Functional Productive Life Research Articles

Analysis of Calving Ease and Stillbirth and Their Impact on the Length of Functional Productive Life in Slovak Holstein Cattle.

The aim of the study was to determine the frequency of births according to the categories of calving difficulty and stillbirths and to evaluate the effect of these factors on the longevity of cows. Longevity is one of the traits that affect the overall profit in the dairy industry. A Weibull proportional hazard model was used to evaluate the influence of functional traits such as calving ease and stillbirth. Longevity was expressed as the length of a functional, productive life from the first calving to death or censoring, which was corrected for milk yield. The database included 918,568 calvings, where calving without assistance represented 83.34%, calving with the assistance of one person or the use of a slight mechanical pull represented 14.47%, difficult calving with the assistance of several people, the use of mechanical traction or the intervention of a veterinarian represented 2.16%, and cesarean section represented 0.03%. The mortality of calves, stillborn or dead within 48 h of birth, represented 1.07% and 6.59%, respectively. The frequency of alive female calves was higher (46.84%) than male calves (45.50%). Cows with higher lactations had almost half as many stillborn calves as heifers. The most stillborn calves were found in difficult births (59.48%). In easy calving, this proportion was 2.48%. Using survival analysis, we estimated the significant influence of the factors such as parity, milk production, herd size, age at first calving, herd × year × season, sex of calf, calving ease, and stillbirth on the length of the functional, productive life of cows. The risk of early culling of the cows with moderately difficult calving was 1.259 times higher than in the cows with easy calving. Difficult calving and cesarean section shorten the productive life, and the risk of culling reached 1.711 and 1.894, respectively. Cows that gave birth to a dead calf achieved a 2.939 times higher risk of culling compared to cows that gave birth to a live calf. In this study, a higher risk of early culling was found in cows that gave birth to a male calf. Evaluation of the calving ease and stillbirth can be used as indirect indicators at an earlier age of the animal in the selection process for long-lived animals with good productive and reproductive performance.

Lifetime productivity: Genetic study of longevity and its associations with economically important traits in dairy buffaloes

To increase the permanence of animals in dairy herds by decreasing involuntary slaughter contributes to the development of a sustainable production system. This sustainability is the result of reduced sanitary costs, increased productive life of females, and increased animal welfare. This study aims to estimate genetic parameters for productive lifespan (PL) and functional productive life (FPL) associated with the following economically important traits: milk (MY), fat (FY), and protein yields (PY); fat percentage (%F) and protein percentage (%P); age at first calving (AFC); and calving interval (CI) in dairy buffaloes. The productive lifespan was defined at 48 (PL48), 60 (PL60), and 72 (PL72) months of age. The (co) variance components were estimated using the multi-trait model and the Gibbs2F90 software. To determine the selection effects for FPL72, a deterministic simulation was performed to obtain the direct and indirect genetic gains. Selection indices were calculated, including or excluding FPL72, considering the economic values of dairy cattle (economic values for 2010 and 2014 – EV10 and EV14). The estimates of heritability of PL and FPL were low, ranging from 0.09 to 0.15 for PL48 and PL72, respectively, and from 0.12 to 0.18 for FPL48 and FPL72, respectively. The genetic correlations of PL or FPL with the productive traits (MY, FY, and PY) ranged from low to moderate, obtaining values between 0.07 (PL48/MY) and 0.34 (FPL72/MY). The genetic correlations of PL or FPL with %F and %P presented negative values, with some values reaching near zero. The estimated genetic correlations between PL or FPL and the reproductive traits ranged from 0.16 (FPL72/CI) to -0.11 (PL48/AFC). Regarding the genetic gain for FPL72, the results showed that indirect selection can be achieved by selecting the productive traits. The expected responses for EV10 and EV14 ranged from +$102 to $147. The results indicate that FPL should be considered in water buffaloes to allow identifying efficient animals. Thus, this trait should be considered in genetic improvement programs.

Genetic evaluation of survival traits in the Holstein dairy cows of Iran

The longevity is an important functional trait for dairy cow breeders. The aim of this study is genetic evaluation of survival traits in the Holstein dairy cows of Iran. A data set of information from the Iranian Holstein dairy cows was used for this study. The culling date of 36340 animals from 65 herds recorded in 1993-2014 was used. Lifespan and Length of productive life (LPL) were analyzed for longevity. Functional productive life (FPL) was estimated. Production traits consisted of first lactation milk and fat yield. The (Co) variance, heritability and genetic correlation were estimated with multiple-trait REML using an animal model. The mean of lifespan and length of productive life were estimated to be 954(±716) and 1710(±721) days respectively. Heritability of LPL and FPL estimated as 0.032(0.012) and 0.028(0.012) respectively. The estimates of genetic and phenotypic correlations of milk yield with LPL and FPL were -0.33, 0.20, 0.10 and 0.25, respectively. Due to the decline in length of productive life, with diagnosis of the involuntary culling in herds is possible to increase the longevity.

Genetic trend of functional productive life in the population of black and white cattle in Serbia

This research was conducted with the aim ?f estimating genetic trend for a functional length of productive life (FLPL) in the population of Black and White cattle in Serbia. Research and bulls genetic evaluation for functional longevity were performed on a set of data provided by Agricultural Corporation Belgrade AD (PKB) which contained data on longevity and origin of 22109 cows out of which 26% records were right-censored. Functional length of productive life (FPLP) represents a time period from the first calving to culling or censoring corrected for milk production. Breeding values were estimated using Weibull method of proportional risks within survival analysis a genetic trend for FLPL was calculated using of a regression analysis. The cows included in the analysis were on average first calved in the age of 809 days and had an average share of 81.9% genes of Holstein Friesian breed. An average length of productive life was 1267 days (41.6 months). Distribution of bull standardised breeding values did not statistically significantly differ from normal distribution. An average standardised breeding value was 99. A slightly positive genetic trend was determined, that is, the length of functional productive life was by selection increased by 0.021 day at an annual level while a reliability of estimated breeding values showed a negative trend.

Linear and nonlinear genetic relationships between type traits and productive life in US dairy goats

Linear or nonlinear genetic relationships between productive life and functional productive life at 72 mo, with final score (SCO), stature, strength, dairyness (DAI), teat diameter, rear legs (side view), rump angle, rump width (RUW), fore udder attachment (FUA), rear udder height, rear udder arch, udder depth (UDD), suspensory ligament (SUS), and teat placement, as well as heritabilities and correlations were estimated from multibreed US dairy goat records. Productive life was defined as the total days in production until 72 mo of age (PL72) for goats having the opportunity to express the trait. Functional productive life (FPL72) was analyzed by incorporating first lactation milk yield, fat yield, protein yield, and SCO in the statistical model. Heritabilities and correlations were estimated using linear mixed models with pedigree additive genetic relationships and ASReml software. Nonlinearity of genetic relationships was assessed based on second-degree polynomial (quadratic) regression models, with the breeding values of PL72 or FPL72 as responses and the breeding values for each type trait (linear and quadratic) as predictor variables. Heritability estimates were 0.19, 0.14, 0.18, 0.20, 0.14, 0.07, 0.28, 0.20, 0.15, 0.13, 0.25, 0.18, 0.20, 0.21, 0.21, and 0.32 for PL72, FPL72, SCO, stature, strength, DAI, teat diameter, rear legs, rump angle, RUW, FUA, rear udder height, rear udder arch, UDD, SUS, and teat placement, respectively. The type traits SCO, RUW, and FUA were the most correlated with PL72 and FPL72, so these may be used as selection criteria to increase longevity in dairy goats. An increase in the coefficient of determination >1% for the second degree, compared with that for the linear model for either PL72 or FPL72, was taken as evidence of a nonlinear genetic relationship. Using this criterion, PL72 showed maximum values at intermediate scores in DAI, UDD, and RUW, and maximum values at extreme scores in FUA and SUS, whereas FPL72 showed maximum values at intermediate scores in DAI and UDD, and maximum values at extreme scores in FUA, RUW, and SUS. Selecting for increased SCO, RUW, and FUA will lead to an increase of FPL72 in goats. Consideration of nonlinear relationships between DAI, FUA, RUW, SUS, and UDD may help in the design of more efficient breeding programs for dairy goats using conformation traits.

Análisis genético para vida productiva en ganado Holstein de México

Se usó la metodología de análisis de supervivencia con un modelo de riesgos proporcionales de Weibull para estudia la duración de vida productiva funcional (DVPF) de ganado Holstein en México, usando un modelo padre-abuelo materno con el software Survival Kit V3.12. La DVPF se calculó como el número de días entre la fecha de primer parto y la fecha de desecho o censura, con un crédito máximo de 305 días por lactación. Los datos analizados se obtuvieron de la Asociación Holstein de México. El archivo final constó de 36,507 registros para DVPF de vacas que parieron por primera vez entre 1995 y 2008. El modelo incluyó la función de riesgo basal de Weibull y los siguientes efectos fijos: edad al primer parto, número de lactación por fase de lactación con cortes en los días 29, 249 y 305 y nivel de producción estandarizado con 10 clases con cambios en cada lactación, incluidas como variables tiempo dependientes y los efectos aleatorios de hato-año de parto y efectos genéticos de padre y abuelo materno. El porcentaje de censura fue de 25.54 %. Todos los efectos fijos analizados fueron significativos (P<0.0001) y tuvieron una influencia importante en el riesgo de desecho de los animales. Las heredabilidades calculadas en escalas logarítmica, original, efectiva y equivalente resultaron de 0.08, 0.13, 0.12 y 0.10 respectivamente, indicando que este carácter se puede integrar efectivamente a los programas de mejoramiento genético como se ha hecho en otras poblaciones de ganado Holstein.

Estimation of genetic parameters for productive life, reproduction, and milk-production traits in US dairy goats

Heritabilities and correlations for milk yield (MY), fat yield (FY), protein yield (PY), combined fat and protein yield (FPY), fat percentage (F%), protein percentage (P%), age at first kidding (AFK), interval between the first and second kidding (KI), and real and functional productive life at 72mo (FPL72) of 33,725 US dairy goats, were estimated using animal models. Productive life was defined as the total days in production until 72mo of age (PL72) for goats having the opportunity to express the trait. Functional productive life was obtained by correcting PL72 for MY, FY, PY, and final type score (FS). Six selection indexes were used, including or excluding PL72, with 6 groups of different economic weights, to estimate the responses to selection considering MY, FY, PY, and PL72 as selection criteria. The main criteria that determined the culling of a goat from the herd were low FS, MY, and FY per lactation. Heritability estimates were 0.22, 0.17, 0.37, 0.37, 0.38, 0.39, 0.54, 0.64, 0.09, and 0.16 for PL72, FPL72, MY, FY, PY, FPY, F%, P%, KI, and AFK, respectively. Most genetic correlations between the evaluated traits and PL72 or FPL72 were positive, except for F% (−0.04 and −0.06, respectively), P% (−0.002 and −0.03, respectively), and AFK (−0.03 and −0.01, respectively). The highest genetic correlations were between FPL72 and MY (0.39) and between PL72 and MY (0.33). Most phenotypic correlations between the traits evaluated and FPL72 and PL72 were positive (>0.23 and >0.26, respectively), except for F% (−0.004 and −0.02, respectively), P% (−0.05 and −0.02), KI (−0.01 and −0.07), and AFK (−0.08 and −0.08). The direct selection for PL72 increased it by 102.28d per generation. The use of MY, FY, PY, KI, or AFK as selection criteria increased PL72 by 39.21, 27.33, 35.90, −8.28, or 2.77d per generation, respectively. The inclusion of PL72 as selection criterion increased the expected response per generation from 0.15 to 17.35% in all selection indices studied.

Estimation of breeding values for functional productive life in the Slovak Holstein population

Genetic evaluation of length of functional productive life was carried out using a Weibull proportional hazard sire-maternal grandsire model. The database included 405 624 Holstein cows with 19.24% censoring. The analyzed effects were parity × stage of lactation, within-herd standard deviations of milk production, herd × year × season interaction, change of herd size with respect to the previous year, age at first calving, and sire and maternal-grandsire effects. Parity × stage of lactation had the most important influence on functional productive life. The results of the analysis confirmed more intensive selection at the beginning of each lactation, whereby the risk ratio increased with each other lactation. Heritability of functional productive life was 0.13 on the original scale. Breeding values of sires were expressed as relative breeding values with a mean of 100 and genetic standard deviation of 12.  

Genetic evaluation of the functional productive life in Slovak Simmental cattle

Abstract. Genetic evaluation of sires based on length of functional productive life of their daughters was carried out using a Weibull proportional hazard sire-maternal grandsire model. The data consisted of 214634 registered Slovak Simmental cows with censoring of 21.34%. Besides the random sire and maternal grandsire effects, the model included time dependent effects parity × stage of lactation interaction, within-herd standard deviations of milk production, herd × year × season interaction, change of herd size with respect to the previous year, and time independent effect age at first calving. Within-herd, the standard deviations of milk production had the most important influence on functional productive life. The highest risk of culling was found in cows with the lowest milk production class (uncompleted lactation). Risk of culling decreased with an increasing milk production class. Estimated heritability of functional productive life was 0.05 on the original scale. Breeding values of sires expressed as a risk ratio of their daughters were between −0.57 and 0.53.

Surgical, Anesthetic, Perfusion-Related Advances in Minimal Access Surgery

As we enter the fifth decade in cardiac surgery, traditionally cardiac surgery has been performed using a median sternotomy with cardiopulmonary bypass providing great access to the heart and all the surrounding structures. During the last decade, there has been a paradigm shift in the methods by which surgery has been performed. The invasiveness of many procedures has been dramatically reduced, with significantly superior outcomes, as evidenced by improved survival, fewer complications, and quicker return to functional health and productive life. This resulted in significant interest and excitement in adopting less invasive techniques in cardiac surgery. Unfortunately, this was an unrealistic expectation due to the limitations that existed in cardiac surgical techniques and conventional endoscopic instruments, cardiac anesthesia, and cardiopulmonary bypass techniques. In this article, the advances in minimally invasive surgical, cardiac anesthesia, and cardiopulmonary bypass techniques in the evolution of minimal access cardiac surgery are summarized.

Relationships between conformation traits and longevity of Holstein cows in the Czech Republic

The relationships between conformation traits and longevity traits were analyzed in 41 489 Holstein cows born in the years 1994–1999 which were culled by 30<sup>th</sup> June 2005. Pearson correlation coefficients between type traits and the herd life or productive life of cows were calculated. The effects of type trait scoring level on the length of productive life were described by means of analyses of variance. The observed correlations between herd life or productive life and type traits are in the range of –0.061 to 0.160. Negative correlations were found for rump angle, rear leg set, udder depth, and teat length. Most of the body traits had slightly positive relationships to herd life, indicating that larger cows live longer. However, body depth and chest width did not have a linear relation to longevity traits. The longest productive life was found in cows undersized in chest width and body depth (P < 0.01). A similar dependence was also found for rump width (P < 0.01). The ideal rear leg set for longevity was scored as average or below average, i.e. moderately curved or slightly straight legs (P < 0.05). Cows with well-attached fore udder, high attached rear udder, strong central ligament, close front teat placement, and with moderately long teats showed the longest functional productive life (P < 0.05–0.001). Linear relationships between longevity traits and general conformation characteristics were found as well.  

Genetic evaluation of productive life in Iranian Holstein using survival analysis

Improvement of herd life increases profitability due to lower replacement costs of heifers, higher proportion of mature cows that produce at their maximum potential and increased opportunity for voluntary culling. Functional productive life (PL) after adjustment for production is the ability of a cow to remain healthy and delay involuntary culling (Ducrocq et al 1988). Survival or failure time analysis has replaced linear model approaches for routine genetic evaluation of dairy cattle in several countries (Sewalem et. al. 2003). It allows proper treatment of censored data, inclusion of time-dependent covariates and skewed or non normal distribution of data. Approximate estimates of the heritability of longevity traits typically range from 0.05 to 0.10 and 0.15 to 0.20 using linear models and survival analysis, respectively (Vollema et al. 2000 and Caraviello et. al. 2004). The objective of this study was to apply survival analysis methodology for assessing the most important factor influencing PL, estimation of genetic parameters of productive life and genetic evaluation in Iranian Holstein dairy cattle.

Implementation of a Routine Genetic Evaluation for Longevity Based on Survival Analysis Techniques in Dairy Cattle Populations in Switzerland

Genetic evaluation of sires for functional longevity of their daughters based on survival analysis has been implemented in the populations of Braunvieh, Simmental, and Holstein cattle in Switzerland. A Weibull mixed sire-maternal grandsire survival model was used to estimate breeding values of sires with data on cows that calved since April 1, 1980. Data on Braunvieh and Simmental cows included about 1.1million records, data on Holstein cows comprised about 220,000 records. Data contained approximately 20 to 24% right-censored records and 6 to 9% left-truncated records. Besides the random sire and maternal grandsire effects, the model included effects of herd-year-season, age at first calving, parity, stage of lactation, alpine pasturing (Braunvieh and Simmental), and relative milk yield and relative fat and protein percentage within herd to account for culling for production. Heritability of functional longevity, estimated on a subset of data including approximately 150,000 animals, were 0.181, 0.198, and 0.184 for Braunvieh, Simmental, and Holstein, respectively. Breeding values were estimated for all sires with at least six daughters or three granddaughters in the data. Breeding values of sires are expressed in months of functional productive life and published in sire catalogs along with breeding values for production traits.

Genetic Evaluation for Longevity of Dutch Dairy Bulls

Parameters needed for survival analysis of longevity records of cows to predict breeding values of their sires were estimated with data on Dutch Black and White and Red and White cows. The heritabilities of functional productive life were 0.041 and 0.036 on the log scale for Black and White and Red and White cows, respectively. Although the heritabilities and other parameters differed between both breeds, the resulting breeding values were hardly affected: the correlation between breeding values of Red and White bulls using either Red and White parameters or Black and White parameters was 0.992. Genetic correlations between the direct breeding value for functional longevity (based solely on longevity of sires’ daughters) and breeding values for conformation, health, and fertility traits were calculated. Several alternative selection indices were investigated using these correlations. Based on the resulting reliabilities, it was concluded that the Dutch breeding value for functional longevity should be based on longevity, rump angle, teat placement, udder depth, feet and legs, and somatic cell count. The index was expressed on a scale with average of 100 and a standard deviation of 4 points (at 80% reliability). The economic value was Dfl. 65 per genetic standard deviation, which was 0.46 times the economic value of INET (Net Milk Revenue Index). For the breeding value for functional longevity that was first published in August 1999, slight modifications in the model were made.

Genetic parameters of functional and fertility determined length of productive life in Swedish dairy cattle

AbstractThe objective of this study was to estimate genetic parameters and breeding values of sires for different definitions of length of productive life in Swedish Red and White dairy cattle. The data consisted of 534 016 daughters with initial calvings between 1988 and 1996. These cows were daughters of 1266 sires (55 of which were considered proven bulls, and treated as fixed effects). The model for the hazard included: a random time-dependent effect of herd-year-season (hys), a fixed time-dependent effect of year-season, a fixed time-dependent effect of parity by stage of lactation, a fixed time-dependent effect of the cow’s peak yield as deviation from her herdmates in that herd-year, a fixed time-independent effect of age at first calving, and random and fixed effects of sire. The hys effect was assumed to follow a gamma distribution and the random sire effect a normal distribution with mean zero and variance Aσ2s, where σ2s is the variance among sires and A the relationship matrix. Length of productive life was defined as the number of days from first calving to culling or end of data. Two types of length of productive life were studied: (1) functional productive life (PL), all cows that were culled before the end of data were considered as uncensored; (2) fertility determined productive life (FPL), only cows that were culled for fertility problems were considered as uncensored. Heritability estimates were 6·9% and 6·1% for PL and FPL, respectively. The approximated genetic correlation estimates between fertility measures in first lactation and FPL was higher than the corresponding estimates with PL. In conclusion, it was feasible to use the trait fertility-determined length of productive life, its heritability was almost as large as for PL, and the genetic correlation with fertility was higher than for PL. However, the expected selection response in fertility from indirect selection on FPL was lower than from direct selection.

Genetic relationships among longevity, milk production, and type traits in Swiss Brown cattle

Abstract The length of productive life and its relationships with production and type traits in Swiss Brown cattle was investigated using data from test sire progeny type evaluation. Data included records on 9 224 daughters of 274 sires, which had an opportunity to stay in the herd for at least 84 mo. True (TPL) and functional (FPL) productive life observed 48, 66, and 84 mo after first calving were analysed. FPL was computed by adjusting TPL for first lactation milk yield relative to herd average. Production traits included first lactation milk, fat and protein yield and fat and protein content. Type traits included measurements for wither height and heart girth and numerical scores of 16 other traits. (Co) variances were estimated with multiple-trait REML using a sire model. Heritabilities for all herd life measures ranged from 0.03 to 0.14 and were considerably higher for TPL than for FPL. Genetic correlations among TPL and corresponding FPL measures were approximately 0.8. The genetic correlations between yield traits and both TPL and FPL were positive and on the average amounted to 0.75 for TPL and 0.35 for FPL. The phenotypic correlations for FPL were all close to zero. Almost all type traits were positively correlated with productive life. The highest genetic correlations were obtained between productive life and udder and teat traits.