Common factors method to predict the carcass composition tissue in kid goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of high moisture corn silage replacing dry corn on intake, apparent digestibility, production and composition of milk of dairy goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Autoclaved, previously used intravaginal progesterone devices induces estrus and ovulation in anestrous Toggenburg goats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Naturally acquired antibodies against Clostridium perfringens epsilon toxin in goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Involvement of L-glutamate and ATP in the neurotransmission of the sympathoexcitatory component of the chemoreflex in the commissural nucleus tractus solitarii of awake rats and in the working heart-brainstem preparation

Peripheral chemoreflex activation with potassium cyanide (KCN) in awake rats or in the working heart-brainstem preparation (WHBP) produces: (a) a sympathoexcitatory/pressor response; (b) bradycardia; and (c) an increase in the frequency of breathing. Our main aim was to evaluate neurotransmitters involved in mediating the sympathoexcitatory component of the chemoreflex within the nucleus tractus solitarii (NTS). In previous studies in conscious rats, the reflex bradycardia, but not the pressor response, was reduced by antagonism of either ionotropic glutamate or purinergic P2 receptors within the NTS. In the present study we evaluated a possible dual role of both P2 and NMDA receptors in the NTS for processing the sympathoexcitatory component (pressor response) of the chemoreflex in awake rats as well as in the WHBP. Simultaneous blockade of ionotropic glutamate receptors and P2 receptors by sequential microinjections of kynurenic acid (KYN, 2 nmol (50 nl)(-1)) and pyridoxalphosphate-6-azophenyl-2',4'-disulphonate (PPADS, 0.25 nmol (50 nl)(-1)) into the commissural NTS in awake rats produced a significant reduction in both the pressor (+38 +/- 3 versus +8 +/- 3 mmHg) and bradycardic responses (-172 +/- 18 versus -16 +/- 13 beats min(-1); n = 13), but no significant changes in the tachypnoea measured using plethysmography (270 +/- 30 versus 240 +/- 21 cycles min(-1), n = 7) following chemoreflex activation in awake rats. Control microinjections of saline produced no significant changes in these reflex responses. In WHBP, microinjection of KYN (2 nmol (20 nl)(-1)) and PPADS (1.6 nmol (20 nl)(-1)) into the commissural NTS attenuated significantly both the increase in thoracic sympathetic activity (+52 +/- 2% versus +17 +/- 1%) and the bradycardic response (-151 +/- 17 versus -21 +/- 3 beats min(-1)) but produced no significant changes in the increase of the frequency of phrenic nerve discharge (+0.24 +/- 0.02+0.20 +/- 0.02 Hz). The data indicate that combined microinjections of PPADS and KYN into the commissural NTS in both awake rats and the WHBP are required to produce a significant reduction in the sympathoexcitatory response (pressor response) to peripheral chemoreflex activation. We conclude that glutamatergic and purinergic mechanisms are part of the complex neurotransmission system of the sympathoexcitatory component of the chemoreflex at the level of the commissural NTS.

Ablation of NK1 receptor bearing neurons in the nucleus of the solitary tract blunts cardiovascular reflexes in awake rats

The nucleus of the solitary tract (NTS) receives primary afferents involved in cardiovascular regulation. We investigated the role of NK1-receptor bearing neurons in the NTS on cardiovascular reflexes in awake rats fitted with chronic venous and arterial cannulae. These neurons were lesioned selectively with saporin conjugated with substance P (SP-SAP, 2 mu M, bilateral injections of 20 nL in the subpostremal NTS, or 200 nL in both the subpostremal and the commissural NTS). Before, and 7 and 14 days after injection of SP-SAP, we measured changes in blood pressure and heart rate induced by i.v. injection of phenylephrine and nitroprusside (baroreceptor reflex), cyanide (arterial chemoreceptor reflex), and phenylbiguanide (Bezold-Jarisch reflex). The smaller injections with SP-SAP completely abolished NK1 receptor staining in the subpostremal NTS. The larger injections abolished NK1 receptor immunoreactivity in an area that extended from the commissural NTS to the rostral end of the subpostremal NTS. The lesions seemed to affect only a limited number of neurons, since neutral red stained sections did not show any obvious reduction in cell number. The smaller lesions reduced the gain of baroreflex bradycardia and the hypotension induced by phenylbiguanide. The larger lesions completely abolished the response to phenylbiguanide, blocked the baroreflex bradycardia induced by phenylephrine, severely blunted the baroreflex tachycardia, and blocked the bradycardia and reduced the hypertension induced by cyanide. Thus, these responses depend critically on NK1-receptor bearing neurons in the NTS. (c) 2006 Elsevier B.V. All rights reserved.

The bradycardic and hypotensive responses to serotonin are reduced by activation of GABA A receptors in the nucleus tractus solitarius of awake rats

We investigated the effects of bilateral injections of the GABA receptor agonists muscimol (GABA A) and baclofen (GABA B) into the nucleus tractus solitarius (NTS) on the bradycardia and hypotension induced by iv serotonin injections (5-HT, 2 µg/rat) in awake male Holtzman rats. 5-HT was injected in rats with stainless steel cannulas implanted bilaterally in the NTS, before and 5, 15, and 60 min after bilateral injections of muscimol or baclofen into the NTS. The responses to 5-HT were tested before and after the injection of atropine methyl bromide. Muscimol (50 pmol/50 nl, N = 8) into the NTS increased basal mean arterial pressure (MAP) from 115 ± 4 to 144 ± 6 mmHg, did not change basal heart rate (HR) and reduced the bradycardia (-40 ± 14 and -73 ± 26 bpm at 5 and 15 min, respectively, vs -180 ± 20 bpm for the control) and hypotension (-11 ± 4 and -14 ± 4 mmHg, vs -40 ± 9 mmHg for the control) elicited by 5-HT. Baclofen (12.5 pmol/50 nl, N = 7) into the NTS also increased basal MAP, but did not change basal HR, bradycardia or hypotension in response to 5-HT injections. Atropine methyl bromide (1 mg/kg body weight) injected iv reduced the bradycardic and hypotensive responses to 5-HT injections. The stimulation of GABA A receptors in the NTS of awake rats elicits a significant increase in basal MAP and decreases the cardiac Bezold-Jarisch reflex responses to iv 5-HT injections.

Nitric oxide modulates the cardiovascular effects elicited by acetylcholine in the NTS of awake rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gastrointestinal parasites in goats from Monte Castelo, Santa Catarina, Brazil

Este trabalho foi realizado com o objetivo de estimar o grau de infecção dos helmintos gastrintestinais em um rebanho caprino criado no Planalto Norte Catarinense. Foram utilizadas 12 fêmeas jovens e 11 adultas, das quais, a cada 28 dias, foram coletadas amostras de fezes diretamente do reto, totalizando 12 coletas, para quantificação de ovos por grama de fezes (OPG) e cultivo de larvas através de pool das amostras positivas do mesmo grupo. A contagem de OPG variou de zero a 10.400 nos animais jovens e de zero a 7.600 nos adultos. As médias do OPG entre as coletas foram de 583,3 a 4.441,7 no grupo jovem e de 418,2 a 2.181,8 nos adultos, sendo observados ovos da ordem Strongylida, dos gêneros Moniezia e Toxocara, bem como oocistos de coccídeos. Os animais mais jovens foram os mais acometidos, sendo o gênero Haemonchus o mais prevalente.

Detection of Toxoplasma gondii in the reproductive system of male goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrasonographic and ecobiometric findings in the eyes of adult goats

Conhecer o aspecto e as dimensões de olhos de cabras facilita o uso da ultrassonografia na avaliação de doenças oculares. O objetivo do presente trabalho foi o de avaliar os achados ultrassonográficos e ecobiométricos em olhos de cabras adultas. Ultrassonogramas nos modos A e B foram realizados em 30 caprinos adultos (60 olhos) (n=15 fêmeas intactas e n=15 machos castrados). O exame ultrassonográfico foi realizado após a instilação de colírio anestésico. Gel a base de água foi utilizado sobre o transdutor de 20 MHz posicionado-o de forma longitudinasobre a córneal, até que imagens no modo B estivessem de acordo com os ecos gerados pelo modo A. Utilizou-se análise estatística para se comparar os achados ecobiométricos entre os sexos (p<0,05). As médias com seus respectivos desvios padrões das estruturas oculares em machos e fêmeas foram, respectivamente, 3,46±0,55, 3,33±0,46mm (profundidade da câmara anterior); 8,60±0,34, 8,65±0,39mm (espessura da lente); 11,34±0,61, 11,39±0,66mm (profundidade da câmara vítrea) e 23,43±0,92, 23,39±0.86mm (comprimento axial do bulbo ocular). Não foi observada diferença significativa entre os olhos direito e esquerdo, assim como entre machos e fêmeas (p>0,05). O aspecto ultrassonográfico de olhos de cabras se assemelha com o de outras espécies domésticas e silvestres.