Impact of management factors on days to conception in dairy heifers
Increasing the number of pregnant heifers per time unit improves reproductive efficiency in dairy herds. The objective of this work was to analyze the effect of management factors on conception. Reproductive events of 2532 heifers throughout 37 years were analyzed adjusting proportional risk models....
| Main Authors: | , , , , , |
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| Format: | Online |
| Language: | spa |
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Facultad de Ciencias Agropecuarias
2020
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| Online Access: | https://revistas.unc.edu.ar/index.php/agris/article/view/25979 |
| _version_ | 1838390406053625856 |
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| author | Vera, Milba Marina Piccardi, Monica Maciel, Martin Franco, Liliana Mezzadra, Carlos Balzarini, Monica |
| author_facet | Vera, Milba Marina Piccardi, Monica Maciel, Martin Franco, Liliana Mezzadra, Carlos Balzarini, Monica |
| author_sort | Vera, Milba Marina |
| collection | Portal de Revistas |
| description | Increasing the number of pregnant heifers per time unit improves reproductive efficiency in dairy herds. The objective of this work was to analyze the effect of management factors on conception. Reproductive events of 2532 heifers throughout 37 years were analyzed adjusting proportional risk models. Days to conception (DC) were measured as the interval in days from the start of the service period (IPS) to conception. The observation period per animal was 90 days. Models adjusted for DC include effects of age at IPS, year, number and season of services, conception rate of bulls, and year-to-season interaction with services. The Weibull model adjusts the DC variation pattern. Conception was lower in heifers under 18 months, in the 2nd and 3rd service, and when bulls with less conception rate were used. Conception was higher in fall services by 1.17 times compared to spring services. Identifying management factors affecting days to conception in heifers allows developing strategies to improve reproductive efficiency in dairy herds. |
| format | Online |
| id | oai:ojs.revistas.unc.edu.ar:article-25979 |
| institution | Universidad Nacional de Cordoba |
| language | spa |
| publishDate | 2020 |
| publisher | Facultad de Ciencias Agropecuarias |
| record_format | ojs |
| spelling | oai:ojs.revistas.unc.edu.ar:article-259792023-11-30T18:46:14Z Impact of management factors on days to conception in dairy heifers Impacto de factores de manejo sobre la concepción en vaquillonas lecheras Vera, Milba Marina Piccardi, Monica Maciel, Martin Franco, Liliana Mezzadra, Carlos Balzarini, Monica Survival analysis reproductive efficiency conception rates eficiencia reproductiva modelo de riesgos proporcionales tasa de concepción Increasing the number of pregnant heifers per time unit improves reproductive efficiency in dairy herds. The objective of this work was to analyze the effect of management factors on conception. Reproductive events of 2532 heifers throughout 37 years were analyzed adjusting proportional risk models. Days to conception (DC) were measured as the interval in days from the start of the service period (IPS) to conception. The observation period per animal was 90 days. Models adjusted for DC include effects of age at IPS, year, number and season of services, conception rate of bulls, and year-to-season interaction with services. The Weibull model adjusts the DC variation pattern. Conception was lower in heifers under 18 months, in the 2nd and 3rd service, and when bulls with less conception rate were used. Conception was higher in fall services by 1.17 times compared to spring services. Identifying management factors affecting days to conception in heifers allows developing strategies to improve reproductive efficiency in dairy herds. El incremento del número de vaquillonas preñadas por unidad de tiempo mejora la eficiencia reproductiva en rodeos lecheros. El objetivo de este trabajo fue analizar el efecto de factores de manejo sobre la concepción. Se analizaron eventos reproductivos en 2532 vaquillonas, ocurridos en 37 años, ajustando modelos de riesgos proporcionales. Los días a la concepción (DC) se midieron como el intervalo en días entre el inicio del período de los servicios (IPS) y la concepción. El período total de observación, por animal, fue de 90 días. Los modelos ajustados para DC incluyeron efectos de edad al IPS, año, número y estación de los servicios, tasa de concepción de los toros y la interacción año con estación de los servicios. El modelo Weibull ajustó el patrón de variación de DC. La concepción fue menor en vaquillonas de hasta 18 meses, en el 2° y 3er servicio, y cuando se usaron toros con baja tasa de concepción. La concepción aumentó en los servicios de otoño en 1,17 veces respecto a las de primavera. La identificación de factores de manejo que afectan los días a la concepción en vaquillonas permite corregir estrategias para mejorar la eficiencia reproductiva en el rodeo. Facultad de Ciencias Agropecuarias 2020-06-30 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion application/pdf https://revistas.unc.edu.ar/index.php/agris/article/view/25979 10.31047/1668.298x.v37.n1.25979 AgriScientia; Vol. 37 No. 1 (2020); 33-40 AgriScientia; Vol. 37 Núm. 1 (2020); 33-40 1668-298X 10.31047/1668.298x.v37.n1 spa https://revistas.unc.edu.ar/index.php/agris/article/view/25979/30033 Derechos de autor 2020 Milba Marina Vera, Monica Piccardi, Martin Maciel, Liliana Franco, Carlos Mezzadra, Monica Balzarini https://creativecommons.org/licenses/by-sa/4.0 |
| spellingShingle | Survival analysis reproductive efficiency conception rates eficiencia reproductiva modelo de riesgos proporcionales tasa de concepción Vera, Milba Marina Piccardi, Monica Maciel, Martin Franco, Liliana Mezzadra, Carlos Balzarini, Monica Impact of management factors on days to conception in dairy heifers |
| title | Impact of management factors on days to conception in dairy heifers |
| title_alt | Impacto de factores de manejo sobre la concepción en vaquillonas lecheras |
| title_full | Impact of management factors on days to conception in dairy heifers |
| title_fullStr | Impact of management factors on days to conception in dairy heifers |
| title_full_unstemmed | Impact of management factors on days to conception in dairy heifers |
| title_short | Impact of management factors on days to conception in dairy heifers |
| title_sort | impact of management factors on days to conception in dairy heifers |
| topic | Survival analysis reproductive efficiency conception rates eficiencia reproductiva modelo de riesgos proporcionales tasa de concepción |
| topic_facet | Survival analysis reproductive efficiency conception rates eficiencia reproductiva modelo de riesgos proporcionales tasa de concepción |
| url | https://revistas.unc.edu.ar/index.php/agris/article/view/25979 |
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