The major impact of the livestock sector on the environment may be reduced by feeding agricultural co-products to animals. Since the last decade, co-products from biodiesel production, such as rapeseed meal (RSM), became increasingly available in Europe. Consequently, an increase in RSM content in livestock diets was observed at the expense of soybean meal (SBM) content. Cultivation of SBM is associated with high environmental impacts, especially when emissions related to land use change (LUC) are included. This study aims to assess the environmental impact of replacing SBM with RSM in finishing pig diets. As RSM has a lower nutritional value, we assessed the environmental impact of replacing SBM with RSM using scenarios that differed in handling changes in nutritional level. Scenario 1 (S1) was the basic scenario containing SBM. In scenario 2 (S2), RSM replaced SBM based on CP content, resulting in reduced energy and amino acid content, and hence an increased feed intake to realize the same growth rate. The diet of scenario 3 (S3) was identical to S2; however, we assumed that pigs were not able to increase their feed intake, leading to reduced growth performance. In scenario 4 (S4), the energy and amino acid content were increased to the same level of S1. Pig performances were simulated using a growth model. We analyzed the environmental impact of each scenario using life-cycle assessment, including processes of feed production, manure management, piglet production, enteric fermentation and housing. Results show that, expressed as per kg of BW, replacing SBM with RSM in finishing pig diets marginally decreased global warming potential (GWP) and energy use (EU) but decreased land use (LU) up to 12%. Between scenarios, S3 had the maximum potential to reduce the environmental impact, due to a lower impact per kg of feed and an increased body protein-to-lipid ratio of the pigs, resulting in a better feed conversion ratio. Optimization of the body protein-to-lipid ratio, therefore, might result in a reduced environmental impact of pig production. Furthermore, the impact of replacing SBM with RSM changed only marginally when emissions related to direct (up to 2.9%) and indirect LUC (up to 2.5%) were included. When we evaluated environmental impacts of feed production only, which implies excluding other processes along the chain as is generally found in the literature, GWP decreased up to 10%, including LUC, EU up to 5% and LU up to 16%.

The objective of this study was to evaluate if a multi-sensor system (milk, activity, body posture) was a better classifier for lameness than the single-sensor-based detection models. Between September 2013 and August 2014, 3629 cow observations were collected on a commercial dairy farm in Belgium. Human locomotion scoring was used as reference for the model development and evaluation. Cow behaviour and performance was measured with existing sensors that were already present at the farm. A prototype of three-dimensional-based video recording system was used to quantify automatically the back posture of a cow. For the single predictor comparisons, a receiver operating characteristics curve was made. For the multivariate detection models, logistic regression and generalized linear mixed models (GLMM) were developed. The best lameness classification model was obtained by the multi-sensor analysis (area under the receiver operating characteristics curve (AUC)=0.757±0.029), containing a combination of milk and milking variables, activity and gait and posture variables from videos. Second, the multivariate video-based system (AUC=0.732±0.011) performed better than the multivariate milk sensors (AUC=0.604±0.026) and the multivariate behaviour sensors (AUC=0.633±0.018). The video-based system performed better than the combined behaviour and performance-based detection model (AUC=0.669±0.028), indicating that it is worthwhile to consider a video-based lameness detection system, regardless the presence of other existing sensors in the farm. The results suggest that Θ2, the feature variable for the back curvature around the hip joints, with an AUC of 0.719 is the best single predictor variable for lameness detection based on locomotion scoring. In general, this study showed that the video-based back posture monitoring system is outperforming the behaviour and performance sensing techniques for locomotion scoring-based lameness detection. A GLMM with seven specific variables (walking speed, back posture measurement, daytime activity, milk yield, lactation stage, milk peak flow rate and milk peak conductivity) is the best combination of variables for lameness classification. The accuracy on four-level lameness classification was 60.3%. The accuracy improved to 79.8% for binary lameness classification. The binary GLMM obtained a sensitivity of 68.5% and a specificity of 87.6%, which both exceed the sensitivity (52.1%±4.7%) and specificity (83.2%±2.3%) of the multi-sensor logistic regression model. This shows that the repeated measures analysis in the GLMM, taking into account the individual history of the animal, outperforms the classification when thresholds based on herd level (a statistical population) are used.

In this study, we describe the monitoring of young broiler chicken vocalisation, with sound recorded and assessed at regular intervals throughout the life of the birds from day 1 to day 38, with a focus on the first week of life. We assess whether there are recognisable, and even predictable, vocalisation patterns based on frequency and sound spectrum analysis, which can be observed in birds at different ages and stages of growth within the relatively short life of the birds in commercial broiler production cycles. The experimental trials were carried out in a farm where the broiler where reared indoor, and audio recording procedures carried out over 38 days. The recordings were made using two microphones connected to a digital recorder, and the sonic data was collected in situations without disturbance of the animals beyond that created by the routine activities of the farmer. Digital files of 1 h duration were cut into short files of 10 min duration, and these sound recordings were analysed and labelled using audio analysis software. Analysis of these short sound files showed that the key vocalisation frequency and patterns changed in relation to increasing age and the weight of the broilers. Statistical analysis showed a significant correlation (P<0.001) between the frequency of vocalisation and the age of the birds. Based on the identification of specific frequencies of the sounds emitted, in relation to age and weight, it is proposed that there is potential for audio monitoring and comparison with ‘anticipated’ sound patterns to be used to evaluate the status of farmed broiler chicken.

Fermentative catabolism (FAAC) of dietary and endogenous amino acids (AA) in the small intestine contributes to loss of AA available for protein synthesis and body maintenance functions in pigs. A continuous isotope infusion study was performed to determine whole body urea flux, urea recycling and FAAC in the small intestine of ileal-cannulated growing pigs fed a control diet (CON, 18.6% CP; n=6), a high fibre diet with 12% added pectin (HF, 17.7% CP; n=4) or a low-protein diet (LP, 13.4% CP; n=6). 15N-ammonium chloride and 13C-urea were infused intragastrically and intravenously, respectively, for 4 days. Recovery of ammonia at the distal ileum was increased by feeding additional fibre when compared with the CON (P<0.05) but was not affected by dietary protein (0.24, 0.39 and 0.14 mmol nitrogen/kg BW/day for CON, HF and LP, respectively; P<0.05). Lowering protein intake reduced urea flux (25.3, 25.7 and 10.3 mmol nitrogen/kg BW/day; P<0.01), urinary urea excretion (14.4, 15.0 and 6.2 mmol N/kg BW/day; P<0.001) and urea recycling (12.1, 11.3 and 3.23 mmol nitrogen/kg BW/day; P<0.01) compared with CON. There was a rapid reduction in 15N-ammonia enrichment in digesta along the small intestine suggesting rapid absorption of ammonia before the distal ileum and lack of uniformity of enrichment in the digesta ammonia pool. A two-pool model was developed to determine possible value ranges for nitrogen flux in the small intestine assuming rapid absorption of ammonia. Maximum estimated FAAC based on this model was significantly lower when dietary protein content was decreased (32.9, 33.4 and 17.4 mmol nitrogen/kg BW/day; P<0.001). There was no impact of dietary fibre on estimates of small intestine nitrogen flux (P>0.05) compared with CON. The two-pool model developed in the present study allows for estimation of FAAC but still has limitations. Quantifying FAAC in the small intestine of pigs, as well as other non-ruminants and humans, offers a number of challenges but warrants further investigation.

A total of 90 cows from three commercial farms were used to evaluate the relationship between subclinical mastitis and clinical mastitis and thermal nociceptive threshold. Milk strips from all udder quarters were tested for clinical mastitis with visual inspection of milk and udder alterations and for subclinical mastitis using California Mastitis Test. Milk yield was recorded, milk was sampled and further analyzed for somatic cells count (SCC). Cows were considered healthy when SCC<200 000 cells/ml and no visual alterations in milk and/or udder, with mild subclinical mastitis when SCC>200 000 cells/ml and no visual alterations in milk and/or udder, with moderate subclinical mastitis when SCC>500 000 cells/ml and no visual alterations in milk and/or udder and with clinical mastitis when visual alterations in milk and/or udder were detected. Nociceptive threshold was evaluated with the thermal threshold meter apparatus applied to the rear legs. Thermal threshold (TT) decreased when we compared healthy cows with cows presenting clinical mastitis and tended to decrease when we compare healthy cows with those with moderate subclinical mastitis. TT was lower at the ipsilateral rear leg compared with the contralateral leg to the infected mammary gland. TT linearly decreases as log10SCC increased and it showed sharp decrease as log10SCC exceed the value of 6.4. Increase in one unit of log10SCC increased the odds of low thermal threshold (lower than 55.8°C). Subclinical mastitis might be a welfare issue as it tended to decrease nociceptive thermal threshold.

Ruminants remain productive during the energy insufficiency of late pregnancy or early lactation by evoking metabolic adaptations sparing available energy and nutrients (e.g. higher metabolic efficiency and induction of insulin resistance). A deficit in central leptin signaling triggers these adaptations in rodents but whether it does in ruminants remains unclear. To address this issue, five mature ewes were implanted with intracerebroventricular (ICV) cannula in the third ventricle. They were used in two experiments with an ovine leptin antagonist (OLA) when well-conditioned (average body condition score of 3.7 on a 5 point scale). The first experiment tested the ability of OLA to antagonize leptin under in vivo conditions. Ewes received continuous ICV infusion of artificial cerebrospinal fluid (aCSF), ovine leptin (4 µg/h) or the combination of ovine leptin (4 µg/h) and its mutant version OLA (40 µg/h) for 48 h. Dry matter intake (DMI) was measured every day and blood samples were collected on the last day of infusion. ICV infusion of leptin reduced DMI by 24% (P<0.05), and this effect was completely abolished by OLA co-infusion. A second experiment tested whether a reduction in endogenous leptin signaling in the brain triggers metabolic adaptations. This involved continuous ICV infusions of aCSF or OLA alone (40 µg/h) for 4 consecutive days. The infusion of OLA did not alter voluntary DMI over the treatment period or on any individual day. OLA did not affect plasma variables indicative of insulin action (glucose, non-esterified fatty acids, insulin and the disposition of plasma glucose during an insulin tolerance test) or plasma cortisol, but tended to reduce plasma triiodothyronine and thyroxine (P<0.07). Overall, these data show that a reduction of central leptin signaling has little impact on insulin action in well-conditioned mature sheep. They also raise the possibility that reduced central leptin signaling plays a role in controlling thyroid hormone production.

Impracticality and cost of existing pain management strategies during surgical castration of beef cattle have limited their widespread implementation on-farm. A farmer-applied topical anaesthetic formulation, originally developed and used commercially to mitigate the pain of mulesing in lambs, was investigated for its potential use for managing pain in surgically castrated calves. This formulation contained lidocaine, bupivacaine, adrenalin and cetrimide. In this study, 24 Angus bull calves were randomly allocated to (1) surgical castration (C, n=8), (2) surgical castration with the post-operative application of topical anaesthetic (CTA, n=8) and (3) sham castration/control (CON, n=8). The experiment was conducted over 2 days, with treatment groups evenly represented across each day. Calves were habituated to handling before the experiment and blood samples were collected for plasma cortisol measurement at defined time periods before, at and post treatment, (at −0.5, 0 h, then +0.5, 1, 1.5, 2, 4 and 6 h). There was a significant effect of time on cortisol concentrations across all treatment groups (P<0.01), with lowest concentrations at −0.5 and 6 h and peak concentration at 0.5 h being significantly higher than the cortisol response at 0 h. The effect of treatment was not significant (P=0.077), however, there was a trend for CON calves to display lower cortisol concentrations than C and CTA calves and CTA calves to display lower cortisol concentrations than C calves. The mean area under the curve (AUC) of CON calves was significantly lower than those of C and CTA calves (P=0.04), however, there was no significant difference between the AUCs of CTA and C calves. Immediate application of topical anaesthetic after surgical castration did not significantly reduce plasma cortisol concentrations. However, the trend for CTA calves to display lower cortisol concentrations than C calves warrants further investigation into the use of TA for pain relief of surgically castrated beef calves.

Bellies derived from the commercial population of pig carcasses are diverse in terms of tissue composition. Knowledge of the factors influencing it and the expected results, permits quick and easy evaluation of raw material. The study was designed to determine the factors affecting the tissues composition of pork bellies and to estimate their lean meat content. The research population (n=140 pig carcasses) was divided into groups according to sex (gilts, barrows), half-carcass mass (<40, 40 to 43.9, 44 to 46.9, ⩾47 kg) and lean meat content class: S (⩾60%), E (55% to 60%), U (50% to 55%), R (<50%). Bellies were subjected to a detailed dissection. Half-carcass mass affected the levels of all the analysed parameters. The only exception was the mass of the fat with the skin in the 40 to 43.9 kg group, for which the value did not differ statistically between the two groups <40 and 44 to 46.9 kg. Decrease in lean meat content affected the growth of the fat and skin mass in a linear way. No differences were observed between class S and E in terms of belly muscle mass. A 0.37% higher share of belly in the half-carcass was found for barrows (P<0.001), although bellies issued from barrows were characterized by a higher proportion of fat with skin compared with gilts (P=0.02). Interactions were observed between sex and half-carcass mass, so the sex of heavy half-carcasses becomes an important determinant for conditioning the muscle content. Equations were calculated and allow a fast and highly accurate determination of the lean meat content in bellies, suggesting they may be used directly in the production line.

The innovations developed by scientists working on animal welfare are often not adopted in practice. In this paper, we argue that one important reason for this failure is that the solutions proposed do not adequately address the societal concerns that motivated the original research. Some solutions also fail because they do not adequately address perceived constraints within the industry. Using examples from our own recent work, we show how research methods from the social sciences can address both of these limitations. For example, those who persist in tail-docking cattle (despite an abundance of evidence showing that the practice has no benefits) often justify their position by citing concern for cow cleanliness. This result informs the nature of new extension efforts directed at farmers that continue to tail dock, suggesting that these efforts will be more effective if they focus on providing producers with methods (of proven efficacy) for keeping cows clean. Work on pain mitigation for dehorning shows that some participants reluctant to provide pain relief believe that the pain from this procedure is short lasting and has little impact on the calf. This result informs the direction of new biological research efforts to understand both the magnitude and duration of any suffering that result from this type of procedure. These, and other examples, illustrate how social science methodologies can document the shared and divergent values of different stakeholders (to ensure that proposed solutions align with mainstream values), beliefs regarding the available evidence (to help target new scientific research that meets the perceived gaps), and barriers in implementing changes (to ease adoption of ideas by addressing these barriers).

Monitoring of feeding and rumination behaviour can provide useful information for dairy herd management. The feeding behaviour of dairy cows can be recorded by different techniques, such as video cameras, weighing troughs or chewing sensors. Among feeding characteristics, individual feed intake of cows is of utmost interest, but as weighing troughs have high space and cost requirements they are used primarily in research studies. The objective of the present study was to evaluate whether records on feeding time or chewing activity or a combination of both contain enough information to estimate feed intake with sufficient accuracy. Feed intake and feeding time per cow were recorded by means of weighing troughs. Concurrently, chewing activity of seven cows was recorded by MSR-ART pressure sensors during five to eight measuring days per cow. Feeding and chewing behaviour were evaluated in time slots (1 min) and additionally assigned to feeding bouts for further analysis. The 1 min time slots were classified into feeding/no feeding or chewing/no chewing by the two systems, and agreement was found in 92.2% of the records. On average, cows spent 270±39 min/day at the feeding troughs and chewed 262±48 min/day. The average fresh matter intake (FMI) was 49.6±5.1 kg/day. Feed intake was divided into 9.7 bouts/day during which cows fed in average 27.8±21.7 min/bout and chewed 27.0±23.1 min/bout. The correlation between FMI and feeding time was r=0.891 and between FMI and chewing time r=0.780 overall cows. Hence, both systems delivered suitable information for estimating feed intake.

The objective was to study milk production, body reserve mobilization, metabolic and hormonal profiles, and ovarian cyclicity of Holstein-Friesian (HOLS) and Montbéliarde (MONT) cows under two low-input dairy production systems with seasonal spring calving: an extensive (EXT; 12 HOLS and 12 MONT) based on permanent diversified grasslands and zero concentrate, and a semi-extensive (SEMI; 12 HOLS and 10 MONT) based on established temporary grasslands and up to 4 kg/day of concentrate. Individual measurements were performed between −4 and 12 weeks of lactation. Cows in EXT secreted less milk (22.1 v. 24.4 kg/day), protein (660 v. 755 g/day) and energy (67.7 v. 74.4 MJ/day), had greater plasma β-hydroxybutyrate (BHBA) (0.97 v. 0.69 mM), lower glucose (59.0 v. 62.0 mg/dl) and IGF-1 (62 v. 71 ng/ml), lower milk fat concentration in fatty acids originating from de novo synthesis (e.g. ∑ 10:0 to 15:0) and greater concentration of those derived in part from mobilization of fat reserves (e.g. 18:0 and ∑>C16), and showed greater frequency of abnormal ovarian cycles compared with SEMI. Across production systems, HOLS produced more milk (24.7 v. 21.8 kg/day), protein (738 v. 674 g/day) and fat (939 v. 819 g/day), secreted more energy (75.1 v. 67.0 MJ/day), lost more body condition score (BCS) (1.41 v. 1.03) and reached a lower BCS nadir (1.12 v. 1.43), had greater plasma BHBA (0.91 v. 0.75 mM), lower insulin (15.9 v. 17.2 µIU/ml) and tended to have lower glucose (59.6 v. 61.4 mg/dl), had lower milk fat concentration in ∑ 10:0 to 15:0, tended to have higher ∑>C16 and tended to show more abnormal estrous cycles compared with MONT. Ultrasound measurements did not differentiate fat mobilization and were confounded by breed differences of skin thickness. The greater nutrient allowance in SEMI improved indicators of physiological status and ovarian function during early lactation compared with EXT, but did not attenuate body reserve mobilization because cows prioritized milk secretion. HOLS secreted more nutrients than MONT but lost more BCS, which negatively affected nutritional balance and tended to affect ovarian cyclicity during early lactation. Breed by system interactions were not observed except for a few variables.

In this study, a video-based infrared camera (IRC) was investigated as a tool to monitor the body temperature of calves. Body surface temperatures were measured contactless using videos from an IRC fixed at a certain location in the calf feeder. The body surface temperatures were analysed retrospectively at three larger areas: the head area (in front of the forehead), the body area (behind forehead) and the area of the entire animal. The rectal temperature served as a reference temperature and was measured with a digital thermometer at the corresponding time point. A total of nine calves (Holstein-Friesians, 8 to 35 weeks old) were examined. The average maximum temperatures of the area of the entire animal (mean±SD: 37.66±0.90°C) and the head area (37.64±0.86°C) were always higher than that of the body area (36.75±1.06°C). The temperatures of the head area and of the entire animal were very similar. However, the maximum temperatures as measured using IRC increased with an increase in calf rectal temperature. The maximum temperatures of each video picture for the entire visible body area of the calves appeared to be sufficient to measure the superficial body temperature. The advantage of the video-based IRC over conventional IR single-picture cameras is that more than one picture per animal can be analysed in a short period of time. This technique provides more data for analysis. Thus, this system shows potential as an indicator for continuous temperature measurements in calves.

This article presents an uncertainty analysis of the productivity of cattle herds in traditional farming systems of West and Central African drylands. The study focused on productivity rates in animal numbers (RN) and meat weights (RW) estimated from a herd growth model, which were compared with FAOSTAT-based estimates. The uncertainty analysis contained the following two steps: uncertainty propagation and a global sensitivity analysis. The analysis was based on a state-of-the-art of the current knowledge and a set of available data on the herd performances. The calculations used Monte Carlo simulations to estimate the 95% confidence intervals (CI) of RN and RW and the standardized regression coefficients method to estimate the contribution of the input variables to the outputs variances. The mean rate RN was estimated to 0.127 animal/animal-year with a 95% CI of (0.091, 0.163) and the mean rate RW to 11.7 kg/animal-year with a 95% CI of (8.8, 14.7), corresponding to relative variation around the mean of about ±29% and ±25%, respectively. The input variables that contributed most to the variance of RN (almost 76% of the output variance) were the calving rate, the adult female mortality rate and the female proportion in the population (determined by the pattern of the male offtake in the herds). The input variables that contributed most to the variance of RW were the same as those for RN plus the adult live weights. The CI ranges that were estimated in this article indicate that productivity rates based on literature data or expert estimations of the herd performances should be considered with caution. Research efforts based on gold-standard herd monitoring protocols accounting for temporal and spatial variations should be undertaken in future to decrease the knowledge gaps on the input variables that contribute most to these ranges.

The aim of this study was to compare low doses of microencapsulated v. pharmacological ZnO in the diet of piglets on growth performance, ileum health status and architecture. One hundred and forty-four piglets weaned at 28 days and divided in 36 pens (two males and two females per pen), received a basal diet (control, Zn at 50 mg/kg) or the basal diet with ZnO at 3000 mg/kg (pZnO), or with lipid microencapsulated ZnO at 150 or 400 mg/kg (mZnO-300 and mZnO-800, respectively). After 14 and 42 days, three pigs per sex per treatment were euthanized to collect the ileum mucosa for immunohistochemistry, histomorphology, inflammatory cytokines and tight junction components gene expression. Data were analyzed with one-way ANOVA. At 0 to 14 days, the pZnO and mZnO-800 groups had greater average daily gain compared with control (P<0.05). Gain to feed ratio (G:F) in the same time interval was higher in pZnO group compared with control thus resulting in higher BW (P<0.05). At day 14, ileum villi height in mZnO-800 pigs was 343 µm v. 309 and 317 µm in control and pZnO, respectively (P<0.01) and villi:crypts ratio (V:C), as well as cells positive to proliferating cell nuclear antigen (PCNA), were greater in all treated groups compared with control (P<0.01). In mZnO-800 group, interferon-γ mRNA was the lowest (P=0.02), and both pharmacological ZnO and mZnO reduced tumor necrosis factor-α protein level (P<0.0001). Compared with pZnO group, mZnO-800 increased occludin and zonula occludens-1 protein level (1.6-fold and 1.3-fold, respectively; P<0.001). At day 42, both groups receiving microencapsulated ZnO had 1.7 kg greater BW than control and did not differ from pZnO group (P=0.01); ileum villi height and V:C ratio were the greatest for pZnO compared with the other groups, whereas PCNA-positive cells were the most numerous in mZnO-800 group (P<0.001). In conclusion, pigs receiving low doses of microencapsulated ZnO had G:F comparable with those receiving pharmacological level of ZnO in the overall post-weaning phase. Moreover, in the first 2 weeks post-weaning, microencapsulated ZnO effect on inflammatory status and ileum structure and integrity was comparable with pharmacological ZnO.

In this paper the feasibility to extract the proportion of pigs located in different areas of a pig pen by advanced image analysis technique is explored and discussed for possible applications. For example, pigs generally locate themselves in the wet dunging area at high ambient temperatures in order to avoid heat stress, as wetting the body surface is the major path to dissipate the heat by evaporation. Thus, the portion of pigs in the dunging area and resting area, respectively, could be used as an indicator of failure of controlling the climate in the pig environment as pigs are not supposed to rest in the dunging area. The computer vision methodology utilizes a learning based segmentation approach using several features extracted from the image. The learning based approach applied is based on extended state-of-the-art features in combination with a structured prediction framework based on a logistic regression solver using elastic net regularization. In addition, the method is able to produce a probability per pixel rather than form a hard decision. This overcomes some of the limitations found in a setup using grey-scale information only. The pig pen is a difficult imaging environment because of challenging lighting conditions like shadows, poor lighting and poor contrast between pig and background. In order to test practical conditions, a pen containing nine young pigs was filmed from a top view perspective by an Axis M3006 camera with a resolution of 640×480 in three, 10-min sessions under different lighting conditions. The results indicate that a learning based method improves, in comparison with greyscale methods, the possibility to reliable identify proportions of pigs in different areas of the pen. Pigs with a changed behaviour (location) in the pen may indicate changed climate conditions. Changed individual behaviour may also indicate inferior health or acute illness.

Energy expenditure (EE) can be estimated based on respiratory gas exchange measurements, traditionally done in respiration chambers by indirect calorimetry (IC). However, the 13C-bicarbonate technique (13C-BT) might be an alternative minimal invasive method for estimation of CO2 production and EE in the field. In this study, four Shetland ponies were used to explore the effect of feeding on CO2 production and EE measured simultaneously by IC and 13C-BT. The ponies were individually housed in respiration chambers and received either a single oral or intravenous (IV) bolus dose of 13C-labelled sodium bicarbonate (NaH13CO3). The ponies were fed haylage 3 h before (T−3), simultaneously with (T0) or 3 h after (T+3) administration of 13C-bicarbonate. The CO2 produced and O2 consumed by the ponies were measured for 6 h with both administration routes of 13C-bicarbonate at the three different feeding times. Feeding time affected the CO2 production (P<0.001) and O2 consumption (P<0.001), but not the respiratory quotient (RQ) measured by IC. The recovery factor (RF) of 13C in breath CO2 was affected by feeding time (P<0.01) and three different RF were used in the calculation of CO2 production measured by 13C-BT. An average RQ was used for the calculations of EE. There was no difference between IC and 13C-BT for estimation of CO2 production. An effect of feeding time (P<0.001) on the estimated EE was found, with higher EE when feed was offered (T0 and T+3) compared with when no feed was available (T−3) during measurements. In conclusion, this study showed that feeding time affects the RF and measurements of CO2 production and EE. This should be considered when the 13C-BT is used in the field. IV administration of 13C-bicarbonate is recommended in future studies with horses to avoid complex 13C enrichment-time curves with maxima and shoulders as observed in several experiments with oral administration of 13C-bicarbonate.

The expertise and knowledge of veterinary advisors on improving animal health management is key towards a better herd health status. However, veterinary advisors are not always aware of the goals and priorities of dairy farmers. To dairy farmers animal health is only one aspect of farm management and resources may be allocated to other more preferred areas. Veterinary advisors may experience this as non-compliant with their advice. To explore the preferences of European Union (EU) organic dairy farmers for improved animal health management relative to other farm management areas an adaptive conjoint analysis (ACA) was performed. A total of 215 farmers participated originating from organic dairy farms in France (n=70), Germany (n=60), Spain (n=28) and Sweden (n=57). The management areas udder health and claw health represented animal health management whereas barn, calf and pasture management represented potential conflicting management areas. Results indicate that EU organic dairy farmers differ in their preferences for improved animal health management within the farming system. In general, improved calf management was the most preferred area and improved claw health management was found to be least preferred, the remaining areas were of intermediate interest. Cluster analyses on claw health measures and udder health measures resulted in respectively seven and nine distinct preference profiles. The results indicate a high degree of variation in farmers’ preference, which cannot be explained by the typical herd characteristics. With the individual preferences revealed by ACA, a veterinary advisor can now find out whether his intended advice is directed at a favourable or unfavourable management area of the farmer. If the latter is the case the veterinarian should first create awareness of the problem to the farmer. Insights in individual farmers preferences will allow veterinary advisors to better understand why farmers were incompliant with their advice and improve their advice by showing, for example, the potential benefits of their advice.

There is increasing concern about welfare of laying hens in cages, and one aspect of this topic relates to bone fragility. Therefore, bone anabolic components such as bovine lactoferrin (bLF) may be an effective strategy to maintain the integrity and health of bones. A total of 1080 eggs were divided into four groups with three replicates, each comprising 270 eggs; (1) control group was injected with 100 μl of normal saline per egg; (2, 3 and 4) groups including 22.5 (low), 45 (medium) and 67.5 µg (high) of bLF in 100 µl of normal saline per egg. Eggs were incubated and after hatching, chicks were reared to 28 weeks of age. Tibia measurements were obtained at hatch and at 28 weeks of age. Tibia weight at hatch, was not influenced by in ovo injection of bLF in comparison with the control. Eggs injected with the high concentration of bLF (67.5 µg of bLF per egg) showed significant strengthening in laying-hen tibias at 28 weeks of age, as measured by ultimate force and bending stress, compared with the control. Egg weights from hens treated with this concentration of bLF were also significantly greater than the control. Our data suggest that tibia cortical thickness is a suitable variable for evaluating bone status reflecting bone integrity and strength. The present study also shows that bLF (67.5 µg of bLF per egg) injected into layer breeder eggs before incubation can be used to improve bone strength and egg weight of laying hens at 28 weeks of age, while having no detrimental effect on embryo hatchability.