Non-organic Farms Research Articles

An environmental cost-benefit analysis of organic and non-organic sheep farming in Iceland

This paper presents an environmental cost-benefit analysis (CBA) comparing organic and non-organic sheep farming in Iceland over three decades. Environmental life cycle costing (ELCC) is the basis for the aggregate cost framework, encompassing costs for investment, operations, maintenance, and environmental externalities. Greenhouse gas emissions are included as an external cost as they relate to the monetization of damages to society. Net present value (NPV) and benefit-cost ratio (BCR) indicators reveal both systems as unprofitable over thirty years with and without subsidies. Depending on the discount rate, the organic farm's BCR ranges from 0.26 to 0.38, with a NPV between (-2.4) and (-1.1) million euros. The non-organic farm's BCR ranges from 0.12 to 0.19, with NPV between (-8.6) and (-3.7) million euros. Greenhouse gas emission costs constitute 28% and 33% of total life cycle costs for organic and non-organic farms. Across three discount rates, the LCC and ELCC per kilogram of organic lamb ranged between €13.78 – 25.27 and €18.23 – 37.07, respectively. The LCC and ELCC per kilogram of non-organic lamb ranged between €9.75 – 18.05 and €13.80 – 28.82, respectively. Due to a shortened value chain, organic sheep farming demonstrated revenue advantages as compared to non-organic. The external cost of greenhouse gas emissions from sheep farming forms a significant portion of lifetime costs suggesting that policymakers could incentivize organic practices aimed at reducing greenhouse gas emissions. Finally, this study provides a deeper understanding of the long-term economic prospectivity of sheep farming under different production approaches.

Persistent Organic Pollutants and Fatty Acid Profile in a Typical Cheese from Extensive Farms: First Assessment of Human Exposure by Dietary Intake.

Dairy products represent an important source of beneficial substances for humans. At the same time, they can expose the consumers to environmental contaminants ingested by animals through their diet, influencing their health negatively. This experiment aims to evaluate the risk and benefits related to the consumption of typical stretched cheeses, considering their fatty acid (FA) profile and persistent organic pollutants (POPs) content. Six representative farms, two of them organic, raising Cinisara cattle were selected, considering the typical extensive management systems, based on feeding of natural pasture integrated with concentrate and hay depending on the availability of forage on pastures. A total of 18 cheeses produced in winter, spring and summer with bulk milk of each farm were sampled and analyzed. The chemical composition of cheeses was influenced by farm management, and the FA profile mainly by the season. In particular, cheeses made in spring showed a healthier FA profile with the content of polyunsaturated fatty acids (PUFA), of omega3-PUFA and omega6/omega3 ratio pair to 7.29%, 1.44% and 1.32, respectively, while in winter 5.44%, 0.98% and 2.55, respectively, and in summer 4.77% 0.49% and 3.04, respectively. Due to high levels of feeding integration, cheese made in winter presented unhealthier characteristics compared to the cheeses made in spring and summer, showing high levels of saturated FA (66.2%, 64.2% and 65.5%, respectively), and large contents of polycyclic aromatic hydrocarbons (PAH) (57.07 ng/g fat, 36.25 ng/g fat and 10.22 ng/g fat, respectively) and polychlorinated biphenyls (PCBs) (36.19 ng/g fat, 4.68 ng/g fat and 3.73 ng/g fat, respectively), mainly in those from non-organic farms. Levels of PCBs considered to be hazardous to human health were found in nine samples.

Survey on the disposal of waste milk containing antimicrobial residues on Swiss dairy farms

Feeding waste milk containing antimicrobial residues (WMA) to calves has been associated with increased antimicrobial resistance in calves' commensal bacterial flora. The objectives of this study were (1) to document practices related to the disposal of WMA on Swiss dairy farms and (2) to evaluate the association between farm characteristics and the feeding of WMA to calves. A web-based questionnaire on practices surrounding waste milk disposal was completed by 1,625 dairy producers (10.9% of solicited producers). Logistic regression models were built to evaluate the association between herd characteristics and the practice of feeding WMA. Waste milk produced during and up to the first milking after completion of antimicrobial treatment or during the withdrawal period was fed to at least some of the calves on 47.3% of respondents' farms. Farms in organic production had lower odds of feeding WMA to calves than nonorganic farms [odds ratio (OR) 0.59]. Farms located in the eastern region of Switzerland, as opposed to those in the western region, had increased odds of feeding WMA to calves (OR 2.01). A yearly average bulk tank somatic cell count ≥150,000 cells/mL was associated with increased odds of feeding WMA to calves compared with the reference category of <100,000 cells/mL (OR 1.62). An average cow-level annual milk production ≥8,500 L was associated with increased odds of feeding WMA to calves compared with farms in the interquartile range with a production of 6,500 to 8,499 L (OR 1.24). Further research is warranted to investigate dairy farmers' motivations affecting this practice, and to quantitatively define calves' exposure to antimicrobial residues and the resulting antimicrobial resistance in calves' commensal flora on these farms.

A holistic sustainability assessment of organic (certified and non-certified) and non-organic smallholder farms in Kenya

The introduction of organic farm management practices in sub-Saharan Africa could act as a lever for supporting regional sustainable development. In this study, we sought to assess the sustainability performance of organic (certified and non-certified) and non-organic farms in the dry Kajiado County and the wet Murang’a County in Kenya, based on four sustainability dimensions: Good Governance, Environmental Integrity, Economic Resilience and Social Well-Being. We collected household survey data from 400 smallholder farms, which were formally characterized into five types (mixed organic and conventional, certified organic, organic, conventional, and subsistence farms). We used multivariate analysis of variance, linear fixed-effects and general linear models to examine differences in sustainability performance. Model results indicate that all farms lack reliable farm management information and that only limited knowledge, skills and social security exist for farmers and farm workers. Comparison of the five farm types indicates no significant differences in their sustainability performance. Nonetheless, certified organic farms had better sustainability performance than non-certified farms due to higher economic resilience, environmental integrity, better support and training for workers. However, except for avoiding the use of agrochemicals in certified farms, there is relatively little difference in the farm management practices across farm types. Our results also indicate that farms in Murang’a were more sustainable than those in Kajiado due to better regional land-tenure security and conflict resolution mechanisms, soil and water conservation measures, and farm commercial viability. Nonetheless, unlike Kajiado, farms in Murang’a showed a tendency toward poor animal husbandry practices which affects overall animal welfare, limited credit uptake and market involvement. The results of this study can support decision making to identify appropriate interventions for improving sustainability in smallholder farms.

Plant Microbial Biostimulants as a Promising Tool to Enhance the Productivity and Quality of Carrot Root Crops.

The interest in studies focused on applying probiotic microorganisms is increasing due to sustainable agriculture development. In this research, we aimed to evaluate the impact of two commercial plant probiotics—ProbioHumus and NaturGel on carrot growth, yield, and quality in organic and nonorganic production systems. The research was carried out under laboratory and field conditions. Plants were treated with probiotics (2 L/ha) at the nine leaves stage. Biometrical measurements and chemical analyses were performed at a maturation stage. The average weight of carrot roots increased by 17 and 20 g in the test variant with ProbioHumus as compared to the control in the organic and nonorganic farms, respectively. Plant microbial biostimulants ProbioHumus and NaturGel had a positive effect on the quality of carrots from organic and nonorganic farms: applied in couple they promoted the accumulation of monosaccharides, ascorbic acid, carotenoids, phenols, and increased antioxidant activity. Quantitative nitrate analysis regardless of the biostimulant used revealed about twofold lower nitrate content of carrots from organic than nonorganic farms, and probiotics did not show a significant effect on nitrate accumulation. Finally, ProbioHumus and NaturGel were effective at low doses. The use of microbial biostimulants can be recommended as an element of cultivation for creating ecologically friendly technologies.

Organic Farming Lessens Reliance on Pesticides and Promotes Public Health by Lowering Dietary Risks

Organic agriculture is a production system that relies on prevention, ecological processes, biodiversity, mechanical processes, and natural cycles to control pests and maintain productivity. Pesticide use is generally limited or absent in organic agroecosystems, in contrast with non-organic (conventional) production systems that primarily rely on pesticides for crop protection. Significant differences in pesticide use between the two production systems markedly alter the relative dietary exposure and risk levels and the environmental impacts of pesticides. Data are presented on pesticide use on organic and non-organic farms for all crops and selected horticultural crops. The relative dietary risks that are posed by organic and non-organic food, with a focus on fresh produce, are also presented and compared. The results support the notion that organic farms apply pesticides far less intensively than conventional farms, in part because, over time on well-managed organic farms, pest pressure falls when compared to the levels on nearby conventional farms growing the same crops. Biopesticides are the predominant pesticides used in organic production, which work by a non-toxic mode of action, and pose minimal risks to human health and the environment. Consequently, eating organic food, especially fruits and vegetables, can largely eliminate the risks posed by pesticide dietary exposure. We recommend ways to lower the pesticide risks by increased adoption of organic farming practices and highlight options along organic food supply chains to further reduce pesticide use, exposures, and adverse worker and environmental impacts.

Review: Use of duality theory in organic farming: Evidence from India

Abstract. Prajapati HR. 2021. Use of duality theory in organic farming: evidence from India. Asian J Agric 5: 45-52. The duality analysis provides an alternative way for solving the problem of cost minimization. In this method, a specified suitable cost function has been used as an objective function with certain constraints, rather than using production functions. In duality theory, both cost and profit functions are used as an objective function under a well-defined production technology along with related behavioral assumptions. This paper has applied translog cost function as an objective function under certain input constraints for the estimation of five input parameters viz. Land, Labor, Capital, Machinery, and Irrigation based on field survey data of 284 organic and non-organic wheat producers in four rain-fed districts of Gujarat. Based on these parameters, all inputs price elasticity and elasticity of input substitution have been calculated using Iterated Smilingly Unrelated Regression Equations (ISURE) method of estimation. The results of the estimation, for both organic and non-organic farms, have found both positive and negative signs as was expected theoretically but the value is not significant.

Reconstructing Connections Among Women, Agriculture and Food in India

The significant participation of women in the food production process can never be denied. Studies say that women play an important role in agricultural process and its related actions like producing crops, horticulture, seeds collection and crop preservations. Women perform around 70 percentage of farming work using their expertise knowledge of biodiversity adding nutrition and value to food than the engineering and non-organic farms. But, from last few decades the participation of women in agriculture is being devalued due to the patriarch developmental projects in agriculture that aims at profit maximisation only. The international agri-business and dominant economics have projected feminine works invisible as female provide food to their household, not to the market. Due to the failure of statistical data, women’s contribution goes unrecorded and unnoticed. This leads not only a violation in women’s economic independence but also it destroys the women’s expertise in the renewability of the nature causing an ecological crisis. The Green revolution, which replaced the traditional method of crop rotation with monoculture, have extracted the energy and nutrition from the food. Hence, in order to retrieve food from this techno-conspiracy, it is very essential to redevelop feminine knowledge of biodiversity in farming. The present paper analyses three things. First, how women, agriculture and food production are interrelated. Secondly, why the devaluation of women’s knowledge and participation from the farm have given birth a hunger game. Finally, how involving women’s knowledge in sustainable agriculture can save the Earth from the hunger crisis.

Biodiversitas Kumbang Koprofagus di Lahan Pertanian Organik dan Non-organik

Coprophagous beetle has important role in decomposition of organic materials. This research aimed to study and analyze the diversity and abundance of coprophagous beetles in organic and non-organic farms. Coprophagous beetles were collected in organic farm of Bina Sarana Bakti and non-organic farm of Seruni in Cisarua, West Java. In each location, twenty dung traps were set up in corn plants, carrot plants, cabbage plants, and onion plants. Totally, 15 species (610 individuals) of coprophagous beetles belonging to two families i.e Scarabaeidae and Aphodiidae were collected. Coprophagous beetles in organic farms (389 individuals, 13 species) more divers than that in non-organic farms (221 individuals, 10 species). There was no dominant species in both of locations (C&lt;0.5). The most dominant species in organic farm was Copris reflexus (49%) and in non-organic farm was Onthopagus pauper (52%). Beetles similarity in organic and non-organic farm was 67%.

Soil fertility and biodiversity on organic and conventional smallholder farms in Kenya

The growth of organic agriculture (OA) in sub-Saharan Africa (SSA) raises the question of how far OA can improve the livelihoods of the many smallholder farmers that have to cope with numerous complex biophysical and socioeconomic challenges. Evidence on the impacts of OA in SSA, particularly on soil fertility and biodiversity, still is scarce and inconclusive. The aim of this study was therefore to evaluate and compare soil fertility, decomposition and biodiversity between 20 organic and conventional farms in two counties (Kajiado and Murang’a) in Kenya. Soil sampled at 0–20 cm depth was analysed for physical and chemical properties. The decomposition of crop residues over 3 months was studied using litterbags while pitfall trapping and the derived diversity indices provided insights into arthropod abundance and diversity. Differences in soil properties, mass loss through decomposition, and arthropod abundance were analysed with linear mixed models. Findings show no statistically significant differences in soil fertility, decomposition and abundance of arthropods between organic and non-organic farms. However, species richness and diversity of arthropods on organic farms was significantly higher than on non-organic farms. Overall, farms in Kajiado had higher soil fertility and arthropod diversity than those in Murang’a, while farms in Murang’a had a higher arthropod abundance. It is argued that similar agricultural practices used in organic and non-organic farming systems, irrespective of county and biophysical conditions, strongly influenced soil fertility and biodiversity. Our results demonstrate that OA has the potential to increase arthropod biodiversity, but its ability to sustain the health of soils depends on numerous factors that are likely to undermine OA efforts in this region.

Organic cattle products: Authenticating production origin by analysis of serum mineral content

An authentication procedure for differentiating between organic and non-organic cattle production on the basis of analysis of serum samples has been developed. For this purpose, the concentrations of fourteen mineral elements (As, Cd, Co, Cr, Cu, Fe, Hg, I, Mn, Mo, Ni, Pb, Se and Zn) in 522 serum samples from cows (341 from organic farms and 181 from non-organic farms), determined by inductively coupled plasma spectrometry, were used. The chemical information provided by serum analysis was employed to construct different pattern recognition classification models that predict the origin of each sample: organic or non-organic class. Among all classification procedures considered, the best results were obtained with the decision tree C5.0, Random Forest and AdaBoost neural networks, with hit levels close to 90% for both production types. The proposed method, involving analysis of serum samples, provided rapid, accurate in vivo classification of cattle according to organic and non-organic production type.

Identifying factors that influence bird richness and abundance on farms

ABSTRACTCapsule: Farmers can influence species richness and abundance of typical farmland birds positively, even on rather small farms (20–50 ha) within intensively farmed areas.Aims: To assess the impact of farm settings, farm characteristics and heterogeneity of habitats on bird species richness and abundance, and to indicate which actions and measures farmers can take to promote farmland birds at a farm level.Methods: Farmland bird species richness and abundance were modelled as a function of farm settings, farm characteristics and semi-natural habitats on 133 farms. The data were analysed at the farm scale, as this is the ‘operating range’ of a farmer, but also at the territory scale, which represents the range birds (mainly passerines) use during the breeding season. Additionally, effects of the farm variables on species abundance/occurrence were investigated for nine widespread species.Results: Farmland bird species abundance (but not richness) was elevated on organic compared to non-organic farms. Farmland bird species richness and abundance increased with decreasing mean field size. Crop diversity had positive effects on five species at the territory scale. Several semi-natural habitats, especially hedgerows, were associated with higher bird species richness and abundance at both farm and territory scales. Settlement revealed rather negative effects at the farm scale, but several positive relations at the territory scale.Conclusion: Birds, especially passerines, are restricted to a small area during the breeding season, and so even small farms can contribute to their protection by growing diverse crops, reducing field size and managing a diversity of semi-natural, uncropped habitats. These measures should ideally be accessible within the relatively small scale of a bird territory.

Subtle differences in birds detected between organic and nonorganic farms in Saskatchewan Prairie Parklands by farm pair and bird functional group

Abstract Organic farming may be more beneficial to biodiversity than nonorganic farming but the comparison is often confounded by regional within-farm and landscape differences. We compared breeding bird species composition and abundance on 10 farm pairs of each type matched at the site level for land cover in the prairie parklands of Saskatchewan, Canada in 1990. Land cover was measured around bird point counts at two extents; ‘site’ (6.3 ha area) and ‘field’ (16.3 ha area). We pooled species into functional groups; linear mixed models showed no significant differences between farm types for species richness but that all birds, migratory birds using crops and aerial insectivores were more abundant on organic farms. A permutational multivariate analysis of variance demonstrated that farm type did not have a significant overall effect on compositional similarity but that pairwise differences existed between about half of the farm pairs (the direction of differences in beta diversity was not consistent between organic and nonorganic farms according to tests for the homogeneity of multivariate dispersions). Farm-pair differences were more pronounced for all birds and for migratory bird species using crops, migratory birds consuming grains and ground feeders, but not grassland birds. nMDS ordinations suggested that there was more variation in species composition and abundance on organic farms than nonorganic ones but the difference was not significant. Distance-based redundancy analysis (dbRDA) was used to examine the main drivers of bird species composition and abundance and to see which extent was most important; land cover at the field extent was more important than land cover at the site extent or the farming practices measured. The most important field-extent land cover was the amount of native grassland, woodland (including shelterbelts) and wetlands. After controlling for significant field-extent land cover, seed treatment, herbicide use, and number of passes were significant. At the site extent, greater non-crop heterogeneity had a significantly positive effect on abundance and species richness of several groups (e.g., grassland birds, migratory granivores, ground feeders, ground nesters) but a negative effect on richness of woodland birds and abundance of aerial insectivores. Relationships with crop heterogeneity were mostly negative and non-significant. Overall land cover heterogeneity at the site level was positively related to the richness of grassland birds. In contrast at the field extent, non-crop heterogeneity did not have any significant effects on the richness and abundance of any functional group. Crop heterogeneity had a significantly negative effect on aerial insectivore richness and abundance. In the early 1990s, differences in birds between organic and nonorganic farms in Saskatchewan were evident but subtle and variable among farms, and apparently most related to land cover-bird assemblage interactions/relationships.

Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions.

Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6-20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale.

A Comparative Analysis of Productivity among Organic and Non-Organic farms in the West Mamprusi District of Ghana

The study was conducted in organic and conventional crop farms in the West Mamprusi District of the Northern Region of Ghana. The key issue the study sought to determine was whether there are productivity differences among organic and conventional crop farms and what factors account for these differences. The results indeed revealed that there are productivity differences among organic and conventional crop farms. However, both had negative total factor productivity growth, largely accounted for by a negative technical change over the period considered. The technical efficiency change, however, was positive for both but much higher for organic farms than conventional farms. More importantly, the study revealed that the type of agriculture practiced by farmers is not the most critical problem confronting farmers as indicated by the negative total productivity growth for both. Major constraints confronting farmers that need to be addressed include better organization on the farmers’ front, improved access to extension and improved access to farm inputs. These challenges notwithstanding, the study revealed that organic agriculture has the potential, in the long run, to achieve much more progress in total factor productivity, compared to conventional agriculture, if the right conditions exist for its uptake and optimal application.

Management and use of dairy cattle feed resources on smallholder certified organic pineapple farms in Central Uganda

Formulation of exclusively organic diets that meet maintenance and production requirements of dairy cattle is a major limitation to production of premium organic products of animal origin. This study was therefore carried out to assess the use and availability of feed resources and the coping strategies used by farmers to overcome dry season feed shortages on 64 smallholder certified organic pineapple farms. Data was collected using semi-structured questionnaires and two focus group discussions. Majority of households were headed by males (62.9%) while average age of respondents was 42.5 years. Farmers allocated more land (P<0.05) to organic pineapple production compared to livestock. Beside dairy cattle, farmers also kept chickens, goats and pigs. Tethering was the commonest cattle management system. Fifty three percent of respondents reported using both natural pastures and crop residues as major dairy cattle feed resources while only 19% reported using elephant grass. Banana peels (25.1%) and sweet potato vines (24.7%) were the most important crop residues fed to cattle. Farmers reported high cost of concentrates and scarcity of feeds as their biggest challenges in dairy cattle production. Of the respondents, 51.4% conserved feed for their cattle as fodder banks. As a coping strategy to feed shortages, majority (42.9%) of farmer scavenged for feed resources from both organic certified and nonorganic neighbouring farms which is contrary to organic livestock farming standards. It was, therefore, concluded that management of livestock feeding in the study area fell short of the requirements for organic livestock feeding standards. Research to develop strategies that can use alternative on-farm feed resources through ensiling organic pineapple wastes during the dry season is recommended as a long term strategy to address feed challenges for organic livestock farmers.

Profitability of Organic Vegetable Production: The Case History of Toktokha Organic Farm, Toebesa Geog, Punakha Dzongkhag

A study was conducted to assess the profitability of organic vegetable production by evaluating the economic performance of Toktokha Organic Farm, Toebesa Geog under Punakha Dzongkhag. The profitability of farm was assessed by preparing an income statement for 2012 which was then compared with the income statements of other organic farms, and non-organic farms from the same region. Information on markets for organic products was collected from Organic Sales Outlet in Centenary Farmers’ Market, Thimphu, by interviewing 30 randomly selected customers in the market. The results showed that the Toktokha Organic Farm was running at a loss in the year 2012, with a negative balance of Nu. 65,429.00, while other vegetable farms at household level were gaining with a mean profit of Nu. 9,440.50 and Nu. 10,052.10 for organic and nonorganic farms respectively from half langdo (about 30 decimal) of vegetable gardens. An independent samples t–test showed that there was no significant difference (p > .05) between organic and non-organic farms in terms of profitability in vegetable production. Most of the Centenary Farmers’ Market customers were not aware of the organic products sold in the Organic Sales Outlet or the Centenary Farmers’ Market.

Gains to species diversity in organically farmed fields are not propagated at the farm level.

Organic farming is promoted to reduce environmental impacts of agriculture, but surprisingly little is known about its effects at the farm level, the primary unit of decision making. Here we report the effects of organic farming on species diversity at the field, farm and regional levels by sampling plants, earthworms, spiders and bees in 1470 fields of 205 randomly selected organic and nonorganic farms in twelve European and African regions. Species richness is, on average, 10.5% higher in organic than nonorganic production fields, with highest gains in intensive arable fields (around +45%). Gains to species richness are partly caused by higher organism abundance and are common in plants and bees but intermittent in earthworms and spiders. Average gains are marginal +4.6% at the farm and +3.1% at the regional level, even in intensive arable regions. Additional, targeted measures are therefore needed to fulfil the commitment of organic farming to benefit farmland biodiversity.

Orchid bees as bio-indicators for organic coffee farms in Costa Rica: Does farm size affect their abundance?

The potential of Euglossini bees, especially Euglossa, as biological indicators of organic vs nonorganic coffee farms was studied in Atenas and San Isidro, Alajuela, Costa Rica using 1.8-cineole as lure. Observations were made for three days at each of four farms and complemented with data from a year of observations. Orchid bees were in greater abundance in the organic farms (t-Student test). However, lower abundances suggest that an organic farm may be negatively affected by the proximity of non-organic farms, depending on its size and distance. Orchid bees may be indicators of organic coffee farms.

Farming practices in Sweden related to feeding milk and colostrum from cows treated with antimicrobials to dairy calves

BackgroundMilk produced by cows in receipt of antimicrobial therapy may contain antimicrobial residues. Such antimicrobial-containing waste milk must be withdrawn from human consumption and is therefore sometimes used as calf feed. Unfortunately, this approach might promote selection of antimicrobial resistant bacteria in the calves’ intestinal microbiota. The objectives of this study were therefore to obtain an overview of waste milk feeding practices on Swedish dairy farms and to investigate if these practices were associated with certain farm characteristics. A representative group of 457 Swedish dairy farmers participated in a web-based survey with questions about the use of colostrum and milk from cows treated with antimicrobials at dry off or during lactation, respectively, as calf feed.ResultsColostrum (milk from the first milking after calving) and transition milk (milk from the second milking to the fourth day after calving) from cows treated with antimicrobials at dry off was fed to calves on 89% and 85% of the farms in the study, respectively. When antimicrobial therapy was given to cows during lactation, 56% of the farms fed milk that was produced during the course of treatment to calves, whereas milk that was produced during the subsequent withdrawal period was fed to calves on 79% of the farms. Surveyed farmers were less prone to feed such milk if the antimicrobial therapy was due to mastitis than other infections. In Sweden, a majority of antimicrobial treatments during lactation are systemic administration of benzylpenicillin and thus, the bulk of waste milk in Sweden is likely to contain residues of this drug. Feeding waste milk to calves was more common on non-organic farms, and on farms located in Southern Sweden, and was less common on farms with cows housed in cold free stalls barns.ConclusionsWaste milk that may contain antimicrobial residues is, at least occasionally, used as feed for calves on a majority of surveyed Swedish dairy farms. Future work should focus on the effect of waste milk feeding on the occurrence of antimicrobial resistant bacteria in the calves’ intestinal microbiota.