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Lugo, Spain

Fouz R.,Africor LUGO | Gandoy F.,Africor LUGO | Sanjuan M.L.,University of Santiago de Compostela | Yus E.,University of Santiago de Compostela | Dieguez F.J.,University of Southern California
Pesquisa Agropecuaria Brasileira

The objective of this work was to identify factors associated with the 56-day non-return rate (56-NRR) in dairy herds in the Galician region, Spain, and to estimate it for individual Holstein bulls. The experiment was carried out in herds originated from North-West Spain, from September 2008 to August 2009. Data of the 76,440 first inseminations performed during this period were gathered. Candidate factors were tested for their association with the 56-NRR by using a logistic model (binomial). Afterwards, 37 sires with a minimum of 150 first performed inseminations were individually evaluated. Logistic models were also estimated for each bull, and predicted individual 56-NRR rate values were calculated as a solution for the model parameters. Logistic regression found four major factors associated with 56-NRR in lactating cows: age at insemination, days from calving to insemination, milk production level at the time of insemination, and herd size. First-service conception rate, when a particular sire was used, was higher for heifers (0.71) than for lactating cows (0.52). Non-return rates were highly variable among bulls. A significant part of the herd-level variation of 56-NRR of Holstein cattle seems attributable to the service sire. High correlation level between observed and predicted 56-NRR was found. Source

Fouz R.,Africor LUGO | Vilar M.J.,University of Helsinki | Yus E.,University of Santiago de Compostela | Sanjuan M.-L.,University of Santiago de Compostela | Dieguez F.J.,University of Santiago de Compostela
Spanish Journal of Agricultural Research

The objective of this study was to investigate the variability in cow’s milk somatic cell counts (SCC) depending on the type of milk meter used by dairy farms for official milk recording. The study was performed in 2011 and 2012 in the major cattle area of Spain. In total, 137, 846 lactations of Holstein-Friesian cows were analysed at 1, 912 farms. A generalised least squares regression model was used for data analysis. The model showed that the milk meter had a substantial effect on the SCC for individual milk samples obtained for official milk recording. The results suggested an overestimation of the SCC in milk samples from farms that had electronic devices in comparison with farms that used portable devices and underestimation when volumetric meters are used. A weak positive correlation was observed between the SCC and the percentage of fat in individual milk samples. The results underline the importance of considering this variable when using SCC data from milk recording in the dairy herd improvement program or in quality milk programs. © 2016 INIA. Source

Mato I.,ADSG Xundeva | Pesqueira N.,ADSG Xundeva | Factor C.,ADSG Xundeva | Sanjuan M.L.,University of Santiago de Compostela | And 5 more authors.
Livestock Science

The present paper was designed to assess the effect of Mycobacterium avium subsp. paratuberculosis (MAP) infection status (antibody positive vs antibody negative, as measured by ELISA) on time to culling and calving difficulty in dairy cows. The study was carried out in 8 dairy farms in Galicia (north-west Spain). All of them were taking part in an ongoing paratuberculosis control program, as well as in a dairy herd improvement program. In order to estimate the relation between time to culling and MAP serological status of dairy cows, the present study followed the Andersen-Gill model for survival analysis. Similarly, in order to evaluate the influence on calving difficulty an ordinal logistic regression model was applied. The results indicated that seropositive cows were more likely to be culled due to death/urgent slaughter (hazard ratio=1.88), low productivity (hazard ratio=2.55), infertility (hazard ratio=4.64) and other causes (hazard ratio=1.67). Additionally, the probability of difficulties at calving time was 2.74 times higher for seropositive cows. The estimated effects could determine the economic benefits of a paratuberculosis control program. 2015 Elsevier B.V. Source

Fouz R.,Africor LUGO | Yus E.,University of Santiago de Compostela | Sanjuan M.L.,University of Santiago de Compostela | Dieguez F.J.,University of Santiago de Compostela
ITEA Informacion Tecnica Economica Agraria

The aim of the present paper was to analyze the causes for culling Holstein dairy animals using data from the Dairy Herd Improvement Program in Galicia. The information in this study was analyzed from records from the dairy herds involved in this program with data concerning only Holstein cattle. To determine the main causes for culling in the herds being studied, records from 22,177 animals (from 2,036 dairy farms) that were culled during the year 2009 were analyzed. Results indicated that in nulliparous animals, "death" was the most frequent reason for culling (63.8% of cases). Culling because of infertility represented 4.3% of losses in this age group, whereas mastitis accounted for 2.4% of losses. In animals between their first and third parities, infertility was the most common culling reason (24.7, 26.3 and 23.1% of cases, respectively). From the fourth parity on, from the assessed reasons for culling which covers 71.2% of the cases, mastitis was the most important (19.1%) followed by infertility (16.9%). The causes of culling varied according to parity, stage of lactation and morphological score of the animals with reproductive problems being the main general cause, followed by mastitis. Source

Fouz R.,Africor LUGO | Yus E.,University of Santiago de Compostela | Sanjuan M.L.,University of Santiago de Compostela | Dieguez F.J.,University of Santiago de Compostela
Livestock Science

A survey was carried out to evaluate the importance of postpartum intra-mammary infections (IMI), on the basis of somatic cell count (SCC), by characterising the behaviour of Linear Score (LS) in cows at calving, during lactation and at drying-off. Throughout 2007, a follow-up was made of 25,216 Friesian cow lactations from 1984 farms within Galician Official Milk Recording (Northwest Spain) selected by simple random sampling. SCC values were calculated from milk taken at each of the monthly tests performed on every sampled animal. Data indicated that the number of observations where LS was higher than 4 (LS > 4) as well as the mean LS during lactation and the LS at drying-off significantly increased when LS at the beginning of lactation was greater than 4. Likewise, this study showed that the probability of an animal drying-off with LS > 4 was significantly higher when the LS increased at the start of lactation. © 2009 Elsevier B.V. All rights reserved. Source

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