RESUMO

This study aimed to evaluate the effects of partially replacing corn silage (CS) with whole-plant soybean silage (SS) or black oat silage (OS) on nutrient intake and digestibility, in vitro neutral detergent fiber degradability of silages, feeding behavior, rumen fermentation, and performance of dairy cows. Twenty-four lactating Holstein cows (6 of which were rumen-cannulated) with 32.5 ± 4.92 kg/d milk yield, 150 ± 84.8 days in milk, and 644 ± 79.0 kg of body weight were used in a 3 × 3 Latin square design to evaluate the following treatments: (1) corn silage diet (CSD): using corn silage as the only forage source in the diet [48% dietary dry matter (DM)]; (2) whole-plant soybean silage diet (SSD): SS replacing 16% of corn silage from CSD; and (3) black oat silage diet (OSD): OS replacing 16% of corn silage from CSD. The inclusion of OS and SS decreased intakes of DM, organic matter, and crude protein. Corn silage had the greatest in vivo effective degradability of DM, and SS had the least effective degradability of neutral detergent fiber. The OSD treatment decreased milk and protein yields, whereas SSD increased rumen ammonia nitrogen concentration compared with the other diets. Cows fed OSD exhibited a greater preference for feed with small particles (<4 mm) compared with those fed SSD. Cows fed treatments containing either SS or OS at the expense of CS had increased rumination and chewing activities. Although replacing CS with OS and SS reduced feed intake, SS had no effect on productive performance of dairy cows.

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RESUMO

This study aimed to evaluate the effects of increasing dietary levels of microalgae (ALG), rich in docosahexaenoic acid (DHA; All-G-Rich, Alltech, Nicholasville, KY), in isolipidic diets, on animal performance, nutrient digestibility, ruminal fermentation, milk fatty acid profile, energy balance, microbial protein synthesis, and blood serum metabolites in mid-lactating dairy cows. Twenty-four Holstein cows [130.3 ± 15.4 d in milk, and 30.8 ± 0.543 kg/d of milk yield (mean ± standard error)] were used in a 4 × 4 Latin square design experiment to evaluate the following treatments: control diet, without addition of ALG; and increasing levels of ALG [2, 4, and 6 g/kg of dry matter (DM)]. The ALG decreased DM intake and increased total-tract DM apparent digestibility. A tendency was observed for a quadratic effect on total-tract NDF digestibility by ALG inclusion, with peak value of the quadratic response at 4.13 g/kg of DM dose. Moreover, ALG increased ruminal pH and decreased acetate and total volatile fatty acid concentrations. Fat-corrected milk and energy-corrected milk were quadratically affected, and a tendency for a milk yield effect was observed when ALG levels increased, whereas maximal yields were observed with intermediate doses. Milk fat, protein, and lactose concentrations were diminished, whereas productive efficiency was improved by the increase of ALG levels. Saturated fatty acid proportions were decreased, whereas polyunsaturated fatty acid proportions were increased when ALG was fed. There was low DHA transfer into milk; however, ALG inclusion decreased C18:0, C18:1 cis-9, C18:2 cis-9,12, and C18:3 cis-9,12,15 proportions, and increased C18:2 cis-9,trans-11, C18:1 trans-9, and C18:1 trans-11 proportions. Gross energy intake was decreased, whereas no effect was observed on digestible, metabolizable, or net energy intake. The ALG inclusion quadratically affected the microbial protein synthesis, with maximal enhancement at 3.24 g/kg of DM dose, and also increased serum cholesterol concentration. Under the conditions of this experiment, the inclusion of ALG in diets for mid-lactating dairy cows decreased feed intake and increased nutrient digestibility, improving productive efficiency and modifying milk fatty acid profile. Estimated intermediate doses (1.22 to 2.90 g/kg of DM) of DHA-rich ALG may be beneficial to milk, fat-corrected milk, and energy-corrected milk yields, and is recommended for dairy cows.

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A Artrite Encefalite Caprina se caracteriza por ser multissistêmica e infecciosa, causada por um lentivírus. O estudo teve como objetivo avaliar a transmissibilidade do Lentivírus Caprino, para fêmeas e sua prole, por meio de sêmen infectado experimentalmente. Para tanto, onze fêmeas livres de CAEV foram inseminadas artificialmente com sêmen de bode livre de CAEV ao qual foi adicionado CAEV-Cork para obter título infectante com carga viral em 105 TCID50/ml. (grupo experimental 1). Destas, seis obtiverem prenhez confirmada, e a sua prole (n=6) constituiu o grupo experimental 2. Duas cabras livres de CAEV foram inseminadas artificialmente com sêmen do mesmo bode, sem o inócuo viral, constituindo-se o grupo controle. O diagnóstico da infecção pelo Lentivírus Caprino, foi realizado por IDGA, cELISA e nested-PCR. As fêmeas foram monitoradas durante 210 dias pós inseminação artificial. Já as proles foram imediatamente separadas das mães após o nascimento, e monitoradas nos momentos hora zero, aos quinze dias de idade e mensalmente, até doze meses de idade. Em relação às cabras, 56,96%(9/158) apresentaram positividade para cELISA, 24,05% (38/158) foram positivas a IDGA e nenhuma para nested-PCR. Em relação aos cabritos, 11,28% (15/133) amostras positivas para nested-PCR, 5,26% (7/133) amostras positivas para IDGA e nenhum para cELISA. As proles do grupo controle apresentaram resultados negativos para as três técnicas. A positividade encontrada em nested-PCR pode indicar grande importância para identificação de animais infectados, porém soronegativos, em situações de soroconversão tardia. De acordo com os resultados, concluiu-se que há a transmissão do Lentivírus caprino para a prole e para as mães pelo sêmen infectado.(AU)

Caprine Arthritis Encephalitis is a multisystemic infectious disease, caused by a lentivirus. The objective of this study was to evaluate the transmissibility of caprine lentivirus to goats and their offspring, through experimentally infected semen. Therefore, eleven free-CAEV goats were artificially inseminated using semen from a free-CAEV buck experimentally infected with CAEV-Cork strain (experimental group one). Pregnancy was confirmed in only six goats and their offspring (n=6) constituted the experimental group two. Two free-CAEV females were artificially inseminated with semen from the same seronegative buck, without viral inoculum to constitute the control group. The diagnosis of caprine lentivirus infection was performed using AGID, cELISA and nested-PCR. All females were monitored for 210 days after artificial insemination. Kids were immediately separated from their mothers after birth, and monitored at zero time, 15 days old and monthly until 12 months old. Regarding goat samples, 56.96% (9/159) were positive in cELISA, 24.05% (38/158) were positive in IDGA and none was positive in nested-PCR. Regarding to the offspring samples, 11.28% (15/133) and 5.26% (7/133) were positive in nested-PCR and IDGA, respectively, while no sample was positive in cELISA. The control group showed no positives in the three techniques. The positivity observed to nested-PCR may show its importance to identify infected, but seronegative animals, in late seroconversion situations. According to results, the transmission of caprine lentivirus to offspring and their mothers through infected semen is possible.(AU)

Assuntos

RESUMO

A Artrite Encefalite Caprina se caracteriza por ser multissistêmica e infecciosa, causada por um lentivírus. O estudo teve como objetivo avaliar a transmissibilidade do Lentivírus Caprino, para fêmeas e sua prole, por meio de sêmen infectado experimentalmente. Para tanto, onze fêmeas livres de CAEV foram inseminadas artificialmente com sêmen de bode livre de CAEV ao qual foi adicionado CAEV-Cork para obter título infectante com carga viral em 105 TCID50/ml. (grupo experimental 1). Destas, seis obtiverem prenhez confirmada, e a sua prole (n=6) constituiu o grupo experimental 2. Duas cabras livres de CAEV foram inseminadas artificialmente com sêmen do mesmo bode, sem o inócuo viral, constituindo-se o grupo controle. O diagnóstico da infecção pelo Lentivírus Caprino, foi realizado por IDGA, cELISA e nested-PCR. As fêmeas foram monitoradas durante 210 dias pós inseminação artificial. Já as proles foram imediatamente separadas das mães após o nascimento, e monitoradas nos momentos hora zero, aos quinze dias de idade e mensalmente, até doze meses de idade. Em relação às cabras, 56,96%(9/158) apresentaram positividade para cELISA, 24,05% (38/158) foram positivas a IDGA e nenhuma para nested-PCR. Em relação aos cabritos, 11,28% (15/133) amostras positivas para nested-PCR, 5,26% (7/133) amostras positivas para IDGA e nenhum para cELISA. As proles do grupo controle apresentaram resultados negativos para as três técnicas. A positividade encontrada em nested-PCR pode indicar grande importância para identificação de animais infectados, porém soronegativos, em situações de soroconversão tardia. De acordo com os resultados, concluiu-se que há a transmissão do Lentivírus caprino para a prole e para as mães pelo sêmen infectado.(AU)

Caprine Arthritis Encephalitis is a multisystemic infectious disease, caused by a lentivirus. The objective of this study was to evaluate the transmissibility of caprine lentivirus to goats and their offspring, through experimentally infected semen. Therefore, eleven free-CAEV goats were artificially inseminated using semen from a free-CAEV buck experimentally infected with CAEV-Cork strain (experimental group one). Pregnancy was confirmed in only six goats and their offspring (n=6) constituted the experimental group two. Two free-CAEV females were artificially inseminated with semen from the same seronegative buck, without viral inoculum to constitute the control group. The diagnosis of caprine lentivirus infection was performed using AGID, cELISA and nested-PCR. All females were monitored for 210 days after artificial insemination. Kids were immediately separated from their mothers after birth, and monitored at zero time, 15 days old and monthly until 12 months old. Regarding goat samples, 56.96% (9/159) were positive in cELISA, 24.05% (38/158) were positive in IDGA and none was positive in nested-PCR. Regarding to the offspring samples, 11.28% (15/133) and 5.26% (7/133) were positive in nested-PCR and IDGA, respectively, while no sample was positive in cELISA. The control group showed no positives in the three techniques. The positivity observed to nested-PCR may show its importance to identify infected, but seronegative animals, in late seroconversion situations. According to results, the transmission of caprine lentivirus to offspring and their mothers through infected semen is possible.(AU)

Assuntos

RESUMO

ABSTRACT: Caprine Arthritis Encephalitis is a multisystemic infectious disease, caused by a lentivirus. The objective of this study was to evaluate the transmissibility of caprine lentivirus to goats and their offspring, through experimentally infected semen. Therefore, eleven free-CAEV goats were artificially inseminated using semen from a free-CAEV buck experimentally infected with CAEV-Cork strain (experimental group one). Pregnancy was confirmed in only six goats and their offspring (n=6) constituted the experimental group two. Two free-CAEV females were artificially inseminated with semen from the same seronegative buck, without viral inoculum to constitute the control group. The diagnosis of caprine lentivirus infection was performed using AGID, cELISA and nested-PCR. All females were monitored for 210 days after artificial insemination. Kids were immediately separated from their mothers after birth, and monitored at zero time, 15 days old and monthly until 12 months old. Regarding goat samples, 56.96% (9/159) were positive in cELISA, 24.05% (38/158) were positive in IDGA and none was positive in nested-PCR. Regarding to the offspring samples, 11.28% (15/133) and 5.26% (7/133) were positive in nested-PCR and IDGA, respectively, while no sample was positive in cELISA. The control group showed no positives in the three techniques. The positivity observed to nested-PCR may show its importance to identify infected, but seronegative animals, in late seroconversion situations. According to results, the transmission of caprine lentivirus to offspring and their mothers through infected semen is possible.

RESUMO: A Artrite Encefalite Caprina se caracteriza por ser multissistêmica e infecciosa, causada por um lentivírus. O estudo teve como objetivo avaliar a transmissibilidade do Lentivírus Caprino, para fêmeas e sua prole, por meio de sêmen infectado experimentalmente. Para tanto, onze fêmeas livres de CAEV foram inseminadas artificialmente com sêmen de bode livre de CAEV ao qual foi adicionado CAEV-Cork para obter título infectante com carga viral em 105 TCID50/ml. (grupo experimental 1). Destas, seis obtiverem prenhez confirmada, e a sua prole (n=6) constituiu o grupo experimental 2. Duas cabras livres de CAEV foram inseminadas artificialmente com sêmen do mesmo bode, sem o inócuo viral, constituindo-se o grupo controle. O diagnóstico da infecção pelo Lentivírus Caprino, foi realizado por IDGA, cELISA e nested-PCR. As fêmeas foram monitoradas durante 210 dias pós inseminação artificial. Já as proles foram imediatamente separadas das mães após o nascimento, e monitoradas nos momentos hora zero, aos quinze dias de idade e mensalmente, até doze meses de idade. Em relação às cabras, 56,96%(9/158) apresentaram positividade para cELISA, 24,05% (38/158) foram positivas a IDGA e nenhuma para nested-PCR. Em relação aos cabritos, 11,28% (15/133) amostras positivas para nested-PCR, 5,26% (7/133) amostras positivas para IDGA e nenhum para cELISA. As proles do grupo controle apresentaram resultados negativos para as três técnicas. A positividade encontrada em nested-PCR pode indicar grande importância para identificação de animais infectados, porém soronegativos, em situações de soroconversão tardia. De acordo com os resultados, concluiu-se que há a transmissão do Lentivírus caprino para a prole e para as mães pelo sêmen infectado.