Quality and sensory milk traits of goats grazing Caatinga or confined receiving either corn or spineless cactus-based diets in the Brazilian semiarid environment

This study aimed to evaluate the yield, physical-chemical properties, fatty acid (FA) profile, and sensory traits of goat milk under different nutritional strategies in a Brazilian semiarid environment. Eighteen lactating crossbred dairy goats were distributed in a completely randomized design with three nutritional strategies: Caatinga strategy (1.5% of body weight with a concentrate supplementation), Corn-based confined strategy, and Spineless Cactus confined strategy. Daily milk yield was recorded, and milk samples were collected from all animals. Goats fed the spineless cactus-based diet presented a higher milk yield than goats feed the other strategies. Moreover, milk from goats fed with a spineless Cactus confined strategy presented higher saturated FA (SFA), and a lower proportion of cis- monounsaturated FA, trans-monounsaturated FA, and c9,t11-18:2 than milk from goats feed the other strategies. Milk from goats in the pasture system presented the highest proportions of 18:2n-6, 18:3n-3, and thus of polyunsaturated FA, when compared with milk from confined goats. We assume that milk from goats grazing in Caatinga pastures presents more benefits to human health due to the positive effects of this diet on the milk's fat content and FA profile, and this feeding strategy also results in a better sensory evaluation that may increase the acceptability of goat milk by consumers. All nutritional strategies evaluated herein and adopted in the semiarid region of Brazil are recommended for maintaining the yield, physical-chemical properties, and acceptability of milk goats.

Genetic diversity and relationships among Nopalea sp. and Opuntia spp. accessions revealed by RAPD, ISSR and ITS molecular markers

BACKGROUND

Dactylopius opuntiae (Cockerell) (carmine cochineal) is an insect pest highly noxious that has spread through cactus pear crops in the Brazilian semiarid region. Knowledge of diversity and genetic relationships of the cactus pear accessions is fundamental to create new varieties resistance to carmine cochineal. Therefore, this investigation was undertaken to assess the genetic diversity and genetic relationships that existed among cactus pear accessions of Nopalea sp. and Opuntia spp. with contrasting resistance to D. opuntiae.

METHODS AND RESULTS

We conducted a molecular analysis in seven cactus pear accessions from the "reference collection" of the Agronomic Institute of Pernambuco, Brazil using RAPD, ISSR and ITS molecular markers. A total of 242 bands were detected from 26 polymorphic primers. The high percentage of polymorphism by RAPD (89.8%), ISSR (81.2%) and ITS (75%) markers suggests that the cactus pear accessions have high genetic diversity. The combined analysis of markers systems enabled the accessions discrimination of about the genus and ploidy, but were incongruous in relation to resistance level to D. opuntiae.

CONCLUSIONS

Genetic diversity, discrimination of about the genus and ploidy was confirmed by merging information from ISSR, RAPD and ITS markers systems. The IPA-200016, IPA-200149, IPA-100004, IPA-200205 accessions are genetically divergent, therefore could be potentially incorporated into any further breeding programs directed to create new varieties of cactus pear resistant to D. opuntiae.