The objective of this study was to evaluate the effect of replacing grain sorghum (GS) with palm kernel cake (PKC) on the performance, carcass traits and meat quality of feedlot steers fed high-grain diets. Forty male ¹/4 Holstein * ¹/4 Nellore steers with an initial weight of 331.1 ± 36.2 kg, at 24 ± 2 months of age, were housed in group stalls (10 cattle/stall) where they received diets containing 0, 80, 160, or 240 g/kg PKC on a dietary dry matter basis. After 126 days, the animals were slaughtered and their carcass and meat evaluated. The replacement of GS with PKC did not influence empty body weight, carcass weight, carcass length, or carcass yield. However, the thickness of subcutaneous fat in the carcass decreased with the replacement of GS with PKC. The meat pH increased linearly, whereas there were no changes in cooking loss, shear force, lightness (L*), and fat or cholesterol contents in the meat of the steers. Partial replacement (41,57%) of GS with PKC is recommended, with an inclusion of up to 240 g/kg PKC in high-grain diets for steers.

A high-grain diet is essential to maximize growth and yield as well as to provide high-quality meat in beef cattle. This study evaluated the effects of including licuri cake in high-grain diets for steers on performance and carcass and meat quality. Forty-four crossbred (1/2 Bos taurus χ 1/2 Bos indicus) castrated steers at 24 months of age, with an initial weight of 358.19 ± 41.57 kg, were used. The animals were distributed into four treatments that consisted of diets including licuri cake (0, 85, 170, or 255 g/kg, dry matter basis). Dry matter intake and digestibility decreased with the inclusion of licuri cake in the diet. However, the addition of the ingredient did not influence the intakes of total digestible nutrients (6.7 ± 0.5 kg/day) or crude protein. Licuri cake inclusion did not influence weight gain (1.5 ± 0.2 kg/day) or hot carcass weight (255.1 ± 24.9 kg). There was also no effect on carcass fat thickness, whereas the cholesterol content in the meat decreased with the addition of the cake. We recommend the inclusion of up to 255 g/kg licuri cake in the diet of feedlot steers fed high-concentrate diets.

Resumo As moscas-das-frutas (Diptera: Tephritidae) representam um risco à fruticultura mundial, especialmente na cultura dos citros, entretanto estudos biológicos demonstram que as moscas-das-frutas não estão perfeitamente adaptadas à estes hospedeiros. Este estudo investigou a oviposição de Anastrepha fraterculus (Wiedemann, 1830) e Ceratitis capitata (Wiedemann, 1824) e sua relação com o pericarpo de frutos cítricos. Foi avaliada a relação entre a profundidade de oviposição de A. fraterculus e de C. capitata e a espessura do epicarpo dos frutos de laranjeira [Citrus sinensis (L.) Osbeck)] ‘Navelina’ e tangerineira [C. reticulata (L.)] ‘Clemenules’ e a influência do mesocarpo de frutos de tangerineira ‘Clemenules’ na oviposição destas espécies. O estudo foi conduzido em condições controladas de temperatura (25 ± 2 °C), umidade relativa (70 ± 10%) e fotofase (12 horas). A. fraterculus e C. capitata depositaram ovos no flavedo de frutos de laranjeira ‘Navelina’ e entre o flavedo e o albedo de frutos de tangerineira ‘Clemenules’. Quando oferecido frutos com mesocarpo exposto, não houve oviposição por ambas as espécies de mosca. Os resultados demonstram que a espessura do epicarpo de frutos cítricos não influenciou a oviposição de A. fraterculus e de C. capitata, a qual não ocorreu na presença apenas do mesocarpo, sugerindo que outros fatores estão envolvidos na oviposição por estas espécies.

Abstract Fruit flies (Diptera: Tephritidae) represent a threat to fruit growing worldwide, mainly the citrus culture, however, biological studies show that fruit flies are not perfectly adapted to this host. This study investigated oviposition of Anastrepha fraterculus (Wiedemann, 1830) and Ceratitis capitata (Wiedemann, 1824) and its relation with the pericarp of citrus fruits. We evaluated the relationship between depth of oviposition of A. fraterculus and C. capitata and epicarp thickness of orange [Citrus sinensis (L.) Osbeck)] ‘Navelina’ and tangerine [C. reticulata (L.)] ‘Clemenules’ and the influence of fruit mesocarp of tangerine ‘Clemenules’ on oviposition of these species. The study was conducted under controlled conditions of temperature (25 ± 2 °C), relative humidity (70 ± 10% RH) and photophase (12 h). A. fraterculus and C. capitata laid their eggs in the flavedo region of orange ‘Navelina’ and between the albedo and flavedo of tangerine ‘Clemenules’. When fruits with mesocarp exposed were offered, there was no oviposition by both fruit fly species. The results show that epicarp thickness of citrus fruits did not influence oviposition of A. fraterculus and C. capitata as oviposition did not occur only in the presence of the mesocarp, suggesting that other factors are involved in oviposition of these species.