Effect of growth rates on hormonal and pubertal status in Nellore heifers early weaned.

This study aimed to determine the effect of growth rates on the hormonal status and puberty onset. Forty-eight Nellore heifers were weaned at 3.0 ± 0.1 (means ± standard error of the mean) months old were blocked according to body weight at weaning (84 ± 2 kg) and randomly assigned to treatments. The treatments were arranged in 2 × 2 factorial according to the feeding program. The first program was high (H; 0.79 kg/day) or control (C; 0.45 kg/day) average daily gain (ADG) from 3rd to 7th month of age (growing phase I). The second program was also high (H; 0.70 kg/day) or control (C; 0.50 kg/day) ADG from the 7th month until puberty (growing phase II), resulting in four treatments: HH (n = 13), HC (n = 10), CH (n = 13), and CC (n = 12). To achieve desired gains, heifers in high ADG program were fed ad libitum dry matter intake (DMI), and the control group was offered around 50% of ad libitum DMI of high group. All heifers received a diet with similar composition. Puberty was assessed weekly by ultrasound examination, and the largest follicle diameter was evaluated every month. Blood samples were collected to quantify leptin, insulin growth factor-1 (IGF1) and luteinizing hormone (LH). At 7 months of age, heifers in high ADG were 35 kg heavier than the control. Heifers in the HH had greater DMI compared with CH in phase II. The puberty rate at 19 months old was greater in the HH treatment (84%) than in the CC (23%), but there was no difference between HC (60%) and CH (50%) treatments. Heifers from HH treatment had greater serum leptin concentration than others at 13 months old, and serum leptin was greater in HH compared with CH and CC at 18 months old. High heifers in phase I had greater serum IGF1 concentration than the control. In addition, HH heifers had a greater diameter of the largest follicle than CC. There was no interaction between phases and age in any variable relative to the LH profile. However, the heifers' age was the main factor that increased the frequency of LH pulse. In conclusion, increasing ADG was associated with greater ADG, serum leptin and IGF-1 concentration, and puberty onset; however, LH concentration was affected mainly by age of the animal. The increasing growth rate at younger age made heifers more efficient.

Implications of growth rates and compensatory growth on puberty attainment in Nellore heifers.

This study investigated the effects of growth rates and compensatory growth on puberty attainment in Nellore heifers. Nellore heifers (n = 120), weaned at 8 ± 0.75 mo of age, were blocked by sire and BW (180 ± 8.6 kg) and assigned randomly to receive 1 of 4 treatments over a 10-mo period. Treatments included ad libitum feeding (high gain, HG), feed intake to gain 0.6 kg/d (medium gain, MG), restricted feeding (0.2 kg/d) for 4 mo followed by ad libitum feeding for 6 mo (compensatory gain, CG), and alternating periods of ad libitum and restricted feeding for 2 mo each throughout the trial (alternated CG, ACG). Puberty was assessed weekly by transrectal ultrasonography. Blood samples were collected at 8, 11, and 18 mo of age and at puberty to determine circulating concentrations of leptin. At 18 mo of age, nonpubertal heifers were treated with a puberty induction protocol using an intravaginal progestin device. There was no treatment effect (P = 0.17) on the percentage of heifers pubertal by 18 mo of age (HG: 66, MG: 40, CG: 58, and ACG: 52%), BW at puberty, and age at puberty. However, HG heifers had higher ADG (P < 0.01), dry matter intake (P < 0.01), and leptin concentrations (P = 0.03) than heifers from other groups. The response to the puberty induction protocol was similar (P = 0.90) among treatments. Regarding sire effects (genetic effects), there was an effect (P = 0.03) on the percentage of heifers pubertal by 18 mo of age and a tendency (P = 0.07) of sire effect in response to the puberty induction protocol. Compensatory growth appears to be an effective managerial approach to decrease feeding costs and stimulate puberty in Nellore heifers.

Bronchoalveolar lavage (BAL) in tapirs (Tapirus terrestris) with Mycobacterium tuberculosis / Lavado broncoalveolar (LBA) em antas (Tapirus terrestris) com Mycobacterium tuberculosis

This paper describes the in vivo Bronchoalveolar lavage (BAL) technique by endoscopy in tapirs (Tapirus terrestris) with clinical signs of tuberculosis. The technique was performed in two tapirs, male and female, from Curitiba Zoo, Paraná, Brazil. A flexible endoscope and a polyethylene catheter were used after the chemical restraint of the animals. For BAL technique, 60mL of saline 0.9% were infused with a polyethylene catheter, introduced by the endoscope's working channel, and 15mL of BAL were recovered, analyzed and submitted to cytocentrifugation. Slides were stained by Papanicolaou, periodic acid-Schiff (PAS) and Ziehl-Neelsen methods contained high quantity of inflammatory cells on light microscopy (macrophages 27.5%, lymphocytes 0.5%, neutrophis 67% and eosinophis 5%). BAL samples were submitted to culture, bacilloscopy and PCR and were negative for both animals. Based on this study, it was concluded that the bronchoalveolar lavage technique in tapirs is feasible, simple, noninvasive, practical and fast, providing an important clinical information in vivo regarding the functional status of the lower respiratory tract...

O presente trabalho descreve a técnica de lavado broncoalveolar (LBA) por endoscopia em antas (Tapirus terrestris) in vivo com sinais clínicos de tuberculose. A técnica foi realizada em duas antas, um macho e uma fêmea, provenientes do Zoológico de Curitiba, Paraná, Brasil, utilizando-se endoscópio flexível e sonda de polietileno, após a contenção química desses animais. Para o LBA, 60mL de solução fisiológica 0,9% foram infundidos com auxílio de cateter de polietileno, introduzido pelo canal de trabalho do endoscópio, e, aproximadamente, 15mL de LBA foram recuperados, acondicionados, analisados e submetidos à citocentrifugação. As lâminas foram coradas pelas técnicas de Papanicolau, ácido periódico de Schiff (PAS) e Ziehl- Neelsen, método que contém altas quantidades de células inflamatórias em microscopia (macrófagos 27,5%, linfócitos 0,5%, neutrófilos 67% e eosinófilos 5%). Amostras de LBA foram submetidas a cultura, baciloscopia e PCR e foram negativas em ambos os animais. Concluiu-se, baseado no presente trabalho, que técnica de lavado broncoalveolar é simples, não invasiva, funcional e rápida. Pode fornecer ao clínico importantes informações acerca do estado de funcionamento do aparelho respiratório in vivo...