Proportional hazard models associated with the survival of dairy goats reared in a tropical environment

Ferreira, Talita Andrade; Martins, P. G. M. A.; Gouveia, Gabriela Canabrava; Abreu, Luíza Rodrigues Alves; Gouveia, Aurora Maria Guimarães; Facó, Olivardo; Colosimo, Enrico A.; Garcia, Iraídes Ferreira Furusho; Pereira, Idalmo Garcia

doi:10.1016/j.smallrumres.2020.106063

Cited by 7 publications

(5 citation statements)

References 34 publications

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“…Table 1 shows the distribution of censored and uncensored records for the length of productive life in the Florida breed. The proportion of right‐censored records was quite low (24.2%), being smaller than that reported in New Zealand dairy goats (32.85%; Gautam et al, 2017) and greater than the value observed in the Saanen breed (19.52%; Ferreira et al, 2020). LPL ranged from 214 to 4761 days (7–156 months).…”

Section: Resultsmentioning

confidence: 56%

“…In dairy goats, studies have been carried out to identify risk factors for the culling of females (Malher et al, 2001 in Alpine and Saanen; Pérez‐Razo et al, 2004 in Mexican breeds; Gautam et al, 2017 in New Zealand breed; Ferreira et al, 2020 in Saanen), but they remain scarce in comparison with the abundant information available for dairy cattle.…”

Section: Resultsmentioning

confidence: 99%

“…Comparisons with other studies are difficult because of the scarcity of studies of longevity using a proportional hazards model in dairy goats and due to differences in the definition of longevity. In fact, few studies on longevity using a Cox model have been carried out until now in dairy goats (Ferreira et al, 2020). However, these authors only evaluated the influence of environment effects, together with morphometric and type traits (Ferreira et al, 2020) or milk solids (Gautam et al, 2017) on female culling, and no genetic parameters were estimated.…”

Section: Resultsmentioning

confidence: 99%

“…In fact, few studies on longevity using a Cox model have been carried out until now in dairy goats (Ferreira et al, 2020). However, these authors only evaluated the influence of environment effects, together with morphometric and type traits (Ferreira et al, 2020) or milk solids (Gautam et al, 2017) on female culling, and no genetic parameters were estimated. Up to now, there have been no studies on the estimation of genetic parameters for productive life in Spanish dairy goats, or with a proportional hazards model, so the current study is the first one to fit these kinds of models.…”

Section: Resultsmentioning

confidence: 99%

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Survival analysis of productive life in Florida dairy goats using a Cox proportional hazards model

Ziadi

Sánchez

et al. 2023

J Animal Breeding Genetics

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Longevity is an economically important trait, since extending the functional life of a doe would allow us to keep the most productive females in the herd as long as possible, and this could result in the increased profitability of dairy farms. Thus, the objectives of this study were to determine the most important factors that influence the length of productive life (LPL) of female Florida goats and to estimate its genetic additive variance using a Cox proportional hazards model. The data consisted of 70,695 productive life records from 25,722 Florida females kidding between 2006 and 2020. A total of 19,495 does had completed their productive life while 6227 (24.2%) does had censored information. The pedigree contained information on 56,901 animals. The average censoring age and average failure age after first kidding for LPL were 36 and 47 months respectively. The model included, as time-independent effects, the age at first kidding and the interaction between herd, year and season of birth of the doe, and as time-dependent effects, the age at kidding, the interaction between herd, year and season of kidding, the within-herd class of milk production deviation, and the interaction between the lactation number and the stage of lactation. All fixed effects had a significant effect on LPL (p < 0.05). Does with older ages at the first kidding and an earlier age at kidding were at higher risk of being culled. A large difference among herds was observed in terms of culling risk, which highlighted the importance of adequate management practices. Also, high-producing does were less likely to be culled.The estimate of the additive genetic variance was 1.844 (in genetic standard deviation), with a heritability estimate of 0.58 ± 0.012. The results of this study are expected to contribute to the development of a genetic model for genetic evaluation of the length of the productive life of Spanish dairy goat breeds.

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Section: Resultsmentioning

confidence: 56%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Survival analysis of productive life in Florida dairy goats using a Cox proportional hazards model

Ziadi

Sánchez

et al. 2023

J Animal Breeding Genetics

View full text Add to dashboard Cite

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“…are being developed to investigate the time animals remain productive in a herd, under the premise that by extending the functional life of females, replacement costs will be reduced due to the better use of the animal in the system (Ferreira et al, 2020). Survival analysis is a statistical methodology that has been used to evaluate data on the time until the occurrence of an event of interest (failure time), in the presence of censorship (Colosimo & Giolo, 2006).…”

Section: Studiesmentioning

confidence: 99%

Cox-Gompertz model for analysis of the time of stay in an Anglo-Nubian goat herd

Lima

Tomazella

Júnior

et al. 2021

Semina: Ciênc. Agrár.

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Anglo-Nubian goats are hardy animals able to adapt to tropical environments, where their farming is usually held on pasture. However, climatic conditions in this environment also favor endoparasitism, which implies a negative aspect if sensitivity to worm infections interferes by reducing the reproductive lifespan of females, as their stay in the herd is a trait of great importance for efficient goat farming. In this respect, this study proposes to use the survival analysis methodology with the Cox-Gompertz proportional hazards model to assess the length of stay in the herd by relating the removal of females due to death with worm infection being the main cause to other forms of culling, using information from 101 Anglo-Nubian goats born from 2009 to 2013 in an experimental herd from Teresina - PI, Brazil. The Cox-Gompertz proportional hazards model chose body condition score, birth weight and birth season as important covariates (p-value ≤ 10%). Body condition score showed to be a favorable factor for the longer stay of the goats in the herd. Eggs per gram, age at first kidding, birth type and dam age were not significant. The Cox-Gompertz proportional hazards model is suitable for fitting the statistical model to estimate the length of stay in the herd, with censoring related to endoparasitism in Anglo-Nubian goats.

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Survival analysis as a tool for breeding management of Nile tilapia in an intensive system

Ferreira,

de Souza,

Matos

et al. 2023

Aquacult Int

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Proportional hazard models associated with the survival of dairy goats reared in a tropical environment

Cited by 7 publications

References 34 publications

Survival analysis of productive life in Florida dairy goats using a Cox proportional hazards model

Survival analysis of productive life in Florida dairy goats using a Cox proportional hazards model

Cox-Gompertz model for analysis of the time of stay in an Anglo-Nubian goat herd

Survival analysis as a tool for breeding management of Nile tilapia in an intensive system

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