A total of 240 Holstein bulls (121 ± 2.0 kg initial BW; 99 ± 1.0 d of age), from 2 consecutive fattening cycles, were randomly allocated in 1 of 6 pens and assigned to 1 of the 3 treatments consisting of different concentrate feeder designs: a control feeder with 4 feeding spaces (CF), a feeder with less concentrate capacity (CFL), and a single-space feeder with lateral protections (SF). Each pen had a straw feeder and a drinker. All animals were fed a high-concentrate diet for ad libitum intake. Concentrate consumption was recorded daily using a computerized feeder, straw consumption was recorded weekly, and BW was recorded every 14 d. Animal behavior was registered on d 1, 3, 5, 8, and 14 and every 28 d by scan sampling. Eating behavior at concentrate feeders was filmed on d 12, 125, and 206. On d 7, 120, and 204, samples of rumen contents were collected for measurement of pH and VFA and blood samples were obtained to analyze NEFA, haptoglobin, glucose, and insulin. Animals were slaughtered after 223 d, and HCW and lesions of the rumen wall and liver were recorded. The accumulative concentrate consumption per animal tended (P = 0.09) to be greater with CF than with CFL and SF. Also, CV of concentrate consumption was greater (P < 0.01) for SF than for CF or CFL. However, feeder design did not influence the other performance and carcass data. Also, no differences among treatments in rumen wall evaluation and liver abscesses were observed. At 7 and 204 d of study, SF bulls had greater (P < 0.05) rumen pH compared with CF and CFL bulls. On d 7, the acetate to propionate ratio from SF was greater (P < 0.05) than for CFL or CF. At d 7, NEFA of SF were greater (P < 0.05) compared with CF and CFL. Bulls fed with CF have the greatest (P < 0.01) concentrate disappearance velocity followed by bulls fed with CFL and finally by bulls fed with SF, and this was associated with different feeding behaviors. Bulls on SF spent more time (P < 0.05) eating straw and exhibited fewer (P < 0.05) displacements at concentrate feeder than CF and CFL bulls. The CFL bulls exhibited (P < 0.01) more attempted mounts and tended (P = 0.10) to exhibit more completed mounts than CF bulls. In conclusion, both alternative feeder designs (CFL and SF) are good strategies to reduce total concentrate consumption without impairing performance, rumen health, or animal welfare in Holstein bulls fed high-concentrate diets. However, at the beginning, there was evidence that animals fed using SF had problems with adaptation.

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The aim of this study was to characterize three different commercial dairy beef fattening systems for intensive Mediterranean fattening programs differing in gender, breed, nutrition, and days of feed in order to describe their performance, behavior, and carcass and meat quality when they were raised simultaneously under the same housing and care conditions. Treatments were three different production systems: (1) crossbred Holstein x beef breeds such as Charolais or Limousine heifers, slaughtered at 10 months of age (CBH10, n = 41); (2) Holstein bulls, slaughtered at 11 months of age (HB11, n = 42); and (3) crossbred Holstein x Angus bulls, slaughtered at 12 months of age (CAB12, n = 37). According to our results, moving from a production system based on Holstein bulls to the crossbred Angus production system has no technical support as no large production and meat quality improvements were observed, and only marketing strategies for meat differentiation and consumer trends could favor this decision.

Twenty-one crossbred Angus bulls (497 ± 7.7 kg of BW and 324 ± 3.0 d of age) were housed individually to evaluate the effect feeding method on feed intake, sorting, animal behavior, and digestibility. Dietary treatments, offered ad libitum, were: complete feed of pellet (concentrate) mixed with chopped straw (5 cm length; TMR); pellet and chopped straw (5 cm length; SS); pellet and long unprocessed straw (15–20 cm length; LS). In SS and LS straw and concentrate were fed separate feeders. Feed intake, fecal and bloat scoring were recorded daily. Behavior (scan sampling), BW, and TMR particle size sorting were recorded fortnightly. Total tract apparent digestibility (day 14 and 35) and rumen pH and VFA samples via rumenocentesis (day 28 and 42) were analyzed. Data were analyzed using a mixed-effect model. No differences in concentrate and straw intake, fecal and bloat scoring among treatments were observed. The straw to concentrate ratio did not differ between SS and LS (8 to 92), and was smaller than the ratio fixed in TMR (15 to 85). TMR bulls sorted (P &lt; 0.05) particles with a size between 1.7 and 4 mm. Treatment did not affect rumination time. TMR showed (P &lt; 0.05) more oral non-nutritive behaviors than SS. Rumen pH was greater (P &lt; 0.01) in TMR than in SS and LS, although it was above 5.6 in all treatments. Rumen acetate to propionate ratio was greater (P &lt; 0.05) in TMR than in SS and LS. LS bulls had greater DM (P &lt; 0.05) and CP (P &lt; 0.01) digestibility compared with SS or TMR bulls. Feeding concentrate and straw (short or long) separately does not increase the risk of rumen acidosis compared with TMR, and feeding long straw separately from the concentrate improves the total tract apparent DM and CP digestibility.

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