A few years ago the carmine cochineal was introduced in the Northeast of Brazil, and its population slowly expanded across the forage cactus plantations of that region. With the occurrence of suitable growth conditions during the drought of 2012, such scale insect reached the condition of pest, and decimated or compromised the productivity of thousands of hectares of forage cactus. It is interesting to note that the long period without drought influenced farmers to neglect the renovation of their forage cactus crops, a fact that became, as from the drought of 2012, a disaster of serious consequences for the local economy. The Agronomic Institute of Pernambuco (IPA) and the Federal Rural University of Pernambuco (UFRPE) have been working with the purpose of selecting clones of forage cactus resistant to carmine cochineal, which has led to the identification of Orelha de Elefante Mexicana, Miúda, Orelha de Elefante Africana, and Sertânia genotypes. From the agronomic point of view, Orelha de Elefante Mexicana has been shown a lesser demand for nutrients, greater tolerant to water stress conditions and higher dry matter production per unit area than Miúda, the best known carmine cochineal-resistant genotype in the region. On the other hand, there is some evidence of reduced dry matter (DM) intake and performance in cows fed on Orelha de Elefante Mexicana, which appears to be associated with different factors such as high levels of malic acid, presence of hairiness, and lower DM content. Therefore, there is a need for studies with lactating cows consuming diets based on carmine cochineal-resistant genotypes as an alternative to
‘Gigante’ forage cactus, which cultivation was strongly reduced in the region due to its susceptibility to carmine cochineal. One of the main objectives of this project was to test different proportions of Miúda and Orelha de Elefante Mexicana, and to determine the concentrate levels in diets based on Orelha de Elefante Mexicana that maximize dry matter intake and milk production. Embrapa Dairy Cattle is contributing to this project through the analysis of milk fatty acid composition of cows fed on different forage cactus-based diets (to our knowledge, there are no such data in the literature) as well as through the co-advising of UFRPE graduate students who performed the experiments. The experiments were conducted at IPA Experimental Stations in Arcoverde (Girolando cows with an average milk production of 14 kg/day) and at São Bento do Una (Holstein cows with an average milk production of 20 kg/day).