Saúde e produção animal em rebanhos leiteiros orgânicos e convencionais – possibilidades e limitações
Jullyana de Souza Silva1, Gisele Maria Fagundes2, João Paulo Guimarães Soares3, Adivaldo Henrique da Fonseca4, Jenevaldo Barbosa da Silva5
1 - Universidade Federal dos Vales do Jequitinhonha e Mucuri
2 - Universidade de São Paulo
3 - Empresa Brasileira de Pesquisa Agropecuaria
4 - Universidade Federal Rural do Rio de Janeiro
5 - Universidade Federal dos Vales do Jequitinhonha e Mucuri
2 - Universidade de São Paulo
3 - Empresa Brasileira de Pesquisa Agropecuaria
4 - Universidade Federal Rural do Rio de Janeiro
5 - Universidade Federal dos Vales do Jequitinhonha e Mucuri
RESUMO -
Sabe-se que os sistemas orgânicos de produção têm consequências positivas sobre a saúde e o bem-estar dos animais. O objetivo desse estudo foi discutir os riscos para a saúde e produção animal em rebanhos leiteiros orgânicos e convencionais. Os resultados apresentados são oriundos de três anos do estudo. A produção de leite em sistema convencional de 10 kg/vaca e 30kg/ha foi significativamente maior quando comparado com 8 kg/vaca e 12kg/ha em sistema orgânico. A incidência de mastite foi significativamente maior no sistema orgânico quando comparação com o sistema convencional. A utilização de antiparasitário foi significativamente maior no sistema convencional em comparação com o sistema orgânico. A resistência parasitária foi de 0% em sistema orgânico e 30% em sistema convencional. Este estudo sugerem que a gestão de pastoreio pode ser eficaz na manutenção de um nível baixo de doenças entre bovinos. É essencial que, no futuro, tenhamos que combinar estratégias e práticas que provavelmente irá exigir mais trabalho e monitoramento.
Palavras-chave: sistema convencional, a produção de leite, sistema orgânico, parasitas
Animal health and production in organic and conventional dairy herds - possibilities and constraints
ABSTRACT - It is widely held that organic systems of production have positive consequences on the health and welfare of livestock. The objective of this study was to discuss the risks for animal health and production in organic and conventional dairy herds. The results presented are from three years of the study. Milk production was 10 kg/cow and 30kg/ha in conventional system was significantly higher when compared with 8 kg/cow and 12kg/ha in organic system. The incidence of mastitis was significantly higher in organic system compared with conventional system. The utilization of antiparasitic was significantly higher in conventional system compared with organic system. The resistance parasite was 0% in organic system and 30% in conventional system. This study suggest than grazing management can be effective in maintaining a low level of diseases amongst livestock. It is essential that for the future, we will have that combine of strategies and practices which will most likely require more work and monitoring.Keywords: conventional system, milk production, organic system, parasites
Introdução
Cattle are economically the most important livestock in Brazil where milk and beef originate from approximately 200 million cattle (the world's largest cattle). These is including 174 million beef cattle and 26 million dairy cows, 1º beef exporter in the world (26% of world exports), 5º largest milk producer in the world (30 billion liters). In 2005 the organic milk production in Brazil was estimated to 0.01% (2.4 million liters) of the total milk production, but in 2010 this production had increased to 0.02% (6.8 million liters) of the national milk production (Soares et al., 2012). Although this slight volume of production and the waiver of some dairy farmers from Brazil, an increase of 187% in organic dairy production was observed for the period 2005 – 2010 (Soares et al., 2012). During the second half of the 20th century and the beginning of the present, the world has experienced an accelerated modernization process with unsustainable long-term growth. Parasites of domestic ruminants directly or indirectly contribute to reduced sustainability affecting food security in subsistence or small scale farming systems, food safety, environment and farmer’s equity (Henrioud, 2011). A variety of factors contribute towards this low production level, such as the lack of research focusing on animal diets, breeding and healthcare, especially with regard to gastrointestinal helminth infections (Larsson et al., 2007; Silva et al., 2011). A major difference between organic and conventional cattle production is that the prophylactic use of anthelmintics is prohibited in organic herds, although anthelmintics are not always used even in conventionally reared cattle (Höglund et al., 2010). Thus, this article aims to discuss the risks for animal health and production in organic and conventional dairy herds.Revisão Bibliográfica
The growth of markets increasingly interested in foods with no chemicals has encouraged producers in agro-exporting countries to adopt organic production systems (Silva et al., 2011). In Brazil, the demand for organic products has been growing by 10% a year, which reflects consumers’ desire to buy product from animals raised in systems that promote animal welfare and are sustainable (D'Almeida, 2005). However, a variety of factors contribute towards this low production level, such as the lack of research focusing on animal diets, breeding and healthcare, especially with regard to gastrointestinal helminth infections (Nardone et al., 2004; Larsson et al., 2007).
Organic production systems is of growing importance in several countries worldwide (Thamsborg, 2001). In Brazil, organic milk production was estimated at 0.01% (2.4 million liters) of the total milk production in 2005. Although Brazilian organic milk is still slight, an increase of 187% was observed between 2005 and 2010 (Soares et al., 2012). Livestock production systems differ in their environmental and economic impacts. The principles and standards employed in organic production constitute a radical break with the productivist paradigm, and are poorly documented in most livestock species (Cabaret, 2003).
The fight against helminths in tropical countries has mainly been conducted through uncontrolled use of anthelminthic compounds (Nansen, 1993). Although these drugs have been shown to have proven efficacy, the lack of protocol for their use in tropical regions, coupled with their disorderly use, has led to increasing production costs (Silva et al., 2011). In addition, the way in which these drugs have been used has contributed towards the emergence of resistant strains (Amarante et al., 2004) and consumers have raised concerns about residue levels in foods (Silva et al., 2011; Silva et al., 2014).
Materiais e Métodos
This study was conducted between January 2007 and December 2009, on an Integrated System for Organic Production, as collaboration between the Brazilian Agricultural Research Corporation and the Agricultural Research Corporation of the State of Rio de Janeiro. The experimental area was located in the municipality of Seropédica, state of Rio de Janeiro, in the microregion of Itaguaí (latitude 22 ° 45'S, longitude 43 º 41'W and altitude 33 meters). Two experiments were conducted simultaneously. The study design was completely randomized. The first treatment consisted of 54 Girolando cows (5/8 Holstein × 3/8 Gyr) aged 3 to 9 years and 24 calves (5/8 Holstein × 3/8 Gyr) aged 1 to 12 months. The cows were kept in 11 paddocks measuring approximately 7000 m2 total. As roughage fodder, the organic farm used Tanzania grass (Panicum maximum cv. Tanzania) during the rainy season while during the dry season, the cows received elephant grass (Pennisetum purpureum Schum cv. Cameroon) plus siratro (Macroptilium atropurpureum (DC) Urb.) and sugarcane (Saccharum spp.) as roughage supplement. The second treatment consisted of 80 crossbred cows (1/2 Holstein x 1/2 Gyr) aged from 3 to 8 years. The cows were kept on pasture (Brachiaria decumbens (Stapf)) paddocks measuring approximately 8500 m2 grazed in 7-day rotations. From birth to 4 months, calves in the conventional system remained in individual stalls and were fed milk twice a day plus concentrate. From 5-12 months of age calves had access to Panicum maximum Jacq. Animals are vaccinated against brucellosis and foot and mouth disease. The parasite control performed on the animals kept in the organic production system was mainly based on rotational grazing, separation of animals by class and according to age, adequate nutrition and supply of hay and silage. In the conventional system, anthelminthic prophylaxis was administered once a month moxidectin (0.2 mg/kg, Cydectin®, Fort Dodge, Brazil). Fecal samples were collected fortnightly from all goats during three years. The numbers of gastrointestinal nematode eggs per gram of feces (EPG), from nematodes gastrointestinal and oocyst of protozoa were counted using the McMaster technique, as described by Gordon and Whitlock (1939). For statistical analysis, the EPG data were initially transformed into log10 (x + 1) in order to normalize them. For quantitative assessment of different parameters, analysis of variance was used, along with the Tukey test at 5% significance, and also linear regression. The operating procedures were performed using the statistical software R Foundation for Statistical Computing, version 2.12.2 (2011).Resultados e Discussão
Milk production was 10 kg/cow and 30kg/ha in conventional system was significantly higher when compared with 8 kg/cow and 12 kg/ha in organic system (Table 1). The incidence of mastitis was significantly higher in organic system compared with conventional system. The utilization of antiparasitic was significantly higher in conventional system compared with organic system. The resistance parasite was 0% in organic system and 30% in conventional system. Another study indicated that production of organic milk in Brazil is economically viable, since the capital return is 5% per year, higher than that of 2% per year obtained by the conventional system (Soares et al., 2012). Even with a reduction of 33% in productivity per cow and with an increase in cost of land (63%) and hand labor (47%), which increased in 50% the total cost per liter of milk produced, the aggregate value of the product from 50 to 70% more than the value of conventional milk (Soares et a., 2012). Thus, to be economically viable the price of milk liter paid to organic farmer needs to be 70% higher than that paid for conventional milk. Although only limited research is available on direct comparisons between the health status of organically reared animals sometimes being compromised (Kyriazakis et al., 2002). Organic farms have reported higher incidence of internal parasitism (17% and 5% respectively) than conventional farms (Svensson et al., 2000). The farms included in the study the use of antiparasitic drugs by farmers was lower in organic, 25% of the total of organic farms included in the study, and high in conventional farms, 83% of the total of conventional. The stock of animals in organic farming was considerably smaller than that of animals in conventional farming. The rotational grazing and animal stocking in paddocks (according to age) resulted in the young animals having lower exposure to pastures infested with larvae released from adult animals. Use of pasture management as an alternative to use of chemical products for controlling helminths has previously shown satisfactory results (Athanasiadou et al., 2002; Silva et al., 2012). In the present study, the animals were managed using a rotational grazing system with low stocking density, which was probably responsible for the low parasite load observed in the animals. The average values and statistic analysis of the helminth egg counts in the feces from cows kept in organic and conventional system are shown in table 2. The results from eggs count showed that Trichostrongyloidea, Trichuris spp., Strongyloides papillosus, Toxocara vitulorum, Moniezia expansa and Eimeria spp. were present. There were significant differences (p < 0.05) in average fecal egg count values over the two systems. Although the calves had been kept on pasture during their first year of life, the parasite load was continually low. However, egg elimination in feces was significantly higher in organic system compared with conventional system. The therapeutic use of anthelmintic drugs was low in organic production system. In fact, farmers organic are allowed to use anthelmintics for controls, as often as it is recommend by their veterinary surgeon, to maintain healthy livestock (Kyriazakis et al., 2002). However this arrangement can protect ruminants from nematode parasites, one should question why the unlimited use of antiparasitic is compatible with the holistic philosophy of organic system, whereas the use of antibiotics is not (Kyriazakis et al., 2002). Almost 5% of the animals kept in organic system received anthelmintics as a part of their worm control strategy and all at the animals kept in conventional system received anthelmintics to the worm control strategy. In UK almost 30% of organic farms used anthelmintic as a part of their worm control strategy (Roderick et al., 1996). Resistance to anthelmintics has being diagnosed in 86% of countries at the world (Henrioud, 2011). In America Latina, pesticide resistance has been the driving force for searching for new alternatives for control when the geoclimatic situation or livestock management have determined that animals should be treated nearly continuously (Henrioud, 2011).Conclusões
Reduced stocking density and rotational pasture management in organic systems likely contributed to lower parasite loads. It is essential that for the future, we will have that combine of strategies and practices which will most likely require more work and monitoring.Gráficos e Tabelas
