Intake and apparent nutrient digestibility, ruminal parameters, and nitrogen balance of lambs fed with corn and forage-free diets with sodium bicarbonate / Consumo e digestibilidade aparente dos nutrientes, parâmetros ruminais e balanço de N de cordeiros confinados recebendo dietas com milho e sem forragem com bicarbonato de sódio

This study evaluated forage-free diets supplemented with sodium bicarbonate (SB) based on ground flint corn on intake, apparent nutrient digestibility, ruminal parameters, and N balance. Four rumen-cannulatedDorper × Santa Inês lambs, with a body weight of 43.4 ± 0.85 kg (mean ± standard deviation) were used. The experimental design was a 4×4 Latin square. Each experimental period lasted 21 days. Experimental diets were: positive control, a diet without SB containing 400 g/kg DM of soybean hulls (CONT), and three diets based on ground flint corn, containing 10 (10SB), 20 (20SB) or 30 (30SB) g/kg DM of SB. Intake of neutral and acid detergent fiber was greater for CONT (P < 0.01) when compared to SB. Intake and apparent nutrient digestibility of dry and organic matter, ether extract, and crude protein did not differ. Intake (P = 0.01) and digestibility (P < 0.01) of non-fiber carbohydrates were greater for SB diets and neutral detergent fiber digestibility was greater (P = 0.03) for CONT. The total digestible nutrients and metabolizable energy were greater for SB (P = 0.04). Rumen concentrations of acetate (P < 0.01), isobutyrate (P < 0.01), butyrate (P < 0.01), isovalerate (P < 0.01), and total short-chain fatty acids (P < 0.01) were greater for CONT. Ruminal pH showed a quadratic (P = 0.05) response to SB levels, with greater values for 20SB. Sodium bicarbonate was efficient in increasing ruminal pH at the level of 20 g/kg DM without interfering with the intake and apparent nutrient digestibility characteristics.

O presente estudo avaliou a suplementação de bicarbonato de sódio (BS) em dietas sem forragem à base de milho moído sobre o consumo e a digestibilidade aparente dos nutrientes, os parâmetros ruminais e o balanço de N. Foram utilizados quatro cordeiros Dorper × Santa Inês, com um peso corporal inicial de 43,4 ± 0,85 kg (média ± desvio padrão). O delineamento experimental foi quadrado latino 4×4. Cada período experimental durou 21 dias. As dietas experimentais foram: controle positivo, sem BS, contendo 400 g/kg de MS de casca de soja (CONT) e três dietas à base de milho moído, sem casca de soja, contendo 10 (10BS), 20 (20BS) ou 30 (30BS) g/kg de MS de BS. O consumo de fibra em detergente neutro e ácido foi maior (P < 0,01)para o CONT quando comparado com BS. O consumo e a digestibilidade aparente da matéria seca, matéria orgânica, extrato etéreo e proteína bruta não diferiram entre os tratamentos. O consumo (P = 0,01) e digestibilidade (P < 0,01) dos carboidratos não fibrosos foram superiores para as dietas contendo BS e a digestibilidade da fibra em detergente neutro foi maior para o CONT. Os teores de nutrientes digestivos totais e energia metabolizável foram superiores para as dietas contendo BS (P = 0,04). A concentração ruminal de acetato (P < 0,01), isobutirato (P < 0,01), butirato (P < 0,01), isovalerato (P < 0,01) e ácidos graxos totais de cadeia curta (P < 0,01) foram mais elevadas para o CONT. O pHruminal apresentou resposta quadrática (P = 0,05) em relação aos níveis de BS, sendo observado maior pH para os animais alimentados com a dieta 20BS. O BS foi eficiente em aumentar o pHruminal no teor de 20 g/kg MS sem interferir no consumo e na digestibilidade aparente dos nutrientes. Portanto, 20 g/kg de MS é a dose indicada de BS em dietas sem forragem para terminação de cordeiros em confinamento.

Performance, nutritional behavior, and carcass characteristics of feedlot lambs fed diets with non-forage fiber source or sodium bicarbonate.

The study was carried out to evaluate the effect of sodium bicarbonate (SB) supplementation in diets and compare its chemical effect with the fiber effect of soybean hulls on performance, nutritional behavior, and carcass characteristics of feedlot lambs. Twenty-eight ram lambs (Dorper × Santa Inês), with an initial body weight of 30.2 ± 4.5 kg and 94 ± 8.4 days old, were used. They were assigned to a randomized complete block design, defined by initial age and body weight. Experimental diets were positive control, diet containing soybean hulls in 400 g/kg dry matter (DM) (CONT), and three diets based on ground flint corn containing 10 (10SB), 20 (20SB), or 30 (30SB) g/kg DM of SB. Among the SB levels, the buffer supplementation quadratically increased dry matter intake, average daily gain, feed efficiency, as well as increased final and slaughter body weight, which led to higher hot and cold carcass weights, loin muscle area, leg compacity index, and weight of neck, shoulder, rib, and leg cuts, with higher values for the 20SB. Feeding SB linearly decreased the area and height of the papillae. None of the animals presented liver abscess; however, two animals from 30SB and one from CONT had F-rumen lesions. The use of SB provided a similar animal performance when compared to the treatment containing soybean hulls. This shows that the chemical effect of the buffer was efficient and provided greater safety for this type of diet without causing damages to the rumen health. Among the SB levels, the best results were observed in the 20 g/kg level (20SB), which shows that the buffer can be used as a strategy for diets with high inclusion of corn and no fiber source.

Discrimination study between the carcass and noncarcass components for interaction between gender, age, and production system in indigenous sheep / Estudo de discriminação entre os componentes da carcaça e não da carcaça para interação entre gênero, idade e sistema de produção em ovinos indígenas

The objective of this work was to evaluate the yields, morphometric measures, carcass, and non-carcass components, and carcass regional and tissue composition of an indigenous sheep (Pantaneiro) of different physiological stages (gender, age, system production. Thirty sheep, eleven lambs, nine wethers, and ten cull ewes were used. The lambs were finished in feedlots, the wethers were maintained on pastures and supplementation, and the cull ewes were maintained on an extensive pasture system with mineral salt ad libitum. Slaughter ages were defined to simulate the most representative products and farming systems. Animals were slaughtered and classified as non- castrated lambs, wethers, and cull ewes. The criteria to slaughter lambs and wethers were the body condition, which ranged from 2.5 to 3.0. Cull ewes were slaughtered based on negative pregnancy diagnosis, regardless of their body condition, which ranged from 4.0 to 4.5. All animals were slaughtered after 16-hours of fasting (solids). The ewes presented the greatest fat thickness, differing significantly from the lambs. The morphometric measures were higher in ewes and lambs. The muscle to fat ratio of the animal's cuts from different physiological stages presented no significant differences. The indigenous Pantaneiro sheep have good potential for meat production regardless of their physiological stages. The ewes stood out, presenting carcasses with good performance considering their potential and longer permanence in the herd due to their reproductive function.(AU)

O objetivo deste trabalho foi avaliar o rendimento, medidas morfométricas, componentes da carcaça e da não carcaça e a composição regional e tecidual da carcaça de ovelhas indígenas (Pantaneiro) de diferentes sistemas de produção, sexo e idade. Foram utilizadas trinta ovelhas, onze cordeiros, nove borregos e dez ovelhas de descarte. Os cordeiros foram terminados em confinamento, os borregos mantidos em pastagem e suplementação, e as ovelhas de descarte mantidas em sistema a pasto extensivo com sal mineral ad libitum. As idades ao abate foram definidas para simular os produtos e sistemas agrícolas mais representativos, cordeiros, borregos e ovelhas de descarte. Os animais foram abatidos e classificados como cordeiros não castrados, borregos e ovelhas de descarte. Os critérios para abate de cordeiros e borregos foram a condição corporal, que variou de 2,5 a 3,0. As ovelhas de descarte foram abatidas com base no diagnóstico de gestação negativo, independentemente da condição corporal, que variou de 4,0 a 4,5. Todos os animais foram abatidos após jejum de 16 horas (sólidos). As ovelhas apresentaram as maiores espessuras de gordura, diferindo significativamente dos cordeiros. As medidas morfométricas foram maiores em ovelhas e cordeiros. A relação músculo / gordura dos cortes dos animais nas diferentes fases fisiológicas não apresentou diferenças significativas. Os ovinos pantaneiros apresentam bom potencial para produção de carne, independentemente de seus estágios fisiológicos. As ovelhas se destacaram, apresentando carcaças com bom desempenho considerando seu potencial e maior permanência no rebanho devido à sua função reprodutiva.(AU)

Effects of type of tropical pasture and concentrate supplementation level on the carcass traits of grazing lambs.

The nutritional requirements can be met, and carcass quality can be achieved by using concentrate supplementation in the diets of grazing lambs. This study evaluated the effects of different concentrate supplementation rates (0 %, 1.5 %, and 3 % of body weight) and tropical pastures (Panicum maximum cv. `Aruana' and Brachiaria brizantha cv. `Marandu') on lamb carcass traits. Thirty-six male Suffolk lambs, with an initial body weight of 22.54  ±  2.72  kg , were evaluated in a 3  × â€¯2 factorial experimental design. The concentrate used consisted of milled soybean, maize, and oat grains. The pasture species affected empty body weight and commercial cuts. The use of concentrate supplementation affected carcass weight, yield, indexes, and commercial cuts. Also, the use of concentrate supplementation improved the weight of muscle and fat content. Based on discriminant analysis it is possible to identify the rearing systems, when all variables where used, or the level of concentrate supplementation when variables of weight were used. Carcasses of animals on grass-only diets were different and easier to discriminate. The use of concentrate supplementation on rearing lambs improves the quality of carcass traits. The period of finishing can be shorted with supplementation of 3 % of body weigh in Aruana and Marandu grass. The discriminant analysis can identify the differences between rearing systems based on all carcass traits. This analysis can be used to develop carcass traceability systems.

Different physiological stages and breeding systems related to the variability of meat quality of indigenous Pantaneiro sheep.

This study configures a first report regarding the variability of meat quality of locally adapted Pantaneiro sheep depending on different physiological stages and breeding systems. Pantaneiro sheep are raised in Brazil under a tropical wetland ecosystem denominated Pantanal. Twenty-nine Pantaneiro sheep from different sex and physiological stages were sorted into three groups, simulating three of the most representative ovine meat products commercialized by South American industries: a) non castrated male lambs (n = 11); b) wethers (n = 9); c) cull ewes (n = 9). Animals from each physiological stage were submitted to different breeding systems, resembling farming strategies adopted in several developing countries of South America. The effect of physiological stages on the quality of meat was accessed using 16 variables measured in the longissimus thoracis et lumborum (LM) and the semimembranosus (SM) muscles. The variables were related to brightness, color, physical aspects, soluble and total collagen as well as chemical traits. The physiological stage was defined as a classification variable in order to proceed ANOVA tests and comparison of means (P<0.05). Multivariate analysis was used to identify patterns of similarity and differentiation between samples of different physiological stages (a, b, c). The results revealed that meat quality varies according to different physiological stages, especially between lambs (a) and cull ewes (c). As a consequence, the physiological stage at slaughter should be taken into consideration to cote the quality of meat from indigenous sheep raised in tropical regions. The results contribute towards sensorial evaluation and the characterization of potential food products derived from indigenous sheep bred under tropical climate in developing countries.