The impact of different levels of functional oil supplementation in combination with salinomycin on growth performance and intestinal microbiota of broilers undergoing Eimeria challenge: An analysis of dynamics.

The effect of salinomycin sodium alone and in combination with functional oils on performance and microbiota of broiler infected Eimeria were evaluated. 512 broilers were randomly assigned to 4 treatments (8 replicates, 16 birds/pen): a Control group (any additives); Ionophore group: salinomycin supplementation at 66 ppm (SS66); Ionophore +0.075% Functional oil (FO) group (SS66 + FO supplementation at 750 ppm); and Ionophore +0.10% FO group (SS66 + FO supplementation at 1000 ppm). At 14 days of age, birds were gavaged with 1 mL of a saline solution containing sporulated oocysts of E. tenella, E. acervulina and E. maxima. Performance indices were measured weekly. At 28 days, intestinal content was collected for microbiota analysis. Broilers of Control group presented the worst performance indices. Broilers of Ionophore + FO (0.075% and 0.10%) groups exhibited a higher BW at 28 days of age. The supplementation of Ionophore +0.075% FO resulted in a higher relative proportion of Firmicutes and a lower proportion of Actinobacteria in the ileum-jejunum. Lactobacillaceae was the dominant family in the jejunal, and ileal microbiotas of broilers fed diets supplemented with Ionophore, Ionophore +0.075% FO and Ionophore +0.10% FO. The supplementation of ionophore yielded higher numbers of Lactobacillaceae, Enterobactereaceae and Cloritridiaceae in the cecal. Ionophore associated with FO controlled the Lactobacillaceae, Enterobactereaceae and Cloritridiaceae families present in the cecum. Therefore, the combination of salinomycin with functional oil showed synergistic effect on performance and modulation of intestinal microbiota of broilers challenged with Eimeria.

Effects of Multistrain Probiotic Supplementation on Sows' Emotional and Cognitive States and Progeny Welfare.

The intensification of production systems has resulted in detrimental effects on sow welfare, which can have an adverse influence on their offspring. Considering the relevance of the microbiota-gut-brain axis, probiotics can mitigate such impacts. To investigate the effects of the dietary inclusion of probiotics on the welfare of sows and piglets, 147 multiparous sows were randomly assigned to two groups: a control group or a group supplemented with a multistrain probiotic from the beginning of pregnancy to the end of lactation. The human-animal relationship (HAR), stereotypic behavior, position changes, salivary cortisol, and plasma serotonin levels were assessed in the sows. The piglets' back test behavior and organ weight were analyzed. The probiotic-supplemented sows exhibited a better HAR index (p = 0.017), which indicated reduced aversion towards humans. The frequency of stereotypies was not influenced by the treatments. However, the supplemented sows spent more time standing (p = 0.054) and less time lying down (p = 0.008). The cortisol level of the supplemented sows was 50% lower (p = 0.047) and the serotonin levels were 11% higher (p = 0.034) than control animals. The multistrain piglets were more passive and less resistant (p = 0.076) in the back test. The organ weights were not influenced by treatments. In conclusion, the sows supplemented with probiotics showed less fear and more motivation indicators, while their piglets showed less aggression behaviors.

Modulation of the intestinal microbiota of broilers supplemented with monensin or functional oils in response to challenge by Eimeria spp.

The objective of this study was to evaluate the effect of supplementation with 100ppm sodium monensin or 0.15% of a blend of functional oils (cashew nut oil + castor oil) on the intestinal microbiota of broilers challenged with three different Eimeria spp. The challenge was accomplished by inoculating broiler chicks with sporulated oocysts of Eimeria tenella, Eimeria acervulina, and Eimeria maxima via oral gavage. A total of 864, day-old male broiler chicks (Cobb) were randomly assigned to six treatments (eight pens/treatment; 18 broilers/pen) in a 3 × 2 factorial arrangement, composed of three additives (control, monensin or blend), with or without Eimeria challenge. Intestinal contents was collected at 28 days of age for microbiota analysis by sequencing 16s rRNA in V3 and V4 regions using the Illumina MiSeq platform. Taxonomy was assigned through the SILVA database version 132, using the QIIME 2 software version 2019.1. No treatment effects (p > 0.05) were observed in the microbial richness at the family level estimated by Chao1 and the biodiversity assessed by Simpson's index, except for Shannon's index (p < 0.05). The intestinal microbiota was dominated by members of the order Clostridiales and Lactobacillales, followed by the families Ruminococcaceae, Bacteroidaceae, and Lactobacillaceae, regardless of treatment. When the controls were compared, in the challenged control group there was an increase in Erysipelotrichaceae, Lactobacillaceae, Bacteroidaceae, Streptococcaceae, and Peptostreptococcaceae, and a decrease in Ruminococcaceae. Similar results were found for a challenged group that received monensin, while the blend partially mitigated this variation. Therefore, the blend alleviated the impact of coccidiosis challenge on the microbiome of broilers compared to monensin.

Farelo de arroz integral processado por infravermelho em diferentes períodos de tempo na dieta de frangos de corte / Full fat rice bran processed by infrared in different time periods in broiler diets

Trata-se de um estudo de metabolizabilidade em frangos de corte Cobb, para testar os benefícios do processamento térmico por infravermelho no farelo de arroz integral (FAI) em diferentes tempos (0, 6, 8 e 10min). O experimento foi realizado através do método de substituição, em que 20% de uma dieta referência (DR) a base de milho e farelo de soja foi substituída pelos FAIs processados em diferentes tempos. Usou-se um delineamento experimental completamente casualizado com 5 tratamentos e 10 repetições de uma ave. Entre 21 e 28 dias de idade das aves, foi feita a coleta total de excretas, com 4 dias de adaptação às dietas e 3 de coleta. A dieta com FAI 6min teve melhor aproveitamento em relação às demais e foi a única que não piorou os coeficientes de metabolizabilidade em relação à DR. Na comparação da metabolizabilidade dos ingredientes isolados, não houve diferenças estatísticas. Porém, conforme aumentou o tempo de processamento, diminuiu a solubilidade e a metabolizabilidade da proteína. O processamento térmico por infravermelho não foi capaz de melhorar a metabolizabilidade do FAI para frangos de corte.

This is a study of metabolizability in broilers Cobb, to test rice bran infrared (RB) thermal processed at different times (0, 6, 8 and 10min). It was used a reference diet (RD) based on corn and soybean in which 20% of RB was included. The experiment design was completely randomized, with 5 treatments and 10 replicates. Each replicate was a 21 day old bird. After 4 days of diet adaptation, total excreta was collected, during 3 subsequent days. Diet with RB processed at 6 was better used than the others, the only one that did not differ from RD. Comparing RB processing times, there were no significant difference between them, regarding digestibility. Processing time was negatively related to protein solubility and protein metabolizability. Infrared heat processing was not able to improve FAI metabolizability for broilers.

Detection of vanC1 gene transcription in vancomycin-susceptible Enterococcus faecalis.

Here we report the presence and expression levels of the vanC1 and vanC(2/3) genes in vancomycin-susceptible strains of Enterococcus faecalis. The vanC1 and vanC(2/3) genes were located in the plasmid DNA and on the chromosome, respectively. Specific mRNA of the vanC1 gene was detected in one of these strains. Additionally, analysis of the vanC gene sequences showed that these genes are related to the vanC genes of Enterococcus gallinarum and Enterococcus casseliflavus. The presence of vanC genes is useful for the identification of E. gallinarum and E. casseliflavus. Moreover, this is the first report of vanC mRNA in E. faecalis.

Detection of vanC 1 gene transcription in vancomycin-susceptible Enterococcus faecalis

Here we report the presence and expression levels of the vanC 1 and vanC 2/3 genes in vancomycin-susceptible strains of Enterococcus faecalis. The vanC 1 and vanC 2/3 genes were located in the plasmid DNA and on the chromosome, respectively. Specific mRNA of the vanC 1 gene was detected in one of these strains. Additionally, analysis of the vanC gene sequences showed that these genes are related to the vanC genes of Enterococcus gallinarum and Enterococcus casseliflavus. The presence of vanC genes is useful for the identification of E. gallinarum and E. casseliflavus. Moreover, this is the first report of vanC mRNA in E. faecalis.

Digestibilidade de nutrientes e balanço de Ca e P em suínos recebendo dietas com ácido butírico, fitase e diferentes níveis de cálcio / Nutrient digestibility and Ca and P balance in pigs receiving butyric acid, phytase and different calcium levels

Estudou-se o uso do ácido butírico (AB) e da fitase em dietas de suínos na fase de crescimento, variando no nível de cálcio. O experimento foi subdivido no tempo em dois períodos de 17 dias, sendo três de adaptação e 14 de mensurações. Em cada período, foram utilizados 16 suínos machos castrados, com peso de 24,6±0,7kg no primeiro e 43,2±1,77kg no segundo período. As dietas diferiam no nível de cálcio (0,5 ou 0,72 por cento), de AB (0 ou 0,3 por cento de butirato de sódio 84 por cento) e de fitase (0 ou 500 FTU kg-1, fitase de origem bacteriana derivada de Escherichia coli). O delineamento foi em blocos casualizados (períodos), em decomposição fatorial 2x2x2, com quatro repetições. Foram avaliadas a digestibilidade aparente dos nutrientes e da energia bruta e o balanço de Ca e P. O AB melhorou a digestibilidade da proteína bruta, mas, de forma individual ou em combinação com a fitase, não aumentou a retenção de minerais. A fitase aumentou a retenção de P, reduzindo sua excreção fecal e urinária. O menor nível de Ca na dieta proporcionou maior retenção de Ca e menor retenção de P, em decorrência do aumento da excreção de P na urina (P<0,0001). Apesar de ter melhorado a digestibilidade protéica, o AB não aumentou a retenção de minerais, nem teve efeito aditivo ao uso de fitase, enquanto que a fitase apresentou efeito positivo para retenção de P.

It was studied the use of butyric acid (BA) and phytase in growing pigs diets, varying calcium level. The experiment was divided into two periods of time, of 17 days, with 3 days of adaptation and 14 of measurements. In each period, it was used 16 barrows weighing 24.6±0.7kg in the first and 43.2±1.77kg in the second. Diets were different in calcium level (0.5 or 0.72 percent), AB (0 or 0.3 percent sodium butyrate 84 percent) and phytase (0 or 500FTU kg-1 phytase of bacterial origin derived from Escherichia coli). The experimental design was in randomized blocks (periods), decomposed in 2x2x2 factorial, with four replications. It was evaluated the apparent digestibility of nutrients, gross energy and balance of Ca and P. AB improved crude protein digestibility, but individually or in combination with phytase did not increase minerals retention. Phytase increased P retention by reducing urinary and fecal excretion. The lowest diet calcium level provided higher Ca retention and lower P retention as a result of increased P excretion in urine (P<0.0001). Despite improving protein digestibility, AB did not increase mineral retention and didn't have an additive effect with the use of phytase, while phytase had positive effect on retention of P.

Inclusão de ácidos graxos de cadeia curta em diferentes níveis de cálcio na dieta de frangos de corte / Inclusion of short chain fatty acids and different calcium levels in diets for broilers

Noventa e seis frangos de corte, machos, de linhagem Cobb e de 21 aos 31 dias de idade foram alimentados com a inclusão de ácidos graxos de cadeia curta (AGCC) e diferentes níveis de cálcio. Foram determinados o balanço de cálcio (Ca) e de fósforo (P), a metabolizabilidade da matéria seca (MetMS), matéria orgânica (MetMO) e matéria mineral, da energia bruta e proteína bruta da dieta, a porcentagem de cinzas nas tíbias ( por centoCzT), além do desempenho das aves. Utilizou-se um esquema fatorial 5x4 (sem ácido orgânico; ácido fórmico, ácido acético, ácido propiônico e ácido butírico) x (0,40, 0,59, 0,78 e 0,97 por cento de Ca), com um delineamento completamente casualizado. O acréscimo de Ca na dieta afetou de forma positiva e quadrática o balanço de Ca e P, sendo os melhores níves estimados em 0,87 e 0,75 por cento de Ca dietético, respectivamente, e afetou positiva e linearmente a MetMS e a MetMO, bem como a por centoCzT. Houve redução na eficiência de retenção do Ca, de forma quadrática, com o aumento do nível de cálcio. Os AGCC não apresentam efeitos detectáveis sobre as respostas estudadas e nem interação com os níveis dietéticos de Ca utilizados. A melhor exigência estimada de Ca dietético, considerando o balanço de cálcio, foi de 0,87 por cento.

Ninety six Cobb male broilers from 21 to 31 days of age were fed including short chain fatty acids (SCFA) and different level of calcium. Calcium (Ca), phosphorus (P), balance, dry, organic and mineral matter metabolizability, crude energy and crude protein metabolizability, tibia ash percentage and animal performance were measured. Experimental diets were assigned in a 5x4 factorial arrangement (without acids, formic acid, acetic acid, propionic acid and butyric acid) x (0.40, 0.59, 0.78 and 0.97 percent of Ca) in a randomized completely design. Increasing Ca levels affected positively and in a quadratic form Ca and P balance and the best levels were estimated at 0,87 percent and 0,75 percent of Ca dietary, respectively and affected linearly dry, organic matter metabolizability and tibia ash percentage. However, the efficiency of Ca retention was decreased quadratically with the increase of Ca level. The SCFA did not show detectable effects on the studied responses, and no interaction with dietary levels of Ca used. The estimated Ca requirement considering calcium balance was 0.87 percent.

Desempenho e peso de frações corporais, na suplementação crescente de lisina, dos 19 aos 40 dias de idade em frangos de corte / Performance and weight of body components of broilers supplemented with increasing lysine levels from 19 to 40 days of age

Este estudo foi conduzido para avaliar o desempenho e o peso das frações corporais de frangos de corte, recebendo dietas com níveis crescentes de lisina digestível (Lis dig) (0,70; 0,80; 0,90; 1,00; 1,055; 1,11; 1,165 e 1,22 por cento). Foram utilizados 320 frangos machos da linhagem CobbXCobb500, dos 19 aos 40 dias de idade. Foram utilizadas duas dietas basais, com 19,0 e 20,5 por cento de proteína bruta; a primeira para os quatro níveis mais baixos de Lis dig e a segunda, para os quatro restantes. As dietas foram formuladas de forma a manter constante a relação de aminoácidos digestíveis Met, Arg e Tre com a Lis dig. Foram avaliados o peso médio, o ganho de peso, o consumo de ração, o consumo de lisina e a conversão alimentar aos 26, 33 e 40 dias de idade. Também nessas idades, o peso das frações corporais, carcaça, peito, coxa, perna, dorso+asa+pescoço+cabeça+patas +gordura abdominal (D+A), vísceras+sangue (V+S) e penas foi determinado. O ganho de peso e a conversão alimentar apresentaram respostas lineares positivas em função dos níveis de Lis dig. Já o consumo de ração não foi influenciado pelos tratamentos. As respostas das frações corporais foram lineares crescentes para peso do peito e da carcaça, em todos os períodos avaliados (26, 33 e 40 dias), com níveis ótimos de Lis dig ≥1,22 por cento. A mesma resposta se deu para peso da coxa aos 26 e 40 dias, para D+A, aos 33 e 40 dias e para peso de perna, aos 26 e 33 dias, enquanto, para peso de perna, aos 40 dias, a resposta foi quadrática, ainda que com nível ótimo de Lis dig. ≥1,22 por cento. Sugere-se que níveis mais elevados de lisina digestível, nas dietas de frangos machos da linhagem Cobb500, sejam estudados.

This study was conducted to evaluate broiler growth performance and body fraction weights , in response to increasing levels of dietary digestible lysine (dig Lys) (0.70, 0.80, 0.90, 1.00, 1.055, 1.11, 1.165 and 1.22 percent). Three hundred and twenty male broilers CobbXCobb500 were used from 19 to 40 days of age. Two basal diets were used with 19 and 20.5 percent of crude protein. The first basal diet was set for the four lower levels of dig Lys, and the second for the other four levels. The diets were formulated to maintain in a constant ratio the digestible Met, Arg and Tre with the dig. Lys. Body weight, weight gain, feed intake, Lys intake and feed conversion were evaluated at 26, 33 and 40 days of age. At these same ages body weight fractions as carcass, breast, thigh, leg, back+wing+thigh wing+head+neck (D+A), viscera+blood and feathers were evaluated:. Weight gain and feed conversion increased positively and linearly with the increasing dig Lys. In other hand, feed intake was not influenced by treatments. Breast and carcass fractions increased linearly in all evaluated periods (26, 33 and 40 days of age), with the best estimated level of dig Lys ≥1.22 percent. The same response was seem for thigh at 26 and 40 days, for D+A at 33 and 40 days, for leg at 26 and 33 and a quadratic response was observed for leg at 40 days, although the best estimated level of dig Lys was equal or higher than 1.22 percent. It is suggested more studies with higher levels of dig Lys in Cobb 500 male broiler chicken diets.

Desempenho, metabolismo e níveis plasmáticos de colesterol e triglicerídeos em frangos de corte alimentados com óleo ácido e óleo de soja / Performance, metabolism and plasma levels of cholesterol and triglycerides in broilers chickens fed with acidulated soybean soapstock and soybean oil

Neste trabalho são relatados três experimentos (EXP) realizados, sendo dois de desempenho e um de metabolismo. O primeiro experimento de desempenho utilizou 384 pintos de corte machos, da linhagem Cobb 500, e foi conduzido com animais de um a 20 dias de idade. O segundo EXP de desempenho foi realizado com as mesmas aves, após homogeneização de todas elas, com 21 a 34 dias de idade, utilizando-se 256 frangos. O ensaio de metabolismo usou 32 frangos e foi realizado com animais de 21 a 34 dias de idade. Testou-se o óleo ácido de soja (OAS) e o óleo degomado de soja (ODS) incluídos na dieta em quatro níveis (2, 3, 4 e 5 por cento), constituindo oito tratamentos com quatro repetições cada, dispostos em fatorial 2x4. Foram avaliados o desempenho e o metabolismo das aves e o coeficiente de metabolismo da matéria seca (CMMS), da gordura bruta (CMGB) e da energia bruta (CMEB) das dietas, além de teores de triglicerídios e colesterol sanguíneo no 34o dia de idade. Nenhuma interação foi observada entre os óleos e os níveis utilizados (P>0,05). Com o aumento do nível de óleo na dieta, observou-se maior peso final das aves (P<0,01) e melhor conversão alimentar (CA) (P<0,01). No EXP de desempenho com animais de um a 21 dias, ocorreu redução no consumo de ração (P<0,01) com a adição de óleo, mas não no EXP com animais de 21 a 34 dias. No ensaio de metabolismo, aves que receberam OAS apresentaram melhor CMMS (P<0,01) em relação ao ODS. O aumento do nível de inclusão de óleo, independentemente do tipo, melhorou o CMMS (P<0,01) e o CMGB (P<0, 01) das dietas. Observou-se maiores níveis de triglicerídios no sangue das aves com maiores níveis de óleo (P<0,01). O OAS mostrou eficiência relativa de 93 e 90 por cento nos EXP de desempenho com animais de um a 20 e de 21 e 34 dias, respectivamente, com base na CA e de 95 por cento, comparado ao ODS, com base em análise de regressão entre o nível de óleo adicionado (X) e o CMGB (Y) determinado no ensaio...

Three experiments (EXP) were carried on; in two of them the focus was performance and the third consisted in a metabolism study. The first EXP used 384 male Cobb 500 strain chicks and was conducted from one to 20 days of age. The second EXP was conducted with the same birds after all of them were homogenized, from 21 to 34 days, using 256 broilers. The metabolism assay utilized 32 broilers and was carried on from 21 to 34 days. Acidulated soybean soapstock (ASS) and soybean oil (SO) included in four levels (2; 3; 4 and 5 percent) were compared, forming eight treatments with four replication each, arranged in a 2x4 factorial. Performance, diet coefficient of metabolism of dry matter (CMDM), of crude fat (CMCF) and of gross energy (CMCE) and also the contents of triglycerides and blood serum cholesterol on the 34th day were evaluated. There was no interaction between oil type and inclusion levels for any response. Increasing oil level in the diet higher body weight (P<0.01) and better feed conversion (FC) (P<0.01) were observed. Only in the first performance EXP, but not in the EXP from 21 to 34 days, reduction in feed intake (P<0.01) by adding oil was observed. In the metabolism assay, birds receiving ASS presented better CMDM (P<0.01), related to SO. Increasing in oil level improved CMDM (P<0.01) and CMCF (P<0.01) of the diets. Higher levels of triglycerides were noticed in the blood serum of birds receaving higher levels of oil (P<0.01). The ASS showed RE of 93 and 90 percent in the performance EXP from 1 to 20 and 21 to 34 days, respectively, based on FC and of 95 percent, compared to SO, based on regression analysis between oil level added (X) and CMCF (Y), determined in the metabolism assay. ASS is a good energetic source for broiler diets, presenting energetic value a bit lower of the SO.

Feeding different levels of vitamin E and selenium has no effect on serum immunoglobulin Y (IgY) production by layers vaccinated against Escherichia coli and avian encephalomyelitis virus

The effects of vitamin E and selenium (Se) supplementation on the immunity of hens vaccinated against a mixture of six swine-pathogenic Escherichia coli (EC) and avian encephalomyelitis virus (AEV) were studied. Antibody production (AbP) was evaluated in ninety 49 to 57-week-old H&N Nick Chick hens fed diets containing 14IU Vitamin E kg-1 (basal diet), 27, 59, 111, or 111IU vitamin E kg-1 + 0.56ppm Se supplementation. At 51 wks of age, half of the hens were vaccinated against EC, and all birds were vaccinated against AEV. At 53-weeks of age, the birds received a second dose of EC vaccine. Blood samples were collected weekly and serum was analyzed by ELISA for anti-EC IgY and was expressed as optical density (OD). Vaccinated hens had higher serum OD than the non-vaccinated hens (P<0.05). Vaccinated hens fed 27 and 59IU of vitamin E/kg had a higher (P<0.05) serum OD than hens fed 111IU + Se. Neither EC nor AEV seem to be appropriate models for the study of the influence of micronutrients on immune responsiveness of older hens.

Os efeitos da suplementação de vitamina E e Selênio (Se) na imunidade de galinhas vacinadas contra uma mistura de 6 sorotipos patogênicos de Escherichia coli (EC) e o vírus da encefalomielite aviária (VEA) foram estudados. A produção de anticorpos foi avaliada em galinhas H&N Nick Chick durante a 49a e 57a semanas de vida. As aves foram alimentadas com dietas contendo 14UI de Vitamina E kg-1 (dieta basal), 27, 59, 111 e 111UI de Vitamina E kg-1 + 0,56ppm Se suplementar. As 51 semanas de idade, metade das galinhas foi vacinada contra EC, e todas as aves foram vacinadas contra VEA. As 53 semanas, as aves receberam a segunda vacina contra EC. Amostras de sangue foram coletadas semanalmente e o soro foi analisado por ELISA para anti-EC IgY e expresso como densidade óptica (DO). Galinhas vacinadas tiveram maior DO do que as não-vacinadas (P<0,05). Aves vacinadas que receberam 27 e 59 UI de vitamina E/kg tiveram maior DO do soro (P<0,05) do que as alimentadas com 111 UI + Se. Os antígenos utilizados mostraram não ser modelos satisfatórios para estudar a influência de micronutrientes na resposta imune de aves mais velhas.

Performance comparison between broilers positive and negative for antibodies against the chicken anemia virus

O vírus da anemia das galinhas (CAV - "chicken anemia virus") está presente em praticamente todos os países investigados, inclusive no Brasil. O objetivo deste trabalho foi determinar qual a diferença de desempenho, comparando frangos positivos (progênie de matrizes vacinadas ou com infecção natural) com frangos negativos para a presença de anticorpos contra o CAV, no sistema atual de criação intensiva. Como resultado, foi observado que os frangos negativos foram significativamente mais pesados que os frangos positivos. Os machos negativos tiveram um peso final 5,43% superior ao dos machos positivos. Não houve diferença significativa entre os tratamentos em relação aos parâmetros de mortalidade e conversão alimentar. Este estudo indicou que a presença de anticorpos contra o CAV em frangos de corte, seja através da vacinação ou infecção natural das matrizes, não gerou uma progênie com melhor desempenho nas condições de criação testadas.

Performance comparison between broilers positive and negative for antibodies against the chicken anemia virus

The chicken anemia virus (CAV) is present in virtually every country investigated, Brazil including. The aim of this study was to determine what the difference in performance is between positive (progeny of breeders vaccinated or with natural infection) and negative broilers to the presence of antibodies against the CAV in currently intensive raising systems. As a result, it was observed that negative broilers were significantly heavier than positive broilers. Negative males had a final weight 5.43% higher than positive males. There was no significant difference among different treatments in relation to parameters as mortality and feeding conversion. These study indicated that the presence of antibodies against CAV in broilers - may it be through vaccination or natural infection of breeders - did not generate progeny with superior performance under the tested raising conditions.

O vírus da anemia das galinhas (CAV - "chicken anemia virus") está presente em praticamente todos os países investigados, inclusive no Brasil. O objetivo deste trabalho foi determinar qual a diferença de desempenho, comparando frangos positivos (progênie de matrizes vacinadas ou com infecção natural) com frangos negativos para a presença de anticorpos contra o CAV, no sistema atual de criação intensiva. Como resultado, foi observado que os frangos negativos foram significativamente mais pesados que os frangos positivos. Os machos negativos tiveram um peso final 5,43% superior ao dos machos positivos. Não houve diferença significativa entre os tratamentos em relação aos parâmetros de mortalidade e conversão alimentar. Este estudo indicou que a presença de anticorpos contra o CAV em frangos de corte, seja através da vacinação ou infecção natural das matrizes, não gerou uma progênie com melhor desempenho nas condições de criação testadas.