RESUMO

This study aimed to evaluate the residual effect of narasin on intake and ruminal fermentation parameters in Nellore cattle fed a forage-based diet. Thirty rumen-cannulated Nellore steers [initial body weight (BW) = 281 ± 21 kg] were allocated to individual pens in a randomized complete block design, with 10 blocks and 3 treatments, defined according to the fasting BW at the beginning of the experiment. The animals were fed a forage-based diet containing 99% Tifton-85 haylage and 1% concentrate. Within blocks, animals were randomly assigned to one of three treatments: (1) forage-based diet without addition of narasin (CON; n = 10), (2) CON diet plus 13 mg of narasin/kg DM (N13; n = 10), or (3) CON diet plus 20 mg of narasin/kg DM (N20; n =10). The experiment lasted 156 d and was divided into two periods. The first period lasted 140 d and consisted of the daily supply of narasin. In the second period (last 16 d), the animals were not supplemented with narasin when the residual effect of the additive was evaluated. The treatments were evaluated by linear and quadratic orthogonal contrasts. The results were reported as least square means and the effect was considered significant when P ≤ 0.05. No treatment × day interaction was identified for dry matter intake (P = 0.27). There was a treatment × day (P ≤ 0.03) interaction after narasin removal for the molar proportion of acetate, propionate, ac:prop ratio, and ammonia nitrogen. The inclusion of narasin decreased linearly (P < 0.01) the molar proportion of acetate (P < 0.01), and this effect persisted until day 5 after narasin withdrawal (P < 0.01). Narasin inclusion linearly increased the molar proportion of propionate (P < 0.04), and linearly decreased (P < 0.01) ac:prop ratio up to 5 d after removing narasin from the diets. No treatment effects were observed (P > 0.45) on days 8 and 16 after the withdrawal. Narasin linearly decreased ammonia nitrogen up to 1 day after withdrawal (P < 0.01). In conclusion, the use of narasin for a prolonged period (140 d) resulted in a residual effect on rumen fermentation parameters after the removal of the additive from the diets.

RESUMO

The study aimed to evaluate if the frequency of narasin supplementation impacts dry matter intake, ruminal fermentation parameters, and apparent digestibility of nutrient in Nellore (Bos indicus) steers fed forage-based diets. A total of 32 rumen-cannulated Nellore steers (initial body weight [BW] = 317 ± 27 kg; age =18 ± 1 mo) were assigned to individual pens in a randomized complete block design according to their initial shrunk BW. Within block, steers were randomly assigned to 1 of 4 treatments: 1) forage-based diet without the addition of narasin (CON; n = 8), 2) CON diet plus 13 ppm of narasin every 24 h (N24; n = 8), 3) CON diet plus 26 ppm of narasin every 48 hours (N48; n = 8), or 4) CON diet plus 39 ppm of narasin every 72 hours (N72; n = 8). The experimental period lasted 30 d, with 18 d for diet adaptation and 12 d for sample collection. The experimental diets contained 95% of Tifton-85 (Cynodon dactylon spp.) haylage and 5% ground corn used as a delivery vehicle for narasin. Ruminal fluid was obtained from d 25 to 30 at 6 h after feeding to determine ruminal fermentation parameters. Narasin supplementation frequency did not affect (P ≥ 0.22) nutrient intake and total tract apparent digestibility. Steers fed N24 and N48 had reduced (P = 0.02) ruminal acetate concentration compared with CON and N72. Daily supply of narasin increased (P = 0.01) the molar proportion of propionate compared with CON and N72, and it did not differ between N24 vs. N48, N48 vs. N72, and N72 vs. CON. Also, N48 steers had greater (P = 0.01) rumen propionate concentration compared with CON. The N24 treatment decreased the Ac:Prop (P = 0.01) and AcBut:Prop (P = 0.02) ratio compared with CON and N72, while N48 had reduced (P = 0.01) Ac:Prop and AcBut:Prop ratio when compared with CON steers. Steers fed N24 and N48 had greater (P = 0.04) ruminal short-chain fatty acids compared with CON, but it did not differ (P > 0.11) between N24, N48, and N72. Supplementing narasin to steers fed forage-based diets decreased (P < 0.01) ruminal ammonia concentration compared with CON steers regardless of supplementation frequency, being the least result observed for N24 steers. Collectively, narasin supplementation frequency affected fermentation parameters without altering the nutrient intake and total tract apparent digestibility. Hence, decreasing frequency of narasin supplementation to Nellore steers fed a forage-based diet did not reduce the capacity to modulate rumen fermentation parameters.

RESUMO

The objective of this study was to evaluate the nonlinear models that best describe the growth curve of ram lambs Ile de France created in intensive system in the state of Paraná. Therefore, there were weighed fortnightly during the period from February 2013 to June 2013, from birth to slaughter (120 days) of 31 Ile de France ram lambs. Growth curves were obtained by nonlinear models Brody, Von Bertalanffy, Gompertz and Logistic in which parameters were considered maturation rate (K), asymptotic weight (A), age of the animal (t) is given by integration determining the proportion of growth after birth (B) and the proportion of asymptotic value at which the inflection point occurs curve (m) in accordance with the adopted model. The parameters were estimated by Marquardt applied to the NLIN procedure of SAS statistical program and the criteria used to verify the accuracy of the fit of the curves were the mean square of the coefficient of determination. The Brody, Von Bertalanffy, Gompertz and Logistic resulted respectively in 26.4579; 26.1668; 26.136; 26.1582 for the mean square and 0.813; 0.958; 0.958; 0.958 for the coefficient of determination. Considering the criteria assumed the Gompertz model, followed by Logistic and Von Bertalanffy, presented the best fit to describe the growth of Ile de France ram lambs.

O objetivo com este trabalho foi avaliar os modelos não lineares que melhor descrevem a curva de crescimento de ovinos machos da raça Ile de France criados em confinamento no estado do Paraná. Para tanto, foram realizadas pesagens quinzenais no período de fevereiro de 2013 a junho de 2013, desde o nascimento até o abate (120 dias) de 31 machos da raça Ile de France. As curvas de crescimento foram obtidas pelos modelos não lineares de Brody, Von Bertalanffy, Gompertz e Logístico em que foram considerados os parâmetros da taxa de maturação (K), peso assintótico (A), idade do animal (t), constante de integração que determina a proporção de crescimento após nascimento (B) e proporção do valor assintótico em que ocorre o ponto de inflexão da curva (m), de acordo com o modelo adotado. Os parâmetros foram estimados pelo método Marquardt aplicado ao procedimento NLIN do programa estatístico SAS e os critérios utilizados para verificar a precisão do ajuste das curvas foram o quadrado médio do resíduo e o coeficiente de determinação. Os modelos Brody, Von Bertalanffy, Gompertz e Logístico resultaram respectivamente em 26,4579; 26,1668; 26,1360 e 26,1582 para o quadrado médio do resíduo e 0,8130; 0,9580; 0,9587 e 0,9580 para o coeficiente de determinação. Considerando os critérios adotados, o modelo Gompertz, seguidopor Logístico e Von Bertalanffy, apresentaram o melhor ajuste para descrever o crescimento dos machos da raça Ile de France.

RESUMO

The objective of this study was to evaluate the nonlinear models that best describe the growth curve of ram lambs Ile de France created in intensive system in the state of Paraná. Therefore, there were weighed fortnightly during the period from February 2013 to June 2013, from birth to slaughter (120 days) of 31 Ile de France ram lambs. Growth curves were obtained by nonlinear models Brody, Von Bertalanffy, Gompertz and Logistic in which parameters were considered maturation rate (K), asymptotic weight (A), age of the animal (t) is given by integration determining the proportion of growth after birth (B) and the proportion of asymptotic value at which the inflection point occurs curve (m) in accordance with the adopted model. The parameters were estimated by Marquardt applied to the NLIN procedure of SAS statistical program and the criteria used to verify the accuracy of the fit of the curves were the mean square of the coefficient of determination. The Brody, Von Bertalanffy, Gompertz and Logistic resulted respectively in 26.4579; 26.1668; 26.136; 26.1582 for the mean square and 0.813; 0.958; 0.958; 0.958 for the coefficient of determination. Considering the criteria assumed the Gompertz model, followed by Logistic and Von Bertalanffy, presented the best fit to describe the growth of Ile de France ram lambs.

O objetivo com este trabalho foi avaliar os modelos não lineares que melhor descrevem a curva de crescimento de ovinos machos da raça Ile de France criados em confinamento no estado do Paraná. Para tanto, foram realizadas pesagens quinzenais no período de fevereiro de 2013 a junho de 2013, desde o nascimento até o abate (120 dias) de 31 machos da raça Ile de France. As curvas de crescimento foram obtidas pelos modelos não lineares de Brody, Von Bertalanffy, Gompertz e Logístico em que foram considerados os parâmetros da taxa de maturação (K), peso assintótico (A), idade do animal (t), constante de integração que determina a proporção de crescimento após nascimento (B) e proporção do valor assintótico em que ocorre o ponto de inflexão da curva (m), de acordo com o modelo adotado. Os parâmetros foram estimados pelo método Marquardt aplicado ao procedimento NLIN do programa estatístico SAS e os critérios utilizados para verificar a precisão do ajuste das curvas foram o quadrado médio do resíduo e o coeficiente de determinação. Os modelos Brody, Von Bertalanffy, Gompertz e Logístico resultaram respectivamente em 26,4579; 26,1668; 26,1360 e 26,1582 para o quadrado médio do resíduo e 0,8130; 0,9580; 0,9587 e 0,9580 para o coeficiente de determinação. Considerando os critérios adotados, o modelo Gompertz, seguidopor Logístico e Von Bertalanffy, apresentaram o melhor ajuste para descrever o crescimento dos machos da raça Ile de France.

RESUMO

A Hemorragia pulmonar induzida pelo exercício (EIPH) é uma síndrome de alta ocorrên­cia nos equinos atletas, sendo o lavado broncoalveolar (BAL), com auxílio de endoscopia, um instrumento importante na avaliação das vias aéreas posteriores, permitindo seu diagnóstico mais preciso. Alguns cavalos tem evidência de hemorragia no pulmão, mas não apresentam sangue visível na traqueia, podendo apresentar resultados falso-negativos. A contagem de célu­las vermelhas no BAL faz com que aumentem as chances de diagnóstico nas EIPH subclínicas. O objetivo do estudo foi avaliar o efeito do método de análise de células vermelhas obtidas em diferentes diluições, bem como avaliar a correlação entre a concentração de células vermelhas determinadas pelo método pelo aparelho CELL-DYN 3700 e a câmara de Neubauer.

RESUMO

A Hemorragia pulmonar induzida pelo exercício (EIPH) é uma síndrome de alta ocorrên­cia nos equinos atletas, sendo o lavado broncoalveolar (BAL), com auxílio de endoscopia, um instrumento importante na avaliação das vias aéreas posteriores, permitindo seu diagnóstico mais preciso. Alguns cavalos tem evidência de hemorragia no pulmão, mas não apresentam sangue visível na traqueia, podendo apresentar resultados falso-negativos. A contagem de célu­las vermelhas no BAL faz com que aumentem as chances de diagnóstico nas EIPH subclínicas. O objetivo do estudo foi avaliar o efeito do método de análise de células vermelhas obtidas em diferentes diluições, bem como avaliar a correlação entre a concentração de células vermelhas determinadas pelo método pelo aparelho CELL-DYN 3700 e a câmara de Neubauer.