Impacts of trace element supplementation on productive/reproductive postpartum performances of grazing dairy heifers from volcanic soils

Abstract

This study has been designed to evaluate the effect of trace elements (TE) on the reproductive and productive performances of postpartum Holstein Friesian heifers, fed on pasture with origin on volcanic soils, poor in TE. Twenty-six heifers pregnant were divided into two groups: experimental (EG) and control (CG) groups (n=13, each group). For animals belonging to the EG, two intra-ruminal capsules with TE were administrated 60 days before partum, while in the CG, no boluses were administered. All animals' blood was collected weekly to assess progesterone levels by the ELFA technique for 11 weeks after partum. TE were evaluated on blood by AAS when the experience started, on the day of delivery, and after 60 days. Before calving, no statistical differences were observed between groups for the trace elements, although it has been noticed that heifers had deficiencies in Selenium, Copper, and Iodine. On the calving day and 60 days after, a statistical increase (p<0.05) in serum Copper and Selenium was observed in the animals belonging to the EG. For the other TE, no statistical differences were observed. Concerning reproductive characteristics, the EG, at five weeks postpartum, 70% of the cows were cyclic, while in the CG in the same period, 33% of animals showed signs of ovarian activity. At the level of productive parameters, no differences were observed between groups. The results obtained by the present study allow concluding that, under our experimental conditions, the administration of trace elements, in addition to reducing postpartum anestrus, increases the quality of the corpus luteum in the postpartum period of heifers.

Evaluation of Two Species of Macroalgae from Azores Sea as Potential Reducers of Ruminal Methane Production: In Vitro Ruminal Assay

“…The excellent soil and climate conditions for grass production in the area under study facilitate the rearing of dairy cattle, which is one of the pillars of the Azorean economy [ 1 ]. However, livestock production faces the challenge of reducing enteric methane emissions, since the weight of methane in the gas emissions profile of the Azores (69.1%), is higher than in mainland Portugal (52.4%) [ 2 ].…”

Seasonal Effect of Grass Nutritional Value on Enteric Methane Emission in Islands Pasture Systems

“…The Azores archipelago, located in the middle of the North Atlantic between latitudes 37 • and 40 • N and longitudes 25 • and 31 • W, is composed of nine islands, and has a territorial area of 223,196 ha. It presents excellent climatic conditions and fertile soils of volcanic origin, enabling direct grazing of cattle throughout the year [10]. Since 2016, the Regional Inventory of Emissions by Sources and Removals by Sinks of Air Pollutants (IRERPA) has been produced annually, where they estimate the production of enteric CH 4 from cattle based on the Tier 2 methodology [11].…”