Effect of processing and feeding strategy of the spineless cactus ( Opuntia fícus-indica Mill.) for lactating cows: Ingestive behavior

The aim of this study was to assess the effects of feeding strategy and processing of the spineless cactus on the ingestive behavior of lactating Holstein cows. Eight cows with a mean live weight of 453 ± 75.8 kg, production of 14 kg of milk per day and 20 weeks of lactation at the beginning of the experiment were distributed into two 4 × 4 Latin squares based on lactation order (primiparous and multiparous). The treatments were distributed in a factorial arrangement, with two forms of cactus processing knife-chopped (KC) and fodder machine (FM) and two different feeding strategies separate concentrate (SC) and total mixed ration (TMR). We visually assessed and recorded behavioral variables at 10-min intervals over 48 consecutive hours. The environment was monitored every hour from 6:00 to 18:00 h using dry-bulb and wet-bulb temperatures. There were no significant differences ( P > 0.05) in the behavioral variables between the visual observations at 24 and 48 h. Ingestion time (276 min/day, P = 0.01) and idle time (612 min/day, P = 0.005) were less when the cactus was processed using the FM than when the cactus was KC, but rumination time (522 min/day, P = 0.005 and 32.4 min/kg dry matter, P = 0.02) and mastication time (798 min/day, P = 0.03) were greater. Less time was spent on ingestion (282 min/day, P = 0.05) and rumination (480 min/day, P = 0.001) when the cactus was supplied as a SC, than when the cactus was supplied as a TMR, but idle time was greater (672 min/day, P = 0.02) with this diet. Cactus processing in a fodder machine is recommended in order to maximize the DM intake and avoid alterations in milk composition. The TMR feeding strategy is recommended in order to reduce selectivity on the part of the cows, which results in an imbalance between the diet offered and that consumed.