Practical Farming Conditions Research Articles

SIMONTO-Pea: Phenological Models to Predict Crop Growth Stages in BBCH of Grain and Green Peas (Pisum sativum) for Temporal Pest Management

Many pests damage pea crops, which potentially leads to reduced quality and yield losses. Since pests occur at different phenological growth stages of pea crops, the prediction of growth stages, for example as BBCH stages, is beneficial. In this study, three models have been developed to simulate growth stages of grain and green pea crops, for the latter with early and late sowing dates. All data, such as BBCH stages and air temperature, were collected in Germany in a three-year study under practical farming conditions at 415 sample sites. For the development of each model, a Gompertz regression model based on the observed data was performed. The model validation suggests that each model precisely and reliably predicts pea crop growth stages for spring-sown peas. Amongst others, the RMSEIndex for grain peas was 3.4; for green peas, early and late sowing dates, respectively, they were 3.4 and 4.5. SIMONTO-Pea (SIMulation of ONTOgenesis) is the first model that predicts detailed pea crop growth stages based on the BBCH scale. This innovation is especially beneficial for users such as advisors and farmers dealing with spring-sown pea crops as a decision support system in monitoring and pest management according to pea crop growth stages.

An Approach towards a Practicable Assessment of Neonatal Piglet Body Core Temperature Using Automatic Object Detection Based on Thermal Images

Body core temperature (BCT) is an important characteristic for the vitality of pigs. Suboptimal BCT might indicate or lead to increased stress or diseases. Thermal imaging technologies offer the opportunity to determine BCT in a non-invasive, stress-free way, potentially reducing the manual effort. The current approaches often use multiple close-up images of different parts of the body to estimate the rectal temperature, which is laborious under practical farming conditions. Additionally, images need to be manually annotated for the regions of interest inside the manufacturer’s software. Our approach only needs a single (top view) thermal image of a piglet to automatically estimate the BCT. We first trained a convolutional neural network for the detection of the relevant areas, followed by a background segmentation using the Otsu algorithm to generate precise mean, median, and max temperatures of each detected area. The best fit of our method had an R2 = 0.774. The standardized setup consists of a “FLIROnePro” attached to an Android tablet. To sum up, this approach could be an appropriate tool for animal monitoring under commercial and research farming conditions.

Does weight matter? Exploring links between birth weight, growth and pig-directed manipulative behaviour in growing-finishing pigs

Damaging behaviour, especially tail and ear biting, are common problems in modern pig production. It has been suggested that a low birth weight could predispose pigs to become tail biters. Further, previous studies have shown somewhat contradictory links between growth rate and damaging behaviours, as well as resulting lesions. The aim of this study was to investigate, under practical farm conditions, if birth weight and growth of pigs are related to the risk for damaging behaviours and their outcomes, namely tail and ear lesions. A total of 386 pigs were followed from birth until the end of finishing period on four commercial farm pairs (piglet-producing and finishing farms). Based on birth weight, pigs were categorised as Small and Others, and pigs were weighed around weaning and in the growing and finishing units. At the two latter phases, they were scored for lesions and observed for pig- and environment-directed manipulative behaviour (PMB and EMB, respectively). PMB was not more common in Small than in Other pigs. However, PMB in the growing unit was positively associated with growth rate during suckling and growing periods (p = 0.04 and 0.05, respectively) and EMB was reduced in pigs with high growth rate (p = 0.02) in the finishing unit. Additionally, ear lesions in the growing unit were related to high growth rate in both the suckling (p = 0.03) and the growing period (p < 0.01). The current study shows no evidence that low birth weight predisposes to become a performer of damaging behaviours. Instead, a high growth rate in the suckling and growing period increased the risk for a high level of pig-directed manipulation as well as for becoming a victim of damaging behaviour in the growing unit. We suggest that this could be a consequence of increased feeding motivation in fast-growing pigs: they might experience more competition for feed, and consequently a higher level of stress, which predisposes to damaging behaviour.

Europe's Farm to Fork Strategy and Its Commitment to Biotechnology and Organic Farming: Conflicting or Complementary Goals?

The European Commission's Farm to Fork (F2F) strategy, under the European Green Deal, acknowledges that innovative techniques, including biotechnology, may play a role in increasing sustainability. At the same time, organic farming will be promoted, and at least 25% of the EU's agricultural land shall be under organic farming by 2030. How can both biotechnology and organic farming be developed and promoted simultaneously to contribute to achieving the Sustainable Development Goals (SDGs)? We illustrate that achieving the SDGs benefits from the inclusion of recent innovations in biotechnology in organic farming. This requires a change in the law. Otherwise, the planned increase of organic production in the F2F strategy may result in less sustainable, not more sustainable, food systems.

The effect of a fodder beet versus rye-grass grazing regime during mid-to-late gestation twin-bearing ewes on dam and progeny performance and lamb survival

ABSTRACT The objective was to determine the effect of grazing fodder beet versus ryegrass-dominant pasture from mid-to-late gestation on dam and offspring performance under practical farming conditions. Twin-bearing ewes were randomly allocated to grazing regimes of either fodder beet plus ad libitum ryegrass/clover hay (FB; n = 100) or ryegrass-dominant pasture plus ad libitum ryegrass/clover hay (RG; n = 100) with three replicates per group, from pregnancy day (P) 100–110 to birth. At P135, 10 ewes per treatment were randomly selected from each replicate, slaughtered and back fat and eye muscle depth and fetal body weight and composition were measured. Samples were evaluated for selected blood metabolites. Ewe BW and BCS change and lamb growth were measured, and lamb survival from birth to weaning calculated. Compared with RG, FB ewes had lower ADG and overall lower BCS resulting from increased mobilisation of both fat and muscle. Lambs born to FB-ewes had lower BW and postnatal growth rates and increased mortality from birth to weaning (29% versus 12%). Body composition and blood parameters indicated that FB compared to RG ewes were subject to undernutrition. This study provides new insights into the consequences of FB grazing regimes, as an alternative to ryegrass pasture, on animal performance.

How can Cattle be Toilet Trained? Incorporating Reflexive Behaviours into a Behavioural Chain.

Simple SummaryThe mixing of bovine faeces and urine leads to climate-damaging ammonia emissions. If cattle could be taught to use a latrine, this would reduce the area of emissions, the separation of excreta could easily be accomplished by mechanical means, and animal health could be improved. Attempts to train toileting in cattle have shown limited success. In children, toileting is trained mainly by (i) interrupting voiding that starts outside the toilet, then taking the child to the toilet and rewarding the resumption of excretion, or (ii) placing the child on the toilet, waiting for urination/defecation and rewarding appropriate excretory behaviour. The first method is reported to be more successful. Thus, a similar procedure was evaluated for training latrine use for urination in calves. On 95% of occasions, the calves inhibited or stopped urination when receiving a signal to move to the latrine, and on 65% of occasions, they reinitiated urination in the latrine. Furthermore, during 63% of urinations in the latrine, the calves oriented towards the reward location before any food was delivered, providing additional evidence that calves can be successfully toilet trained with food rewards.Untrained cattle do not defecate or urinate in defined locations. The toilet training of cattle would allow urine and faeces to be separated and stored, reducing climate-damaging emissions and improving animal health. In a proof-of-concept study, we evaluated a novel protocol for toilet training in cattle. Five heifer calves (and yoked controls) were trained in the voluntary (operant) behaviours of a toileting chain. Then, reflexive urinating responses were incorporated into the chain, with toileting signalled by a tactile (vibratory) stimulus. On 95% of occasions, the calves inhibited/interrupted urination when receiving the stimulus, and on 65% of these occasions, reinitiated urination in the latrine. Furthermore, during 63% of urinations in the latrine, the calves oriented to the reward location before any food was delivered, providing additional evidence that calves can be successfully toilet trained with food rewards. Yoked controls failed to learn most of the operant elements and all the reflexive responses of toilet training. The results show that reflexive behaviours can be incorporated into voluntary toileting sequences with cattle and extend the range of species that can be toilet trained. Future refinement of the protocol to allow training under practical farm conditions offers the potential to mitigate climate damage and improve animal health.

Determination of Cyclopropenoid Fatty Acids in Ewe Milk Fat by GC-MS after Intravenous Administration of Sterculic Acid.

Cyclopropenoid fatty acids (CPEFA), found in oilseeds from Malvaceae and Sterculiaceae, have been shown to interfere with the endogenous synthesis of several bioactive lipids of dairy fat, such as cis-9, trans-11 18:2 and cis-9 18:1, by inhibiting Δ9-desaturase. No previous study has reported the presence of sterculic acid in animal fat and its incorporation in tissues after its administration, due to the lack of a proper methodology. In the present research, a GC-MS method based on cold base derivatization to fatty acids methylesters was developed to determine CPEFA in ewe milk triglycerides, after infusing sterculic acid (0.5 g/day) to six lactating ewes. An alternative derivatization based on silanyzation followed by GC-MS analysis was also tested, showing its possible applicability when CPEFA are present in the form of free fatty acids. Sterculic acid was detected in ewe milk triglycerides, demonstrating its incorporation from the bloodstream into milk by the mammary gland. The mean transfer rate represented 8.0 ± 1.0% of the daily dose. This study provides, for the first time, the presence of sterculic acid in milk fat, supporting the importance of understanding its occurrence in vivo and encouraging further research to determine whether it can be present in foods, such as dairy products, obtained under practical farming conditions.

Response of maize leaf decomposition in litterbags and soil bags to different tillage intensities in a long-term field trial

In a long-term tillage field trial under practical farming conditions in Central Germany, the decomposition of maize (Zea maize L.) leaf litter was monitored for 8 months in litterbags and soil bags, where non-decomposed litter was mixed into soil and recovered as particulate organic matter (POM). The objective was to determine which methodological approach is more suitable to reflect tillage effects on litter decomposition and microbial turnover in no-tillage and grubber (15 cm), i.e. a rigid tine cultivator, treatments in comparison with mouldboard ploughing (25 cm). Under no-tillage, CO2-C efflux monitored for 22.5 months was lowest, although this soil contained the highest soil organic C and microbial biomass C contents at 0–5 cm depth. One reason is the slow warming in spring due to the highest volumetric water content, leading to the lowest mean soil temperature. Maize leaf litter was more rapidly decomposed in the soil bags, with a mean mass loss rate constant k = 0.0108 d−1, than in the litterbags, with k = 0.0063 d−1. This difference mainly occurred during the initial 3-month period after burying. In the soil bags, the mass loss rate constant for maize leaf litter was significantly higher in the no-tillage than in the plough treatment. In contrast, the mean microbial C use efficiency of the maize leaf litter of 0.27 in the soil bags was not affected by the tillage treatments. Although both methods are in principle suitable for monitoring decomposition processes, the soil bag method has advantages, as initial accessibility to decomposing microorganisms is facilitated.

Using Acceleration Data to Automatically Detect the Onset of Farrowing in Sows.

The aim of the present study was to automatically predict the onset of farrowing in crate-confined sows. (1) Background: Automatic tools are appropriate to support animal surveillance under practical farming conditions. (2) Methods: In three batches, sows in one farrowing compartment of the Futterkamp research farm were equipped with an ear sensor to sample acceleration. As a reference video, recordings of the sows were used. A classical CUSUM chart using different acceleration indices of various distribution characteristics with several scenarios were compared. (3) Results: The increase of activity mainly due to nest building behavior before the onset of farrowing could be detected with the sow individual CUSUM chart. The best performance required a statistical distribution characteristic that represented fluctuations in the signal (for example, 1st variation) combined with a transformation of this parameter by cumulating differences in the signal within certain time periods from one day to another. With this transformed signal, farrowing sows could reliably be detected. For 100% or 85% of the sows, an alarm was given within 48 or 12 h before the onset of farrowing. (4) Conclusions: Acceleration measurements in the ear of a sow are suitable for detecting the onset of farrowing in individually housed sows in commercial farrowing crates.

Effect of disodium/calcium malate or supplementation on growth performance, carcass quality, ruminal fermentation products, and blood metabolites of heifers.

The aim of this study was to assess the effects of malate salts and culture on growth performance, carcass quality, ruminal fermentation products, and blood metabolites in heifers raised under southern Europe practical farm conditions. A total of 108 Charolaise cross heifers (214 ± 27.3 kg BW and 6.4 ± 1.1 mo of age) were housed in 18 pens of 6 animals each and used in a 114-d feedlot study. There was a totally randomized experimental design, and 6 pens were assigned to each of the following experimental diets: a control (no supplementation), the control plus 4 g of disodium/calcium malate mixture per kilogram of concentrate (2.12 g malate/kg), and the control plus 0.15 g of CBS 493.94 per kilogram of concentrate (1.5 × 10 cfu/kg). The control diet consisted of wheat-barley-based pelleted concentrate (32% starch, DM basis) and full-length barley straw. Concentrate and straw were fed separately ad libitum (5% orts) in an 88:12 ratio. On Days 0, 56, and 114, ruminal fluid and blood samples were obtained from each heifer between 2 and 2.5 h after the morning feeding by ruminocentesis and tail venipuncture, respectively. Body weight, concentrate ADFI, and G:F were recorded at 28, 56, 84, and 114 d. At slaughter, hot carcass weight and yield and carcass classification were determined in 2 representative heifers per pen (12 animals per dietary treatment). Supplementation with malate salts or did not affect concentrate ADFI ( = 0.98), ADG ( = 0.74), or G:F ( = 0.50) at any time during the experiment. At slaughter, there were no differences in carcass weight ( = 0.86), classification ( = 0.18), or carcass yield ( = 0.84) among experimental groups. Also, there were no differences treatments on ruminal pH ( = 0.24), ruminal fermentation products ( = 0.69, = 0.88, and = 0.93 for total VFA, NH-N, and lactate, respectively), and blood metabolites ( = 0.96, = 0.82, and = 0.15 for glucose, urea N, and lactate, respectively). In conclusion, under the feeding and management conditions of this study, diet supplementation with malate salts or did not have any significant effects on growth performance, carcass quality, ruminal fermentation products, and blood metabolites.

Automatic estimation of number of piglets in a pen during farrowing, using image analysis

The objective was to develop a camera based monitoring system of the farrowing process in sows. The system, when used in practical farm conditions, should support the farm staff in reducing the problems of mortality in piglets due to perinatal asphyxia and crushing. The experiments took place in the research farm of the University of Veterinary Medicine Vienna, using a herd of 120 Large White sows. Data were collected from sows housed in farrowing pens with possibility of temporary crating. The farrowing process of 8 sows was video recorded and labelled for a period of 6 h before the start of farrowing until the end of farrowing. Timestamps of births of all piglets in the litter were labelled. Images obtained during the experiment were segmented with focus on piglet detection. Three parameters were extracted from segmented images: number of objects detected, area and perimeter of all objects. On the basis of the parameters, a Transfer Function (TF) model was estimated with output variable defined as number of piglets in the pen. The developed model explained 82% (R2) variability in the training set composed of 5 sows and 81% (R2) in the validation set composed of 3 sows. Number of piglets in the pen was estimated with a standard error of 1.73 piglets in the training set and 1.72 in the validation set. The potential application of the developed technique is monitoring of start of farrowing, perinatal asphyxia and crushing in piglets.

ERM booster vaccination of rainbow trout using diluted bacterin: Field studies

Enteric Red Mouth Disease ERM caused by Yersinia ruckeri infection is associated with morbidity and mortality in salmonid farming but immersion vaccination of fry may confer some protection for a number of months. Revaccination of rainbow trout, even by use of diluted ERM immersion vaccine, can under laboratory conditions extend the protection period. The present field study investigated the applicability of the method under practical farming conditions (freshwater earth ponds supplied by stream water). Primary immersion vaccination of trout (3–4g) for 30s in Y. ruckeri bacterin (diluted 1:10) in April 2015 was followed 3months later (July 2015) by 1h bathing of rainbow trout in bacterin (diluted 1:650 or 1:1700) in order to evaluate if this time saving vaccination methodology can improve immunity and protection. Trout were subjected in farms to natural Y. ruckeri exposure in June and July and non-vaccinated and non-boostered fish were less protected as they exhibited increased mortality compared to booster vaccinated fish. Blood and tissue samples were recovered from one farm in the autumn. No significant antibody titer differences were detected between groups but immunohistochemical investigations showed elevated densities of IgM and IgT positive lymphocytes in spleen tissue of vaccinated fish. The limitations and interpretations of the field results are discussed in the light of other infections (parasitic and bacterial) recorded during this farm study. Statement of relevanceThe present study is relevant for aquaculture of rainbow trout reared in freshwater farms. One of the main problems in freshwater fish farming is infections caused by Yersinia ruckeri, eliciting the disease Enteric Red Mouth Disease (ERM). The present manuscript describes how fish farmers can save time and improve their economy by using a bath vaccination method against this disease when they handle and transport their fish for other reasons (transport between farms or ponds).

Welfare Indicators of Milking Sheep and Goats in Commercial Farms in Spain:Evaluation and Differences among Species, Locations and Performances

The objective of this work was to evaluate a system for assessing the welfare of milking sheep and goats in practical farm conditions. The system uses indicators of environmental, management and facilities related welfare. In order to evaluate the animal welfare, 12 indicators ranked in 3 groups were defined: Environment Animal Welfare (EAW, n = 4) (temperature, airflow, ventilation and ammonia load) Management Animal Welfare (MAW, n = 5) (animal load, bedding, comfort, stress and cleanness of animals) and Facilities Animal Welfare (FAW, n = 3) (feeders of concentrate, feeders of forage and watering). All indicators were evaluated from 1 to 10 taking into account objective and subjective criteria. In addition, the average of scores of the three groups (EAW, MAW, and FAW) and the Global Animal Welfare (GAW) score (the average of all the indicators) were also calculated. One hundred and one assessments (49 in goat and 52 in sheep) were carried out in intensive farms in Spain from 2005 to 2011. The indicators were then compared by farm size, geographical location and production level of the farms. Results obtained show the relationships between the welfare indicators and the zoo technical characteristics of the farms.

Effectiveness of gaseous CO2 fertilizer application in China's greenhouses between 1982 and 2010

The biological utilization of CO2 represents a promising application for carbon capture, utilization, and storage (CCUS) technologies. The Technical Assessment Report of Carbon Dioxide Utilization in China recommends gaseous fertilization in greenhouses as an important technological use of CO2. However, the effectiveness of gaseous CO2 fertilizers at increasing crop yields unpredictable due to varying climatic and technological conditions in China. Here, we analyzed 188 articles on gaseous CO2 fertilization technology in China published from 1982 to 2010. We found that gaseous CO2 fertilizers enhanced the yield of representative fruit vegetable (i.e., cucumber, tomato, chili, zucchini, eggplant, and strawberry) by 33.31% over the past three decades. In addition, crop maturity also advanced (by an average of 6.87 days) and crop resistance to diseases and pests was enhanced. We observed a relatively good linear relationship between crop yield increases and increased CO2 fertilizer application for cucumber and chili once 240.0–3042.75kg gaseous CO2 fertilizer was applied per hectare. For the other four crops, a positive correlation was observed. The mean increase in the yield of the six fruit vegetables supports the Technical Assessment Report of Carbon Dioxide Utilization in China, which adopted a 30% increase in yield by gaseous CO2 fertilizers to calculate the economic benefits of this technique. Finally, we suggest that methods of fertilization and business modes of gaseous CO2 fertilizer application that fit practical farming conditions in China should be proposed to serve as references for the development of gaseous CO2 fertilization for CCUS engineering.

Polyphenol-rich plant extracts inhibit Lawsonia intracellularis in two complementary bioassays

Porcine intestinal adenomatosis (PIA) is a disease of the gastrointestinal tract of grower piglets, caused by the Gram-negative bacterium Lawsonia intracellularis (LI). It is characterized by excessive proliferation of infected enterocytes, leading to ineffective digestion, reduced nutrient absorption and diarrhea. It is common practice to control the disease by temporary use of antibiotics during the critical phase. However, prudent use of antibiotics in animal production is imperative, which may be supported by alternative control strategies. Feed additives like organic acids, probiotics or phytogenics have shown the potential to substitute antibiotics in other contexts before. Here, we report on the antibacterial activity of plant-derived samples against LI in two especially developed in vitro bioassays. In vitro research on LI is complicated because the bacterium requires animal host cells to proliferate. In the first assay, antibacterial effects of samples were determined after fluorescent staining by a viability test kit and evaluation by flow cytometry. The second approach involved McCoy's mouse fibroblasts, which were infected by LI and the effect on bacterial proliferation was measured after fluorescent antibody staining and evaluation by a microplate fluorescence reader. Both assays allowed simple and automatised testing and several plant-derived samples showed anti-lawsonial activities in one or both approaches. Water extracts of oak and chestnut wood inhibited LI viability and proliferation as determined by both assays. These materials are known to be rich in polyphenols. The identity of active compounds however remains to be revealed. Furthermore, field trials under practical farming conditions shall clarify if phytogenics may offer comparable protection against PIA as currently used antibiotics.

Short communication: Feeding linseed oil to dairy goats with competent reticular groove reflex greatly increases n-3 fatty acids in milk fat

A crossover experiment was designed to compare the effects of 2 ways of feeding linseed oil on milk fat fatty acid (FA) composition. Ten lactating goats, trained to keep competent their inborn reticular groove reflex, received a daily dose of linseed oil (38g/d) either with their solid (concentrate) feed (CON) or emulsified in skim milk and bottle-fed (BOT). Two groups of 5 goats received alternative and successively each of the treatments in two 15-d periods. α-Linolenic acid in milk fat rose up to 13.7% in the BOT versus 1.34% in the CON treatment. The n-6 to n-3 FA ratio was significantly reduced in goats receiving bottle-fed linseed oil (1.49 vs. 0.49). Contents of rumen biohydrogenation intermediates of dietary unsaturated FA were high in milk fat of goats under the CON treatment but low in those in the BOT treatment. These results point to a clear rumen bypass of the bottle-fed linseed oil. This strategy allows obtaining milk fat naturally very rich in n-3 FA and very low in trans FA. Translating this approach into practical farm conditions could enable farmers to produce milk enriched in specific FA.

Impact of feeding mixtures of herbs on parasitic parameters in small ruminants

Introduction: Commercial available mixtures of herbs promise a wide range of effects wether more „stress resistance“ or „natural deworming“. Material and methods: Three commercial mixtures of herbs were used in the additional feeding of ewes and goats in three farms: The powdery herbs P (garlic, turmic, himalayan cedar, ginger, long pepper) was fed daily for three weeks (8 g/day/animal) to sheep on farm 1 and to goats on farm 3. The pelleted herbs V (garlic, slippery elm, peppermint, thyme, cleavers, cinnamon, common nettle, quassia root) was fed daily for one week (10 g/day/animal) to sheep on farm 1 and the herbal extract herbs A (garlic, mugwort, walnut, clove) was fed daily for one week (20 ml/day/animal) to sheep on farm 2. In farm 1 three month after feeding herbs P to the trial group, sheep were split up again to trial and control group to feed herbs V. Herbs V feeding in farm 1 was monthly repeated twice, herbs A feeding in farm 2 was repeated monthly once. Fecal egg count (fec) was recorded just before additional feeding of the herbs started (week 0). Further fecal egg counts were conducted in regulary monthly intervalls (goats only once). All animals were on pasture during the whole grazing season. Results: In farm 1 no differences could be recorded wether between control and herbs P nor between control and herbs V. Sheep started with moderate fec and 12 weeks later had low fec. Fec in herbs V was numerically lower in herbs V than in control group. In farm 2 fec in herbs A was significant lower in trial group only after the first feeding periode. No differnces could be seen in farm 3 between control and trial group of the goats. Conclusions: The additional feeding of herbal mixtures following producers guidelines under practical farming conditions could not present any lasting effect on fecal egg ouptut in sheep and goats. More examinations are necesarry to verify effects to animals at least how "stress resistance" can be verified.

Comparative Evaluation of Productivity and Cost Effectiveness of Catfish Fingerling Production in Earthen Pond and Recirculation System in Ibadan, Nigeria

Despite the popularity of the African catfish and its great market potentials, the production is still basically at subsistence level due majorly to inadequate supply of seed for stocking. This has been linked to the absence of reliable production techniques for the mass production and rearing of the species under practical farming conditions. The purpose of this study therefore, was to find a suitable culture system for the mass production of catfish (Clarias gariepinus) fingerlings. Protected earthen pond and a unit of recirculation system were used. Fertilized eggs fromfemale were divided into two equal halves and incubated under the same conditions. Forty-nine thousand frys each were stocked into the protected earthen pond and a unit recirculation system respectively. The frys in the two systems were raised for twenty one days and fed the same quantityand quality of feed throughout the period. The survival rate of the frys in the recirculation system was 79% as against 17% in the earthen pond. However, bigger sized (2.2 ± 0.23g) fingerlings were obtained from the earthen pond relative to those cultured in the recirculation system (0.9 ±0.07g). The cost of raising frys in a recirculation system (N34,000) was twice that needed for earthen pond (N17,000), but this was more than made up for in the profit from sales, which was N311,360 and N99,156 respectively. The main reason for fish farming is the expected return tobe, therefore, the choice of income-generating activities, amongst several options available, should be made on the grounds of their expected returns.

Health of farmed fish: its relation to fish welfare and its utility as welfare indicator

This brief review focuses on health and biological function as cornerstones of fish welfare. From the function-based point of view, good welfare is reflected in the ability of the animal to cope with infectious and non-infectious stressors, thereby maintaining homeostasis and good health, whereas stressful husbandry conditions and protracted suffering will lead to the loss of the coping ability and, thus, to impaired health. In the first part of the review, the physiological processes through which stressful husbandry conditions modulate health of farmed fish are examined. If fish are subjected to unfavourable husbandry conditions, the resulting disruption of internal homeostasis necessitates energy-demanding physiological adjustments (allostasis/acclimation). The ensuing energy drain leads to trade-offs with other energy-demanding processes such as the functioning of the primary epithelial barriers (gut, skin, gills) and the immune system. Understanding of the relation between husbandry conditions, allostatic responses and fish health provides the basis for the second theme developed in this review, the potential use of biological function and health parameters as operational welfare indicators (OWIs). Advantages of function- and health-related parameters are that they are relatively straightforward to recognize and to measure and are routinely monitored in most aquaculture units, thereby providing feasible tools to assess fish welfare under practical farming conditions. As the efforts to improve fish welfare and environmental sustainability lead to increasingly diverse solutions, in particular integrated production, it is imperative that we have objective OWIs to compare with other production forms, such as high-density aquaculture. However, to receive the necessary acceptance for legislation, more robust scientific backing of the health- and function-related OWIs is urgently needed.

Acceptance of artificial nesting sites by pollinating mason bees in commercial fruit plantations (Hymenoptera, Megachilidae: mixed Osmia cornuta and O. rufa population)

During a four yeas long experiment a simple bee shelterswas found to be a propermethod to increase the size ofmixed natural populations of the early season Osmia cornuta and O. rufa under practical farm conditions. Instead of the number of pesticide applications the earliness of the flowering of the fruit species in the orchards was found to be themost important factor in the rate of acceptance of reed as nestingmediumby Osmias in the bee shelter. This relationship was negative and highly significant (r = –0.829, p&lt;0.001). This means that much higher acceptance of artificial nestingmedia in bee shelters and consequentlymuch higher population increase of the two early seasonmason bee species can be expected in orchards with early than with late flowering fruit species. Mixed orchards or early flowering orchards surrounded by other orchards falling in bloom later consecutively may also be much favourable to mason bees because they can find continuous food (pollen) supply there for a much longer time during their period of activity than in orchards planted with a single fruit species and being apart from orchards of other fruit species.