily milk production for a given sampling technique. The practical application of the predicted standard errors is discussed.


1978 ◽  
Vol 91 (3) ◽  
pp. 645-651 ◽  
Author(s):  
J. A. Adeneye ◽  
Adetowun K. Adebanjo

SummaryDuring the period 1962–73, the majority of the 92 lactations of imported British Friesian animals were initiated during the dry season (October–March). The following average values were obtained: lifetime number of lactations, 4·5; lifetime milk production, 9392 kg; age at producing first live calf, 39·6 months; milk yield of nine lactations, 2159 kg; lactation length, 336·5 days; daily milk yield, 6·3 kg; 305-day milk yield, 2012 kg; dry period, 173 days.Milk production was highest in the fourth lactation when the animals averaged 7 years old. Differences in milk yield among lactations were small. Peak daily milk yield was greatest in the third lactation and was reached within the first 21 days of each of the first four lactations. A second but lower peak with the highest milk production persistencies at a later stage of lactation apparently depended on feed availability. The 305-day milk yield was reasonably predicted from the 100- and 200-day yields.Lactations subsequent to abortions and stillbirths were slightly longer, gave less milk (P > 0·05) and were followed by longer dry periods than those initiated by normal births.


2003 ◽  
Vol 46 (3) ◽  
pp. 213-224 ◽  
Author(s):  
W. Grzesiak ◽  
J. Wojcik ◽  
B. Binerowska

Abstract. In the present study, the prognostic values of multiple and spline regression models were tested for 305-day lactation milk yield of cows. The predictors were: HF genes proportion in cow's genotype; average milk yield for 305-day lactation from 4 first milkings of all cows in a barn, in which a cow was used in a given year; month of calving; and average daily milk yield from first four test-day milkings. Models were developed basing on 628 first lactations of BW cows with average 71% HF genes proportion. Subsequently, the predictive values of the models examined were verified on the grounds of next 105 first lactations. Prognostic differences of the models examined were determined, finding the prognosis obtained with the spline regression more accurate (smaller prediction error, higher coefficient of correlation for prognosis and real values in the model containing information from first three test-day milkings). These models are easy to construct and may be useful in practical estimation of cow lactation yields. They may be used for predicting the actual lactation yield in order to minimise production costs and achieve better production results.


Author(s):  
Atakan Koç ◽  
Ramazan Gürses

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.


2007 ◽  
Vol 50 (6) ◽  
pp. 535-548
Author(s):  
A. A. Amin

Abstract. Random regression animal model was applied for analyzing the relationships between test-day milk yields (DY), and milk flow rate (FR). The current study involved 169,491 sample test-day records of Hungarian Holstein- Friesian cows. A quadratic random regression was applied for declaring additive genetic variances in all studied traits during biweekly observations across the first three parities. Estimates of heritability for test-day milk yield and udder milk flow rates ranged from 0.09 to 0.58 and from 0.02 to 0.50, respectively through 42 milk-weeks (Wk). The highest heritability estimates occurred during the end of trajectory for both traits. In general DY tended to be more heritable than FR across lactation except during the first few weeks of lactation. Performance of DY was less affected by environmental variation than FR, while both values were moderate to high (0.63 to 0.75). Correlations among measurements showed that additive correlations (Ra) of 4WkFR with the reminder part of lactation were high during early and late lactation. Also 24WkFR was more genetically correlated with next measures and reached Ra = 0.94. Whereas 42WkFR was high additively correlated with other biweekly measurements and ranged from 0.53 to 0.99. Performance of early and late DY was negative additively correlated and ranged from −0.03 to −0.53. Heritability of DY within levels of FR ranged from 0.09 to 0.33 within very slow and medium milk flow, respectively. Correlations among both traits increased linearly toward lactation end. DY during 24Week and 42Week of lactation accounted the highest additive correlations with FR across lactation. Estimated breeding values for DY and FR increased in different rates with progressing lactation. These results may indicate that individual selection results would be favorably achieved during the late part of lactation. More details about estimates of breeding values, estimates of permanent environmental and additive genetic correlations for all traits were tabulated.


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