Resumen Esta revisión tuvo como objetivo exponer las relaciones entre los aditivos en la dieta de los rumiantes y las consecuencias causadas en su nutrición. Los aditivos alimentarios se utilizan en la nutrición de los rumiantes para mejorar las características productivas y/o la calidad de los productos. Hay diversas categorías de aditivos disponibles para la nutrición de rumiantes, con énfasis en antibióticos, prebióticos, probióticos, extractos de plantas y enzimas exógenas. Los antibióticos, los aceites esenciales y el quitosano actúan seleccionando bacterias sensibles y consecuentemente modulan el patrón de fermentación ruminal. Los prebióticos favorecen la microbiota, proporcionando una mayor digestión y producción de ácidos grasos volátiles. Los probióticos son microorganismos que mejoran el ambiente ruminal, lo que resulta en una mayor digestión y producción de ácidos grasos volátiles. Las enzimas exógenas actúan sinérgicamente con las enzimas secretadas por los microorganismos ruminales, además de favorecer la adhesión microbiana y colonización de las partículas, ayudan en la degradación del alimento. Los taninos, ya sea alterando el estándar de fermentación y/o modificando la microbiota ruminal, todos los aditivos son efectivos para mejorar el rendimiento animal. Sin embargo, los efectos de los aditivos sobre los productos están relacionados con la calidad de la dieta.

Abstract This review illustrates the relationships between additives in the diets of ruminants and the consequence for ruminant nutrition. Feed additives are used to improve animal perfor mance and/or the quality of the products. There are several categories of additives available for ruminant nutrition, with emphasis on antibiotics, prebiotics, probiotics, plant extracts, and exogenous enzymes. Antibiotics, essential oils, and chitosan act by selecting sensitive bacteria, consequently modulating the ruminal fermentation pattern. Prebiotics favor microbial growth, providing greater digestion and the production of volatile fatty acids. Probiotics are living microorganisms that improve the ruminal environment, promoting microbial growth and resulting in increased digestion and the production of volatile fatty acids. Exogenous enzymes act synergistically with the enzymes secreted by the ruminal microorganisms, besides favoring microbial adhesion and colonization and facilitating feed degradation. Tannins, whether altering the fermentation standard and/or modifying the ruminal microbiota population, are effective in improving animal performance. However, the effects of additives on the quality of the products are linked to diet quality.

ABSTRACT The objective was to determine the optimal dehydrated passion fruit pulp replacing ground corn in diets for goat kids. We used 24 crossbred castrated goat kids with initial body weight of 26.6±0.3 kg. The experimental period was 23 days, with 15 days of adjustment and acclimatization (mostly to the installation and diet). Kids were distributed in a randomized experimental design with four treatments of 0, 80, 160, or 240 g/kg of dehydrated passion fruit residue as a supplementary inclusion in the dry matter (DM) content of the diet. The statistical model considered the fixed effect of the included amount of residue from dehydrated passion fruit. Analysis of variance was conducted using the PROC GLM of SAS. Intakes of DM and total digestible nutrients (TDN) were not affected by residue inclusion. However, neutral detergent fiber (NDF) intake increased linearly. The inclusion linearly decreased intake of ether extract (EE) and non-fibrous carbohydrates (NFC). Crude protein (CP) intake was quadratically affected, with a greater value under treatment of 160 g/kg passion fruit. Dry matter and NFC digestibility decreased linearly with the amount of passion fruit included in diet. Fecal N and total N excretion values (in g/d and %N intake) increased linearly. Nitrogen balance and N retained values showed a quadratic increase, with greater values under the 160 g/kg inclusion. Time spent ruminating, DM and NDF eating efficiency, and g DM/bolus chewed were affected quadratically by inclusion of passion fruit residue. The replacement of ground corn with dehydrated passion fruit residue at a level of 160 g/kg is recommended for diets of goat kids to improve their NDF and CP intake and their N balance without affecting DM and TDN intakes.

ABSTRACT The objective of this work was to use biometric measurements to predict carcass characteristics of lambs of the Morada Nova breed. We used 48 lambs with mean initial body weight (BW) of 15.0±0.04 kg and slaughter body weight (SBW) of 26.37±2.43 kg. The animals were weighed weekly and underwent a period of adaptation of 15 days before slaughter. The biometric measurements were obtained the day before slaughter, comprising body length, withers height, rump height, thigh length, breast width, rump width, thigh perimeter, rump perimeter, thorax perimeter, leg length, and body condition score. Additional measurements included slaughter BW and empty BW (EBW). The data recorded at slaughter comprised the weights of the viscera, carcass, and internal fat and offal. The in vivo measurements of body length were present in most of the equations for predicting the SBW, EBW, hot carcass weight (HCW), and cold carcass weight (CCW). The SBW and EBW presented a variation of approximately 9%. The variables that evaluated the carcass, HCW, and CCW demonstrated less data variation than SBW and EBW, which was probably because these measurements were obtained following evisceration and skinning, thus removing factors of more significant variation in vivo . The prediction models found in the present study varied with an R² of 0.49-0.93, indicating high levels of variation. In sum, biometric measurements can be used to predict the carcass characteristics of Morada Nova lambs with different body conditions.

Um experimento foi conduzido com o objetivo de estudar os efeitos dos níveis de cálcio nas rações sobre o desempenho e a qualidade de ovos de poedeiras comerciais. Foram utilizadas 216 poedeiras da linhagem Lohmann Brown no período de 39 a 55 semanas de idade. O delineamento utilizado foi inteiramente casualizado, composto de seis níveis de cálcio (3,0; 3,4; 3,8; 4,2; 4,6; 5,0%) e seis repetições de seis aves por parcela. Os níveis de cálcio avaliados não influenciaram os parâmetros produtivos, mas afetaram significativamente as porcentagens de albúmen e casca do ovo. O aumento do cálcio na dieta promove incremento na qualidade da casca do ovo em relação aos demais componentes do ovo. Recomenda-se nível de 4,3% de cálcio em dietas para poedeiras semipesadas após o pico de postura.

Two hundred and sixteen layers were raised from 39 to 55 weeks of age to study the effects of levels of calcium in the rations on performance and eggs quality of brown commercial layers. A completely randomized experimental design were used with six levels of calcium (3.0; 3.4; 3.8; 4.2; 4.6 and 5.0%) and six replicates of six layers hens. There was no effect of calcium levels on hen performance, however significantly affected the percentage of albumen and egg shell. The increase of calcium in the diet promoted increment in egg shell quality in relationship to other eggs components. The calcium level of 4.3% is recommended for brown layer hens after production peak.