RESUMO

This study evaluated the effects of narasin on intake and rumen fermentation characteristics of Bos indicus steers offered a high-forage diet for 140 d. On day 0 of the study, 30 rumen-fistulated Nellore steers [initial body weight (BW) = 281 ± 21 kg] were assigned to 30 individual pens in a randomized complete block design according to their initial BW. Animals were randomly assigned to 1 of the 3 treatments: 1) forage-based diet without narasin (CONT; n = 10), 2) CONT diet plus 13 ppm of narasin (13NAR; n = 10), and 3) CONT diet plus 20 ppm of narasin (20NAR; n = 10). The forage used was Tifton-85 (Cynodon dactylon spp.), whereas the carrier for narasin was a 50:50 mixture of soybean hull:corn. The experimental period was divided into 5 periods of 28 d each. Throughout the experimental period, total dry matter intake (DMI) was recorded daily, whereas mineral salt intake was recorded weekly. Blood and ruminal fluid samples were collected on day 0 (prior to treatment feeding), 28, 56, 84, 112, and 140 of the study. Moreover, total tract apparent nutrient digestibility was performed for a 5-d period every 28 d. No treatment effects were observed on forage, mineral, concentrate, or total DMI (P ≥ 0.22). Nonetheless, 13NAR tended to have a greater mineral intake vs. 20NAR cohorts (P = 0.08) Narasin-supplemented animals had reduced rumen acetate, Ac:Pr ratio, as well as greater (P ≤ 0.02) rumen propionate concentrations vs. CONT cohorts. Moreover, 13NAR increased rumen propionate and decreased butyrate, Ac:Pr vs. 20NAR cohorts (P ≤ 0.01). Throughout the experimental period, narasin-supplemented animals had reduced ammonia concentrations vs. CONT cohorts (P < 0.01), whereas no differences were observed between 13NAR and 20NAR (P = 0.80). No treatment or dose effects were observed (P ≥ 0.23) on DM, organic matter (OM), protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), and mineral digestibility. Animals fed 13NAR had a reduced mean plasma urea concentration vs. CONT cohorts (P = 0.03), whereas no further differences were observed (P ≥ 0.12). In summary, narasin supplementation to beef steers offered a high-forage diet did not impact forage, mineral, and total DMI, as well as nutrient digestibility, whereas rumen fermentation characteristics, rumen ammonia, and plasma urea concentrations were positively impacted and lasted throughout the experimental period. Additionally, 13 ppm of narasin resulted in a reduced Ac:Pr ratio and rumen ammonia when compared to animals supplemented with 20 ppm.

RESUMO

The objective in this trial was to determine the effects of partial replacement of ground corn by citrus pulp or soybean hulls on performance and carcass characteristics of feedlot goat kids. Twenty one Boer x Saanen kids (initial BW 15.8 ± 0.7kg), nine males and 12 females, were distributed in a complete randomized block design, according to sex and initial body weight. Treatments were set by replacing 50% of ground corn (DM basis) for citrus pulp or soybean hulls; whereas, forage concentrate ratio was of 10:90. Partial replacement of corn by citrus pulp or soybean hulls increased dry matter intake, average daily gain and final body weight, but feed efficiency was not affected. There was no difference between citrus pulp or soybean hulls. Inclusion of coproducts increased slaughter weight, hot and cold carcass weight and longissimus muscle area, with no difference between citrus pulp and soybean hulls. Subcutaneous fat thickness, hot and cold carcass yields, shrink after chilling and body wall thickness were not affected by treatments. Citrus pulp and soybean hulls can replace 50% of ground corn (DM basis) increasing dry matter intake and weight gain in goat kids enabling higher slaughter weight at earlier age.

O objetivo neste estudo foi avaliar a substituição parcial do milho pela polpa cítrica (PC) ou casca de soja (CS) sobre o desempenho e as características de carcaça de cabritos confinados. Foram utilizados 21 cabritos Boer x Saanen (PC inicial de 15,8±0,7kg), sendo nove machos e 12 fêmeas, distribuídos em delineamento experimental de blocos completos casualizados (7 blocos e 3 tratamentos). Os tratamentos foram definidos pela substituição de 50% do milho pela PC ou CS (% da MS). As dietas continham 90% de concentrado e 10% de volumoso. A substituição parcial do milho pela PC ou CS aumentou o consumo de matéria seca (CMS), o ganho médio diário de peso corporal (GMD) e o peso corporal final, porém a eficiência alimentar não foi alterada. A inclusão dos coprodutos aumentou o peso corporal ao abate (PCA), o peso de carcaça quente (PCQ) e fria (PCF) e a área de olho de lombo (AOL). Não houve diferença entre os coprodutos com relação ao desempenho e às características de carcaça. A substituição de 50% do milho (64,2% de MS) pela polpa cítrica ou casca de soja, em dietas com alto concentrado, aumenta o consumo de matéria seca e o ganho médio diário de peso dos cabritos, possibilitando maior peso ao abate com idade menor.

Assuntos

RESUMO

The objective in this trial was to determine the effects of partial replacement of ground corn by citrus pulp or soybean hulls on performance and carcass characteristics of feedlot goat kids. Twenty one Boer x Saanen kids (initial BW 15.8 ± 0.7kg), nine males and 12 females, were distributed in a complete randomized block design, according to sex and initial body weight. Treatments were set by replacing 50% of ground corn (DM basis) for citrus pulp or soybean hulls; whereas, forage concentrate ratio was of 10:90. Partial replacement of corn by citrus pulp or soybean hulls increased dry matter intake, average daily gain and final body weight, but feed efficiency was not affected. There was no difference between citrus pulp or soybean hulls. Inclusion of coproducts increased slaughter weight, hot and cold carcass weight and longissimus muscle area, with no difference between citrus pulp and soybean hulls. Subcutaneous fat thickness, hot and cold carcass yields, shrink after chilling and body wall thickness were not affected by treatments. Citrus pulp and soybean hulls can replace 50% of ground corn (DM basis) increasing dry matter intake and weight gain in goat kids enabling higher slaughter weight at earlier age.(AU)

O objetivo neste estudo foi avaliar a substituição parcial do milho pela polpa cítrica (PC) ou casca de soja (CS) sobre o desempenho e as características de carcaça de cabritos confinados. Foram utilizados 21 cabritos Boer x Saanen (PC inicial de 15,8±0,7kg), sendo nove machos e 12 fêmeas, distribuídos em delineamento experimental de blocos completos casualizados (7 blocos e 3 tratamentos). Os tratamentos foram definidos pela substituição de 50% do milho pela PC ou CS (% da MS). As dietas continham 90% de concentrado e 10% de volumoso. A substituição parcial do milho pela PC ou CS aumentou o consumo de matéria seca (CMS), o ganho médio diário de peso corporal (GMD) e o peso corporal final, porém a eficiência alimentar não foi alterada. A inclusão dos coprodutos aumentou o peso corporal ao abate (PCA), o peso de carcaça quente (PCQ) e fria (PCF) e a área de olho de lombo (AOL). Não houve diferença entre os coprodutos com relação ao desempenho e às características de carcaça. A substituição de 50% do milho (64,2% de MS) pela polpa cítrica ou casca de soja, em dietas com alto concentrado, aumenta o consumo de matéria seca e o ganho médio diário de peso dos cabritos, possibilitando maior peso ao abate com idade menor.(AU)

Assuntos

RESUMO

ABSTRACT: The objective in this trial was to determine the effects of partial replacement of ground corn by citrus pulp or soybean hulls on performance and carcass characteristics of feedlot goat kids. Twenty one Boer x Saanen kids (initial BW 15.8 ± 0.7kg), nine males and 12 females, were distributed in a complete randomized block design, according to sex and initial body weight. Treatments were set by replacing 50% of ground corn (DM basis) for citrus pulp or soybean hulls; whereas, forage concentrate ratio was of 10:90. Partial replacement of corn by citrus pulp or soybean hulls increased dry matter intake, average daily gain and final body weight, but feed efficiency was not affected. There was no difference between citrus pulp or soybean hulls. Inclusion of coproducts increased slaughter weight, hot and cold carcass weight and longissimus muscle area, with no difference between citrus pulp and soybean hulls. Subcutaneous fat thickness, hot and cold carcass yields, shrink after chilling and body wall thickness were not affected by treatments. Citrus pulp and soybean hulls can replace 50% of ground corn (DM basis) increasing dry matter intake and weight gain in goat kids enabling higher slaughter weight at earlier age.

RESUMO: O objetivo neste estudo foi avaliar a substituição parcial do milho pela polpa cítrica (PC) ou casca de soja (CS) sobre o desempenho e as características de carcaça de cabritos confinados. Foram utilizados 21 cabritos Boer x Saanen (PC inicial de 15,8±0,7kg), sendo nove machos e 12 fêmeas, distribuídos em delineamento experimental de blocos completos casualizados (7 blocos e 3 tratamentos). Os tratamentos foram definidos pela substituição de 50% do milho pela PC ou CS (% da MS). As dietas continham 90% de concentrado e 10% de volumoso. A substituição parcial do milho pela PC ou CS aumentou o consumo de matéria seca (CMS), o ganho médio diário de peso corporal (GMD) e o peso corporal final, porém a eficiência alimentar não foi alterada. A inclusão dos coprodutos aumentou o peso corporal ao abate (PCA), o peso de carcaça quente (PCQ) e fria (PCF) e a área de olho de lombo (AOL). Não houve diferença entre os coprodutos com relação ao desempenho e às características de carcaça. A substituição de 50% do milho (64,2% de MS) pela polpa cítrica ou casca de soja, em dietas com alto concentrado, aumenta o consumo de matéria seca e o ganho médio diário de peso dos cabritos, possibilitando maior peso ao abate com idade menor.