A new genotype of spineless cactus is being used in the diets of dairy cattle that are raised in semiarid regions. However, little is known about its nutritional value. This study aimed to evaluate the effects of replacing Miúda (Nopalea cochenillifera Salm Dyck) with Orelha de Elefante Mexicana (Opuntia stricta [Haw.] Haw.) spineless cactus, on nutrient intake and digestibility, milk yield and composition, feeding behaviour, microbial protein synthesis, nitrogen balance, and ruminal and blood parameters of dairy cows. Ten Girolando cows, 500 ± 51.6 kg bodyweight, were distributed in a double Latin square design 5 x 5. The treatments consisted of replacement levels of Miúda (MIU) by Orelha de Elefante Mexicana (OEM) at 0, 25, 50, 75, and 100%. The intake and digestibility of dry matter (DM) (14.38-12.95 kg d ) and total digestible nutrients (TDN) (9.38-7.92 kg d ) increased linearly. Thus, OEM could replace 100% MIU in diets with 48% of spineless cactus, for crossbred lactating cows with 12.5 kg d -1 milk yield. Therefore, OEM is a viable new option for producing milk in smallholder livestock systems in semi-arid regions. ______________________________________________________________________________________

The objective of this work was to evaluate the nutritional value of erect prickly pear (EPP) (Opuntia stricta), stored for different periods, and its acceptability by Girolando heifers. Five heifers were distributed in a 5x5 Latin square. The treatments were as follows: EPP without storage time; stored EPP for three post-harvest periods - 7, 14, and 21 days; and cochineal nopal cactus (CNC) (Nopalea cochenillifera) without storage time, as a control treatment. The diets offered to the animals were composed of cacti of the different treatments, as well as sugarcane silage and soybean meal, and were evaluated for their chemical composition, intake, and nutrient digestibility. The ingestive behavior of the heifers was evaluated. The cactus EPP did not differ from the CNC for organic matter, crude protein, neutral detergent fiber corrected for ash and protein, nonfibrous carbohydrates, total carbohydrates, ether extract, and mineral matter; however, EPP stored for different periods differed from CNC for dry matter and indigestible neutral detergent fiber. Heifer weights varied 1.35 kg with the low inclusion of concentrate in the diet. The cactus erect prickly pear maintains constant both its nutritional value and its acceptability to Girolando heifers, after storage for different periods up to 21 days.

-The objective of this study was to evaluate the effect of different concentrate levels (40, 50, 60, and 70% on dry matter basis) on intake, digestibility of nutrients, and performance of heifers fed sugarcane bagasse as exclusive roughage. Twenty Girolando heifers, with an average body weight of 198±25.6 kg were assigned to a completely randomized design, established according to body weight.

The aim of this research was to evaluate the effect of different concentrate levels in diets based on cactus Opuntia Stricta (Haw.) Haw cladodes on the performance of lactating Girolando cows. Methods: The experiment involved 10 Girolando multiparous dairy cows at 512.6 kg of body weight (BW) and producing 13.2 kg milk/d, allocated into two 5×5 Latin squares. The experi mental treatments consisted of control diet composed by cactus Nopalea cochenillifera. Salm Dyck. cladodes (Nopalea), forage sorghum silage and concentrate at 20% on dry matter (DM) basis, and four concentrate levels diets (20%, 24%, 28%, and 32%) plus cactus Opuntia stricta (Haw.) Haw. cladodes (Opuntia) and forage sorghum silage. Results: Regarding cows fed control diet, the nutrients intake were greater than for cows fed with cactus Opuntia and concentrate. Regarding concentrate levels, intakes of DM, organic matter (OM), crude protein (CP), nonfiber carbohydrates (NFC), and total digestible nutrients of cows increased linearly. Organic matter, CP, and NDF digestibilities were similar in between to control diet and cactus Opuntiabased diets. The digestibility of NFC increased linearly when the concentrate was inserted. The N balance was the same for control diet and cactus Opuntiabased diets, irrespective the concentrate levels. Conclusion: For cows producing 14 kg/d with 3.5% of fat, it is recommended 32% of con centrate to be included in cactus Opuntiabased diets, and the increase in concentrate level promotes a linear increase in milk yield.

Spineless cactus is an important part of dairy cow diet in the semiarid Brazilia. Severe infestation of cochineal (Dactylopius opuntiae Cockerell) destroyed a vast area of the most common species of cactus planted in the region; Opuntia ficus-indica Mill. resistant varieties with superior agronomic performance were recently selected, but they still need to be tested with dairy cows. We evaluated the use of a resistant variety, ‘Orelha de Elefante Mexicana’ (OEM, Opuntia spp.), in dairy cow diet. We tested its effect on intake, nutrient digestibility, microbial protein, blood parameters and performance of lactating cows. Ten cows with an average milk yield of 20 kg/day were assigned to an experiment using a double 5 × 5 Latin square design. The experimental diets consisted of five replacement levels of Nopalea cochenillifera Salm Dyck cv. (‘Miúda’) by ‘OEM’ (0%, 25%, 50%, 75% and 100%) on a dry-matter (DM) basis) and were formulated considering the ingredient composition. The roughage:concentrate ratio was 70:30 on a DM basis. The replacement of ‘Miúda’ by OEM did not change the intake (kg/day) of DM (18.0), organic matter (16.3), crude protein (CP, 2.8), total digestible nutrients (11.6), non-fibre carbohydrates (7.6) and neutral detergent fibre (5.7), or the apparent digestibility (g/kg) of DM (655), organic matter (694), CP (739) and non-fibre carbohydrates (950), whereas apparent digestibility of neutral detergent fibre increased linearly. Microbial protein production (1.5 g/day), microbial protein efficiency (129.2 g CP/kg total digestible nutrients), plasma urea nitrogen (21.4 mg/dL), nitrogen balance (123 g/day), feed efficiency (1.1), nitrogen efficiency (0.2), milk production (20.0 kg/day), fat-corrected milk production (20.1 kg/day) and milk composition were not influenced by the replacement. Therefore, we recommend the use of OEM in the diet of lactating cows with an average milk yield of 20 kg/day.