Economic feasability of the use of Feed additives

Literature review indicates a potential positive impact of using feed additives on growth, feed conversion, nitrogen, phosphorous and manure production in pig farming. The analysis of the technical, farm economic and environmental impact results in opportunities to farmers towards decreasing production costs and improving farm labour income. The impact of using feed additives is analysed based on calculation models, taking into account the regional environmental policy and its implications for pig farming. The labour income with and without feed additives are compared. Three groups of feed additives are considered: performance enhancers, phytase and amino acids. The calculations and figures in this article apply to the situation on typical pig farms in Flanders, Belgium. The approach and conclusions are however generally applicable on the condition of adapted assumptions, input parameter values and environmental policy of other regions. From the evaluation of the alternative feed systems, environmental policy and farm size, the optimal solution for the Flemish farmer is discussed.

(Article by Prof. Dr Viaene - [email protected] - and Wim Verbeke, University of Ghent, Department Agricultural Economics, Belgium)

Attachment pigpro.pdf (21 k)

Due to consolidation and concentrations of animals at large facilities, animal feeding operations have emerged as a major potential polluter of water bodies in the United States. Concern over excessive amounts of nitrogen and phosphorus at individual livestock facilities has led to the augmentation of federal regulations governing water pollution. Federal mandatory controls and voluntary guidelines seek to reduce contaminant pollution from animal feeding operations. The examination of the regulatory instruments suggest more scientific information is needed to identify which livestock facilities are major sources of pollution and to determine whether the regulations reasonably respond to nutrient problems.

The Swedish animal production system: Could it be applied across the European Union"

(by Prof. Dr Viaene - [email protected], University of Ghent, Department Agricultural Economics, Belgium - 01/1997)

In 1995, Sweden joined the European Union along with Austria and Finland. Since then, Sweden has been questioning many of the systems in place within the EU, particularly in the agricultural and environmental areas. A derogation was received from certain EU rules until 1st January 1999.

One specific area has been on the validity and acceptability of the European Unions' animal production model and the use of approved in-feed anti-microbial additives for meat producing animals. These anti-microbial products have been used for over 25 years and are under constant scientific evaluation by the Directorate DG VI (Agriculture) of the European Commission.

Prof. Dr. Viaene from the Ghent University, Department of Agricultural Economics, has examined the premise that the Swedish animal production model could be extended to the total European Union to the benefit of farmers,
allied trades and consumers.

Attachment sweden.pdf (61 k)

SEEDORF, J.; J. HARTUNG; M. SCHR�DER; K.H. LINKERT; V.R. PHILLIPS; M.R. HOLDEN; R.W. SNEATH; J.L SHORT; R.P. WHITE; S. PEDERSEN; T. TAKAI; J.O. JOHNSEN; J.H.M. METZ; P.W.G. GROOT KOERKAMP; G.H. UENK; C.M. WATHES (1998):

Concentrations and emissions of airborne endotoxins and microorganisms in livestock buildings in Northern Europe. J. agric. Engng Res., 70 (1), 97-109.

The concentration of airborne endotoxins and microorganisms in livestock buildings (cattle, pig, poultry) was surveyed in four European countries (England, The Netherlands, Denmark and Germany). Measurements were made during the day and night. The endotoxin concentrations were determined from dust samples separated into inhalable and respirable fractions. Airbome microorganisms were classified as total bacteria, Enterobaeteriaceae and total fungi.
The lowest endotoxin concentrations were found in cattle houses. The highest concentrations of endotoxin were measured in poultry houses, especially percheries, with an overall mean of 692 and 49 ng/m� for inhalable and respirable fractions, respectively. Endotoxin concentration was usually higher in the day than at night. These concentrations give cause for concern for the health of stockmen working in such buildings. The corresponding mean emission rates from poultry houses were 678 and 43 �g/h (500 kg) liveweight, respectively, 51 and 6 �g/h (500 kg) liveweight from pig buildings and 9 and 1 mg/h (500 kg) liveweight from cattle houses.
A new automated bioaerosol sampler was developed, which allows remote, independent sampling of airborne microorganisms. Its principle of operation is similar to a slit sampler: airborne microbes are collected by impaction on an agar surface. Most measurements of airborne microorganisms were made in Germany. The indoor concentration of total bacteria was 6.43 log colony- forming units (cfu)/m� in broiler houses, 5.1 log cfu/m� in pig buildings and 4.3 log cfu/m� in cattle buildings. During the day, the overall concentration of Enterobacteriaceae ranged between 3 and 4 log cfu/m�. The mean fungi concentration for cattle was 3.8, for pigs 3.7 and for poultry 4.0 log cfu/m� during the day. Slightly lower concentrations were measured at night. No significant correlation was found between the concentrations of endotoxin and Enterobacteriaceae.
The highest emission rate of total bacteria and fungi was measured for broilers, i.e. 9.5 and 7.7 log cfu/h (500 kg) liveweight, respectively. Buildings for laying hens had the highest mean emission rate of 7.1 log cfu/h (500 kg) liveweight for Enterobacteriaceae.

HARTUNG, J. (1998):
Nature and amount of aerial pollutants from livestock buildings. Dtsch. tier�rztl. Wschr. 105, 213-216

The air in animal housing contains gases, odours, dust particles and microorganisms which are discharged by way of the ventilation system into the environment. There is increasing concern within parts of the population that these compounds may affect the respiratory health of people living close to livestock enterprises. A brief survey is presented on airborne emissions from live- stock buildings. About 136 gaseous compounds are analysed in animal house air of which only 22 are quantified. The most environment-related compounds are ammonia and methane. It is assumed that German animal husbandry emits up to 750 000 Mg ammonia per year. The concentrations of airborne microorganisms in livestock buildings are between some 100 and several 1000 per liter. Staphylococcae, streptococcae, colilike bacteria, fungi, moulds and yeasts are regularly found. The 24 h average concentrations of dust in animal barns vary considerably. In poultry houses the highest inhalable resp. respirable dust concentrations (up to 10 mg/ml resp. 1.2 mg/m3) were found, followed by pig houses (5.5 mg/m3 resp. 0.46 mg/m�) and cattle barns (1.22 mg/m� resp. 0.17 mg/m�). The concentrations of endotoxins in the airborne dust can range from 0.6 ng/m� (cattle, respirable dust) to 860 ng/m3 (laying hens, inhalable dust). The presently discussed occupational health threshold at the workplace is around 5 ng/m� (50 EU/m�). The emission rate for respirable dust from piggeries is at about 60 mg/h, from poultry houses nearly 300 mg/h and from cattle barns at 20 mg/h, related to 500 kg liveweight of the animals. Little is known about the distances these particles are transported through the air outside the animal buildings.

SEEDORF, J.; SCHR�DER, M.; HARTUNG, J. (1998):
Emissionen und Immissionen aus einem Entenmaststall. Zentralblatt f�r Hygiene und Umweltmedizin, 201, 387-403.

In a field study emissions and immissions (receptor exposition) of bioaerosols emitted from and near a duck fattening house (25 m distance) were investigated. Within the livestock building mean concentrations of 3,342,289 CFU m-3 for airborne total mesophilic bacteria were determined. Total dust and endotoxin yields were 1.9 mg m-3 and 7,132.4 ng m-3, respectively. Additionally, enterobacteria, mesophilic and thermotolerant fungi as well as mesophilic actinomycetes were detectable. Measurements of immissions have shown that downwind in the rear of the house a mean total germ concentration of 10,007 CFU m-3 was measurable in contrast to the upwind side of the building, where no airborne mesophilic bacteria were found. Higher concentrations downwind were generally determined for total dust, mesophilic fungi and actinomycetes, too, but not so for endotoxins. A supporting application of a numeric dispersion model confirmed the immissions for total mesophilic bacteria measured near by the duck fattening house. From this viewpoint immission predictions can be made in future for varying input data, i.e. wind conditions, or different components of bioaerosols.

J. Kamphues und Diane Hebeler (1999): Antibiotic Growth promoting feed additives - an assessment from the point of view of animal nutrition

�bers. Tierern�hrg. (1999) 27, 1-28

From 01.07./01.09.1999 on six further antibiotic growth promoters have been banned - with only four substances remaining in this group of feed additives. Therefore the discussion on a possible induction of bacterial resistance by antibiotic growth promoters, especially in potentially pathogenic bacteria, will sooner or later come to an end which is not least in the interest of the reputation of animal husbandry and food of animal origin.

Unfortunately, no short-term solution for health problems by legislation - especially in the gastrointestinal tract - during rearing and the beginning of the fattening period is possible as experiences in Sweden have distinctively shown. Anyway, growth promoting feed additives were not a cure-all of rearing problems, in spite of their use considerable amounts of antibiotics were prescribed during this period. But growth promoters (especially chinoxalines) were most suitable for the prophylaxis of a microbial imbalance in the gastrointestinal tract. Therefore after the ban of these effective representatives of feed additives the amount of prescribed antimicrobial drugs for metaphylaxis and therapy should be critically observed.

The questions of practicable alternatives will be primarily addressed to the fields of animal nutrition, veterinary medicine and feed industry. To answer these questions and to evolve new solutions (as well as to check their suitability in practice) is considerably more intricate than simply to ban these substances which is more attractive for the media, however.

It is no progressive solution to give up antimicrobial growth promoters as feed additives and to use the same substances (for example olaquindox) as therapeutics now (prescribed by veterinarians) or to switch to zincoxide or copper (in a dosage high above all nutrient requirements) in order to prevent postweaning problems due to E. coli. But one has to take into consideration the reasons for the use of antibiotics (growth promoters and therapeutics) or other "aids" (e.g. ZnO, Cu) in food producing animals (especially in beef-cattle, pigs and poultry) in "modern" production systems. The matter for conflict is the contrast between a minimized use of antimicrobial substances, as science as well as general public demand, and the requirements of "modern" livestock industry (rationalisation, increase in performance, specialisation, concen-tration) and general economy (save of resources, lowering of production costs). These well-known and expected problems arise in an almost exemplary manner in the case of antibiotic growth promoting feed additives. Therefore it is most difficult to impart suggestions to the persons involved as well as to the public.

KAMPHUES, J. (1998): Specific features of feeding animals in organic agriculture.
Dtsch. Tier�rztl. Wschr. (1998) 105, 307-312

Summary

Food produced in ecological agriculture becomes popular more and more. In the interest of consumers (to protect against deception) and of producers (to contrast with conventionally produced food) it is necessary to define the conditions and circumstances when products can be declared as ecological. Up to now there are definitions of housing and feeding animals in organic agriculture only are set up by private organisations and associations, but in the future we will have a direction of the European community (Nr. 2092/91 EWG), extended by directives and restrictions focussed on animal husbandry and feeding. Aim of this contribution is to give information on special restrictions on feeds and feeding of food producing animals in organic agriculture (preconditions in the case that labelling as "ecologically produced" is intended). Conventionally produced feedstuffs are restricted, common complete diets and some special feed additives (for example growth promoters) are not allowed. Feeding according to species specific requirements (herbivorous animals) as well as according to age and development (for example minimum duration of suckling periods) is intended. On the other hand there is a conscious renunciation of maximizing animals' performance (and plant yields). Consequences, risks and conflicts of different aims in feeding in accordance with ideas of organic agriculture are discussed. Various efforts at sustainability of conventional agriculture are influenced markedly by ideas and concepts established in organic agriculture primarily.

RADE,C. , und J. KAMPHUES (1999): Effects of feeds and feeding on the health of the respiratory tract in animals and people handling animals

�bers.Tierern�hrg. (1999) 27, 65-121

Summary

Respiratory tract disease in livestock, but also in companion animals is one of the major reasons for poor performance, increased costs for veterinary services, animal losses, and complaint of carcass quality (alterations of lung tissue). Therefore, continous critical monitoring and optimizing of the stable climate is firstly indicated.
The present article deals with the possible direct and indirect influences of feed and feeding on respiratory health effects and lung disease (nutrient deficiency or oversupply as predisposing factors). Inhalative challenge of the respiratory tract with feed components and contaminants in airborne stable dust is counted among those direct effects, while indirect influences are represented by detrimental effects of feedstuff metabolites on animal health after oral uptake (e.g. higher concentrations of noxious gases in animal houses due to increased release of H2S and NH3 by livestock and slurry). Furthermore, some intoxications lead to clinically manifest lung disease (e.g. hypervitaminosis D) or are associated with unspecific respiratory symptoms at least, whereas nutrient deficiency may predispose the respiratory tract to viral or bacterial infections (e.g. vitamin A deficiency).
There is special focus on the way in that feed and feeding affect the air quality in animal houses especially with regard to concentration and composition of airborne stable dust. The underlying pathologic principles of respiratory distress include mechanical irritation, "clogging" of mucociliar clearance mechanisms and reversible inflammatory changes as well as allergic asthma-like reactions and chronic bronchitis with irreversible alterations in lung tissue, depending on quality and duration of inhalative challenge. With regard to aetiology organisms like mites, moulds and bacteria - all found most frequently in the fraction of smaller-sized particles of feed dust - and some of their metabolites (e.g. lipopolysaccharides, occasionally mycotoxins) are of special interest. In order to minimize inhalative challenge by feed dust feed structure and feeding technique have to be taken into account as well as potential nutrient oversupply (e.g. protein, sulphur) and its consequences for the animal itself and the amount of noxious gases in the air of animal houses.
These considerations imply that the potential effects of feed and feeding should not be neglected in case of respiratory tract disease becoming a "herd problem" in livestock or even horses, although optimizing the stable climate (e.g. ventilation technique) may be the prerequisite. Last but not least even humans handling feedstuffs or taking care for animals are at risk to be exposed to health hazards associated with feed and feeding, as the data presented in this paper about respiratory syndroms among occupational disease cases in farm workers and veterinarians reveal.

Encouraging Sustainability for Animal Feeding Operations
by Terence J. Centner

Due to storm events, inadvertent spills and careless practices, animal feeding operations have denigrated water quality in the United States. Governments at all levels are taking action to reduce and eliminate pollution problems from these operations. The numerous legislative and regulatory responses have not been very resourceful. The command and control provisions may respond to public concerns, but their generalized coverage makes them costly and imposes expenses on producers who are not causing any problems. Governments need to consider alternative strategies that would incorporate sustainable agricultural practices into controls governing animal wastes. Some type of relationship between cropland and the animal wastes from feeding operations should be incorporated into the regulatory system to more accurately account for environmental costs.

Environmental consequences of food consumption: A modular life cycle assessment to evaluate product characteristics

Niels Jungbluth

Who hasn't been standing once in front of the supermarket shelf and asked herself if the organic carrots from Italy or the cauliflower from her own country is the most ecological choice for the next meal, and then, finally, has decided to buy the delicious asparagus from the USA. The extent of environmental impacts of food consumption depends on various factors. It is not easy for consumers or even for experts to account for these impacts.
The goal of this research work was to assist consumers in considering environmental aspects. Separate LCA's were calculated to assess various aspects of the consumers' choices, e.g., the type of agricultural practice, the origin of the product, the use of packaging material, the type of preservation, and the consumption (including home transport, conservation, and preparation). A modular LCA approach was developed to model the impacts of the consumers' decisions. This simplified method allows investigating the ecological tradeoffs among different decision parameters (such as assessing a biological product from the Netherlands vs. greenhouse from Switzerland). Most of the decision parameters might have an influence on the overall impacts of a vegetable product. Greenhouse production and products transported by airplane cause the highest environmental impact. The agricultural production determines the overall environmental impacts of meat products. The total impacts for purchased vegetable or meat products might vary by a factor of nine or seven respectively. It could be shown that the environmental impacts of purchases by different consumer subgroups vary. Different hints for consumers were ranked, according to the variation of average impacts, due to a marginal change of consumption patterns.

Attachment summary-nj.pdf (76 k)

HARTUNG, J. and SEEDORF, J. (1999): Orientating investigations on atmospheric endotoxin concentrations.Dtsch. tier�rztl. Wschr. 106, 522-525

Airborne endotoxins are supposed to influence the respiratory health of animal and man in animal housings as well as at certain work places in agriculture. Little is known about the usual concentrations of endotoxin in the outdoor atmosphere. Therefore in a field study 30 air samples were taken, 22 samples in a rural region, and 8 in a more residential and industrial area. The samples were taken by impingement and filtration. The analysis was carried out by means of the chromogen-kinetic limulus amoebocyte lysate test (LAL-Test). The median concentration of all samples was 0.36 ng/m�. The highest median concentration of 0.49 ng/m� was found in summer with a maximum value of 1.80 ng/m� indicating large variations. In the other seasons the median concentrations (ng/m�) were distinctly lower (spring: 0.30, n=11; autumn: 0.26, n=5; winter: 0.19, n=3). No significant differences were observed between farming and residential areas at this low concentration level. The concentrations of endotoxin found in this study were far below all threshold limits which are presently discussed for work places.

J. Seedorf and J. Hartung (1999):
Investigations of the bioaerosol reduction efficiency of livestock-related biofilters and bioscrubbers. Berl. M�nch. Tier�rztl. Wschr. 112, 444-447

Biofilters and bioscrubbers are ultimate tools to control odour emissions from animal houses in pig and poultry production. Little is known about the efficiency of these devices to remove airborne particulate pollutants such as dust, microorganisms and endotoxins from the exhaust air of animal houses. Preliminary results of a one year field campaign two piggeries show that the biofilter reduces the number of particles in the exhaust air by 79 to 96 %. The efficiency of the bioscrubber was found at 22 % only. The biofilter reducted the amount of mesophilic bacteria by 11 % and 71 %, respectively. The amount of thermotolerant fungi was reduced by 71 %, too. The concentration of endotoxin and mesophilic fungi in the clean air after the bioscrubber was 3.8 times resp. 2.7 times higher than in the air of the piggery. The washing water which is regularly recirculated in both systems was highly contaminated with varying amounts of air contaminants. It seems that the quality of the washing water distinctly influences both the reduction efficiency of both systems.

How do animal health products contribute to economic and environmentally-friendly livestock farming

Jacques Viaene & Ann De Craene (University of Ghent - November 1998)

The purpose of this research is to analyse the opinion of EU veterinarians with regard to the possible impact of veterinary medicinal products on the environment as well as to analyse the actual impact of veterinary medicinal products on performance and so, indirectly, on environmental burden and benefit.

Attachment howdoahp.pdf (1378 k)

[1]G. Hamscher, [1]S. Sczesny, [1]A. Abu-Quare, [2]H. H�per and [1]H. Nau

[1] Zentrumsabteilung f�r Lebensmitteltoxikologie, Zentrum f�r Lebensmittelwissenschaften, Tier�rztliche Hochschule Hannover, Bischofsholer Damm 15, 30173 Hannover.
[2] Nieders�chsisches Landesamt f�r Bodenforschung (NLfB), NLfB-Au�enstelle Bremen, Friedrich-Mi�ler-Str. 46/48, 28211 Bremen

Identification of tetracycline and chlortetracycline in soil fertilized with animal slurry

Our investigations show for the first time that residues of the commonly used veterinary drugs tetracycline and chlortetracycline can be detected in the surface of soil (0-40 cm) fertilized with animal slurry. The maximum concentrations found employing liquid chromatography combined with electrospray ion-trap tandem mass spectrometry were 32,3 �g/kg for tetracycline and 26,4 �g/kg for chlortetracycline. No antibiotics were detected in soil which remained untreated with slurry since approximately 5 years. Leaching of these compounds into seeping water sampled at a depth of 80-140 cm could not be detected with the methods used. The significance of the detected antibiotic residues in soil samples for the quality of food of animal orign or any ecotoxicological consequences needs further investigations. The knowledge about the concentrations of veterinary drug residues resulting from animal husbandry in the environment is the first step for such a risk assessment.

(See DTW 08/2000, in press)