ABSTRACT.- The objective of the study was to determine if a feeding system with a variable supply of grass promoted rapid changes in the fatty acid profile and technological and health indices of milk obtained from North American (NAHF) and New Zealand (NZHF) Holstein-Friesian cows. Two feeding strategies were conducted: fixed grass (GFix) and maximized grass intake when available (GMax).

Increasing production efficiency is key to meet the growing global demand for animal products in the future and to improve sustainability of production systems. The aim of this work is to evaluate the correlation between different production indices that would allow to select more efficient animals within their production systems.

Mitochondrial fatty acid (FA) oxidation is a major source of energy, providing substrates for oxidative phosphorylation and ketogenesis.

Contenido. Síntesis de la Situación Agroclimática de Mayo-- Perspectivas Climáticas Trimestrales elaboradas por el IRI de la Universidad de Columbia (Más información puede encontrarse en el sitio del IRI:http://www.iri.columbia.edu) -- Índice de Vegetación (NDVI) -- Precipitaciones -- Porcentaje de Agua Disponible (PAD) -- Agua No Retenida (ANR) -- Índice de Bienestar Hídrico (IBH) -- Perspectivas Climáticas Jun-Jul-Ago elaboradas por el IRI de la Universidad de Columbia. Destacamos para este mes:Previsión de temperaturas mínimas.

The temperament of dairy cows interferes in milk yield and quality, but there is a lack of consensus throughout the literature. Thus, systematic review (SR) and meta-analysis (MA) methodologies were used to assess the effects of dairy cow temperament on milk yield. Our literature search included four electronic databases (CABI Abstracts, Web of Science, PubMed, and Scopus) and bibliographies of the publications included on MA. As inclusion criteria, we considered publications about the temperament of lactating cows and its effect on daily milk yield and total milk yield (whole lactation).

The temperament of dairy cows interferes in milk yield and quality, but there is a lack of consensus throughout the literature. Thus, systematic review (SR) and meta-analysis (MA) methodologies were used to assess the effects of dairy cow temperament on milk yield. Our literature search included four electronic databases (CABI Abstracts, Web of Science, PubMed, and Scopus) and bibliographies of the publications included on MA. As inclusion criteria, we considered publications about the temperament of lactating cows and its effect on daily milk yield and total milk yield (whole lactation).

ABSTRACT.- In pasture-based dairy systems, grazing management strategies have focused mainly on achieving a high herbage harvest per hectare, whereas strategies oriented to maximizing the intake rate of herbage have been recently explored.

ABSTRACT.- The transition from pregnant non lactating condition to non pregnant lactating status is a period of dramatic changes for the cow, which has to adapt its metabolism to the strong requirements for milk production. From the equilibrium that the cow resolves this period will depend the capacity to maximize milk production and quality, to evade metabolic diseases and ensure the following pregnancy.

ABSTRACT.- The transition from pregnant non lactating condition to non pregnant lactating status is a period of dramatic changes for the cow, which has to adapt its metabolism to the strong requirements for milk production. From the equilibrium that the cow resolves this period will depend the capacity to maximize milk production and quality, to evade metabolic diseases and ensure the following pregnancy.

ABSTRACT.- Newborn ruminants depend on colostrum intake immediately after birth to obtain immunoglobulins for effective transfer of passive immunity (TPI). As colostrum may also be a vehicle of infectious agents, heat treatment of raw colostrum is a practice aimed at eliminating or reducing its pathogen load. Despite the usefulness of heat treatment in preventing the transmission of infectious colostrum-borne diseases, heat treatment of colostrum may have some side effects.