A. C. R. Cavalcante

Interaction of parasitism and nutrition and their effects on production and clinical parameters in goats

Weaned wether goats (n = 144) approximately 6 months of age were placed in a 2 x 3 factorial design experiment for 5 months to test the main effects and interaction of two levels of nutrition (growth + maintenance, NUT1; twice growth + maintenance, NUT2) and three levels of Haemonchus contortus burden (0, 500 and 2000 larvae administered every 2 weeks: W0, W500 W2000, respectively) on weight, feed intake, level of infection and packed cell volume (PCV). The rationale for the experimental design was based on the lack of information concerning the interaction between nutritional status and worm burden. Results indicated significant effects of worm burden levels on PCV, faecal egg contents (eggs per gram of feces (EPG)), actual worm numbers, feed intake and efficiency of feed utilization. Nutrition x worm burden interactions were also significant for PCV and EPG. However, the differences detected for PCV and actual worm numbers did not translate into large or consistent differences in body weight. Goats on NUT2, after an initial period, showed little difference in body weight, irrespective of worm burden. Within the NUT1 level, W0 kids weighed more than W500 or W2000 kids throughout the study. Although not statistically significant, this constitutes a trend towards an interaction between nutrition and worm burden. In both nutrition levels, there were no body weight differences between W500 and W2000 until the last 14 days. Feed intake was depressed in the first 3 months of the experiment for infected animals, but was subsequently followed by a compensatory reaction. Lower establishment rates, based on actual worm counts, were observed for the higher infection level, but in both infection levels establishment rates tended to decrease with time. Nutrition was found to be more important to counteract the consequences of a parasitic infection than to counteract the establishment of that same infection.

Resistência anti-helmíntica em rebanhos caprinos no Estado do Ceará

Goats of 45 farms in the State of Ceara, Brazil, were treated with anthelmintics for gastrointestinal nematodes, and their resistance to the anthelmintics was evaluated. On each farm 30 kids were weighed, ear-tagged and divided into three groups of ten. The first group received oxfendazole at 4.75mg/kg, the second levamisole at 7.5mg/kg, and the third group remained untreated as control. All goats were drenched according to their individual body weight. Fecal samples were collected from all animals (treated and control) on the day of treatment and 7 days later, to provide material for egg counts and larval cultures. Among 34 surveyed herds 20.6% showed levamisole resistance, 17.6% showed resistance to benzimidazole, and 35.3% had multiple resistance. At the time of the assessment 52.9% of the farmers were using broad spectrum anthelmintics. Only 26.5% of the surveyed herds had nematode populations susceptible to the anthelmintics assessed. The results of larval cultures showed that larvae surviving the treatment with oxfendazole were mainly Haemonchus sp and, to a lesser extent, Oesophagostomum sp; those surviving levamisole treatment were Haemonchus sp, Oesophagostomum sp and Trichostrongylus sp.

Risk factors for infection by Toxoplasma gondii in herds of goats in Ceará, Brazil

In order to identify possible risk factors for T. gondii infection in goat herds in Ceara, Brazil, 2362 serum samples were tested by ELISA. The serological prevalence was 25.1%. The risk factors identified for Toxoplasma gondii infection in goat herds were age, number of cats, use of wooden feeding troughs and absence of feeding troughs. Goats older than 37 months had 2.01 (CI 95%; 1.55 - 2.61) higher risk of infection than younger animals. Greater risk of infection was observed in farms with more than 10 cats (OR = 1.73; CI 95%; 1.01 - 3.33). The use of wooden feeding troughs represented a high probability of infection (OR = 7.81; CI 95%; 1.66 - 36.67). The lack of feeding troughs also represented a high probability of infection (OR = 5.50; CI 95%; 1.24 - 24.39).

Interaction of parasitism and nutrition in goats: effects on haematological parameters, correlations, and other statistical associations.

Weaned wether goats (n = 144) approximately 6 months of age were placed in a 2 x 3 factorial experiment to test the effects and interaction of two levels of nutrition (growth+maintenance, NUT1; and twice growth+maintenance, NUT2) and three levels of Haemonchus contortus burden (0, 500, and 2000 larvae administered every 2 weeks; W0, W500, and W2000, respectively) on packed cell volume, red blood cell count, total serum protein and leukocytes. The statistical analysis revealed clear and proportionate differences among levels of infection for all variables. A significant (P < 0.05) nutritional effect was also found associated with all the variables except leukocytes. Nutrition by worm load interactions were found for packed cell volume and leukocytes. The neutrophil/lymphocyte ratio was higher in the NUT1-infected animals, leading to the nutrition by worm load interaction for leukocytes. An analysis for the different leukocyte types revealed significant (P < 0.05) differences among infection levels for lymphocytes, while nutrition level was found to be a significant effect for basophil count and immature white cells. Several significant correlations were observed between pairs of variables. Faecal egg output could be predicted from actual worm count in three of the four necropsy periods. The clear differences observed for blood parameters were not present in production traits, suggesting that physiological thresholds may play an important role in framing the metabolic activity of biological organisms. Total serum protein was the best indicator of these effects on production parameters.

Haemonchus contortus resistance to ivermectin and netobimin in Brazilian sheep

Suffolk, Texel, Hampshire Down and Ile de France sheep from the municipalities of Porto Amazonas, Piraquara and Araucaria in the State of Paraná, and Bagé in the State of Rio Grande do Sul were brought to Sobral, State of Ceará, to be used in a cross-breeding project. On arrival they had clinical signs of nematode parasitosis, and one Suffolk female died. The animals were treated orally with ivermectin (0.2 mg kg-1) and fifteen days later with netobimin (20.0 mg kg-1). Neither drug reduced the egg counts (measured in eggs per gram, EPG) significantly, and this suggested that the nematodes in the sheep were resistant to the anthelmintics used. Haemonchus contortus was the species involved. The egg counts were reduced after oral treatment with trichlorfon (100.0 mg kg-1). Haemonchus contortus larvae obtained from these animals before trichlorfon treatment and passaged through two nematode-free sheep were used in a further experiment. Twenty 6- to 9-month-old nematode-free lambs were infected with the H. contortus larvae (10,000 per animal) and after the infection was confirmed, were randomly divided into four groups of five animals. Group I was orally treated with ivermectin at 0.2 mg kg-1, Group II with oral netobimin at 20.0 mg kg-1, Group III with oral trichlorfon at 100.0 mg kg-1 and Group IV was a non-treated control. Egg counts and faecal cultures were taken before dosing on the day of treatment and seven days later when all animals were necropsied and the nematodes were collected from the abomasa and counted.(ABSTRACT TRUNCATED AT 250 WORDS)

Eimeria species in dairy goats in Brazil

The focus of this work is to determine the distribution and identify species of Eimeria parasites of dairy goats in the livestock of the National Goat and Sheep Research Center in Sobral, State of Ceará, Northeast Brazil. Results showed the presence of multiple species in 196 of 215 analyzed samples (91.2%). Fifty five out of these were from kids (28%) and 141 from adult goats (72%). Eight different Eimeria species were identified and their prevalence in the herd was: Eimeria alijevi Musaev, 1970 (26.7%), E. arloingi (Marotel, 1905) Martin, 1909 (20.6%), E. hirci Chevalier, 1966 (18%), E. ninakohlyakimovae Yakimoff & Rastegaieff, 1930 (16.2%), E. jolchijevi Musaev, 1970 (8.7%), E. christenseni Levine, Ivens & Fritz, 1962 (6%), E. caprovina Lima, 1980 (2.8%) and E. caprina Lima, 1979 (1%). Moreover, E. ninakohlyakimovae showed higher prevalence in kids (97%), followed by E. arloingi and E. alijevi (88%). On the other hand, E. alijevi (77%) was more common in adult goats followed by E. hirci (74%) and E. ninakohlyakimovae (70%). The species E. caprina had low frequency in both kids (27%) and adult goats (13%). Data indicated that infection was relatively common among kids and adult goats. The implementation of a routine diagnostic strategy can be useful in maintaining Eimeria populations under monitoring and will enable the determination of its potential impact on dairy goat herds in Northeast Brazil.

A salinomicina para o controle da eimeriose de caprinos leiteiros nas fases de cria e recria

Salinomicin was evaluated for the control of caprine eimeriosis in the pre-weaning (PRW) and post-weaning (POW) phases. Twenty seven crossbred goat kids were randomly distributed among three treatments: T0, not medicated (check group); T and T 2 daily medicated with 1.0 and 2.0mg/kg living weight of salinomicin, respectively. In the PRW, there were not significant differences (P>0.05) in the daily weight gain among the treatments. However, in the POW, the T0 group presented daily weight gain inferior (P>0.05) to the T1 and T2 groups, which did not statiscally differ (P>0.05) between themselves. The average number of oocistes per gram of faeces in the T0 at the two studied phases was significatively higher (P 0.05) between themselves. The average carcass yield was significantly lower (P 0.05) to the T1 group. The use of salinomicin resulted in higher weight gains by the lambs, and improved the economic yield. The treatments T1 and T2 were equivalent in the caprine eimeriosis control since both treatments presented higher weight gains and lower oocistogram than the treatment T0. However, treatment T1 should be recommended due to its better economic efficiency.

Soroprevalência e fatores associados à infecção por Toxoplasma gondii em caprinos de propriedades rurais do município de Mossoró, RN

The municipality of Mossoro, RN, Northeastern Brazil, is featured on goat rearing. Toxoplasmosis is a zoonosis which is more pathogenic for goats when compared with other animals for slaughter. In this species, the protozoan is often responsible for reproductive problems and economic losses. In order to identify the seroprevalence and risk factors of toxoplasmosis in goats of farms in this municipality, serum samples from 338 animals (320 females and 18 males) of 15 production units were tested by enzyme immunoassay (ELISA). Of the 15 farms, 14 had animals positive for Toxoplasma gondii, and in these the total number of seropositive animals were 125 (123 females and 2 males), yielding a prevalence of 37.0%. There was a significant relationship (p<0.05) between prevalence and sex, and between the prevalence and breed of animals. The most important risk factors associated with T. gondii infection were: water supply with odds ratio (OR=2.635), containers for water animals located outside the premises of property (OR=3.121) and the exploitation of dairy type (OR=2.546). For the analysis of the avidity ELISA, was found females of reproductive age in the acute phase of infection.

Efficiency of water use and nitrogen for goat milk production in irrigated pasture to different management

Abstract: The aim was to determine the efficiency of use of water and nitrogen for forage production and goat-milk production on an irrigated Tanzania Guineagrass (Panicum maximum cv. Tanzânia) pasture subjected to different management practices. The management levels tested were combinations among nitrogen fertilization levels and post-grazing residual heights (ResH): Intensive (ResH = 33.0cm and 600.0kg N/ha.year-1); Moderate (ResH = 47.0cm and 300.0kg N/ha.year-1); Light (ResH = 47cm and 0kg N/ha.year-1); and Conventional (ResH = 33cm and 0kg N/ha year-1). The efficiency of water use for forage production was higher in intensive and Moderate management. The Conventional management was recommended only for forage production since there is no nitrogen input available because this result was similar to Intensive management in water efficiency. The efficiency of water use to produce goat milk was higher in Intensive management. Moderate management presented higher efficiency of nitrogen to produce forage. On the other hand, Intensive management was more efficient using nitrogen in goat milk production. The amount of water needed to produce one liter of goat milk varied from 893.20 to 3,933.50L. In the moderate management, up to 121.48kg forage and 21.56kg of milk were produced for every kilogram of N utilized. Intensive management is advantageous for water use efficiency as well nitrogen efficiency to produce goat milk in cultivated pasture. [Eficiencia de uso de agua e nitrogenio para producao de leite de cabra em pastagem irrigada sob diferentes manejos]. Resumo: Objetivou-se determinar a eficiencia de uso de agua e nitrogenio para a producao de forragem e de leite de cabra em pasto irrigado de capim-tanzânia, submetido a diferentes manejos. Os manejos testados foram combinacoes entre niveis de adubacao nitrogenada e alturas residuais pos-pastejo (Altr): intensivo (Altr = 33,0cm e 600,0kg N/ha.ano-1); moderado (Altr = 47,0cm e 300,0kg N/ha.ano-1); leve (Altr = 47,0cm e 0kg N/ha.ano-1) e convencional (Altr = 33,0cm e 0kg N/ha.ano-1). A eficiencia do uso de agua para producao de forragem foi obtida nos manejos intensivo e moderado. O manejo convencional so foi interessante no caso da producao de forragem em situacao de ausencia de nitrogenio, nao diferindo do manejo intensivo para a eficiencia de uso de agua. A eficiencia de uso de agua para a producao de leite foi maior no intensivo. A maior eficiencia do uso de nitrogenio para produzir forragem foi no moderado, enquanto a maior eficiencia de nitrogenio para a producao de leite foi no intensivo. A quantidade de agua para produzir um litro de leite de cabra variou de 893,20 em manejo intensivo a 3.933,50L em convencional. Manejo intensivo e vantajoso para eficiencia de uso de agua e nitrogenio para a producao de forragem e de leite de cabra.