Improvement of the Welfare Quality scoring model for dairy cows to fit experts' opinion.

After several years of implementation, the original Welfare Quality scoring model for dairy cows appears to be highly sensitive to the number and cleanliness of drinkers and not enough to the prevalence of diseases, and as a consequence may not fit the opinion of some animal welfare experts. The present paper aims to improve the Welfare Quality calculations for the criteria 'Absence of prolonged thirst' and 'Absence of disease' in dairy cows, so that the results are more sensitive to input data and better fit experts' opinion. First, we modified the calculation of 'Absence of prolonged thirst' by linearising the calculation for drinkers' availability to avoid threshold effects. Second, we modified the calculation of 'Absence of disease' by applying a Choquet integral on the three lowest spline-based scores for each health disorder to limit compensation between health disorders. Third, we performed a global sensitivity analysis of the original and the alternative scoring models. Fourth, we compared the results obtained with the original and the alternative models with eight experts' opinions on two subsets composed of 44 and 60 farms, respectively, inspected using the Welfare Quality protocol and on which experts gave their opinion on the overall level of animal welfare. Results show that the alternative model significantly reduced the 'threshold effects' related to the number of drinkers and the compensation between health disorders. On the first subset, the alternative model fits the experts' opinion slightly better than the original model (P = 0.061). On the second subset, the models performed equally. In conclusion, the proposed refinements for calculating scores are validated since they significantly reduced 'threshold effects' and the influence of measures related to drinkers. It also reduced the compensation between health disorders by considering only the three lowest scores and thus increasing the influence of measures related to health disorders, and slightly improve at overall score level the accordance with experts' opinion.

Review: Assessment of dairy cow welfare at pasture: measures available, gaps to address, and pathways to development of ad-hoc protocols.

Pasture is generally perceived as positive for dairy cow welfare, but it nevertheless exposes cows to heat, parasites, and other challenges. This review is intended for people ready to design comprehensive protocols for assessing the welfare of dairy cows at pasture. We provide an overview of the benefits and risks of pasture for cows, and then go on to identify the available and feasible measures for assessing cow welfare at pasture and the gaps that need to be addressed to develop specific welfare measures. Some of the measures from on-farm welfare assessment protocols designed for indoor use (e.g. Welfare Quality®) are relevant for cows at pasture (e.g. lameness scoring). However, the timing, location and/or method for certain measures (e.g. observation of social behaviour) need to be adapted to the pasture context, as cows at pasture can roam over a large area. Measures to address specific pasture-related risks (e.g. heat stress, biosecurity) or benefits (e.g. expression of a wide range of behaviours) should be implemented in order to capture all dimensions of cow welfare at pasture. Furthermore, cow welfare is liable to vary over the grazing season due to changes in weather conditions, grass quality and pasture plots that induce variations in lying surface conditions, food availability, distance to walk to the milking parlour, and so on. It is therefore important to investigate the variability in different welfare measures across the pasture season to check whether they hold stable over time and, if not, to determine solutions that can give an overview across the grazing season. Sensors offer a promising complement to animal and environment observations, as they can capture long-term animal monitoring data, which is simply not possible for a one-day welfare-check visit. We conclude that some measures validated for indoor situations can already be used in pasture-based systems, while others need to be validated for their fitness for purpose and/or use in pasture conditions. Furthermore, thresholds should probably be determined for measures to fit with pasture contexts. If all measures can be made adaptable to all situations encountered on farms or variants of the measures can at least be proposed for each criterion, then it should be possible to produce a comprehensive welfare assessment protocol suitable for large-scale use in near future.

Animal welfare official inspections: farmers and inspectors shared concerns.

Official inspections to check the compliance of farms with European legislation to protect farm animals are often perceived negatively by farmers. In addition, the inspections have a limited effect on improving farm compliance. We looked at the perceptions of both farmers and their inspectors about animal welfare and the inspections in a case study of dairy production in France. The identification of gaps and commonalities between both parties should help us to propose improvements in the inspection method by which inspections could more likely encourage compliance with animal welfare legislation. To achieve this aim, we conducted semi-structured interviews with 22 dairy farmers and their 19 inspectors. Both farmers and inspectors described animal welfare in terms of the state of the animal and of the living conditions and care provided to them. The majority of farmers found that the official checklist used by the inspectors is inappropriate to assess the welfare of their animals; inspectors themselves reported that they often use their own criteria and indicators (often based on the observation of animals) in addition to the official checklist. Both groups disagreed with some requirements of the legislation. These findings suggest that the content and background of the legislation to protect animals should be made clearer to both farmers and inspectors and that these two groups of actors should be involved in the definition of key points to be checked on farms, with special attention to animal-based indicators. All this could improve farmers' engagement with the results of the inspections and, hopefully, could lead to better compliance with legislation and improvements in animal welfare on farms.

New recommendations for self-locking barriers to reduce skin injuries in dairy cows.

The design of self-locking barriers can affect cows' skin injuries and impair welfare. This study aimed to propose and refine recommendations, expressed relatively to the cows' dimensions, for self-locking barrier design to reduce risks for skin injuries on the neck/shoulder/back and on carpus of dairy cows. We recorded individual body dimensions and the dimensions of self-locking barriers (e.g. top rail height) and assessed skin injuries on 3801 cows from 131 loose-housing dairy farms. We explored the significant associations between presence/absence of skin injuries and self-locking barrier dimensions using weighted multivariable logistic regression, taking into account the diversity of feeding barriers within each farm. The robustness of the models was assessed by cross-validation. Cows had skin injuries mainly on the neck/shoulder/back (29.0%) and, to a lesser extent, on the carpus (14.0%). The final multivariable logistic regression models comprised 13 factors for skin injuries on the neck/shoulder/back, and 11 factors for skin injuries on the carpus. Skin injuries were significantly reduced when the self-locking barriers were inclined (neck/shoulder/back) and when the cows used a feeding table (i.e. flat) instead of a feeding manger or cribs (i.e. hollow) (carpus). A top rail height >1.05 × cow height (measured at withers) was significantly associated with fewer skin injuries on the neck/shoulder/back and on carpus. Skin injuries on the neck/shoulder/back and carpus were significantly reduced when the bottom rail was on the food side relative to the wall, and at a height <0.39 of cow height. Skin injuries were significantly less frequent when the separation wall had no sharp edges on the food side (neck/shoulder/back), was >0.4 of cow height (carpus), was thinner than 15 cm (neck/shoulder/back and carpus) and when the height of the feeding step was 0.04 to 0.1 of cow height (neck/shoulder/back) and the length of the feeding step was <0.2 of cow length (carpus). A headlock articulation nut positioned between 0.62 and 0.78 of cow height significantly reduced skin injuries on the neck/shoulder/back. Here, by combining the diversity of on-farm self-locking barriers and their respective dimensions, we were able to refine the International Commission of Agricultural and Biosystems Engineering recommendations for self-locking barrier design and to propose new ones. This information now needs to be confirmed on other datasets, but can already help farmers and dairy industry stakeholders improve the design of self-locking barriers to improve dairy cow welfare.

Relationships between welfare and reproductive performance in French dairy herds.

This study aimed to investigate the relationship between cow reproductive performance and welfare evaluated at the herd level using the Welfare Quality protocol. The 11 criteria, four principles (good feeding, good housing, good health and appropriate behavior, scale 0-100) and overall welfare category (excellent/enhanced/acceptable/not classified = poor welfare) were included as risk factors for calving to first service interval (CFSI) and calving rate (CR). The confounding factors cow breed, parity, season of calving and AI, calving to AI interval, rank of AI (1-3) and milk production were taken into account. The sample included 3951 AIs (2172 AI1, 1182 AI2, 597 AI3) in 124 French commercial dairy herds. Median CFSI was shorter for the cows bred in herds with a higher overall welfare category (median 75 and 76 days in enhanced and acceptable herds vs. 86 in poor welfare ones, P = 0.02). The scores for absence of injuries and expression of social behavior tended to be associated with CFSI (P < 0.10). Calving rate (34.5%) was not related to the overall welfare category. However, CR was positively related to the good housing score and a positive trend was observed with the scores for absence of prolonged hunger and absence of injuries. In conclusion, this study confirms a positive relationship between CFSI and welfare in dairy cows with no explicit links with specific aspects of animal welfare.

[Cohort of patients initiated to home ventilation. Observational and prospective study]. / Cohorte de patients nouvellement traités par ventilation non invasive à domicile. Étude observationnelle, prospective et multicentrique.

Cohort of patients initiated to home ventilation. Observational and prospective study. The effectiveness of home noninvasive ventilation (NIV) for chronic respiratory failure (CRF) is well established. However, few data are available about home NIV prescription and utilization according to the different etiologies of respiratory failure. The ANTADIR Federation, in partnership with the Ventilatory Support Group of the French Speaking Pulmonary Society, has set up a national, observational and multicenter cohort study. The main goal of this study is to analyze the clinical data justifying home NIV prescription in patients with chronic respiratory insufficiency. The secondary objectives will be to assess: the evolution of comorbidities or their occurrence, hospitalizations, NIV compliance, dropout and survival. The population includes patients with chronic respiratory failure newly initiated onto NIV, both in a stable state and following an acute exacerbation who qualify for long-term NIV. Data collected include: diagnosis and comorbidities, age, sex, BMI, biomarkers (hematocrit, arterial blood gases, total CO2) and functional data (FEV1, VC, TLC), nocturnal results (SaO2, PtcCO2), type of ventilator used, ventilator parameters and mask type. Follow-up data will be collected at 4 months, 1 year and 2 years and will include: hospitalizations, changes in prescription, adherence, dropouts and deaths. This work will make it possible to obtain new scientific information on long-term NIV use in France.

Trained-user opinion about Welfare Quality measures and integrated scoring of dairy cattle welfare.

The Welfare Quality (WQ) protocol for on-farm dairy cattle welfare assessment describes 27 measures and a stepwise method for integrating values for these measures into 11 criteria scores, grouped further into 4 principle scores and finally into an overall welfare categorization with 4 levels. We conducted an online survey to examine whether trained users' opinions of the WQ protocol for dairy cattle correspond with the integrated scores (criteria, principles, and overall categorization) calculated according to the WQ protocol. First, the trained users' scores (n = 8-15) for reliability and validity and their ranking of the importance of all measures for herd welfare were compared with the degree of actual effect of these measures on the WQ integrated scores. Logistic regression was applied to identify the measures that affected the WQ overall welfare categorization into the "not classified" or "enhanced" categories for a database of 491 European herds. The smallest multivariate model maintaining the highest percentage of both sensitivity and specificity for the "enhanced" category contained 6 measures, whereas the model for "not classified" contained 4 measures. Some of the measures that were ranked as least important by trained users (e.g., measures relating to drinkers) had the highest influence on the WQ overall welfare categorization. Conversely, measures rated as most important by the trained users (e.g., lameness and mortality) had a lower effect on the WQ overall category. In addition, trained users were asked to allocate criterion and overall welfare scores to 7 focal herds selected from the database (n = 491 herds). Data on all WQ measures for these focal herds relative to all other herds in the database were provided. The degree to which expert scores corresponded to each other, the systematic difference, and the correspondence between median trained-user opinion and the WQ criterion scores were then tested. The level of correspondence between expert scoring and WQ scoring for 6 of the 12 criteria and for the overall welfare score was low. The WQ scores of the protocol for dairy cattle thus lacked correspondence with trained users on the importance of several welfare measures.

Fattening performance, metabolic indicators, and muscle composition of bulls fed fiber-rich versus starch-plus-lipid-rich concentrate diets.

The aim of this study was to compare the responses in fattening performance and meat composition for high-concentrate diets rich in either starch and lipids (especially omega-3 fatty acids) or fibrous by-products. A total of 140 Charolais bulls (initially 319 ± 27 kg BW) were allocated to 3 high-concentrate diets and were fattened for up to 18 mo. The diet treatments included concentrate mixtures rich in either fiber (FR; n = 56) or starch plus linseed (diets SL and SLR; n = 56 and n = 28, respectively) and barley straw. The concentrate mix was offered ad libitum in SL and FR diets but was kept isoenergetic to the FR diet in the SLR diet. Bulls were weighed every 15 d. Feed intake was measured daily. Carcass composition was assessed for all animals slaughtered at 699 ± 65 kg BW. Meat nutritional quality traits (e.g., fat content and fatty acid composition focusing on n-6 and n-3 polyunsaturated fatty acids) were measured on the longissimus thoracis, rectus abdominis, and semitendinosus muscles. Metabolic enzyme activity (phosphofructokinase, lactate dehydrogenase, and cytochrome-c oxidase) was measured on these muscles and on liver. The SL diet bulls had greater fattening performance, BW gain (P = 0.006), and efficiency for growth (P = 0.025) at an energy intake similar to that of FR diet bulls. They also had heavier carcasses with a greater proportion of fat. However, liver samples showed no difference in specific metabolic activity. Compared to bulls fed the SL diet, bulls fed SLR consumed 15% less energy and had lower BW gain (P < 0.001) but were slightly more efficient for growth (P = 0.010). They had lower carcass weight but a greater muscle-to-fat ratio. Compared to bulls fed the FR diet, SLR bulls had lower than planned NEg intake and lower BW gain but did not have differences in body composition. Compared to the FR diet, the SL diet led to a greater omega-3 fatty acid content because of a greater supply of dietary linoleic acid, especially in lean muscle.

[Assessment of recent weight history before instituting continuous positive airways pressure in a cohort of patients with severe obstructive sleep apnoea/hypopnea syndrome]. / Histoire pondérale récente, avant l'institution de la pression positive continue, dans une cohorte de patients ayant un syndrome d'apnées-hypopnées obstructives du sommeil sévère.

OBJECTIVES: The aim of this study is to evaluate the recent weight history in patients with the obstructive sleep apnoea/hypopnoea syndrome (OSAHS) needing treatment with continuous positive airways pressure (CPAP). PATIENTS AND METHODS: Over a period of 18 months, a self-administered questionnaire concerning recent weight history was given to patients during the installation of CPAP. RESULTS: The study population consisted of 1337 patients. An increase in weight of at least 5% over the 5 years preceding the institution of CPAP was found in 44% of patients. This increase was moderate (5-10%), important (10-20%) and very important (>20%) in respectively 12.3%, 16.1% and 15.6% of patients. The patients with important or very important weight gain differed from those whose weight remained steady in a higher percentage of women, young people, and patients with a higher prevalence of obesity, persistent smoking, a history of venous thromboembolism and treatment with anti-depressants. CONCLUSION: A recent increase in weight is frequently seen in severe OSAHS and is associated with some clinical characteristics.

Description and factors of variation of the overall health score in French dairy cattle herds using the Welfare Quality(®) assessment protocol.

Extensive information is available in the literature on the specific risk factors of the main health disorders afflicting dairy cattle herds. However, it remains difficult to manage a herd's overall health because measures to control one risk factor can exacerbate the risk of another disease. To achieve and maintain good overall herd health, livestock systems and management practices need to simultaneously take into account all of the main health disorders. We aimed to identify the characteristics of systems and practices conducive to good herd health using the Welfare Quality(®) assessment protocol for cattle. This protocol allows an assessment of the level of health and welfare at the herd level according to the opinion of a selected group of 13 experts from animal sciences. Our objectives were to (i) describe the distribution of dairy herds' health scores in a representative sample of French dairy cattle herds, and (ii) to investigate systems (housing system, milking system, herd size, breed, farm location) and management practices associated with variations of the overall health score of dairy herds. This protocol was carried out on 130 farms between December 2010 and March 2011. A multivariable analysis of variance (ANOVA) was performed to investigate the factors of variation of the overall health score at the herd level. The overall health scores of the farms in the sample were classified as moderate for the vast majority of farms (95.4%) (mainly due to subclinical mastitis, dystocia and pain induced by disbudding/dehorning) and varied little between farms. Some livestock systems were associated with a higher overall health score: straw yards and milking parlors (P<0.0001), highland vs. lowland locations (P=0.013), Montbeliarde rather than Holstein breeds (P=0.006). Some management practices also were associated with a higher level of health: medium herd average parity (P=0.03), low proportion of dirty cows (P=0.002) and low proportion of cows with abnormal body condition (P=0.04). These results suggest that some systems contribute to better health and that improvement of health can be obtained in the short term by the modification of routine management practices.

Identifying and monitoring pain in farm animals: a review.

One important objective for animal welfare is to maintain animals free from pain, injury or disease. Therefore, detecting and evaluating the intensity of animal pain is crucial. As animals cannot directly communicate their feelings, it is necessary to identify sensitive and specific indicators that can be easily used. The aim of the present paper is to review relevant indicators to assess pain in several farm species. The term pain is used for mammals, birds and fish, even though the abilities of the various species to experience the emotional component of pain may be different. Numerous behavioural changes are associated with pain and many of them could be used on farms to assess the degree of pain being experienced by an animal. Pain, as a stressor, is associated with variations in the hypothalamic-pituitary-adrenal axis as well as in the sympathetic and immune systems that can be used to identify the presence of pain rapidly after it started. However, most of these measures need sophisticated equipment for their assessment. Therefore, they are mainly adapted to experimental situations. Injuries and other lesional indicators give information on the sources of pain and are convenient to use in all types of situations. Histopathological analyses can identify sources of pain in experimental studies. When pronounced and/or long lasting, the pain-induced behavioural and physiological changes can decrease production performance. Some indicators are very specific and sensitive to pain, whereas others are more generally related to stressful situations. The latter can be used to indicate that animals are suffering from something, which may be pain. Overall, this literature review shows that several indicators exist to assess pain in mammals, a few in birds and very few in fish. Even if in some cases, a single indicator, usually a behavioural indicator, may be sufficient to detect pain, combining various types of indicators increases sensitivity and specificity of pain assessment. Research is needed to build and validate new indicators and to develop systems of pain assessment adapted to each type of situation and each species.

Positive attitudes of farmers and pen-group conservation reduce adverse reactions of bulls during transfer for slaughter.

Transfer to slaughter may be very stressful for cattle and negatively affect their ultimate carcass pH. A potential link between farmers' attitudes, farmers' behaviour, responses of animals to handling and carcass pH in beef bull production was questioned. Whether carcass pH depends on experiences in handling and social mixing was analysed. We conducted a survey on commercial farms where we questioned farmers on their work and beliefs about bulls. Farmers' behaviour with bulls during a test and bulls' behaviour during loading in the truck for transport to the slaughterhouse were observed. The ultimate carcass pH was measured. Farmers tended to behave more gently with their bulls when they had positive attitudes towards gentle contacts with bulls (P = 0.07). The loading of bulls in the truck tended to be more difficult when the farmer was more ready to approach his bulls (P = 0.07). Carcass pH was higher for bulls that had not been transferred from a breeding to a finishing unit (P = 0.03). It tended to be higher when the farmer did not display a gentle behaviour (P = 0.09). The link between farmers' attitudes and farmers' behaviour and the lower meat pH resulting from a gentle farmers' behaviour during finishing are consistent with previous findings in pig, veal or dairy productions. However, the present links were weaker than in the other productions, probably due to the low frequency of close contacts between farmers and beef bulls. When loading bulls into a truck, handlers use the tendency of animals to avoid people, hence overly positive behaviour with the animals during finishing may result in more difficulties at loading. In that case, use of alternative driving aids should be recommended. Our results on carcass pH suggest some habituation to transport among bulls transferred between breeding and finishing, even though the two experiences are several months apart. In view of our results, it seems that contacts with bulls, when they are needed, should be gentle.

Pre-slaughter conditions, animal stress and welfare: current status and possible future research.

The present paper describes the main procedures used to slaughter fowl, pigs, calves and adult cattle, sheep, and farmed fish, starting on the farm and ending with the death of the animal at the abattoir. It reviews the currently known causes of stress, indicated by behavioural and physiological measurements on the animal level, and by post-mortem muscle metabolism. During the pre-slaughter period, psychological stress is due to changes of environment, social disturbances and handling, and physical stress is due to food deprivation, climatic conditions, fatigue, and sometimes pain. The exact causes of stress depend, however, on the characteristics of each species, including the rearing system. For fowl, bird catching and crating, duration and climatic conditions of transport and of lairage and shackling are the main known pre-slaughter stress factors. For pigs, stress is caused by fighting during mixing of pens, loading and unloading conditions, and introduction in the restrainer. Handling and novelty of the situation contribute to the stress reactions. For veal calves and adult cattle, disruption of the social group, handling, loading and sometimes unloading conditions, fatigue, novelty of the situation and for calves mixing with unfamiliar animals are known stress factors. Gathering and yarding of extensively reared lambs and sheep causes stress, particularly when shepherd dogs are used. Subsequent transport may induce fatigue, especially if sheep are commercialised through auctions or markets. In farmed fish, stress is predominantly related to environmental aspects such as temperature, oxygen, cleanliness of the water and, to a certain extent, stocking density and removal of the fish from the water. If transport and lairage conditions are good and their durations not too long, they may allow pigs, calves and adult cattle, sheep, and fish to rest. For certain species, it was shown that genetic origin and earlier experience influence reactions to the slaughter procedure. Stunning techniques used depend on the species. Pigs and fowl are mostly electrically or gas-stunned, while most adult cattle are stunned with a captive bolt pistol. Calves and sheep may be electrically stunned or with a captive bolt pistol. Various stunning methods exist for the different farmed fish species. Potential causes of stress associated with the different stunning procedures are discussed. The paper addresses further consequences for meat quality and possible itineraries for future research. For all species, and most urgently for fish, more knowledge is needed on stunning and killing techniques, including gas-stunning techniques, to protect welfare.

[Social and housing conditions of patients with chronic respiratory failure treated in the ANTADIR Federation]. / La vie quotidienne et sociale des patients insuffisants respiratoires chroniques sévères pris en charge dans le réseau ANTADIR.

INTRODUCTION: Chronic respiratory failure (CRF) has an impact on quality of life because of respiratory handicap. METHODS: The purpose of this study was to analyse the daily life and social activities of patients with CRF. A questionnaire was addressed to over 9000 patients being cared for in the ANTADIR homecare network, with over a 60% response rate. RESULTS: The data showed that patients were old, and frequently had comorbidity. The predominant diagnosis was chronic obstructive airways disease (COPD) and the number of women in this population continues to increase. Respiratory handicap led to a loss of autonomy, a reduction in social activity and mobility of patients, but the impact differed markedly according to the cause of the respiratory failure, as well as age and social class. A typological study of behavioural characteristics revealed three groups of patients with contrasting profiles. CONCLUSION: These results lead to recommendation for better management of social aspects of patient care in the ANTADIR network.

Variations in meat pH of beef bulls in relation to conditions of transfer to slaughter and previous history of the animals.

Animals are subjected to various events that cause physical exhaustion and psychological stress during transfer to slaughter. This can lead to defective meat quality. Some animals may be better able to withstand the stress of transfer, depending on their previous experience of transport and on their finishing conditions (mixing, farmers' attitudes). The objective of this study was to assess the impact of 1) the conditions of transfer to slaughter (including duration of the journey, waiting time at lairage, etc.); and 2) the bulls' previous history (including experience in transport, mixing during finishing, and the farmers' attitudes) on the reactions of bulls to transfer and on their meat quality. We conducted a survey in commercial conditions. The history of the bulls and the facilities on the farms were noted; farmers were questioned on their attitudes; the bulls' reactions to loading into and unloading from the truck were observed; journey-related data were collected; and cortisol concentration at slaughter and the pH of the LM and the rectus abdominis were measured. Our study confirmed that certain physical factors associated with transport can increase stress and limit the decline of meat pH. These factors include the absence of loading facilities on the farm, transport on a warm day, or a short waiting time at lairage. Social aspects also played a role; the presence of bulls from the same finishing group limited stress and improved the pH decline. Events and management before transfer were also of importance; the farmer awareness of the sensitivity of bulls to humans or to feeding schedules but the absence of a positive attitude toward close contacts with bulls were all likely to limit stress or its consequences on meat pH. Although these results need to be confirmed in controlled experiments, they suggest that good management of beef bulls before and during transfer is essential to meat quality.

Behavior, physiology, and performance of bulls mixed at the onset of finishing to form uniform body weight groups.

In some production settings, beef bulls are mixed at the beginning of the finishing period to obtain homogeneous groups to facilitate finishing and to produce more homogeneous carcasses. Given the stress induced by mixing, we questioned whether this practice was profitable. Sixty-four young bulls were finished in groups of four over 8 mo. They were either mixed or unmixed and had either homogeneous vs. heterogeneous BW at the beginning of finishing. Behavioral traits (social behavior following mixing and general activities during the finishing period), stress measurements (cortisol concentration, adrenal weight, catecholamine-synthesizing enzyme activity, and pain sensitivity), and production traits (growth rate, homogeneity, feed efficiency, and carcass measurements) were evaluated. Bulls reacted to the mixing with increased frequency of social interactions (agonistic interactions: 17.9 in mixed vs. 1.2 in unmixed bulls, P < 0.001; sexual interactions: 9.6 vs. 1.7, P < 0.001; nonagonistic interactions: 5.25 vs. 3.1, P < 0.05). Agonistic and sexual interactions were more frequent between bulls of homogeneous BW (P < 0.05). Throughout the finishing period, the synchronization of activity tended to be lower between mixed bulls (P = 0.09). At slaughter, the activity of tyrosine hydroxylase, a catecholamine-synthesizing enzyme, was increased in mixed bulls (1.52 vs. 1.16 nmol.h(-1).mg(-1), P < 0.05), which may indicate chronic stress. No differences were noted in ADG or carcass traits among treatments. The variability of BW within groups increased in groups that were initially homogeneous, whereas it decreased in groups that were initially heterogeneous. In conclusion, mixing young beef bulls at the beginning of the finishing period did not have detrimental effects on health and production, but mixing induced stress, perhaps due to decreased cohesion within groups. Thus, we failed to confirm the proposed benefit of mixing bulls to homogenize their BW at the onset of finishing because BW homogeneity within groups was not maintained throughout the finishing period.

Portable oxygen therapy: use and benefit in hypoxaemic COPD patients on long-term oxygen therapy.

In 159 chronic obstructive pulmonary disease (COPD) patients (139 males, mean age 62 +/- 8 yrs, arterial oxygen tension (PaO2) 7.2 +/- 0.9 kPa), on long-term oxygen therapy (LTOT), we evaluated the effects of portable oxygen therapy both on the daily duration of oxygen therapy and on daily activities. They were given two types of LTOT at random: group A (n = 75), oxygen concentrators only (OC); group B (n = 84), either small oxygen cylinders plus OC (B1 = 51) or liquid oxygen (B2 = 33). The patients were followed-up for one year by means of: a) medical examination every three months; b) monthly home interviews concerning the daily duration of oxygen therapy, the utilization of the devices and the daily activities of the patients; c) a measurement of the daily oxygen usage. The results show that: 1) there are no significant clinical and functional differences between groups A and B at the onset of and throughout the study; 2) in group B the daily use of oxygen therapy is significantly longer than in group A (17 +/- 3.5 h.day-1 vs 14 +/- 3 h.day-1, p less than 0.01) without any difference between groups B1 and B2; 3) outdoor walking activities are different between groups A and B, at least in those patients using oxygen more than 18 h.day-1. Only 60% of patients in group B (55% of B1; 67% of B2) use their portable devices outdoors and for walking. No strict predictive criterion of this use is found in our study.(ABSTRACT TRUNCATED AT 250 WORDS)