Validation of the fCAL turbo immunoturbidimetric assay for measurement of calprotectin in porcine and bovine fecal samples.

The concentration of calprotectin in feces is a well-studied marker of gastrointestinal inflammation in humans. However, little is known about fecal calprotectin in farm animals. In this work, we have validated an immunoturbidimetric method for fecal calprotectin (Bühlmann fCAL® turbo assay, Schönenbuch, Switzerland) in porcine and bovine fecal samples. Linearity was evaluated by serial dilution (R2 > 0.97 was obtained for both species). Accuracy was assessed by a recovery study, with results between 80 and 120% for low, medium, and high samples in both species. Intra- and inter-assay variability was <20%. Limit of detection was 6.4 µg/g in pig and 5.3 µg/g in cow. Limit of quantification was 13.4 µg/g (pig) and 11.1 µg/g (cow). Additionally, clinical validation has been included to evaluate the ability of the assay to detect inflammatory status in the intestine under different management conditions. In experiments with porcine, it was found that piglets treated with ZnO had lower concentrations of fecal calprotectin. In a second experiment in bovine, calves with diarrhea had higher concentration of fecal calprotectin. The Bühlmann fCAL® turbo assay is suitable for measurement of calprotectin in porcine and bovine fecal samples. Moreover, fecal calprotectin could be a good biomarker of intestinal inflammation in both species.

Citrus Flavonoids Supplementation as an Alternative to Replace Zinc Oxide in Weanling Pigs' Diets Minimizing the Use of Antibiotics.

Since citrus flavonoids have antioxidant and anti-inflammatory properties, it was hypothesized that these compounds would become a suitable alternative to the use of therapeutic doses of zinc oxide at weaning. A total of 252 weaned pigs ([LargeWhite × Landrace] × Pietrain) were distributed according to BW (5.7 kg ± 0.76) into 18 pens (6 pens per diet, 14 pigs/pen). Three experimental diets for the prestarter (0-14 d postweaning) and starter (15-35 d postweaning) period were prepared: (i) a nonmedicated (CON) diet, (ii) a CON diet supplemented with zinc oxide at 2500 mg/kg, amoxicillin at 0.3 mg/kg and apramycin at 0.1 mg/kg (ZnO), and (iii) CON diet with the addition of a commercial citrus flavonoid extract at 0.3 mg/kg and amoxicillin at 0.3 mg/kg (FLAV). Pig BW, ADG, ADFI, and FCR were assessed on d7, d14, and d35. Samples of intestinal tissue, cecal content, and serum were collected on day seven (18 piglets). FLAV treatment achieved greater BW and ADG during the starter and for the entire experimental period compared with the CON diet (p < 0.05), whereas ZnO pigs evidenced intermediate results. Jejunum tissue analysis showed that pigs fed the FLAV diet overexpressed genes related to barrier function, digestive enzymes, and nutrient transport compared to those pigs fed the CON diet (p < 0.05). An increase in the abundance of bacterial genera such as Succinivibrio, Turicibacter, and Mitsuokella (p < 0.05) was observed in the FLAV compared with the CON and ZnO piglets. ZnO and FLAV increased the expression of TAS2R39, while ZnO pigs also expressed greater TAS2R16 than CON (p < 0.05) in the intestine. FLAV treatment improved the gut function, possibly explaining a higher performance at the end of the nursery period. Consequently, citrus flavonoids supplementation, together with amoxicillin, is a promising alternative to the use of zinc oxide plus amoxicillin and apramycin in weanling pigs, minimizing the use of antibiotics.

Characterization of Three Different Mediterranean Beef Fattening Systems: Performance, Behavior, and Carcass and Meat Quality.

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.

Supplementing Citrus aurantium Flavonoid Extract in High-Fat Finishing Diets Improves Animal Behavior and Rumen Health and Modifies Rumen and Duodenum Epithelium Gene Expression in Holstein Bulls.

One hundred and forty-six bulls (178.2 ± 6.64 kg BW and 146.0 ± 0.60 d of age) were randomly allocated to one of eight pens and assigned to control (C) or citrus flavonoid (BF) treatments (Citrus aurantium, Bioflavex CA, HTBA, S.L.U., Barcelona, Spain, 0.4 kg per ton of Bioflavex CA). At the finishing phase, the dietary fat content of the concentrate was increased (58 to 84 g/kg DM). Concentrate intake was recorded daily, and BW and animal behavior by visual scan, fortnightly. After 168 d, bulls were slaughtered, carcass data were recorded, and rumen and duodenum epithelium samples were collected. Performance data were not affected by treatment, except for the growing phase where concentrate intake (p < 0.05) was lesser in the BF compared with the C bulls. Agonistic and sexual behaviors were more frequent (p < 0.01) in the C than in the BF bulls. In the rumen epithelium, in contrast to duodenum, gene expression of some bitter taste receptors (7, 16, 39) and other genes related to behavior and inflammation was higher (p < 0.05) in the BF compared with the C bulls. Supplementing citrus flavonoids in high-fat finishing diets to Holstein bulls reduces growing concentrate consumption and improves animal welfare.

Effects of Flavonoids Extracted from Citrus aurantium on Performance, Behavior, and Rumen Gene Expression in Holstein Bulls Fed with High-Concentrate Diets in Pellet Form.

Flavonoid supplementation may modify the behavior and rumen inflammatory response of fattening bulls, and this could be related to the concentrate presentation (mash or pellet) form. In the present study, 150 Holstein bulls (183.0 ± 7.53 kg BW and 137 ± 1.8 d of age) were randomly allocated to one of eight pens and assigned to control (C) or (BF) (Citrus aurantium, Bioflavex CA, HealthTech Bio Actives, Spain, 0.4 kg per ton of concentrate of Bioflavex CA, 20% naringin). Concentrate (pellet) intake was recorded daily, and BW and animal behavior fortnightly. Animals were slaughtered after 168 d of study, and ruminal epithelium samples were collected for gene expression analyses. Treatment did not affect animal performance; however, BF supplementation reduced agonistic interactions and oral non-nutritive behaviors and increased the time devoted to eating concentrate and ruminating activity (p < 0.05). The gene expression of some genes in the rumen epithelium was greater or tended to be greater in BF than C bulls (bitter taste receptor 16, cytokine IL-25, ß-defensin; p < 0.10; pancreatic polypeptide receptor 1 and tumor necrosis factor alpha; p < 0.05). In conclusion, flavonoid supplementation modifies the expression of genes in the rumen epithelium that could be related to inflammation and animal behavior modulation.

Strategies for Feeding Unweaned Dairy Beef Cattle to Improve Their Health.

In order to answer the question of whether nutritional interventions may help to reduce the incidence of respiratory disease in dairy beef calves at arrival, the present review is divided in three sections. In the first section, the nutrition of calves previous to the arrival from the origin farm to the final rearing farm is reviewed. In the second section, the possible consequences of this previous nutrition on gut health and immune status upon arrival to the rearing farm are described. The main consequences of previous nutrition and management that these unweaned calves suffer at arrival are the negative energy balance, the increased intestinal permeability, the oxidative stress, the anemia, and the recovery feed consumption. Finally, in the third section, some considerations to advance in future nutritional strategies are suggested, which are focused on the prevention of the negative consequences of previous nutrition and the recovery of the gut and immune status. Moreover, additional suggestions are formulated that will be also helpful to reduce the incidence of bovine respiratory disease (BRD) that are not directly linked to nutrition like having a control golden standard in the studies or designing risk categories in order to classify calves as suitable or not to be transported.

Effects of Exogenous Glucoamylase Enzymes Alone or in Combination with a Neutral Protease on Apparent Total Tract Digestibility and Feces D-Lactate in Crossbred Angus Bulls Fed a Ration Rich in Rolled Corn.

The aim of this study was to evaluate the effect of two glucoamylases (GA) and the combination of one GA with a neutral protease on apparent total tract digestibility in beef bulls fed a total mixed ration (TMR) rich in rolled corn. Sixteen Angus beef bulls (266 ± 4.9 kg of initial BW, and 182 ± 1.7 d of age) were distributed in 4 blocks, each block consisted of 4 animals balanced by BW. The experimental design was a 4 × 4 Latin square (4 blocks and 4 periods, 2 w per period). Four treatments were tested; (1) control, (2) GA preparation from Trichoderma reesei (TrGA); (3) GA from Aspergillus fumigatus (AfuGA); (4) AfuGA in combination with a neutral protease from Bacillus amyloliquefaciens (BamPro). Apparent total tract digestibility and fecal D-lactate concentration were analyzed. Enzyme supplementation, regardless of enzyme type, increased apparent total tract digestibility of dry matter (from 66.7% to 73.1% ± 2.01), and starch (from 74.7% to 81.8% ± 2.25), without affecting feces D-lactate concentration. Irrespective of glucoamylase type, glucoamylase supplementation improved apparent digestibility of dry matter and starch, and the addition of a protease did not have additional benefits on nutrient digestibility.

Effect of particle size of a mash concentrate on behavior, digestibility, and macroscopic and microscopic integrity of the digestive tract in Holstein bulls fed intensively.

Twenty-four individually housed Holstein bulls (456 ± 6.9 kg of body weight and 292 ± 1.4 d of age) were enrolled in a complete randomized experiment involving four dietary treatments to evaluate the potential effect of mash particle size of diets in finishing beef diets on behavior, digestibility, and macro- and microscopic changes of the digestive tract. The four treatments were all ingredients sieved at 2 mm (HM2), all ingredients sieved at 3 mm (HM3), all ingredients, but corn, sieved at 2 mm and corn at 10 mm (HM210), and all ingredients, but corn, sieved a 3 mm and corn at 10 mm (HM310). For the HM210 and HM310 mashes, corn ground at 10 mm was mixed with the remaining concentrate ingredients ground at 2 or 3 mm, respectively. Concentrate (36% corn, 19% barley, 15% corn gluten feed, 8.4% wheat; 14% crude protein, 3.28 Mcal of ME/kg) consumption was recorded daily and straw consumption weekly. To register behavior, animals were filmed for 24 h on a weekly basis. At day 49 of study nutrient digestibility was estimated. Bulls were slaughtered after 56 d of exposure to treatments. Digestive tract and hepatic lesions were recorded, and tissue samples from the digestive tract collected. Geometric mean particle size was 0.61 ± 0.041, 0.76 ± 0.041, 0.62 ± 0.041, 0.73 ± 0.041 mm, and percentage of particles between 0.5 and 1 mm were 68 ± 2.9, 46 ± 1.7, 46 ± 5.0, and 39 ± 3.3 g/100 g for HM2, HM210, HM3, and HM310, respectively. Performance, total tract digestibility, or digestive tract integrity did not differ when ingredients were ground at 2 or 3 mm. Grinding corn with a hammer mill sieve size of 10 mm reduced feed efficiency and decreased total tract apparent dry matter, and organic matter digestibility compared with treatments from which all ingredients were ground at 2 or 3 mm. Straw intake was greatest and starch digestibility was least in the HM210 treatment. Last, only minor differences among treatments in rumen wall color, rumen papillae fusion, and histological conformation were observed. In summary, to improve feed efficiency, grinding corn at 10 mm is not recommended. In the present study, grinding procedure did not have a great effect on behavior and/or digestive tract health; however, under commercial conditions (group housing), grinding procedures that cause small mean particle sizes or particle size heterogeneity may increase the risk to suffer digestive tract lesions.

Effects of acarbose on ruminal fermentation, blood metabolites and microbial profile involved in ruminal acidosis in lactating cows fed a high-carbohydrate ration.

The objective was to evaluate the effects of an inhibitor of alpha-amylase and glucosidase (acarbose, Pfizer Limited, Corby, UK) on ruminal fermentation, blood metabolism and microbial profile in dairy cows in a 2x2 cross-over experiment. Eight Holstein cows fitted with rumen cannulas (milk yield, 24.3+/-2.35 kg/d, body weight, 622+/-54 kg, days in milk, 183+/-67, 5 multiparous and 3 primiparous) were used. Treatments were: control (no additive, CTR) and alpha-amylase and glucosidase inhibitor (0.75 g acarbose-premix/cow per d, AMI). Animals were given ad-libitum access to a high non-fibre carbohydrate (NFC) partial mixed ration (PMR) containing 17.6% crude protein, 28.3% neutral detergent fibre, and 46.5% NFC in the dry matter and supplementary concentrate during milking. Blood samples were taken to determine blood glucose, insulin and urea within the first hour after the morning feeding on two separate days in each period. Samples of ruminal contents were collected during 3 d in each period at 0, 4 and 8 h after feeding to determine volatile fatty acid and ammonia-N concentrations and to quantify protozoa, Streptococcus bovis and Megasphaera elsdenii. Rumen pH was recorded electronically at 22-min intervals during 6 d in each period. Results were analysed using a mixed-effects model. Cows on AMI treatment spent less time with ruminal pH <5.6 compared with cows in the CTR group (3.74 and 6.52+/-0.704 h/d, respectively). Cows in the AMI group had greater daily average pH compared with those in the CTR group (6.05 and 5.92+/-0.042, respectively). AMI animals tended (P=0.09) to have lower Str. bovis to Meg. elsdenii ratio than CTR (4.09 and 26.8+/-12.0, respectively). These results indicate that dietary supplementation with acarbose in dairy cattle fed high-production rations may be effective in reducing the time for which rumen pH is suboptimal, with no negative effects on ruminal fermentation and blood metabolites.

Associations between lameness and production, feeding and milking attendance of Holstein cows milked with an automatic milking system.

A longitudinal study involving 73 primiparous (PP) and 47 multiparous (MP) Holstein cows was conducted over an 8-month period to assess the associations between locomotion score (LCS) and milk production, dry matter intake (DMI), feeding behaviour, and number of visits to an automatic milking system (AMS). Twice weekly, all cows were locomotion scored (scale 1-5) by the same observer. Individual eating behaviour and individual feed consumption at each cow visit to the feed troughs, individual milk production, the time of milking, and the number of milkings for each cow were recorded for the day of locomotion scoring and the day before and after. Dependent variables, such as milk yield, DMI, etc. were modelled using a mixed-effects model with parity, LCS, days in milk (DIM), the exponential of -0.05 DIM, and the interaction between parity and LCS, as fixed effects and random intercepts and random slopes for the linear and the exponential of -0.05DIM effects within cow. LCS did not affect time of attendance at feed troughs, but affected the location that cows occupied in the feed troughs. The time devoted to eating and DMI decreased with increasing LCS. Milk production decreased with LCS>3. The number of daily visits to the AMS also decreased with increasing LCS. The cows with high LCS were fetched more often than the cows with low LCS. Overall, PP cows were more sensitive to the effects of increasing LCS than were MP cows. The decrease in milk production observed with increasing LCS seemed to be affected similarly by the decrease in DMI and by the decrease in number of daily visits to the AMS. A further economic loss generated by lame cows with AMS will be associated with the additional labour needed to fetch them.

Performance and behaviour of calves reared in groups or individually following an enhanced-growth feeding programme.

Nineteen calves were reared in individual pens (IP), and twenty calves were grouped in four pens of five calves each (GP) to study the effects of grouping on behaviour and performance. All calves were on an enhanced-growth feeding programme and had unlimited access to starter. Total dry matter intake (DMI) body weight (BW), serum urea, non-esterified fatty acid (NEFA), cortisol, insulin, and glucose concentrations, and immune response to vaccination were measured. Behaviour patterns categorized as: non-nutritive oral behaviour, cross-sucking, inter-sucking, and self-grooming, were monitored 20 min following the morning and afternoon milk replacer consumption, and at the same times after weaning. There were no differences in final BW and starter DMI between treatments. The decrease of average daily gain (ADG) during the week following weaning was more pronounced in GP than in IP calves. Serum NEFA concentration increased at the beginning of the study in IP calves but serum urea concentrations were greater in GP than in IP calves the week after weaning. Self-grooming increased in both treatments throughout the study but GP calves increased non-nutritive oral behaviour and decreased cross-sucking and inter-sucking behaviours throughout the study. Rearing calves in groups following an enhanced-growth feeding programme did not increase starter intake. Furthermore, cross-sucking and inter-sucking behaviours in calves reared in groups did not seem to cause increased metabolic or immunological distress.