RESUMO
The objective of this study was to evaluate the economic and financial viability of finishing of two sexes of Brazilian Somalis sheep in feedlot receiving diets with 0 and 15% reduction in the total digestible nutrients and crude protein contents. A completely randomized design was adopted, in a 2 × 2 factorial arrangement, with treatments consisting of two sexes (non-castrated males (21.13 ± 5.00 kg) and females (17.99 ± 3.79 kg) and two diets (0 and 15% reduction in the levels of total digestible nutrients and crude protein). Four simulations of productive scenarios were carried out: non-castrated males receiving the diet with 0% reduction; non-castrated males receiving the diet with 15% reduction; females receiving the diet with 0% reduction and females receiving the diet with 0% reduction, for a period of 70 days in feedlot. The highest costs of the system were with feeding and other costs, mainly the acquisition of animals. For both sexes, the 0% reduction diet showed the highest total cost, total revenue, break-even point. Non-castrated males fed a non-reduced diet and females fed a 15% reduction diet had higher net income, rate of return, total productivity, net present value, internal rate of return, profitability index and profitability rate. Less favorable situations were not profitable for any scenario. However, the increase in sales price favorability makes the activity viable. The reduction of total digestible nutrients and crude protein affects the economic and financial viability of Brazilian Somalis sheep. For non-castrated males it is recommended the diet without reduction and for females the diet with 15% reduction of nutrients.
Assuntos
Ração Animal , Criação de Animais Domésticos , Fenômenos Fisiológicos da Nutrição Animal , Dieta , Animais , Masculino , Feminino , Brasil , Ração Animal/análise , Ração Animal/economia , Criação de Animais Domésticos/economia , Criação de Animais Domésticos/métodos , Dieta/veterinária , Dieta/economia , Carneiro Doméstico/fisiologia , Carneiro Doméstico/crescimento & desenvolvimentoRESUMO
The objective of this study was to evaluate the metabolic profile of Santa Inês ewe lambs fed diets for early or late-maturing diets with or without nutrient restrictions. The experiment consisted of a 2 × 2 completely randomized factorial experiment with either early- or late-maturity feed formulation according to "Nutrient Requirements of Small Ruminants" with or without 15% crude protein (CP) and total digestible nutrients (TDN) restrictions in diets formulated, five replications, and 20 ewe lambs averaging 15.1±2.6 kg. Lambs on early-maturity diets consumed greater (P<0.05) dietary ether extract (EE), non-fibrous carbohydrates, and TDN than those on late-maturity diets. Lambs on early-maturity diets had 7.11% greater dry matter digestibility (DMD) compared to lambs fed late-maturity diets. Lambs fed late-maturity diets, in general, had greater intake (IN), excreted (EN), and retained (RN) N as well as greater RN/IN and EN/IN ratios. There were no differences in blood total protein or albumin among lambs fed for different finishing maturity targets. Diets designed for late-maturing lambs resulted in greater microbial N and CP as well as rumen and metabolizable, degradable, and undegradable rumen and metabolizable CP. The selection of diets for early or late maturity carcasses depends on the production system goals. Diets without restrictions are recommended for early-maturity carcass finishing while diets with 15% CP and TDN restriction are recommend for late-maturity finishing.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Digestão , Ração Animal/análise , Animais , Dieta/veterinária , Feminino , Metaboloma , Nutrientes , Rúmen , Ovinos , Carneiro Doméstico , DesmameRESUMO
The objective of this study was to identify by microhistological technique the reference chemical components for use as indicators of the nutritive value of Caatinga plants forage grazed by sheep throughout the year. A flock of twenty mixed-race meat ewes, multiparous, in production, with an average 34.84 ± 1.75 kg live weight and 36 months of age was assigned to supplement treatment of 0, 200, 350, and 500 g concentrate/head/day for 3 years. The experiment was designed as a randomized complete design with repeated measures over time. Supplementation with concentrate did not influence chemical composition of selected forage. In contrast, season heavily influenced diet chemical composition. Canopy stratum, season, and plant botanical family of selected species affected forage chemical composition selected by ewes. The ewes selected forage with greater nutritive value during the rainy season. Based on principal component analysis of the nutritive value of the primary forage species selected, ewes preferentially grazed plants contained greater neutral detergent fiber, acid detergent fiber, crude protein (CP), C fraction of nitrogenous compounds, and carbohydrate fractions A + B1 and C compared to the average native Caatinga herbage. Rangeland botanical composition and ewe diet varied during the year, affecting forage nutrients on offer, with the best diet selected during the rainy season because of the presence of dicotyledonous herbaceous species rich in CP as well as soluble carbohydrates and nitrogenous compounds. Concentrate supplement strategies for ewes on rangelands, such as Caatinga, should be determined by herbaceous species nutritive value during the rainy season and deep-rooted perennial dicotyledons during the dry season. These include the need to monitor ewe selection of forage species and their nutritive value, which is effectively accomplished with fecal microhistological techniques.
Assuntos
Ração Animal , Suplementos Nutricionais , Ração Animal/análise , Animais , Dieta/veterinária , Feminino , Valor Nutritivo , Estações do Ano , OvinosRESUMO
Our objective was to evaluate the effect of 15% crude protein (CP) and total digestible nutrient (TDN) restriction vis-á-vis that recommended by NRC (2007) on feed intake, digestibility, and average daily gain (ADG) of confined Morada Nova lambs. Twenty lambs with 18.8 ± 2.8 kg liveweight were assigned to a randomized 2 × 2 factorial experiment with either early- or late-maturity feed formulation according to "Nutrient Requirements of Small Ruminants" with or without 15% CP and TDN restriction. The early-maturity diet, independent of restriction, resulted in greater dry matter and organic matter intake and increased rumination efficiency and feed conversion. Early-maturity diets also had the greatest nutrient digestibility as well as ADG and total gains. With late-maturity diets, independent of restriction, there were greater CP and TDN digestibilities as well as neutral detergent fiber (NDF) feed efficiency. However, when 15% of nutrients were restricted for late-maturity lamb diets, there was greater NDF intake and greater ether extract digestibility. Unrestricted early-maturity lamb diets was the better diet for confined Morada Nova lambs. Attention should be given to minimum effective NDF consumed and physically effective for this diet formulation. The use of late-maturity diets as recommended by NRC (2007) allows for 15% restriction of CP and TDN in Morada Nova lambs without negative effects on performance. This restriction should be tested in other tropical breeds to determine wider application.