The study aimed at comparing three strategies of supplementing selenium (Se) during the finishing period of Charolais young bulls:(1) administration of sodium selenite throughout the finishing (NaSe); (2) administration of an Se-enriched yeast strain (Saccharomyces cerevisiae NCYC R397) throughout the finishing (Se-Y); (3) administration of sodium selenite for 140 days replaced by Se-enriched yeast during the last 70 days of finishing (Switch). Eighty-four young bulls (mean initial BW 5 434.2 6 31.9 kg; mean age 5 382 6 52 days) were stratified by live weight and equally assigned to one of three Se treatments. Experimental groups were fed the same diets and the inclusion rate of the different treatments was targeted to achieve 0.3 mg of Se/kg of dry matter (DM) in the complete feed. The average daily gain of bulls was 1.36 kg/d and no differences due to Se treatment were recorded. Dry matter intake and feed conversion ratio were not affected by Se treatment resulting in, on average, 10.3 kg/d and 7.65, respectively. Repeated blood samples were taken at days 0, 120, 180 and 210 of finishing to assess the Se status of the animals. As compared to NaSe, both organic Se treatments (Se-Y and Switch) increased plasma Se in the last two sampling sessions according to a significant treatment 3 time interaction (P , 0.001). A similar trend was observed for serum total antioxidant status of the young bulls, whereas there was only a significant time effect (P , 0.001) on glutathione peroxidase activity that was raised by all Se treatments. The finishing period lasted 210 days and at the abattoir there were no differences across Se treatments in carcass weight and dressing percentage. A higher Se content in the Longissimus thoracis (LT) muscle was instead observed in Se-Y samples as compared with NaSe (0.85 v. 0.47 mg/kg DM; P , 0.05). Meat quality evaluation was carried out on LT samples after 6 and 11 days of ageing under a vacuum package. Regardless of ageing time, meat from young bulls supplemented with Se yeast had higher colour lightness (L*) values than those receiving NaSe (38.1 v. 36.6; P , 0.01) and showed a significant decrease in shear force (3.69 v. 4.22 kg/cm 2 ; P , 0.01). The outcomes of the study suggest that the provision of Se yeast throughout the finishing period is a strategy to increase the benefits of the replacement of sodium selenite with organic selenium in beef cattle.

Polish Friesian male calves (n = 78) were used to investigate the effects of innovative feeding plans based on the provision of large amounts of solid feeds on growth performance, welfare, and carcass characteristics of veal calves. Groups of calves (initial BW 71.5 ± 3.7 kg) were fed 1 of 3 treatments (26 calves/treatment): 1) milk replacer plus corn grain (CG), 2) milk replacer plus an 80:20 mixture (as-fed basis) of corn grain and wheat straw (CGS), or 3) milk replacer plus a 72:20:8 mixture (as-fed basis) of corn grain, wheat straw, and extruded soybean, respectively (CGSES). All the treatments provided at least 170 kg DM/calf from solid feed throughout the 206 d of fattening. Type and concentration of milk replacer were the same for all calves throughout fattening. Calves fed CGSES received 96% of the daily amount of milk replacer delivered to CG and CGS to balance the dietary CP content. No differences (P ≥ 0.063) among treatments were observed for growth performance and DMI. Health status of CG calves was less than CGSES calves, as indicated by the greatest (P < 0.001) proportion of milk replacer refusal events and the greatest (P < 0.001) incidence of treatments for respiratory disorders. Inclusion of straw and soybean in the solid feeds increased (P < 0.001) the daily intake of iron in CGS and CGSES as compared with CG; however, blood hemoglobin concentrations measured at d 5 and 31 were greater (P < 0.05) than when measured on d 80, 122, and 206 of fattening. Feeding treatment did not (P ≥ 0.107) affect HCW, dressing percentage, or carcass color. Calves fed CG had heavier (P < 0.001) reticulorumens and more (P < 0.001) developed rumens than CGS and CGSES calves, but 84% and 68% of CG rumens (P < 0.001) showed overt signs of hyperkeratinization and plaques, respectively. These alterations of rumen mucosa were not detected in CGSES calves, and only 8% of CGS calves had rumen plaques. Regardless of feeding treatment, postmortem inspection recorded a prevalence of more than 84% abomasal lesions. When feeding veal calves with large amounts of solids, it is advisable to avoid the provision of corn grain alone and replace part of the cereal with a roughage source to improve calf health and prevent rumen mucosa alterations.

The aim of this study was to compare a fully slatted concrete floor (concrete slatted (CS)) with the same floor on which synthetic rubber slats were placed on the concrete slats (rubber slatted (RS)) as housing solution for finishing beef cattle. The present study involved five commercial beef cattle farms in which the floor of at least three pens was kept as fully slatted, and in an equal number of pens a rubber cover was placed on the floor, tightly matching the gap profile of the concrete slats to allow the drainage of manure. A total of 326 finishing beef bulls were used (153 on CS and 173 on RS), and regardless of the floor treatment animals were housed in groups of 6 to 12 bulls/pen with a space allowance of 3.1 ± 0.2 m 2 /bull. Bulls had similar initial live weights (422.3 kg on CS and 425.0 kg on RS), but bulls on RS were heavier at the end of the finishing period with a higher average daily gain than bulls kept on CS (1.53 v. 1.46 kg/day; P < 0.05). The proportion of bulls treated for locomotor problems was lower in RS pens compared with CS. Rubber covering prevented the occurrence of bursitis, but it increased the odds for hoof overgrowth at end of the finishing period. Hoof overgrowth detected in vivo in bulls on RS was confirmed at the slaughterhouse by the longer dorsal wall and diagonal lengths of the hoof as well as by a more acute toe angle. Compared with bulls on CS, bulls on RS showed less inactivity and resting time, increased social interactions, decreased abnormal lying down and unsuccessful attempts to lie down, as well as shortened the time for lying down. Bulls in RS pens were dirtier compared with those in CS pens, likely due to the draining gaps being reduced to 11.6 ± 1.2% of the total pen surface compared with the 16.9 ± 1.7% in CS pens. This study gave further evidence about the positive effects of the RS floor on growth performance and welfare of finishing beef cattle, although compromising cleanliness and hoof overgrowth.Keywords: beef cattle, welfare, slatted floor, rubber covering ImplicationsFinishing beef cattle in pens with floors that both improve animal welfare and reduce labour as that required for deep litter management is quite challenging. This study gives evidence of how covering the fully slatted concrete floor with rubber slats resulted in a reduced number of treatments for locomotor problems and a lower percentage of bulls with bursitis. The rubber allowed better expression of the speciesspecific behavioural pattern and enhanced bulls' growth performance. The negative effects of this type and design of rubber surface on bulls' cleanliness and hoof overgrowth might be reduced by improved drainage and abrasion.

The study compared the effects of enriching a basic solid feed mixture made of corn grain and straw with a protein source (extruded pea) or with urea on growth, health, behavior, and carcass quality of veal calves. Seventy-nine calves, divided according to their initial body weight (59.8 ± 6.9 kg) into 3 groups (5 pens of 5 or 6 animals per group), were allotted to 1 of 3 experimental feeding treatments: milk replacer plus an 85:15 (as-fed basis) mixture of corn grain and wheat straw (CGS); milk replacer plus a 72:15:13 mixture of corn grain, wheat straw, and extruded pea (CGS-EP); or milk replacer plus an 83.3:16:0.7 mixture of corn grain, wheat straw, and urea (CGS-U). All feeding treatments were targeted to provide 140 kg of dry matter (DM)/calf of solid feed during the 201-d fattening cycle, and the greater crude protein content of the mixtures supplemented with protein or urea was balanced by restricting to 96% the daily amount of milk replacer delivered to CGS. Results did not differ among feeding treatments for average daily gain or solid feed intake but, net of meal refusal events, the average daily intake of milk replacer was 1.73, 1.66, and 1.60 kg of DM/calf for CGS, CGS-EP, and CGS-U, respectively. The overall mean hemoglobin values from samples taken at d 11, 40, 83, 126, and 196 were lower for CGS-U calves (9.1 ± 0.2 g/dL) compared with CGS (9.8 ± 0.2 g/dL), whereas those of CGS-EP were intermediate (9.4 ± 0.2 g/dL). Behavioral observations showed a frequency of oral stereotypes <1.2% for all feeding treatments. Longer eating and chewing or ruminating time was recorded for CGS-U calves compared with CGS and CGS-EP calves. All carcasses had satisfactory color for the veal market and none of the carcass traits were affected by the feeding treatments. The proportions of tongues and lungs with signs of lesions, forestomach development, abomasal lesions, and rumen plaques did not differ among feeding treatments. Hyperkeratinization of rumen papillae was observed only in CGS-U calves with a prevalence of 11.3%. Based on these findings, providing a corn grain and straw solid feed mixture enriched with extruded pea or urea was an effective strategy to reduce milk replacer consumption, lowering total feeding cost per calf by 3.0 to 3.4% and 6.9 to 7.2%, respectively. This economic advantage was supported by the lack of detrimental effects on calf growth performance, behavior, and carcass quality. However, the occurrence of rumen papillae hyperkeratosis may raise some concerns about the use of urea.

The study compared behaviour and clinical parameters of beef cattle housed on two different types of floor (fully slatted vs. deep litter) considering animals belonging to 2 live weight classes (less vs. more than 350 kg). The assessment of behavioural and clinical parameters was carried out in 20 intensive farms, all rearing imported bulls. Floor type had no effect on cattle behaviour except for the duration of the lying down sequence, which lasted more for bulls kept on slats. Slatted floor increased also the likelihood of occurrence of hair and skin lesions and lameness. On the other hand, bulls cleanliness was more likely to be impaired on bedded floor. Regarding the class of live weight, behavioural observation showed lighter animals performing more antagonistic interactions, while horning resulted more frequent in heavier bulls. Avoidance distance test indicated that bulls >350 kg were more fearful of humans. About health status, light animals were more affected by respiratory disease and hairless patches, likely because they are more sensitive to the stressful situations imposed by their transfer and adaptation to the new housing environment of the fattening unit. The risk of skin lesions and dirtiness increased instead in heavier bulls