scholarly journals Genetic analysis of productive life length in Holstein dairy cows using Weibull proportional risk model

2016 ◽  
Vol 59 (3) ◽  
pp. 387-393 ◽  
Author(s):  
Hamed Amirpour Najafabadi ◽  
Saeid Ansari Mahyari ◽  
Mohammad Ali Edriss ◽  
Eva Strapakova
Keyword(s):  
Milk Production ◽  
Risk Model ◽  
Holstein Cows ◽  
Average Lifetime ◽  
Dairy Herds ◽  
Logarithmic Scale ◽  
Age At First Calving ◽  
Productive Life ◽  
Isfahan Province ◽  
The Mean

Abstract. In recent decades, there has been a downward trend in length of productive life (LPL) in Holstein cows across industrial dairy herds. This study examined the factors that might influence LPL and estimated the genetic parameters of LPL in Holstein dairy herds in Isfahan province, Iran. LPL is defined as the number of days between the first calving and the end of recording. Data consisted of 35 137 records of productive life from registered cows that started first calving between 1991 and 2012. Cows that remained alive at the end of the study were considered right-censored. The average lifetime for culled and censored cows was 938 and 1003 days, respectively. A survival analysis was applied using a proportional risk model with a Weibull distribution. Milk production was divided into five groups, where the culling risk of cows with a milk yield of less than 1.5 standard deviations (SD) of the mean was 3.5 times greater than the culling risk of high-producing cows producing more than 1.5 SD above the mean. Results showed that culling risk increased almost linearly beyond the milk production groups. Furthermore, somatic cell count and age at first calving significantly increased the culling risk across the herds. The results for the combined effect of parity  ×  stage of lactation showed a decrease in culling risk during the first calving, and an increase during the further parities. Moreover, a higher age at first calving was observed, reflecting a lower risk of culling. Estimated heritability were 0.074 and 0.18 based on a logarithmic scale and original scale, respectively. According to the results, use of Weibull models showed that the proportional culling risk was higher in low-production cows, but a higher risk ratio was revealed in high-milk-production cows. However, there were some fluctuations in genetic trends, but an overall increase was observed in LPL which will lead to a longer LPL of Holstein cows in Isfahan province.

scholarly journals Association between age at first calving and milk production in first lactation on longevity traits in Holstein cows

2020 ◽  
Vol 36 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Denis Kucevic ◽  
Snezana Trivunovic ◽  
Zika Soronja ◽  
Dobrila Jankovic ◽  
Dragan Stanojevic ◽  
...  
Keyword(s):  
Milk Production ◽  
Statistical Significance ◽  
Mean Value ◽  
Holstein Cows ◽  
Age At First Calving ◽  
Productive Life ◽  
Correlation Data ◽  
High Statistical Significance ◽  
Holstein Friesian ◽  
High Level

The objective of this research was to determine the association between age at first calving (AFC) and milk production in the first lactation of longevity traits for Holstein cows. The research was conducted on 2307 cows raised on 4 farms in AP Vojvodina. The cows were culled in the period from 2017 to 2018. The cows belonged to the group of Holstein Friesian breed of cattle. Cow longevity was observed using three parameters: number of lactations (NL), lifetime milk yield (LMY) and length of productive life (LPL). The research involved the influence of the farm on which the animals realized their production, the season of first calving. A mean value obtained for the length of productive life in the analysed population was 1207 days (3.30 years on average). During this period the animals on average realized 2.45 lactations and produced on average 18798 kg milk. All studied traits showed a high level of variability. From these data, the study sought to determine the influence of factors on the traits of longevity, our research present that studied factors showed high statistical significance on these traits except in the case of the season of first calving where a statistical significance effect wasn?t observed. The season of first calving did not affect the animal traits for longevity and, generally, didn?t affect the calving interval. Regarding the obtained correlation data between age at first calving and length of productive life, it can be concluded that belated AFC leads to reduced reproductive performance.

scholarly journals Factors affecting the functional length of productive life in Slovak Pinzgau cows

2008 ◽  
Vol 53 (No. 3) ◽  
pp. 91-97 ◽  
Author(s):  
G. Mészáros ◽  
J. Wolf ◽  
O. Kadlečík
Keyword(s):  
Milk Production ◽  
Linear Increase ◽  
Production Level ◽  
Proportional Hazard ◽  
Proportional Hazard Model ◽  
Age At First Calving ◽  
Factors Affecting ◽  
Productive Life ◽  
The Impact ◽  
Effect Of Age

A proportional hazard model was used to analyze the impact of the most important factors on the length of productive life in 44 796 Slovak Pinzgau cows. The calculations were carried out with Survival Kit 3.12. The milk production level within a herd was the most important factor. The relation between the milk production level and the culling risk was strongly non-linear. Cows with extremely low milk production (less than 1.5 standard deviations below average) had a 4.8 times higher culling risk than average cows. The culling risk for the highest yielding cows was about one half of the risk of average cows. In the first lactation the culling risk was highest at the beginning and decreased in the course of lactation whereas in subsequent lactations the culling risk was highest at the end of lactation. The risk decreased with parity. The effect of age at first calving did not have a large influence on the length of productive life, although a linear increase in culling risk was observed as the age at first calving increased. Cows from expanding herds were at lower risk to be culled compared to cows in herds of stable and decreasing size.

USE OF MILK RECORDS IN ONE HERD TO PREDICT A COW’S PRODUCTION IN A SECOND HERD

1976 ◽  
Vol 56 (2) ◽  
pp. 187-191 ◽  
Author(s):  
E. B. BURNSIDE ◽  
M. G. FREEMAN ◽  
T. R. BATRA ◽  
G. B. WEAVER
Keyword(s):  
Weighted Regression ◽  
Holstein Cows ◽  
Dairy Herds ◽  
Productive Life ◽  
Ability Estimates ◽  
Future Production ◽  
Class Average ◽  
Days Open

The objective was to relate the average herdmate milk deviation of cows which completed one or more records in each of two Canadian dairy herds. Record of Performance records of Canadian Holstein cows transferred at least once during their productive life were studied to evaluate the use of milk records in one herd to predict a cow’s production in a second herd. Each record was adjusted for days open and age-at-calving and then expressed as a deviation from first lactation or second and later lactation herdmate averages. Weighted regression of the cow’s average herdmate deviation in the second herd on her real producing ability estimated in the first herd was 0.87 ±.07 Breed Class Average (BCA). Weighted regression of the cow’s average BCA in the second herd on her real producing ability estimated from absolute BCA’s was much lower (0.30 ±.05). Approximately 80% of the cows ranked similarly on deviations in the second herd as they did in the first herd. A study of cows transferred from low to high producing herds revealed that real producing ability estimates based on herdmate deviations were excellent indicators of future production (b = 0.98 ±.15). The regression for cows transferred from high to low producing herds was lower (b = 0.44 ±.17).

scholarly journals Genetic evaluation for length of productive life in Slovak Pinzgau cattle

2008 ◽  
Vol 51 (5) ◽  
pp. 438-448 ◽  
Author(s):  
G. Mészáros ◽  
C. Fuerst ◽  
B. Fuerst-Waltl ◽  
O. Kadlečík ◽  
R. Kasarda ◽  
...  
Keyword(s):  
Milk Production ◽  
Proportional Hazards ◽  
Genetic Evaluation ◽  
Data Set ◽  
Final Model ◽  
Breeding Values ◽  
Age At First Calving ◽  
Clear Tendency ◽  
Productive Life ◽  
Increasing Risk

Abstract. The proportional hazards method was used to estimate breeding values for functional length of productive life within the endangered Slovak Pinzgau population. The analyzed data set contained 21,985 cows, daughters of 254 sires. The risk of culling was higher for cows with lower milk production relative to herd average, higher age at first calving and in herds decreasing in size. In the first lactation the culling risk was highest at the beginning, and decreased during lactation. From second lactation onwards an increasing risk was observed. The effect of breed composition was found insignificant, and was not included into final model. A heritability of 0.05 was estimated for functional length of productive life. The average reliability of estimates was 0.25. No clear tendency in average breeding values by year of birth of bulls was observed.

scholarly journals Effect of Age at First Calving on First Lactation Milk Yield in Holstein Cows from Costa Rican Specialized Dairy Herds

2014 ◽  
Vol 04 (09) ◽  
pp. 197-203
Author(s):  
Mauren Salazar-Carranza ◽  
Gloriana Castillo-Badilla ◽  
Jaime Murillo-Herrera ◽  
Frank Hueckmann-Voss ◽  
Juan José Romero-Zúñiga
Keyword(s):  
Milk Yield ◽  
Costa Rican ◽  
Holstein Cows ◽  
Dairy Herds ◽  
Age At First Calving ◽  
Effect Of Age

scholarly journals THE TESTING OF SEVERAL FEED INTAKE PREDICTION EQUATIONS USING FARM DATA

1981 ◽  
Vol 61 (1) ◽  
pp. 159-164 ◽  
Author(s):  
D. H. YUNGBLUT ◽  
J. B. STONE ◽  
G. K. MACLEOD ◽  
G. F. WILSON
Keyword(s):  
Body Weight ◽  
Milk Production ◽  
Body Condition ◽  
Feed Intake ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Dairy Herds ◽  
Regression Equations ◽  
Acid Detergent Fibre ◽  
The Mean

Data were collected during three visits to each of 19 dairy herds in the Guelph area. Feed intake, body condition and heart girth of all milking cows were recorded during each visit. Samples of all feeds were taken and analyzed for dry matter and acid detergent fibre. Cow weight was estimated from heart girth after grouping cows according to body condition. Milk production and fat test data were obtained from DHI records. Four regression equations were used to predict total feed dry matter intake. The mean daily feed intake was 2.8% of body weight. Eleven of the herds were within ± 10% of this value, four were above this range and four were below. The number of herds in which mean predicted intake was within ± 10% of observed intake, above this range or below this range, were (1) 7, 5, 7 (2) 12, 2, 5 (3) 11, 2, 6 (4) 8, 9, 2 for the four equations, respectively. Equations 2 and 3 were more accurate in predicting mean dry matter intake than Eq. 1 or 4.

scholarly journals Genetic evaluation for longevity of Croatian Simmental bulls using a piecewise Weibull model

2013 ◽  
Vol 56 (1) ◽  
pp. 89-101
Author(s):  
S. Jovanovac ◽  
N. Raguž ◽  
J. Sölkner ◽  
G. Mészáros
Keyword(s):  
Milk Production ◽  
Weibull Model ◽  
Fixed Time ◽  
Herd Size ◽  
Genetic Evaluation ◽  
Genetic Trend ◽  
Data Set ◽  
Breeding Values ◽  
Age At First Calving ◽  
Productive Life

Abstract. Genetic evaluation of sires for functional longevity was conducted using survival analysis techniques. The data set consisted of 49 659 Simmental cows with first calving from 1997 to 2008. A piecewise Weibull sire model was used to estimate breeding values of 251 bulls for functional length of productive life of their daughters. The model was stratified by parity i.e. a separate baseline hazard was computed for each stratum. Besides the random sire effect, the model included the fixed time independent effects of age at first calving, herd size and region as well as the time dependent effects of relative milk production and year*season of first calving. The highest impact on longevity was found for relative milk production. Cows with the lowest milk yields were at approximately 2.7 times higher risk of culling compared to cows with average milk production. Effects of age at first calving, herd size and country region had lower impact on longevity. Sire variance was 0.023 which results in a heritability of 0.06 for functional length of productive life. The average approximate reliability of estimated breeding values was 0.49. Genetic trend showed no clear tendency by year of birth of bulls.

scholarly journals Effect of Age at First Calving on First Lactation Milk Yield, Lifetime Milk Production And Longevity of Cows

2019 ◽  
Vol 19 (1) ◽  
pp. 189-200
Author(s):  
Anna Sawa ◽  
Kamil Siatka ◽  
Sylwia Krężel-Czopek
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Considerable Decrease ◽  
Age At First Calving ◽  
Productive Life ◽  
Active Population ◽  
Holstein Friesian ◽  
Effect Of Age ◽  
Friesian Cows

AbstractThe objective of the study was to analyse the effect of age at first calving (AFC) on first lactation milk yield, lifetime milk production and longevity of dairy cows. The study used SYMLEK data on the milk yield and culling of 111 857 Polish Holstein-Friesian cows from the active population in Pomerania and Kujawy, Poland. The cows first calved during 2000–2009 and were used or removed from the herds until the end of 2015. For each cow, calculations were made of first lactation milk yield, lifetime milk production, first lactation milk yield per milking day, lifetime milk production per day, as well as the lifespan (length of productive life, duration of rearing) and number of calvings. Based on the age at first calving (duration of the rearing period), the cows were grouped as follows: ≤22, 22.1–24.0, 24.1–26.0, 26.1–28.0, 28.1–30.0, 30.1–32.0 and >32 months. The GLM, CORR PEARSON and FREQ procedures from the SAS package were used in the statistical calculations. Considering first lactation milk yield, lifetime milk production and longevity, it is recommended that the cows should be first milked between 22.1 and 26.0 months of age. This is supported by the approximately 24% higher lifetime milk production in relation to the latest calving cows (P<0.01). Late commencement of the first milking (especially after 28 months) causes a considerable decrease in the first lactation milk yield and lifetime milk production, shortens the productive period, reduces the number of calvings, and increases culling rate due to low milk yield and udder diseases.

scholarly journals Impact of frequency of milking on milk yield and fertility of Holstein cows undergoing extended lactations due to failure to conceive

2021 ◽  
pp. 113
Author(s):  
Jesús Mellado ◽  
Jessica Flores ◽  
Francisco G. Véliz ◽  
Ángeles de Santiago ◽  
José E. García ◽  
...  
Keyword(s):  
Observational Study ◽  
Milk Production ◽  
Milk Yield ◽  
Reproductive Performance ◽  
The Other ◽  
Holstein Cows ◽  
Dairy Herds ◽  
Northern Mexico ◽  
Total Milk ◽  
Services Per Pregnancy

The objective of this observational study was to determine the effect of two (2x) compared to three (3x) times a day milking in Holstein cows undergoing lactations ≥600 d on milk production and reproductive performance. Two large adjacent commercial dairy herds with similar size, facilities, and management in a hot area of northern Mexico (25° N) were used. Cows in one herd (n= 214) were milked two times a day (2x), the other herd was milked three times a day (3x; n=245) and both groups were milked for at least 600 days. For cows in first lactation, total milk yield did not differ between 3x and 2x cows (19796 ± 3354 vs. 19269 ± 3652 kg; p > 0.10) in lactations with an average of 696 and 650 days in milk (DIM), respectively. Multiparous 3x cows produced more total milk days than 2x cows (20942 ± 3920 vs. 18910 ± 2632 kg; p < 0.01) with greater (p < 0.01) DIM for 3x (685 ± 117 days) than 2x (631 ± 88 days) cows. Lactation persistence was greater (p < 0.05) in 2x (62 ± 9%) than 3x (60 ± 10%) cows. Overall conception rate (CR) did not differ between 2x and 3x cows (53.3% vs. 49.8%) but 3x cows required one more service (p < 0.01) to get pregnant than 2x animals.  Given that average milk yield throughout the complete lactation did not differ between 2x (29.8 ± 2.0 kg) and 3x (29.3 ± 2.9 kg) cows, it was concluded that two-times-a-day milking is equally effective as three-times-a-day milking to attain acceptable milk yield in lactations over 600 days. However, reproductive performance based on first-service CR and services per pregnancy was negatively affected by three-times-a-day milking.

21 RELATIONSHIP BETWEEN DURATION OF ESTRUS BEHAVIOR DETERMINED BY RADIOTELEMETORY SYSTEM AND THREE FACTORS (MILK PRODUCTION, STEROID HORMONE, AND OVULATION TIME) IN DAIRY COWS

2007 ◽  
Vol 19 (1) ◽  
pp. 129 ◽  
Author(s):  
H. Yoshioka ◽  
H. Matsuda ◽  
K. Sasaguri ◽  
M. Yonai
Keyword(s):  
Dairy Cows ◽  
Steroid Hormones ◽  
Milk Production ◽  
Steroid Hormone ◽  
Low Fertility ◽  
Holstein Cows ◽  
Dairy Herds ◽  
The Past ◽  
Walking Activity ◽  
The Individual

Many studies have reported on the low fertility of dairy herds during the past several years. The object of this study was to investigate the relationships between duration of estrus and various factors (milk production, peripheral steroid hormones, and period from estrus to ovulation). All primiparous and multiparous Holstein cows (n = 62) were fitted pedometers (Gyuho; Comtec, Miyazaki, Japan) that measure total counts of walking activity per hour and send the individual cow

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