The impact of floor type on lameness and hoof health of dairy origin bulls

This study aimed to evaluate the effect of using different floor types to accommodate growing and finishing beef cattle on lameness. In all, 80 dairy origin bulls were blocked according to live weight and breed into 20 groups, and randomly allocated within groups to one of four treatments. The floor types studied were fully slatted flooring throughout the entire experimental period (CS); fully slatted flooring covered with rubber strips throughout the entire experimental period (RS); fully slatted flooring during the growing period and then moved to a solid floor covered with straw bedding during the finishing period (CS-S) and fully slatted flooring during the growing period and then moved to fully slatted flooring covered with rubber strips during the finishing period (CS-RS). The total duration of the study was 204 days. The first 101 days was defined as the growing period, with the remainder of the study defined as the finishing period. During the growing period, there was a tendency for bulls accommodated on CS to have a higher locomotion score compared with those accommodated on RS (P=0.059). However, floor type had no significant effect on locomotion score during the finishing period. There was also no significant effect of floor type on digital dermatitis during both the growing or finishing period. Floor type had no significant effect on swelling at the leg joints at the end of the finishing period. Bulls accommodated on RS had the least probability of bruised soles during both the growing and finishing period (P<0.01). Growing bulls accommodated on CS had significantly greater front heel height net growth compared with those accommodated on RS (P<0.05). However, bulls accommodated on RS had a tendency to have greater front toe net growth compared with those accommodated on CS (P=0.087). Finishing bulls accommodated on CS-RS had the greatest front toe net growth (P<0.001). Heel height net growth was greatest in bulls accommodated on CS-S (P<0.001). Floor type had no significant effect on mean maximum hoof temperature during the growing period. Finishing bulls accommodated on CS-S had a significantly lower mean maximum hoof temperature compared with those accommodated on any other floor type (P<0.001). The study concluded that rubber flooring is a suitable alternative to fully slatted flooring, reducing the prevalence of bruised soles. Despite greater toe net growth in bulls accommodated on rubber flooring, there was no effect of floor type on locomotion score, suggesting that increased toe net growth does not adversely affect walking ability. In addition, although mean maximum hoof temperature was lowest in bulls accommodated on straw bedding, there was no evidence to suggest this is indicative of improved hoof health.     

The effect of diet and covering fully slatted concrete floors with rubber strips on the intake,performance and cleanliness of dairy-origin bulls

Fully slatted concrete floors are prevalent in beef cattle housing. However, concerns have been raised about welfare of cattle accommodated on slats. The objective of this study was to evaluate the effect of diet and floor type on the intake, performance and cleanliness of dairy-origin bulls from a mean age of 8 months to slaughter at 15.5 months old. Forty-eight bulls, which had a mean initial live weight of 212 kg (SD = 23.7), were allocated one of four treatments which consisted of two floors and two diets, arranged in a 2×2 factorial design. The floors evaluated were a fully slatted concrete floor and a fully slatted concrete floor covered with rubber; while the diets offered were either a high concentrate diet or a grass silage-based diet supplemented with concentrates. Over the entire experimental period, floor type had no significant effect on intake. Interestingly, however, when bulls were offered concentrates ad libitum, those accommodated on rubber covered slats consumed more concentrates than those accommodated on concrete slats. No effect of floor type on intake was noted when bulls were offered the grass silage supplemented with concentrate diet. There were no significant interactions between floor and diet on animal performance. Animals accommodated on rubber covered slats had a significantly better performance than those accommodated on concrete slats, as assessed by live weight at slaughter and live weight gain/day (P < 0.01) and estimated carcass gain/day (P < 0.05). The diet offered had no significant effect on animal performance. Bulls accommodated on rubber covered slats were significantly cleaner than those accommodated on concrete slats on day 97 (P < 0.001), but there was no significant effect of floor type when measured at other time points in the experiment. It is concluded from this study that diet has an important role to play in assessing bulls’ responses in performance to the effect of covering concrete slatted floors with rubber. Bulls offered a high concentrate diet had a higher concentrate intake, higher performance but a similar feed conversion ratio (FCR) when accommodated on rubber covered slats compared to those accommodated on fully concrete slatted floors. Animals offered this intensive diet were less efficient (as measured by a higher FCR) than those offered a supplemented grass silage-based diet.     

The effect of floor type on the performance,cleanliness, carcass characteristics and meat quality of dairy origin bulls

The aim of this study was to evaluate the effect of using different floor types to accommodate growing and finishing beef cattle on their performance, cleanliness, carcass characteristics and meat quality. In total, 80 dairy origin young bulls (mean initial live weight 224 kg (SD=28.4 kg)) were divided into 20 blocks with four animals each according to live weight. The total duration of the experimental period was 204 days. The first 101 days was defined as the growing period, with the remainder of the study defined as the finishing period. Cattle were randomly assigned within blocks to one of four floor type treatments, which included fully slatted flooring throughout the entire experimental period (CS); fully slatted flooring covered with rubber strips throughout the entire experimental period (RS); fully slatted flooring during the growing period and moved to a solid floor covered with straw bedding during the finishing period (CS-S) and fully slatted flooring during the growing period and moved to fully slatted flooring covered with rubber strips during the finishing period (CS-RS). Bulls were offered ad libitum grass silage supplemented with concentrates during the growing period. During the finishing period, bulls were offered concentrates supplemented with chopped barley straw. There was no significant effect of floor type on total dry matter intake (DMI), feed conversion ratio, daily live weight gain or back fat depth during the growing and finishing periods. Compared with bulls accommodated on CS, RS and CS-RS, bulls accommodated on CS-S had a significantly lower straw DMI (P<0.01). Although bulls accommodated on CS and CS-S were significantly dirtier compared with those accommodated on RS and CS-RS on days 50 (P<0.05) and 151 (P<0.01), there was no effect of floor type on the cleanliness of bulls at the end of the growing and finishing periods. There was also no significant effect of floor type on carcass characteristics or meat quality. However, bulls accommodated on CS-S had a tendency for less channel, cod and kidney fat (P=0.084) compared with those accommodated on CS, RS and CS-RS. Overall, floor type had no effect on the performance, cleanliness, carcass characteristics or meat quality of growing or finishing beef cattle.     

Effect of overlaying rubber on fully slatted concrete floors on hoof health and lying postures in finishing dairy-origin bulls offered two contrasting diets

Fully slatted concrete floors are labour-efficient, cost-effective and thus common in beef cattle housing. However, the welfare of cattle accommodated on them has been questioned. The objective of this study was to evaluate the effect of floor and diet on hoof health and lying behaviours of housed dairy-origin bulls, from a mean age of 8 months to slaughter at 15.5 months old. Forty-eight bulls, which had a mean initial live weight of 212 (SD = 23.7) kg, were allocated to one of four treatments, which consisted of two floors and two diets arranged in a 2 × 2 factorial design. The floors evaluated were a fully slatted concrete floor and a fully slatted concrete floor overlaid with rubber, while the diets offered were either a high concentrate diet or a grass-silage-based diet supplemented with concentrates. The mean total duration of the study was 216 days. Floor had no significant effect on claw measurements measured on day 62 or 139. However, bulls accommodated on slats overlaid with rubber had a tendency to have a higher front toe length measured pre-slaughter than those accommodated on concrete slats (P = 0.063). Floor had no significant effect on the net growth of toes or heels during the duration of the study. The number of bruises (P < 0.01) and the bruising score (P < 0.05) were significantly higher on day 62 in bulls accommodated on fully slatted concrete floors than on concrete slats overlaid with rubber, but there was no significant effect of floor on these parameters on day 139 or at the measurement taken pre-slaughter. There was a tendency for bulls accommodated on concrete slats to have a higher probability of having sole bruising at the end of the experiment than those accommodated on slats overlaid with rubber (P = 0.052). Diet had no significant effect on toe length or heel height, number of bruises, or overall bruising score at any time point of the study. There was little evidence in the current study to suggest that bulls lying on fully slatted concrete floors could not express lying postures similar to those on concrete slats overlaid with rubber.     

Health,behaviour and growth performance of Charolais and Limousin bulls fattened on different types of flooring

Intensive fattening of late-maturing breeds on concrete or rubberized slatted floors is the prevalent beef production system in mainland Europe. The rationale behind this study is that specific beef breeds with different slaughter weights might have a diverse response to different flooring systems. The study aimed at assessing whether growth performance, health, behaviour and claw condition of two beef breeds, Charolais (CH) and Limousine (LIM), would be affected by their housing on concrete (CS) or rubber-covered (RCS) fully slatted floor. A total of 228 CH (116 on CS; 112 on RCS) and 115 LIM (57 on CS; 58 on RCS) were housed in four and two commercial farms, respectively, in groups of 9.0 ± 2.1 animals/pen with an average space allowance of 3.1 ± 0.2 m². Draining gaps of CS and RCS pens were 16.9 ± 1.7% and 11.6 ± 1.2% of the total surface, respectively. Bulls of both breeds had similar initial body weight (429.4 ± 31.5 kg for CH; 369.6 ± 31.7 kg for LIM), and they were slaughtered when they reached suitable finishing. Charolais had a higher final body weight (BW) than LIM (750.8 ± 8.6 v. 613.7 ± 10.9 kg; P < 0.01), and bulls of both breeds on RCS had higher average daily gain than on CS (1.47 ± 0.02 v. 1.39 ± 0.02 kg/day; P < 0.05). The percentage of bulls early culled or treated for locomotor disorders were reduced by RCS only for LIM, while RCS tended to prevent the occurrence of bursitis for both breeds. During two 8-h behavioural observations, bulls on RCS performed more head butt/displacements and chases than on CS, and they reduced the frequency of abnormal lying down events. The use of RCS increased mounts’ frequency only in LIM, while its reduced drainage capacity impaired only the cleanliness of CH. Postmortem hoof inspection showed longer claw dorsal wall and diagonal lengths, and sharper toe angles for CH on RCS than LIM on both floors. Results of this study point out that fully slatted floors, regardless of being rubberized or not, are not suitable for bulls finished at a final BW above 700 kg due to their detrimental effects on health and welfare. The use of RCS could be recommended as an alternative to CS only if bulls are slaughtered at a lower final BW (around 600 kg), like in the case of LIM breed.     

Assessment of welfare of finishing beef cattle kept on different types of floor after short- or long-term housing

This study aimed at evaluating short- and long-term effects of housing beef cattle on deep litter (DL) or concrete fully slatted floor (FS) on their welfare. Animal-based measures of the Welfare Quality® assessment protocol for cattle were used to assess health status and behaviour of bulls. The assessment was carried out in a large commercial farm on 15 batches of bulls (4 DL and 11 FS) 1 month after their receiving day (short-term) and on 12 batches (three DL and nine FS) the week before slaughter (long-term). Signs of better comfort on deep litter in terms of shorter lying down durations (5.1±0.5 v. 6.5±0.4 s; P<0.05) and lower risk of hairless patches (odds ratio=0.09; 95% confidence interval=0.01 to 0.68; P<0.05) were already observed after 1 month. Heavy bulls after a long-term housing on FS showed a higher prevalence of bursitis, hairless patches and lesions/swellings than animals on DL. Bulls on fully slatted floor were at higher risk of early culling (odds ratio=6.44; 95% confidence interval=1.57 to 26.37; P<0.01), mainly due to musculoskeletal system pathologies/lameness. Deep litter proved to be a valid alternative to slatted floor, making animals more confident to interact with powerful movements such as mounting at the end of the finishing period. A negative aspect of the deep litter was the poor cleanliness of the bulls. Compared with the fully slatted floor, there were higher odds ratios for dirty bulls at both, the short- (odds ratio=25.09; 95% confidence interval=8.96 to 70.22; P<0.001) and the long-term housing (odds ratio=276.13; 95% confidence interval=98.21 to 776.38; P<0.001). In order to improve health and welfare of beef cattle finished at a heavy weight, deep litter systems are a promising alternative to fully slatted floors. However, proper management of deep litter is necessary to maintain satisfactory cleanliness of the bulls.     

Influence of a raised slatted area in front of the nest on leg health,mating behaviour and floor eggs in broiler breeders

European farms for broiler breeders often have raised slatted areas in front of the nests, but in other regions of the world no raised slatted areas are provided. This study aimed to investigate the effects of a raised slatted area on leg health, mating behaviour and floor laying behaviour. Ten groups of 33 broiler breeder hens and three males were housed in two pen types: with or without a raised slatted area in front of the nests. Each pen had one plastic and one wooden nest. Between 25 and 31 weeks of age, ten marked hens per pen were weighed and assessed weekly on foot pad dermatitis, hock burn and wounds. At the end of week 31, animals were euthanized and bone strength of the tibia and humerus of these individuals was assessed. At 24, 27 and 30 weeks of age, mating behaviour was observed for an hour per pen, noting both numbers of successful and unsuccessful copulations. The number of eggs laid in the nests and on the floor was recorded daily between 20 and 31 weeks of age. Foot pad dermatitis scores were affected by age, but not by pen type. Generally, there were only minor issues with foot pad dermatitis (scores < 11 on a 0–100 scale), probably due to the young age of the hens. Body weight was not affected by pen type, while the prevalence of hock burns was too low to analyse and no difference in bone strength was found for the tibia and the humerus. Overall, mating behaviour was less frequent in pens with raised slats than in pens without raised slats (29 ± 2 vs 35 ± 3 times/h) and more frequent at 27 weeks of age than at 24 and 30 weeks of age (38 ± 1 vs 31 ± 4 and 27 ± 2 times/h). The pens with raised slats had a lower percentage of floor eggs than pens without raised slats (11.2 ± 0.4 vs 19.3 ± 0.5%). The wooden nest was preferred over the plastic nest as on average 63% of the eggs were laid in the wooden nest. This study shows that providing raised slats decreases mating behaviour and percentage of floor eggs, although its effects on leg health remain inconclusive.     

Effect of space allowance and floor type on performance,welfare and physiological measurements of finishing beef heifers

Accommodating cattle indoors during the winter is widely practiced throughout Europe. There is currently no legislation surrounding the space allowance and floor type that should be provided to cattle during this time, however, concerns have been raised regarding the type of housing systems currently in use. The objective of the study was to investigate the effect of space allowance and floor type on performance and welfare of finishing beef heifers. Continental crossbred heifers (n=240: mean initial live; weight, 504 (SD 35.8) kg) were blocked by breed, weight and age and randomly assigned to one of four treatments; (i) 3.0 m², (ii) 4.5 m² and (iii) 6.0 m² space allowance per animal on a fully slatted concrete floor and (iv) 6.0 m² space allowance per animal on a straw-bedded floor, for 105 days. Heifers were offered a total mixed ration ad libitum. Dry matter intake was recorded on a pen basis and refusals were weighed back twice weekly. Heifers were weighed, dirt scored and blood sampled every 3 weeks. Whole blood was analysed for complete cell counts and serum samples were assayed for metabolite concentrations. Behaviour was recorded continuously using IR cameras from days 70 to 87. Heifers’ hooves were inspected for lesions at the start of the study and again after slaughter. Post-slaughter, carcass weight, conformation and fat scores and hide weight were recorded. Heifers housed at 4.5 m² had a greater average daily live weight gain (ADG) than those on both of the other concrete slat treatments; however, space allowance had no effect on carcass weight. Heifers accommodated on straw had a greater ADG (0.15 kg) (P<0.05), hide weight (P<0.01) better feed conversion ratio (P<0.05) and had greater dirt scores (P<0.05) at slaughter than heifers accommodated on concrete slats at 6.0 m². The number of heifers lying at any one time was greater (P<0.001) on straw than on concrete slats. Space allowance and floor type had no effect on the number of hoof lesions gained or on any of the haematological or metabolic variables measured. It was concluded that increasing space allowance above 3.0 m²/animal on concrete slats was of no benefit to animal performance but it did improve animal cleanliness. Housing heifers on straw instead of concrete slats improved ADG and increased lying time; however carcass weight was not affected.     

Reduced space in outdoor feedlot impacts beef cattle welfare

There is a trend to reduce the space allowance per animal in cattle feedlot, despite its potential negative impact on animal welfare. Aiming to evaluate the effects of space allowance per animal in outdoor feedlots on beef cattle welfare, a total of 1350 Nellore bulls (450 pure and 900 crossbred) were confined for 12 weeks using three space allowances: 6 (SA6), 12 (SA12) and 24 (SA24) m²/animal (n = 450 per treatment). Bulls were housed in three pens per treatment (n = 150 per pen). The first 6 weeks in the feedlot were defined as ‘dry’ and the last as ‘rainy’ period, according to the accumulated precipitation. Animal-based (body cleanliness, health indicators and maintenance behaviour) and environmental-based indicators (mud depth and air dust concentration) were assessed weekly during the feedlot period. Most of the health indicators (nasal and ocular discharge, hoof and locomotion alterations, diarrhoea, bloated rumen and breathing difficulty) were assessed in a subset of 15 animals randomly selected from each pen. Coughs and sneezes were counted in each pen. Maintenance behaviours (number of animals lying and attending the feed bunk) were recorded with scan sampling and instantaneous recording at 20-min intervals. Postmortem assessments were carried out in all animals by recording the frequencies of macroscopic signs of bronchitis, pulmonary emphysema, nephritis and urinary cyst and by measuring the weight and cortical and medullar areas of adrenal glands (n = 30 per pen). Compared with SA12 and SA24, SA6 showed a greater number of sneezes per minute during the dry period and a greater percentage of animals with locomotion alterations during the rainy period. Coughing, diarrhoea and nasal discharge affected a larger number of animals in the SA6 relative to the other two groups. During the rainy period, there was a lower percentage of animals with nasal and ocular discharge, and a greater percentage of animals with abnormal hoof and lying. A lower percentage of animals in SA6 and SA12 (but not SA24) attended the feed bunk during the rainy relative to the dry period. A mud depth score of 0 (no mud) was most frequent in SA24 pens, followed by SA12 and then SA6. Adrenal gland weight and cortical area were lower in SA24 animals compared with those in SA6 and SA12. The results show that decreasing the space allowance for beef cattle in outdoor feedlots degrades the feedlot environment and impoverishes animal welfare.     

Effect of rubber mats and perforation in the lying area on claw and limb lesions of fattening pigs

Claw and leg lesions are frequently observed in finishing pigs and are likely to compromise their welfare. Providing softer than the usual concrete flooring may reduce both the frequency and severity of these lesions. Therefore, this study evaluated the influence of rubber mats and floor perforation in the lying area on claw and leg health of finishing pigs. A total of 240 Swiss Large White finishing pigs from on average 24.9 kg until 102.3 kg were used in four batches, with six groups of 10 animals per batch. The six experimental pens initially measured 1.85×3.55 m and were enlarged after 6 weeks to 1.85×5.25 m. In all pens, one third of the floor space was built as a defecating area consisting of a concrete floor with 15% perforation. The remaining two thirds of the pen were designed as a lying area whose floor quality differed between the pens. It either consisted of concrete elements or was covered with rubber mats, and perforation of both floor types was either 0%, 5% or 10%. All individuals were scored for claw and leg lesions at the beginning, in the middle and at the end of the 12-week fattening period. Lesions were summarised in scores based on the results of a principal component analysis. The influence on lesion scores of floor material, amount of perforation in the lying area, assessment time, and sex was examined using mixed-models. The total claw lesion score and the total limb lesion score as well as the claw angle increased from the beginning to the end of the fattening period. The values for both scores were slightly lower for animals kept on rubber mats compared with animals kept on concrete floor. There was no effect of the percentage of perforation on the examined outcome variables. In conclusion, our results indicate that rubber mats in the lying area bring about improvements in some aspects of claw and leg health in fattening pigs, whereas there is no effect of floor perforation.     

Feedlot performance and rumen morphometrics of Nellore cattle adapted to high-concentrate diets over periods of 6, 9, 14 and 21 days

The energy content of finishing diets offered to feedlot cattle may vary across countries. We assumed that the lower is the energy content of the finishing diet, the shorter can be the adaptation period to high-concentrate diets without negatively impacting rumen health while still improving feedlot performance. This study was designed to determine the effects of adaptation periods of 6, 9, 14 and 21 days on feedlot performance, feeding behaviour, blood gas profile, carcass characteristics and rumen morphometrics of Nellore cattle. The experiment was designed as a completely randomised block, replicated 6 times, in which 96 20-month-old yearling Nellore bulls (391.1 ± 30.9 kg) were fed in 24 pens (4 animals/pen) according to the adaptation period adopted: 6, 9, 14 or 21 days. The adaptation diets contained 70%, 75% and 80.5% concentrate, and the finishing diet contained 86% concentrate. After adaptation, one animal per pen was slaughtered (n = 24) for rumen morphometric evaluations and the remaining 72 animals were harvested after 88 days on feed. Orthogonal contrasts were used to assess linear, quadratic and cubic relationships between days of adaptation and the dependent variable. Overall, as days of adaptation increased, final BW (P = 0.06), average daily gain (ADG) (P = 0.07), hot carcass weight (P = 0.04) and gain to feed ratio (G : F) (P = 0.07) were affected quadratically, in which yearling bulls adapted by 14 days presented greater final BW, ADG, hot carcass weight and improved G : F. No significant (P > 0.10) days of adaptation effect was observed for any of feeding behaviour variables. As days of adaptation increased, the absorptive surface area of the rumen was affected cubically, where yearling bulls adapted by 14 days presented greater absorptive surface area (P = 0.03). Thus, Nellore yearling bulls should be adapted by 14 days because it led to improved feedlot performance and greater development of rumen epithelium without increasing rumenitis scores.     

Effects of two stall flooring systems on the behaviour of tied dairy cows

Effects on dairy cow behaviour of a new type of flooring in tie-stalls, with the ability to drain faeces and urine, was studied in a controlled randomised trial in one Swedish university herd. Forty-two Swedish Red and White cows were kept tied in traditional long-stalls (2.20m). In 21 stalls (one stall row), the rearmost 0.74m of the solid stall floor had been replaced with nine rubber-coated 53mm wide slats, divided by 29mm slots. Stalls with rubber slats were equipped with 20mm ethyl-vinyl-acetate (EVA) mats in the front part and littered with 0.7kg of wood shavings daily, while stalls with a solid floor had standard rubber mats and received 3kg of chopped straw daily as bedding. Behaviour was compared between the two stall types, using video recordings of 12 matched pairs of cows for two complete 24h periods each. Statistical analysis was done using the Student's t-test for matched pairs or the sign test. Cows on the rubber slatted flooring lie down and rise normally and without any increased risk of slipping. They lay down more comfortably, i.e. spent on an average 23% less time preparing to lie down, and slipped less frequently during rising. There was some evidence of a preference for a solid floor when lying.     

The effect of long or chopped straw on pig behaviour

In the EU, pigs must have permanent access to manipulable materials such as straw, rope, wood, etc. Long straw can fulfil this function, but can increase labour requirements for cleaning pens, and result in problems with blocked slatted floors and slurry systems. Chopped straw might be more practical, but what is the effect on pigs’ behaviour of using chopped straw instead of long straw? Commercial pigs in 1/3 slatted, 2/3 solid pens of 15 pigs were provided with either 100 g/pig per day of long straw (20 pens) or of chopped straw (19 pens). Behavioural observations were made of three focal pigs per pen (one from each of small, medium and large weight tertiles) for one full day between 0600 and 2300 h at each of ~40 and ~80 kg. The time spent rooting/investigating overall (709 s/pig per hour at 40 kg to 533 s/pig per hour at 80 kg), or directed to the straw/solid floor (497 s/pig per hour at 40 kg to 343 s/pig per hour at 80 kg), was not affected by straw length but reduced with age. Time spent investigating other pigs (83 s/pig per hour at 40 kg), the slatted floor (57 s/pig per hour) or pen fixtures (21 s/pig per hour) was not affected by age or straw length. Aggressive behaviour was infrequent, but lasted about twice as long in pens with chopped straw (2.3 s/pig per hour at 40 kg) compared with pens with long straw (1.0 s/pig per hour at 40 kg, P=0.060). There were no significant effects of straw length on tail or ear lesions, but shoulders were significantly more likely to have minor scratches with chopped straw (P=0.031), which may reflect the higher levels of aggression. Smaller pigs showed more rooting/investigatory behaviour, and in particular directed towards the straw/solid floor and the slatted floor than their larger pen-mates. Females exhibited more straw and pen fixture-directed behaviour than males. There were no effects of pig size or sex on behaviour directed towards other pigs. In summary, pigs spent similar amounts of time interacting with straw/solid floor when long and chopped straw were provided, and most aspects of pig-directed behaviour and injuries were not affected by straw length. There was an increase in pigs with minor shoulder lesions with chopped straw, perhaps because of increased aggression. The use of chopped straw as an enrichment material for pigs warrants further investigation in larger and more detailed studies.     

Partial Replacement of Ground Corn with Glycerol in Beef Cattle Diets: Intake,Digestibility, Performance,and Carcass Characteristics

The objective of this study was to evaluate the effects of replacing dry ground corn with crude glycerol on intake, apparent digestibility, performance, and carcass characteristics of finishing beef bulls. A completely randomized block design experiment with 25 d for adaptation and 100 d for data collection was conducted, in which 3,640 Nellore bulls (367 ± 36.8 kg; 18 ± 3 mo) were blocked by body weight and assigned to 20 pens. Bulls were randomly assigned to one of four treatments: 0, 5, 10, and 15% (dry matter basis) of crude glycerol in the diet. Initially, 20 bulls were slaughtered to serve as a reference to estimate initial empty body weight, which allowed for carcass gain calculation. Bulls were weighed at the beginning, at two-thirds, and at the end of the experiment for performance calculations. Carcass measurements were obtained by ultrasound. Fecal output was estimated using indigestible neutral detergent fiber as an internal marker. Data were analyzed using the mixed procedures in SAS 9.2 (SAS Institute Inc., Cary, NC). Intake of dry matter, organic matter, and neutral detergent fiber decreased linearly (P < 0.05) with crude glycerol inclusion. However, crude glycerol levels did not affect (P > 0.05) intakes of crude protein, non-fiber carbohydrates, and total digestible nutrients. Digestibility of dry matter, organic matter, neutral detergent fiber, and total digestible nutrients increased quadratically (P < 0.05) with the inclusion of crude glycerol in the diet. Crude glycerol inclusion did not change the intake of digestible dry matter, average daily gain, final body weight, carcass gain, carcass dressing, gain-to-feed ratio, Longissimus thoracis muscle area, and back and rump fat thicknesses (P > 0.05). These results suggest that crude glycerol may be included in finishing beef diets at levels up to 15% without impairing performance and carcass characteristics.     

Effect of a ceiling fan ventilation system on finishing young bulls’ health,behaviour and growth performance

This research aimed at assessing the effects of a ceiling fan ventilation system on health, feeding, social behaviour and growth response of finishing young bulls fattened indoors during a mild summer season. A total of 69 Charolais young bulls were housed in six pens without any mechanical ventilation system (Control) and in six pens equipped with ceiling fans. The experimental period lasted 98 days from June until mid-September 2014. Four experimental days were considered in order to assess the effect of the ventilation system under two different microclimatic conditions: 2 alert days at monthly interval with temperature humidity index (THI) between 75 and 78, and 2 normal days with THI⩽74. Health and behaviour of the bulls were evaluated through 8-h observation sessions starting after morning feed delivery. The study was carried out during a rather cool summer with a climate average THI of 68.9 and 4 days with average THI>75. Despite these mild climate conditions, ceiling fans lowered litter moisture and acted as a preventive measure for bulls’ dirtiness (odd ratio=47.9; 95% CI 19.6 to 117.4). The risk of abnormal breathing was increased for Control bulls (odd ratio=40.7; 95% CI 5.4 to 304.2). When exposed to alert THI conditions, respiration rate and panting scores increased and rumination duration dropped in Control bulls compared with bulls provided with a ceiling fan. During observations under alert THI, bulls spent less time eating, more time being inactive and consumed more water compared with normal THI conditions. Bulls’ daily dry matter intake measured during the observation sessions decreased on alert compared with normal THI days (P<0.001) due to a drop of intake during the daylight hours. Ceiling fan treatment had no effect on bulls’ growth performance or water consumption but these results most likely depended on the mild climate conditions. Ceiling fans proved to mitigate some of the negative effects of heat stress on bulls’ behaviour (rumination, lying down and drinking water) and respiration rate, however. The lack of a significant improvement of bulls’ growth response should not discourage beef farmers from using ceiling fans in indoor systems, considering the likely increase in frequency and intensity of heat waves in the planet’s temperate areas induced by global warming.     

Improved tenderness of beef from bulls supplemented with active dry yeast is related to matrix metalloproteinases and reduced oxidative stress

Supplementing diets with active dry yeast (ADY, Saccharomyces cerevisiae) improves the carcass quality grade of beef cattle and the tenderness of beef. The relevant mechanisms have not been fully elucidated, but may be related to the effect of ADY on oxidative stress and the activity of matrix metalloproteinases (MMPs). To provide further insight into these mechanisms, this study evaluated the influence of ADY supplementation on growth performance, carcass traits, meat quality, concentrations of MMPs in serum (MMP-2, MMP-9 and MMP-13), oxidative stress indices and antioxidant capacity indices in beef cattle. Forty-six crossbred Simmental × Yanbian bulls (～18 months of age, BW 436 ± 35 kg) participated in a 145-day finishing trial. ADY supplementation significantly improved marbling deposition, intramuscular fat content, and beef tenderness (P < 0.05); altered individual fatty acid proportions in the beef and increased saturated fatty acids while decreasing polyunsaturated fatty acids (P < 0.05); significantly decreased the abundance of reactive oxygen species in serum and meat; significantly increased the level of superoxide dismutase in meat (P < 0.05); tended to increase the level of catalase (P = 0.075) in serum and glutathione reductase (P = 0.066) in meat; and increased the secretion of MMPs. The improvement of beef tenderness following ADY supplementation of finishing bulls is related to the effects of ADY on the secretion of MMPs and the lowering of oxidative stress.     

Longitudinal gait development and variability of growing pigs reared on three different floor types

Biomechanical investigation into locomotor pathology in commercial pigs is lacking despite this being a major concern for the industry. Different floor types are used in modern, intensive pig production systems at different stages of the pigs’ production cycle. The general perception holds that slatted and/or hard solid concrete surfaces are inferior to soft straw-covered floors regarding healthy musculoskeletal development. Previous studies have compared pigs housed on different floor types using clinical, subjective assessment of leg weakness and lameness. However, reliability studies generally report a low repeatability of clinical lameness scoring. The objective of this study was to quantitatively assess the long-term effect of pen floors, reflected in the biomechanical gait characteristics and associated welfare of the pigs. A cohort of 24 pigs housed on one of three different floor types was followed from 37 to 90 kg average liveweight, with gait analysis (motion capture) starting at 63 kg. The three floor types were fully slatted concrete, partly slatted concrete and deep straw-bedded surfaces, all located within the same building. Pigs underwent five repeated camera-based motion captures, 7 to 10 days apart, during which 3D coordinate data of reflective skin markers attached to leg anatomical landmarks were collected. Pigs walked on the same solid concrete walkway during captures. One-way ANOVA and repeated measures ANOVA were used to analyse the gait data. Results revealed changes over time in the spatiotemporal gait pattern which were similar in magnitude and direction for the pigs from different floor types. Significant increases in elbow joint flexion with age were observed in all pigs (P⩽0.050; +6°). There were few differences between floor groups, except for the step-to-stride ratio in the hind legs being more irregular in pigs housed on partly slatted floors (P=0.012; 3.6 times higher s.d.) compared with those on 5 to 10 cm straw-bedding in all pen areas. As the level of clinical problems was generally low in this cohort, it may be that floors elicit problems only when there is a primary predisposing factor increasing weakness in susceptible tissues.     

Influence of different types of environmental enrichment on the behaviour of finishing pigs in two different housing systems: 3. Hanging toy versus rootable toy of the same material

This study aimed to assess the effects of (1) environmental enrichment with either straw bedding or a plastic toy and (2) the way in which the plastic toy was presented on the behaviour of finishing pigs in two different housing systems. One thousand and twenty four (Large White × Landrace) × Large White pigs were housed contemporarily in either a straw-based (ST) or fully slatted (FS) building from 35 kg to slaughter at 104 kg. In each building, half of the pens received additional environmental enrichment in the form of a hanging plastic toy. The remaining pens in the ST house were enriched only by the straw bedding. In the FS house, the remaining pens were provided with a rootable toy of the same plastic material presented on the floor of the pen. There was no significant effect of housing system on the level of manipulation of the hanging toy. Within the FS system, the level of manipulation of the hanging toy tended to be higher than that of the plastic toy presented on the floor (P = 0.052). Neither form of additional environmental enrichment provided a comparable level of occupation to that of straw bedding. In the absence of straw, more investigatory behaviours were directed towards both pen-mates (P < 0.001) and pen components (P < 0.001). Further study is required to identify functional forms of environmental enrichment in slatted systems to occupy pigs and prevent them from performing adverse behaviours.     

The Effect of Claw Lesions and Claw Infections on Lameness in Loose Housing of Pregnant Sows

During a 12-month period lameness, claw lesions and claw infections were studied in 15 herds with loose housing of pregnant sows on partly slatted concrete floors. Of these herds, 12 herds had concrete slats and 3 herds had plastic slats. The mean prevalence proportion of lame sows in the herds was 13.1%. The risk of lameness increased with increasing claw lesion score and with the presence of claw infections. In the herds with concrete slats, the relative risk of lame sows was 2.4 times higher than in the herds with plastic slats. In the herds with poor floor hygiene, the relative risk of lameness was 2.8 times higher than in the herds with dry and clean floors. The mean prevalence proportion of sows with claw infections at the 3 separate examinations in the 15 herds was 3.8%. Claw infections were more prevalent in herds with dirty floors and in herds with little space per animal (<2m2). In the herds with concrete slats, the relative risk of claw infections was 2 times higher than in the herds with plastic slats.     

Effect of wheat dried distillers grains and enzyme supplementation on growth rates,feed conversion ratio and beef fatty acid profile in feedlot steers

The objectives of this study were to determine: (1) the effect of wheat dried distillers grain with solubles (DDGS) inclusion, and (2) dietary feed enzyme (FE; Econase XT) supplementation in a finishing diet containing wheat DDGS on fatty acid profile of the pars costalis diaphragmatis muscle of beef cattle. A total of 160 crossbred yearling steers with initial BW of 495±38 kg were blocked by BW and randomized into 16 pens (10 head/pen). The pens were randomly assigned to one of the four treatments: (1) control (CON; 10% barley silage and 90% barley grain-based concentrate, dry matter (DM) basis); (2) diet containing 30% wheat DDGS in place of barley grain without FE (WDG); (3) WDG diet supplemented with low FE (WDGL; 1 ml FE/kg DM); and (4) WDG diet supplemented with high FE (2 ml FE/kg DM). The pars costalis diaphragmatis muscle samples were collected from cattle at slaughter at the end of the finishing period (120 days) with a targeted live weight of 650 kg. No differences in organic matter intake, final BW and average daily gain were observed among treatments. However, steers fed WDG had greater (P<0.01) feed conversion ratio than those fed CON, and increasing FE application in wheat DDGS-based diets tended (P<0.10) to linearly decrease feed conversion ratio. In assessing the effects of including WDG diets without FE, concentration of total polyunsaturated fatty acids (PUFA) in muscle tended to be greater (P<0.10) for steers fed WDG than steers fed CON. In addition, inclusion of wheat DDGS into the diet increased (P<0.05) concentration of CLA and vaccenic acid (VA) in muscle and also resulted in a higher (P<0.05) ratio of n-6/n-3 PUFA compared with that from steers fed CON diet. Increasing FE application in wheat DDGS-based diets did not modify the concentrations of individual or total fatty acids. These results suggest that inclusion of wheat DDGS in finishing diets may improve fatty acid profile of beef muscle which could benefit human health.