Physicochemical characteristics and sensory attributes of meat from heavy-weight Iberian and F1 Large White × Landrace pigs finished intensively or in free-range conditions.

Iberian (IB, n = 60) and crossbred Large White × Landrace (F1, n = 58) pigs were slaughtered at 160 kg, after finishing under intensive conditions or on pasture and acorns. The study was carried out as a factorial arrangement of treatments, and physicochemical properties and sensory attributes of meat were assessed in Longissimus thoracis samples. Physical characteristics included the assessment of drip loss, cooking loss, shear force, and color coordinates in meat samples processed at 2 and 9 d postmortem. The interactions of genetic group and finishing system were significant (P < 0.05) for cooking loss in meat aged for 9 d and for sensorial tenderness and global acceptability of meat, but none of the other physicochemical, color coordinates, and sensory variables analyzed showed a significant interaction. Genetic group was the main factor influencing the variables analyzed, with a major (P < 0.01) influence on all meat physicochemical characteristics and sensory attributes. Relative to F1 pigs, the IB produced meat with higher intramuscular fat content and marbling score, more appealing color coordinates, lower shear force, and higher sensorial tenderness. The finishing systems affected (P < 0.05) most physical characteristics, but not chemical composition of meat and their impact on sensory properties was small. The tenderness, juiciness, and global acceptability of meat were much higher in IB pigs, and flavor was also more desirable, but the difference was smaller. The differences in sensory properties between meats originating from the two genetic groups were largely explained by the higher fat deposition in IB pigs, such that a higher level of marbling was positively associated with all the sensory attributes evaluated. Ageing meat for up to 9 d postmortem benefited pork quality, improving meat tenderness, and color, particularly in crossbred pigs and those finished intensively.

Effects of dietary inclusion of citrus pulp and rockrose soft stems and leaves on lamb meat quality and fatty acid composition.

Meat from lambs finished with high-starch diets often contains low concentration of vaccenic (t11-18:1) and rumenic (c9,t11-18:2) acids and high concentration of t10-18:1. We hypothesized that replacing cereals by dehydrated citrus pulp (DCP) and the inclusion of tanniferous feed sources in oil supplemented diets might reduce the accumulation of t10-18:1 and increase the t11-18:1 and c9,t11-18:2 in lamb meat, without affecting the productive performance. In total, 32 lambs were assigned to four diets which combine two factors: basal diet (BD) (cereals v. DCP) and Cistus ladanifer (CL) (0 v. 150 g/kg dry matter). Feed intake, average daily weight gain and carcass traits were not affected by treatments, except for dressing percentage that was reduced with DCP (P=0.046). Both DCP and C. ladanifer reduced tenderness and juiciness of meat, and C. ladanifer also reduced (P0.05) by diets. However, DCP increased the proportions of odd-chain FA (P=0.005) and several minor biohydrogenation (BH) intermediates in meat lipids. C. ladanifer had few effects on meat FA profile. The proportions of t11-18:1 and c9,t11-18:2 were high in all diets (5.4% and 1.5% of total FA, respectively) and were not influenced by the treatments. Basal diet and CL showed some significant interactions concerning FA composition of intramuscular fat. In diets without C. ladanifer, replacement of cereals by DCP increased the 18:0 (P<0.05) and decreased t10,c12-18:2 (P<0.05), t10-18:1 (P<0.10) and t10-/t11-18:1 ratio (P<0.10) with a large reduction of the individual variation for t10-18:1 and of t10-/t11-18:1 ratio. Combined with cereals, C. ladanifer increased 18:0 and reduced the BH intermediates in meat. Replacement of cereals by DCP seems to promote a more predictable FA profile in lamb meat, reducing the risk of t10-shifted BH pathways in the rumen.

Carcass characteristics and fat depots in Iberian and F Large White × Landrace pigs intensively finished or raised outdoors in oak-tree forests.

A factorial experiment was performed with 117 barrows belonging to the Iberian (IB) and crossbred F Large White × Landrace (F) genetic groups, either intensively finished (IN) or finished outdoors on pasture in an oak and cork tree forest (EX). Information was collected on carcass weight, yield, and dimensions; weight of organs, carcass cuts, and abdominal fat depots; backfat depth; measurements of the longissimus thoracis (LT); and yield of different leg tissues. For the 41 slaughter and carcass traits analyzed, the interaction between genetic group and finishing system was significant ( < 0.05) in 18 traits, and overall, there was a more pronounced influence of genetic group than of finishing system. In most variables, particularly those related with fat deposition, the interaction reflected mostly changes in mean differences among genetic groups rather than in their ranking, where IB pigs consistently produced fatter carcasses, regardless of the finishing system. Liver weight in IB-EX pigs was lower by nearly 8% when compared with F-EX or IB-IN pigs, but the opposite pattern was found in F pigs, where liver weight in F-EX pigs was higher by 16% relative to IB-EX pigs or to F-IN pigs. The deposition of adipose tissue was much larger ( < 0.05) in IB pigs compared with F pigs, with means for fat depots in IB pigs that were higher by about 25% in total abdominal fat, 94% in dorsal fat depth, 72% in intermuscular plus subcutaneous fat in the leg, and over 300% in intramuscular fat (IMF). The deposition of lean tissue was much lower in IB pigs ( < 0.05), with means for trimmed loin weight corresponding to about one-half of the means obtained in F pigs, whereas lean percentage in the leg of IB pigs was about two-thirds of the mean in F pigs and the mean area of the LT was nearly one-half of that observed in F pigs in the same finishing system ( < 0.05). A strong correlation was observed between the various fat depots when the full data set was considered (correlations of IMF with abdominal fat and backfat depth of 0.65 and 0.83, respectively; < 0.05), but the correlations were much smaller when they were estimated within breed, particularly for IB pigs (-0.10 and 0.20 for the correlations of IMF with abdominal fat and backfat depth, respectively; > 0.05), indicating that it is feasible to reduce subcutaneous and abdominal fat without compromising IMF and meat quality.

Lipid profile and cholesterol of pork with the use of glycerin in feeding / Perfil lipídico e colesterol da carne de suínos com uso de glicerina na alimentação

The aim of this work was to evaluate the effects of adding different levels of glycerin in the feeding on the lipid profile and cholesterol of the meat of finishing pigs. The experiment was arranged in a completely randomized design (CRD) with factorial 5x2, being five levels of glycerin in the diet and two genders. Sixty (60) swine of the Topigs genetics (30 barrows and 30 gilts) were used; they presented initial average weight of 79.3+4.0kg and were finished with the weight of 106.2+4.5kg. The levels of glycerin utilized were 0, 50, 100, 150 and 200g/kg in the natural matter. The analyses of lipid and cholesterol profile were conducted in the muscles longissimus dorsi (loin) andsemimembranosus (ham) on the left side of the carcasses. Interaction occurred between the levels of crude glycerin in the diet and the sexual category for the profile of fatty acids and cholesterol. On the loin the meat of the barrows presented higher means of C16:0, C16:1, C20:3ω3, C18:1ω9c, Total of saturated (SFA) and monounsaturated (MUFA) fatty acids. On the ham, increased means were found for the fatty acids C18:1ω9c, MUFA, activity of ∆9-desaturaseC18 and ElongaseC16-18 in barrows. The sows' meat presented higher proportions of polyunsaturated fatty acids and of the series ω6 for both the cuts. The amount of cholesterol in the sows' meat presented increase according to the level of glycerin in the meat. The barrows' meat presented indices of atherogenicity greater than the gilts. The levels of glycerin altered the lipid profile and cholesterol content according to the sexual category, promoting a distinct effect on the loin and ham.(AU)

O objetivo deste trabalho foi avaliar os efeitos do fornecimento de diferentes níveis de glicerina na alimentação sobre o perfil lipídico e colesterol da carne de suínos em terminação. O delineamento experimental foi organizado inteiramente ao acaso (DIC), com fatorial 5x2, sendo: cinco níveis de glicerina na dieta e dois sexos. Foram utilizados 60 suínos da genética Topigs (30 machos castrados e 30 fêmeas), apresentando peso médio inicial de 79,3+4,0kg, e foram terminados com peso de 106,2+4,5kg. Os níveis de glicerina utilizados foram de 0, 50, 100, 150 e 200g/kg na matéria natural. As análises de perfil lipídico e de colesterol foram realizadas nos músculos longissimus dorsi (lombo) e semimembranosus (pernil) do lado esquerdo das carcaças. Ocorreu interação entre os níveis de glicerina bruta na dieta e a categoria sexual para o perfil de ácidos graxos e colesterol. A carne dos machos castrados apresentou no lombo maiores médias de C16:0, C16:1, C20:3ω3, C18:1ω9c, Total de ácidos graxos Saturados (SFA) e Monoinsaturados (MUFA). No pernil, maiores médias foram verificadas para os ácidos graxos C18:1ω9c, MUFA, atividade da ∆9-desaturaseC18 e ElongaseC16-C18 em machos castrados. A carne das fêmeas suínas apresentou maiores proporções de ácidos graxos poli-insaturados e da série ω6 para ambos os cortes. A quantidade de colesterol na carne das fêmeas suínas apresentou aumento em função do nível de glicerina na dieta. A carne dos machos castrados apresentou maiores índices de aterogenicidade que das fêmeas. Os níveis de glicerina alteraram o perfil lipídico e teor de colesterol em função da categoria sexual, promovendo efeito diferenciado no lombo e pernil.(AU)

Mortadella sausage manufactured with Caiman yacare (Caiman crocodilus yacare) meat, pork backfat, and soybean oil.

Mortadellas manufactured using Caiman yacare meat (70%) and pork fat (30%) were reformulated by substituting pork fat with increasing amounts of soybean oil (25%, 50%, and 100%) and evaluated 7, 30, and 60 days post-manufacture. The substitutions resulted in an increase in fat content and in the percentage of polyunsaturated fatty acids (total PUFA; 18:2 n-6 and 18:3 n-3), and a reduction in saturated fatty acids (total SFA; 14:0 and 16:0). These alterations reduced (P<0.01) the indices of atherogenicity and thrombogenicity by 4- to 5-fold in the formulation with 100% soybean oil compared to the original formulation. The levels of TBARS obtained at day 7 were positively correlated (P<0.01) with 18:2 n-6 and 18:3 n-3 (r=0.83 and 0.84, respectively) and negatively correlated with 17:0 and 17:1 (r=-0.91 and -0.89, respectively). All formulations received favourable overall acceptability by the sensory panel.

Heterosis for meat quality and fatty acid profiles in crosses among Bos indicus and Bos taurus finished on pasture or grain.

Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus×B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner-Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n-6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ(9) desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism.

Qualidade da carne de frangos caipiras abatidos em diferentes idades / Quality meat in chicken country slaughter different ages

Neste trabalho, foram avaliadas as características físico-químicas e de composição centesimal da carne de frangos machos de três linhagens utilizadas para criação semi-intensiva: Redbro Cou Nu - Vermelho de Pescoço Pelado (Pescoço Pelado); Redbro Plumé - Vermelho de Pescoço Emplumado (Pesadão) e Gris Barre Plumé (Carijó). Foram analisadas diferenças em relação à linhagem e à idade de abate (70, 85 e 110 dias). Na carne do peito, não foi verificado efeito de linhagem sobre os parâmetros de cor (L*, a* e b*) e pH final. Houve comportamento diferenciado para as aves em relação a qualidade da carne do peito, com menores valores de maciez para linhagem Pesadão e de Perda de Peso por Cozimento para linhagem Carijó. A linhagem Carijó apresentou, para a carne de peito aos 110 dias, os menores valores de umidade e as maiores médias de proteína. Os valores de proteina reduziram para linhagem Pescoço Pelado a partir de 85 dias. Na coxa, a partir de 110 dias, foi verificada redução dos valores de L* (luminosidade) e aumento das médias de a* (vermelho). Os valores de força de cisalhamento e extrato etéreo aumentaram para peito e coxa a partir dos 110 dias. As linhagens Pesadão e Pescoço Pelado apresentaram de forma geral, melhores aspectos físico-quimicos, que são os atributos de maior preferência pelo consumidor em função deste tipo de produto.

The objective of this work was to evaluate the physical and chemical characteristics and composition of meat from male broilers from three strains used for the semi-intensive development: Redbro cou nu - Red naked neck (Label Rouge); Redbro plume - Red neck feathered (Pesadão) and Gris Barre plume (Carijó). We analyzed differences in relation to genetic and slaughter age (70, 85 and 110 days). There was no effect of strain on the color parameters (L * a * b *) and final pH of breast meat. There was different behavior for broilers to quality of breast meat with lower tenderness values for strain Pesadão and Cooking Loss for a strain Carijó. The Carijó line presented the lowest humidity and the highest average protein values for breast meat at 110 days. The protein values reduced in the Label Rouge strain from 85 days forward. In the thigh, decreased levels of L* (brightness) and increase in the average a* (redness) was found from 110 days forward. The Shear Force and ethereal extract for breast and thigh increased from 110 days forward. Pesadão and Label Rouge strains generally presented better physical-chemical attributes, which are preferred by consumers due to this type of product.

Meat quality and lipid profiles in crossbred lambs finished on clover-rich pastures.

Meat quality traits were compared in Texel x Polwarth and Texel x Corriedale ram lambs, with live weight of 25kg, finished on pastures rich in white clover. The two crossbred groups showed similar results (P>0.05) for pH, moisture, protein, meat color, individual SFA and total SFA. Fat content was higher and cholesterol lower in Texel x Polwarth lambs (P<0.05), which also had higher amounts of MUFA (P<0.05) and lower levels of total PUFA and n-6 PUFA (P<0.01). Differences in meat quality among the two crossbred groups were minor, and possibly not perceptible from the consumer standpoint. However, both groups of lambs produced lean meat with high amounts of PUFA (>16%), possibly due to the ingestion of white clover in the finishing period. Overall, these results indicate that a differentiated product can be obtained in these conditions, with higher nutritional value than conventional lamb meat.

Genotype x environment interactions for fatty acid profiles in Bos indicus and Bos taurus finished on pasture or grain.

A study was conducted to characterize lipid profiles in the M. longissimus thoracis of commercial Brazilian beef and to assess how those profiles are influenced by finishing system, genetic group, and their interaction. Intramuscular fat (IMF) and fatty acid (FA) profiles were determined in 160 bulls of the Bos taurus (n = 75) and Bos indicus (n = 85) genetic groups, finished on pasture (n = 46) or with grain supplementation (n = 114) and slaughtered in a commercial abattoir. Finishing system had a major impact on the deposition of IMF, as well as on the concentration of SFA, PUFA, and their ratio, but genetic groups showed important differences in the ability to convert SFA into cis-9 MUFA and to convert 16:0 into 18:0. When compared with pasture-finished animals, those finished with grain had greater content of IMF and SFA (P < 0.01), similar amounts of MUFA (P > 0.05), and about one-half the amount of PUFA (P < 0.01). Except for MUFA, differences in FA profiles among finishing systems were mostly mediated through their effect on IMF, even though the relationship of IMF with groups of FA differed among finishing systems. Under grain finishing, B. taurus had less SFA and greater MUFA than B. indicus (P < 0.01), but no differences were observed in PUFA (P > 0.05). With pasture-finishing, no differences were observed among the 2 genetic groups in SFA and MUFA (P > 0.05), but PUFA were decreased in B. taurus (P < 0.01). When genetic groups were compared in grain-finishing, B. taurus had a decreased ability for elongation and B. indicus had a decreased aptitude for desaturation of FA. On the other hand, with pasture-finishing a greater deposition of intermediate FA from ruminal biohydrogenation was observed in B. indicus than in B. taurus. Overall, FA profiles were affected more by finishing system in B. indicus than in B. taurus.

Protection against high-dose homologous infection in calves immunized with intestine or membrane extracts from Haemonchus placei.

Control of Haemonchus placei, one of the most important cattle nematodes in Brazil, relies on the use of anthelmintics. However, there is a need for integrated control, which includes active immunization. The aim of this work was to assess the protection afforded to calves by immunization with adult H. placei extracts against a high-dose challenge infection, a condition frequently found in the tropics. Holstein calves aged 8-10 months were immunized four times with intestinal extracts (Group D) or with a Triton X-100-soluble fraction of adult H. placei (Group A), challenge-infected with 120,000 infective larvae and sacrificed 40 days later. Immunized animals had higher IgG titers than the controls against tested fractions after the 2nd immunization, peaking after the 4th. Sera from both immunized groups recognized bands of similar apparent mass in both antigenic preparations, some of which were similar in molecular weight to Haemonchus contortus antigens with known protective effect to sheep. Egg counts were 49% and 57% lower in Groups A and D than in controls, respectively. High levels of protection were observed in two of the four calves in Group D, as evidenced by very low worm numbers recovered at necropsy, absence of eggs in the uteri of the recovered females and reduced worm length. Group D animals also showed milder signs of anemia than the other infected animals. Results demonstrate that protection against homologous high-dose challenge can be achieved by immunizing calves with H. placei gut antigens.

A family of activation associated secreted protein (ASP) homologues of Cooperia punctata.

Activation-associated secreted proteins (ASP) of nematodes have been studied as potential vaccine components. In this study we report the cloning and analysis of cDNA and genomic sequences of Cooperia punctata and establish the presence of two 75% identical ASP-1 genes in C. punctata. Additional C. punctata ASP paralogues were shown to be present. Analysis of PCR products amplified from genomic DNA from a pool of worms revealed extensive sequence diversity within this family of proteins, reflecting the presence of different ASP paralogues in a single worm as well as extensive polymorphisms between different worms. ASP proteins contain a conserved region called the sperm-coating protein (SCP) domain of unknown function, which is present as a single copy in proteins from yeast and a wide range of multi-cellular organisms. Only in three nematodes has a protein composed of duplicated SCP-domains been identified. C. punctata is the first organism in which at least two such genes are found. Database searches identified similarity of the C-terminal cysteine-rich domain of ASP proteins to a nematode metallothionein motif. Cp-asp-1b was expressed in Escherichia coli and both the N-terminal and C-terminal domain were shown to be recognized by sera of C. punctata infected bovines. The description of the asp gene family of C. punctata provides the basis for more detailed studies into the extent of variation and immunological recognition of this family that may assist in rational vaccine design.

Teaching of undergraduate veterinary parasitology: the South American perspective.

Undergraduate teaching of veterinary parasitology in South American countries is basically similar to most of the veterinary schools and offers lectures and practicals in parasitology (P) predominantly in the second year of the curriculum, and parasitic diseases (PD) in the third year, but in some schools also in the fourth and fifth years. However, there is a great variation in teaching hours allocated to P/PD between totals of about 50-169 h during the full curriculum. In addition to the lectures and practicals, schools are increasingly using tools (CD-ROMs) for self-instruction and new forms of education, such as workshops, round tables, and field practicals. The large number of important parasite species of large and small animals in tropical and subtropical areas would require additional hours for teaching--at least in some of the schools--considering the multidisciplinary characteristics of veterinary parasitology.

Cooperia punctata trickle infections: parasitological parameters and evaluation of a Cooperia recombinant 14.2 kDa protein ELISA for estimating cumulative exposure of calves.

Three groups of four calves each were trickle infected with three different levels of Cooperia punctata: 310 (group A), 1250 (group B) and 5000 (group C) third stage infective larvae (L3) twice a week over a 17-week period. Group D was the non-infected control group. Parasitological parameters as faecal egg counts (epg), worm burdens, size of worms and number of eggs per female were collected and the differences between the groups compared. Serological analyses were also conducted to investigate the efficiency of a recombinant C. oncophora CoES 14.2kDa protein in an ELISA to detect C. punctata antibodies. Group C had higher faecal egg counts until week 9 when the values decreased to those in group B. Mean faecal egg counts in group A were always lower than in the two other infected groups. The worm burdens were highest in group C, and lowest in group A, although the number of worms as a percentage of total larval intake was higher for the lower group. The mean length of the worms was shorter and the number of eggs per female lower for group C than for both other groups. ELISA using the CoES 14.2kDa proved to be efficient in measuring C. punctata antibodies. For group C it took 4 weeks to get increased levels of antibodies and this was one and 2 months more for groups B and A, respectively. Overall, there was a congruent relation between C. punctata antibodies and the cumulative exposure to the three different levels of trickle infections.

In vitro interaction of Brazilian strains of the nematode-trapping fungi Arthrobotrys spp. on Panagrellus sp. and Cooperia punctata.

In vitro tests were carried out to verify the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Cooperia punctata, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to C. punctata, for all the fungal treatments. Also, variable predatory capacity was observed for different fungal isolates belonging to the same genus when applied to different nematode species.

In vitro interaction of Brazilian strains of the Nematode-trapping fungi Arthrobotrys spp. on Panagrellus sp. and Cooperia punctata

In vitro tests were carried out to verify the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Cooperia punctata, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to C. punctata, for all the fungal treatments. Also, variable predatory capacity was observed for different fungal isolates belonging to the same genus when applied to different nematode species

A Cooperia punctata gene family encoding 14 kDa excretory-secretory antigens conserved for trichostrongyloid nematodes.

A polymorphic set of 14 kDa excretory-secretory (E-S) antigen-encoding cDNAs, with similarity to a previously characterized 15 kDa E-S antigen of Haemonchus contortus, was cloned from Cooperia punctata. Five cDNAs encoding predicted proteins of 70-80% identity were sequenced. Genomic analyses of individuals proved the existence of three 14 kDa E-S antigen-encoding genes, excluding that the differences reflected polymorphisms between individuals in a population. Southern blots indicated the presence of additional members of this gene family. Thus, despite the fact that heterologously expressed C. punctata 14 kDa E-S products are shown to be recognized by immune sera, potential pitfalls in the development of a recombinant vaccine are presented by this genetic diversity. Vaccine design could be further rationalized by knowledge of the function, and possible redundancy in function, of the E-S products which is presently lacking. The limitations encountered in assigning a function to the 14/15 kDa family of E-S proteins that is thus far unique to the trichostrongyloid nematodes are discussed.

In vitro activity of Brazilian strains of the predatory fungi Arthrobotrys spp. on free-living nematodes and infective larvae of Haemonchus placei

In vitro tests were carried out to assess the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Haemonchus placei, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to H. placei, for all the fungal treatments. Also, variable predatory capacity was observed for different fungal isolates belonging to the same genus when applied to different nematode species

In vitro activity of Brazilian strains of the predatory fungi Arthrobotrys spp. on free-living nematodes and infective larvae of Haemonchus placei.

In vitro tests were carried out to assess the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Haemonchus placei, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to H. placei, for all the fungal treatments. Also, variable predatory capacity was observed for different fungal isolates belonging to the same genus when applied to different nematode species.

Dynamics of the humoral immune response of calves infected and re-infected with Cooperia punctata.

The dynamics of the humoral immune response of calves were analysed after primary infection and re-infection with the intestinal nematode Cooperia punctata. 12 male 5 month-old Holstein-Friesian calves were randomly divided into two groups A and B. At the beginning of the experiment Group A animals were each infected experimentally with a single oral dose of 130,000 infective third stage larvae (L3) of C. punctata. The animals of Group B were kept as non-infected controls. The two calves from Group A with the highest infections died of cooperiosis at 32 and 44 days after infection (DAI), respectively. On DAI 100 the calves were treated with the recommended dose of oxfendazole. On DAI 180 the remaining four calves of Group A and three animals of Group B (B1) were infected with 260,000 L3 of C. punctata, while the other three calves of Group B (B2) served as non-infected controls. Monitoring of the humoral immune response predominantly demonstrated an IgG1 response against both adult and L3 antigen of C. punctata. Moreover, re-infections increased the levels of these immunoglobulins. IgA levels were less increased than IgG1 and no significant increase was observed in IgG2 and IgM levels. Immunoblotting analysis showed that total IgG present in the serum of the primary infected animals mainly reacted against adult proteins of 12-14 and 17-20 kDa and against L3 proteins of 33 and 43 kDa. After re-infection total IgG reacted with the same adult proteins but also with an adult 29 kDa protein.

Comparaçäo entre patogenia e susceptibilidade de bezerros Nelore e Holandês à infecçäo experimental com Haemonchus placei (Place, 1893) / Comparative susceptibility and pathogeny of Nelore and Holstein-Friesian calves to the experimental infection of Haemonchus placei (Place, 1893)

Dois grupos de cinco bezerros, das raças Holandesa e Nelore, com idade aproximada de nove meses, receberam por via oral uma dose única de 1.000 larvas infectantes (L3) por kg de peso corporal de Haemonchus placei. Os animais foram mantidos sob observaçäo clínica após a infecçäo. Amostras de sangue foram coletadas semanalmente por punçäo venosa, desde uma semana antes, até a oitava semana pós-infecçäo. Os estudos hematológicos abrangeram hematócrito, contagem diferencial de leucócitos, determinaçöes de hemoglobina, fibrinogênio e proteínas plasmáticas. Os exames parasitológicos compreenderam exames de fezes semanais com contagem de ovos (OPG) e estimativa de cargas de vermes na necropsia. Amostras de tecido da mucosa do abomaso foram submetidos a estudos histopatológicos. Ambos os grupos mostraram números crescentes de OPG após a quinta semana, sendo que os bezerros de raça Holandesa apresentaram maiores contagens do que os da raça Nelore. Na terceira semana pós-infecçäo e até o final do experimento, os bezerros da raça Holandesa tiveram anemia e hipoproteinemia, enquanto que os bezerros Nelore näo apresentaram alteraçöes significativas desses parâmetros. A necropsia, os bezerros da raça Holandesa apresentaram uma carga de vermes significativamente maior dos que os da raça Nelore. As alteraçöes patológicas visíveis e lesöes histopatológicas foram similares, embora macroscopicamente fossem levemente mais evidentes na raça Holandesa. Estes resultados demonstram que bezerros da raça Holandesa säo mais susceptíveis à infecçäo e aos efeitos patogênicos de H. placei do que bezerros da raça Nelore