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Medellín, Colombia

To aim to estimate the variation in total dry matter intake (DMIt) in Holstein cows in northern Antioquia in the three thirds of lactation and in two seasons (high and low precipitation) grazing meadows kikuyo (Cenchrus clandestinus), nine cows (three by lactation third) of five herds during the 2013 rainy season and the dry season of 2014 for a total of 90 cows. Chromium oxide was used as external marker and indigestible dry matter as an internal marker to estimate the dry matter intake of prairie (DMIp). The measurement of consumption of dietary supplements made directly at the feeders during milking. Data were analyzed under a completely randomized design in a factorial arrangement 3x2 with the SAS statistical package. There was an interaction between the stage of lactation and the season, showing that DM intake of pasture was lower for cows in early lactation and in the dry season. The consumption of concentrate supplements declined with advancing lactation and increased during the dry season. The total DM intake was not affected by the stage of lactation nor the season. © 2015, Fundacion CIPAV. All rights reserved. Source

Reyes J.,University of Prince Edward Island | Chaffer M.,University of Prince Edward Island | Sanchez J.,University of Prince Edward Island | Torres G.,CES University | And 5 more authors.
Journal of Dairy Science | Year: 2015

A randomized controlled trial was performed in 17 Colombian dairy herds to determine the cure risk among cows subclinically infected with Streptococcus agalactiae exposed to 2 antibiotic therapies. Composite milk samples were collected before milking at the onset of the trial (pretreatment) and 2 subsequent times over a period of approximately 63 d. The intramammary application (IMM) of ampicillin-cloxacillin was compared with the intramuscular application (IM) of penethamate hydriodide, and cure risks after an initial and retreatment application were assessed. Cure risk after the initial treatment was higher (82.4%) for the IMM treatment than for IM therapy (65.8%). However, no difference was observed in the cure risk of refractory cases after retreatment (IMM. =. 52.6% vs. IM. =. 51.2%). The cumulative cure risk (both initial and retreatment) was 90.4 and 82.9% for the IMM and IM products, respectively. A 2-level random effects logistic model that controlled for pretreatment cow-level somatic cell count, indicated that IM treatment (odds ratio. =. 0.37) had a lower cure risk than IMM and a tendency for a lower cure risk with increasing baseline somatic cell count. Our findings suggest that both products and administration routes can reduce the prevalence of S. agalactiae in affected herds, but the IMM product had a better efficacy in curing the infection. In addition to the treatment protocol, the cow somatic cell count should be considered when making management decisions for cows infected with S. agalactiae. © 2015 American Dairy Science Association. Source

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