scholarly journals Study on Friesian Herds Raised in Egypt and Germany – I. Estimate of non-genetic effects and genetic parameters

2000 ◽  
Vol 43 (2) ◽  
pp. 101-114
Author(s):  
E. S. Tawfik ◽  
M. K. Mohsen ◽  
A. Y. Salem ◽  
H. G. El-Awady
Keyword(s):  
Least Squares ◽  
Milk Yield ◽  
Genetic Correlations ◽  
Positive Association ◽  
Genetic Effects ◽  
Lactation Period ◽  
Negatively Associated ◽  
Abstract Data ◽  
Partial Linear ◽  
Friesian Cows

Abstract. Data on 2422 and 27756 Friesian cows in Egypt and Germany, respectively, were used to estimate genetic and non-genetic effects on initial milk yield in 70 days (IMY), 305-day milk yield (305-dMY), lactation period (LP) and calving interval (CI). Data were collected in the period from 1987 to 1992 in Egypt and from 1979 to 1993 in Germany. Least Squares analysis shows the significant effect of season and year of calving and parity on all traits. Least Squares analysis indicates that winter and spring calvers had the higher value in all traits studied than summer and autumn calvers of Friesian cows in Egypt, while in German Friesian cows, the autumn calvers had the higher value in all traits studied than summer and spring calvers. The results show that the milk yield increased with increased lactation Orders. Partial linear and quadratic regression coefficients indicate that age at calving was negatively associated with CI, while it showed positive association with LP and 305-dMY in Friesian cows in Egypt, while in German Friesian cows age at calving was negatively associated with LP and CI, while associated positively with milk yield. Heritabilities were 0.24, 0.22, 0.14 and 0.16 for IMY, 305-dMY, LP and CI, respectively of Friesian cows in Egypt and were 0.34, 0.24, 0.08 and 0.09 for IMY, 305-dMY, LP and CI, respectively in German Friesian cows. All phenotypic and genetic correlations between different traits studied were positive and significant.

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 The use of dijkstra mechanistic model for genetic analysis of the lactation curve characteristics and their relationships with age at first calving and somatic cell score of Iranian dairy cows

2020 ◽  
Vol 42 ◽  
pp. e50181
Author(s):  
Mahdi Elahi Torshizi ◽  
Homayoun Farhangfar
Keyword(s):  
Somatic Cell ◽  
Genetic Correlation ◽  
Milk Yield ◽  
Mechanistic Model ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Specific Rate ◽  
Lactation Period ◽  
Age At First Calving ◽  
Lactation Curve

The objective of this study was to estimate lactation curve parameters with Dijkstra mechanistic model and to evaluate genetic and phenotypic relationships between the parameters and the average somatic cell count in primiparous cows. The finding indicated that heritability estimates for partial milk yield (PMY1, PMY2 and PMY3), total 305-day milk yield (TMY305), decay parameter (λ2), age at first calving (AFC) and peak yield (PY) were moderate while the heritability of persistency (PS%), average somatic cell score (AVGSCS), time to peak yield (TP), initial milk production (λ0), specific rate of cell proliferation at parturition (λ1), and specific rate of cell death (λ3) were quite low. Genetic correlations between both AFC and PS% traits with average somatic cell scores was negative (-0.047 and -0.060) but low positive genetic correlation were between partial milk yields (PMY1 and PMY3) while negative genetic correlation (-0.06) was obtained between TMY305 and AVGSCS. Differences between TMY305 of cows with less than 100000 cells mL-1 and cows with >1,500,000 cells mL-1 was approximately 708 Kg and is equivalent to 8% loss of milk yield/cow during lactation period and also loss of persistency (11.1 %( was shown for the extreme classes of SCC in this study.

scholarly journals Milk production in Finnsheep and Romanov breeds

1988 ◽  
Vol 60 (6) ◽  
pp. 603-607
Author(s):  
W. J. Boylan ◽  
H. Sakul
Keyword(s):  
Least Squares ◽  
Milk Production ◽  
Milk Yield ◽  
Milk Composition ◽  
Lactation Period ◽  
Composition Data ◽  
Mating Design ◽  
Sheep Breeds ◽  
A Value ◽  
Diallel Mating Design

The Finn, Romanov and several U.S. sheep breeds were machine milked to obtain information on several measures of milk production and milk composition. Data were obtained over at wo year to four year period utilizing 146 purebred ewe records and 165 crossbred ewe records. The level of milk production for a 130 day lactation period for the breeds evaluated was generally low compared to traditional European dairy breeds. The least-squares overall mean for milk yield was 68.8 liters. The Suffolk (80.5 liters) and the Rambouillet (75.3 liters) were superior. The Targhee, Dorset and Lincoln breeds followed in order for milk yield. The Finn (64.0 liters) and Romanov (39.1 liters) were lowest. Finn sired crossbred ewes had the highest level of milk production (84.4 liters) in a four breed diallel mating design of Finn, Dorset, Lincoln and Rambouillet breeds. A value of 15.4 % was found for heterosis in milk production.

scholarly journals A comparison of different methods of estimating sire transmitting ability of some milk traits in a herd of Holstein Friesian cattle

2000 ◽  
Vol 43 (2) ◽  
pp. 115-122
Author(s):  
H. Atil ◽  
A. S. Khattab
Keyword(s):  
Least Squares ◽  
Milk Yield ◽  
Lactation Period ◽  
Milk Traits ◽  
Linear Unbiased Prediction ◽  
Age At First Calving ◽  
Holstein Friesian ◽  
Genetic And Phenotypic Correlations ◽  
Best Linear Unbiased ◽  
Friesian Cattle

Abstract. A total of 1931 normal first lactation records of Holstein Friesian cows kept at Dena Farm in Egypt during the period from 1987 to 1994 were used to estimate phenotypic and genetic parameters for 90 day milk yield (90 dMY), 305 day milk yield (305 dMY) and lactation period (LP). In addition, 76 bulls with at least ten daughters were used to compare three methods of sire transmitting ability. A least Squares analysis of variance show significant effect of month and year of calving and age at first calving for different traits studied, except the effect of age at first calving on LP. Heritability estimates for 90 dMY, 305 dMY and LP were 0.39 ± 0.08, 0.27 ± 0.07 and 0.14 ± 0.05, respectively. Genetic and phenotypic correlations between different traits were positive and significant. Sires with at least ten daughters were evaluated by best linear unbiased prediction (BLUP), least Squares means (LSM) and regression of the future daughters mean on the present daughters mean. The product moment correlations between different traits studied were positive and high (= 0.96).

scholarly journals Study on Friesian Herds Raised in Egypt and Germany – II. Genetic and phenotypic trends in estimated transmitting ability

2000 ◽  
Vol 43 (4) ◽  
pp. 399-410
Author(s):  
M. K. Mohsen ◽  
E. S. Tawfik ◽  
A. Y. Salem ◽  
H. G. El-Awady
Keyword(s):  
Total Variation ◽  
Milk Yield ◽  
Original Data ◽  
Genetic Change ◽  
Calving Interval ◽  
Lactation Period ◽  
Genetic Value ◽  
Friesian Cows

Abstract. Original data consisted of 774 first lactation records of daughters of 124 sires of Friesian herds in Egypt and 9219 first lactation records of daughters of 679 sires of Friesian herds in Germany used to estimate genetic and phenotypic trends of initial milk yield in 70 days (IMY), 305-day milk yield (305-dMY), lactation period (LP) and calving interval (CI). Sire component of variance was consistently about 9.88%, 10.75%, 4.63% and 5.03% for IMY, 305-dMY, LP and CI, respectively of the total Variation in Friesian cows in Egypt and about 16.69%, 16.69%, 3.63% and 4.37%, for IMY, 305-dMY, LP and CI, respectively of the total Variation in Friesian cows in Germany. Annual genetic change was 29.98 kg, 112.99 kg, −0.92 d and 1.78 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Egypt and was 70.41 kg, 200.38 kg, 0.12 d and −1.05 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Germany. Annual phenotypic trend was 13.83 kg, 48.00 kg, −1.66 d and −1.82 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Egypt and was 21.00 kg, 104.00 kg, 0.17 d and 0.78 d for IMY, 305-dMY, LP and CI, respectively for Friesian cows in Germany. The present results show that sires used in the later years were of superior genetic value than those used in the earlier years.

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

FACTORS INFLUENCING LACTATION PERFORMANCE OF RANGE BEEF AND DAIRY-BEEF COWS

1984 ◽  
Vol 64 (2) ◽  
pp. 267-277 ◽  
Author(s):  
SARAH BUTSON ◽  
R. T. BERG
Keyword(s):  
Milk Yield ◽  
Average Daily Gain ◽  
Significant Proportion ◽  
Positive Association ◽  
Negative Association ◽  
Regression Coefficients ◽  
Lactation Period ◽  
Lactation Performance ◽  
Beef Breed ◽  
Factors Influencing

An investigation was carried out to study factors influencing milk yields and milk constituents among range cows. June and September measurements of milk yield and constituent percentages of butterfat (BF), protein (PT) and lactose (LT) were taken using 206 and 222 cows in 1976 and 1977, respectively. The cows, representing four beef and dairy-beef breed groups, were from the University of Alberta beef herd and ranged in age from 2 to 10 years. Regression of milk yield on calf age (CA) demonstrated a negative association over the lactation period measured, although regression coefficients were not statistically significant. Associations between all constituent yields with CA were negative. However, regression coefficients of June and September constituent percentage variables on CA indicated a more positive association as lactation progressed. Cow weight loss during gestation, cow weight at calving and ADG during lactation did not account for a significant proportion of the variation in either milk or constituent yields or constituent percentages over and above main effects. The association between cow ADG during lactation and all yields was negative although not statistically significant. Calf birth-weight was positively associated with all yields, and showed negative association with BF% and PT%. Calf average daily gain measured from birth to September was highly associated with yields of milk and constituents, declining from June to September. Its association with BF% and PT% was negative. Cow calving interval was introduced as a possible factor influencing milk yields of 3- and 4-yr-old and mature cows. Its association with lactation performance was however, not significant. Key words: Lactation, range cows

Genetic aspects of condition score, heart girth and milk-yield traits in Italian Friesian cows

1999 ◽  
Vol 24 ◽  
pp. 159-164
Author(s):  
L. Gallo ◽  
P. Carnier ◽  
M. Cassandro ◽  
R. Dal Zotto ◽  
G. Bittante
Keyword(s):  
Milk Yield ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Repeated Measurements ◽  
Protein Yield ◽  
Yield Traits ◽  
Dry Period ◽  
Condition Score ◽  
Heritability Estimates ◽  
Friesian Cows

AbstractFunctional traits related to costs are currently of interest for selection and management of dairy cattle. The present study was aimed to estimate heritability for body condition score (BCS) and heart girth (HG), to investigate the genetic relationships between BCS, HG and milk-yield traits using a test-day model and to analyse the consistency of the estimates in different lactation stages. Cows from 25 dairy herds were scored for BCS and measured for HG at 3-month intervals for 2 years. Approximately 5000 test-day observations on BCS, HG and milk fat and protein yield from 1429 Italian Friesian cows were analysed using two approaches: (1) repeated observations were treated as repeated measurements of the same trait, both within and across lactations; (2) observations collected in different stages of lactation (dry period, 1 to 75 days in milk (DIM), 76 to 130 DIM, 131 to 210 DIM, 211 to 300 DIM) were treated as different traits. (Co)variance components and related parameters were estimated using REML multiple-trait procedures and unequal design animal models.Heritability estimates (approach 1) for fat and protein test-day yield, BCS and HG were 0.22, 0.18, 0.29 and 0.33, respectively. BCS was negatively correlated with yield traits (-0.43 and -0.48 for fat and protein yield, respectively) but positively correlated (0.33) with HG. Genetic relationships between HG and milk-yield traits were negligible. Heritability estimates (approach 2) were 0.28 and 0.27 for BCS recorded in the first half of lactation (1 to 75 and 76 to 130 DIM, respectively), 0.36 for BCS measured on cows in the second half of lactation and 0.32 for BCS recorded on dry cows. Heritability estimates for HG in different lactation stages ranged from 0.31 to 0.40. Genetic correlations between BCS measured in different lactation stages were generally high (0.85 or more), with the exception of the correlation between the first and the last stage of lactation (0.74) and of the relationships between the beginning of lactation and the dry period (0.7). Genetic correlations between HG measured in different lactation stages were mostly higher than 0.80.

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