RESUMO
Yeast and fibrolytic enzymes serve as additives incorporated into the nutrition of ruminants to regulate rumen fermentation and increase the digestibility of fiber, thereby enhancing the efficiency of rumen fermentation. Two experiments were conducted to assess the impact of five diets: a control diet without additives, diets with yeast (Saccharomyces cerevisiae) or exogenous fibrolytic enzymes (EFE), and diets with a blend of 0.7yeast + 0.3EFE or 0.7EFE + 0.3Yeast (based on recommended levels in g/kg of total DM). In the first experiment, 40 five-month-old Santa Ines lambs (mean weight 25.0 ± 1.3 kg) were distributed in a completely randomized design (5 treatments and 8 lambs) for 81 days to evaluate performance, ingestive behaviour, and serum metabolites. In the second experiment, 25 Santa Ines male lambs weighing 25.7 ± 4.1 kg were housed in metabolic cages, in a randomized design with 5 treatments and 5 lambs, evaluating digestibility, nitrogen balance, and rumen pH. EFE supplementation increased intakes of dry matter (DM), total digestible nutrients (TDN), and apNDF (mean of 38.1, 5.26, and 27%, respectively) compared to yeast or the 0.7yeast-0.3EFE blend. Feed conversion was most efficient (mean of 27.1%) in lambs fed Yeast, 0.7EFE + 0.3yeast, and the control diet. Lambs fed 0.7yeast + 0.3EFE spent less time eating (mean of 16.5%) and more time idling (mean of 10.75%), whereas EFE-fed lambs spent more time eating (mean of 19.73%), and 0.7EFE + 0.3yeast-fed lambs spent more time ruminating (mean of 20.14%). Control group lambs chewed and ruminated less (means of 24.64 and 17.21%, respectively) compared to other treatments. Lambs on the 0.7yeast + 0.3EFE blend had higher eating and rumination efficiency rates for DM and apNDF (mean of 19.11 and 17.95%, respectively) compared to other additive treatments or individual additives. They also exhibited lower (means 7.59 g/d) urinary N excretion, with improved N retention (mean 3185 g/d) compared to the control group. There were significant effects on serum albumin and cholesterol concentrations, with the 0.7yeast + 0.3EFE blend showing higher albumin (mean 4.08 g/dL) levels, while diets without additives and yeast-EFE blends had higher cholesterol (mean of 62.51 g/dL) concentrations. Including Saccharomyces cerevisiae yeast along with 0.7 yeast + 0.3 EFE blend is recommended when feeding similar lamb diets to those used herein because it improves the efficiency of intake, rumination of DM and NDF, and nitrogen utilization without affecting the lamb performance.
Assuntos
Ração Animal , Dieta , Suplementos Nutricionais , Digestão , Rúmen , Saccharomyces cerevisiae , Animais , Ração Animal/análise , Masculino , Digestão/efeitos dos fármacos , Dieta/veterinária , Suplementos Nutricionais/análise , Fenômenos Fisiológicos da Nutrição Animal , Carneiro Doméstico/fisiologia , Fermentação , Distribuição Aleatória , Fibras na Dieta/análise , Fibras na Dieta/administração & dosagemRESUMO
This study aimed to evaluate forage production and ingestive behavior of Morada Nova sheep in an intensive system with capim-tamani grass in both monoculture and silvopastoral irrigated systems in the Semi-arid region. Eighteen adult sheep, approximately 3 years old, with an average body weight of 26.8 ± 4.3 kg, were allocated to treatments with capim-tamani grass cultivated in monoculture and in silvopastoral systems with Caatinga trees. The experiment followed a completely randomized complete block design with two plots and three replications. Forage production, consumption, and behavioral activities were the assessed variables. The animals remained in the pasture daily between 6 am and 6 pm. No effects of the monoculture and silvopastoral systems were observed on the structural and productive characteristics of the capim-tamani grass pasture. There were also no observed effects on body condition score, consumption, and disappearance rate of dry matter (DM) and other nutrients in both systems. However, there was an interaction between the time animals spent under shade in monoculture and silvopastoral systems. In general, the animals spent more time under shade where there were trees, except during the period between 2 pm and 4 pm, when the times were similar. On average, the animals spent approximately 15.6% (equivalent to 1.87 h) of their total time in the artificial shade available in the monoculture system, whereas in the silvopastoral system, they remained under natural shade for approximately 40% (five and a half hours) of their time spent in the pasture during the day. The grazing frequency in both systems was approximately 70% (8.4 h) in relation to the total time spent in the pasture. The capim-tamani grass pasture managed intensively with sheep in the silvopastoral system showed similar forage production and consumption compared to the monoculture system. There was a positive influence of trees on the duration of solar radiation exposure to the animals throughout the day. The results support the need to provide shade for sheep, as well as to promote these sustainable systems in semi-arid regions.
Assuntos
Ração Animal , Criação de Animais Domésticos , Comportamento Alimentar , Poaceae , Animais , Criação de Animais Domésticos/métodos , Ração Animal/análise , Irrigação Agrícola , Ovinos/fisiologia , Carneiro Doméstico/fisiologia , Masculino , FemininoRESUMO
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 the study was to evaluate the effect of the inclusion of cocoa bran in the diet of lambs and its effect on reproductive parameters. For this, 40 lambs were randomly assigned to four treatments, and including 0, 10, 20 and 30% levels of cocoa bran in the concentrate. Blood was collected to measure cholesterol and testosterone and semen for physical and morphological evaluation; testicular biometry and morphometry were also evaluated. There was significant difference (P < 0.05) in body weight and tubulosomatic index between the lambs in the control treatment and those in the 30% cocoa bran treatment. There was no difference in testicular biometry, physical and morphological parameters of fresh semen, testicular morphometry, and volumetric ratio between lambs in all the treatments (P < 0.05). In addition, there was no difference in plasma cholesterol or testosterone concentration (P > 0.05). Thus, it is possible to include up to 30% of cocoa bran in diet without affecting the reproductive parameters of lambs.
Assuntos
Ração Animal , Colesterol , Dieta , Carneiro Doméstico , Testículo , Testosterona , Animais , Masculino , Ração Animal/análise , Dieta/veterinária , Testículo/anatomia & histologia , Carneiro Doméstico/fisiologia , Testosterona/sangue , Colesterol/sangue , Colesterol/análise , Cacau/química , Reprodução , Sêmen/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Distribuição Aleatória , Ovinos/fisiologiaRESUMO
The Morada Nova sheep breed is essential for the economy of the semi-arid region of Northeast Brazil, standing out for its adaptability, resistance to parasites and reproductive ability. However, the white variant is endangered, highlighting the importance of studies on its productivity to support conservation efforts. This study focuses on the growth curve of the Morada Nova sheep breed, using nonlinear models and analyzing flock profiles. Total of 764 observations of 165 animals from four farms in Ceará and Rio Grande do Norte, Brazil, were analyzed. Canonical discriminant analysis (CDA) was used for the exploratory analysis and four nonlinear models were used to study the growth curve. Weight from birth to 270 days of age, absolute growth rate (AGR), and the impact of sex on growth curves were assessed. Sex and farm are significant discriminating variables (P < 0.05) for the studied effects (weight and age). Weight was the primary phenotypic biomarker that discriminated between the two indicators, while age was a discriminating indicator only for the core effect. The Gompertz model was the most efficient, presenting the lowest residuals and greatest convergence. The study reveals new information about the growth of Morada Nova sheep, the white variety, including weight differences between the sexes at all analyzed ages and an inflection point before 90 days of age. These discoveries contribute to the understanding of the breed's growth and help in the formulation of conservation strategies.
Assuntos
Carneiro Doméstico , Animais , Brasil , Masculino , Feminino , Carneiro Doméstico/crescimento & desenvolvimento , Carneiro Doméstico/genética , Carneiro Doméstico/fisiologia , Peso Corporal , Ovinos/crescimento & desenvolvimento , CruzamentoRESUMO
The present study describes the expression of genes in the Longissimus dorsi muscle related to meat quality of hair lambs finished in an Integration Crop-Livestock system. Twenty-eight non-castrated lambs of two breeds, Somalis Brasileira and Santa Inês, at 120 ± 15 days of age, with an average initial live weight of 18 ± 3.1 kg, were kept in a pasture-based finishing system with supplementation. Upon reaching 28 kg body weight, animals were sent for slaughter. Samples of the Longissimus dorsi and Biceps femoris muscle were harvested for analyses of gene expression and physicochemical properties. Significant differences were detected between the breeds for tissue and chemical composition, whereas the physical aspects did not differ. We observed the expression of six genes related to lipid synthesis (acetyl-CoA carboxylase [ACACA], fatty acid synthase [FAS], stearoyl-CoA desaturase [SCD], lipoprotein lipase [LPL], cell death-inducing DFFA-like effector A [CIDEA], and thyroid hormone responsive [THRSP]) and six genes related to molecular synthesis (myostatin [MSTN], growth differentiation factor 8 [GDF8], insulin-like growth factor 1 [IGF1], insulin-like growth factor 2 [IGF2], delta-like 1 homolog [DLK1], and growth hormone receptor [GHr]) in both breeds. The Santa Inês breed and the Somalis Brasileira showed similar expression patterns of genes related to lipogenesis and myogenesis of the Longissimus dorsi muscle, with the exception of the THRSP gene, in which the Somalis Brasileira have more receptors for the action of thyroid hormones, which resulted in greater thickness of fat in the carcass (subcutaneous fat) and higher lipid content in the chemical composition of the meat.
Assuntos
Músculo Esquelético , Carneiro Doméstico , Animais , Músculo Esquelético/metabolismo , Músculo Esquelético/química , Carneiro Doméstico/genética , Carneiro Doméstico/fisiologia , Masculino , Expressão Gênica , Carne Vermelha/análiseRESUMO
The aim was to evaluate the quality of the sheep skin of different sex classes submitted to different levels of feed restriction. Sheep without defined racial pattern of different sex classes (15 non-castrated males, 15 castrated males and 15 females), with initial body weight of 18.1 ± 0.4 kg and mean age of 90 days were distributed in a factorial 3 × 3, with three sex classes and 3 levels of feed restriction (ad libitum intake and restricted intake at 70 and 80%), with 5 repetitions. After slaughter, the skins were collected for physical-mechanical tests. The effect of the sex classes x levels of dietary restriction interaction was observed for transverse thickness and longitudinal rupture elongation (p < 0.05). Animals fed ad libitum had greater longitudinal transverse thickness (p < 0.05). Animals fed ad libitum and 70% feed restriction showed greater transverse elongation at break (p < 0.05). As for the difference between sex classes in the transverse thickness variable for tearing strength, the interaction sex classes x levels of feed restriction for transverse thickness, longitudinal thickness, transverse tearing strength and longitudinal tearing strength occurred (p < 0.05). Feed restriction reduces the physical quality of the skin of sheep of different sex classes, and the use of castrated male sheep in positive energy balance is recommended to obtain leather with greater thickness, longitudinal rupture elongation and transverse tear strength.
Assuntos
Pele , Animais , Masculino , Feminino , Carneiro Doméstico/fisiologia , Carneiro Doméstico/crescimento & desenvolvimento , Fatores Sexuais , Privação de Alimentos/fisiologia , Ração Animal/análise , Ovinos/fisiologia , Ovinos/crescimento & desenvolvimento , Orquiectomia/veterináriaRESUMO
Ensilage of refused fruit with forage is a viable approach to increase resource use in ruminant feed. The objective of this study was to investigate the impact of ensiling refused melon fruit (RMF) with Canarana grass on the intake, apparent digestibility, serum biochemistry, performance, carcass traits, and meat attributes of feedlot lambs. Four distinct silage treatment types were prepared by ensiling RMF at 0 g/kg (control), 70 g/kg, 140 g/kg, and 210 g/kg (as fed) with Canarana grass. Twenty-eight male Santa Inês lambs (7 lambs per treatment), initially weighing 22.3 ± 1.0 kg at 120 days of age, were distributed in a completely randomized design and confined for a total of 96 days, including a 23-day adaptation period and 73 experimental days in a feedlot. The lambs received the treatment-silage in diets as a complete mixture with a roughage: concentrate ratio of 30:70. The inclusion of RMF in Canarana grass ensilage decreased (P < 0.05) the lambs' intake of dry matter, crude protein and metabolisable energy. The inclusion of RMF in ensilage had a quadratic effect (P < 0.05) on the digestibility of non-fibrous carbohydrates. The serum total protein and cholesterol levels decreased (P < 0.05) with the inclusion of RMF in the ensilage, but we observed no effect on the final weight and average daily gain of the lambs. The feed efficiency increased (P < 0.05) by including RMF in the Canarana grass ensilage. The RMF in the ensilage did not influence cold carcass weight and yield. The fat content of the meat decreased (P < 0.05) with the inclusion of RMF in the ensilage. It is recommended the inclusion of up to 210 g/kg of RMF in Canarana grass ensilage to increase feed efficiency and avoid impacts on the performance and carcass attributes of confined lambs.
Assuntos
Dieta , Digestão , Carneiro Doméstico , Silagem , Animais , Digestão/efeitos dos fármacos , Masculino , Silagem/análise , Dieta/veterinária , Carneiro Doméstico/fisiologia , Carneiro Doméstico/crescimento & desenvolvimento , Carneiro Doméstico/sangue , Fenômenos Fisiológicos da Nutrição Animal , Ração Animal/análise , Cucurbitaceae/química , Frutas/química , Distribuição AleatóriaRESUMO
The increasing global demand for food and the strong effect of climate change have forced animal science to advance regarding new methods of selection in search of more efficient animals in production systems. Feed consumption represents more than 70% of the costs of sheep farms, and more efficient animals can increase the farmers' profitability. One of the main measures of feed efficiency is estimated residual feed intake (RFI), created in 1963 by Robert Koch for estimation in cattle and later adapted for sheep. Animals with negative RFI values (RFI-) are more efficient than animals with positive values (RFI+), with influence on the variables of performance, carcass quality and production of enteric gases. The RFI is the most common and accepted metric of the feed efficiency trait for genetic selection, since it is independent of growth traits, unlike the feed conversion ratio. The purpose of this review article was to present updated literature information on the relationship of RFI estimates with performance measures, molecular markers, greenhouse gas production and feed efficiency, the technical aspects and physiological basis of metabolic in sheep.
Assuntos
Ração Animal , Animais , Ração Animal/análise , Criação de Animais Domésticos/métodos , Ingestão de Alimentos/fisiologia , Ovinos/fisiologia , Ovinos/crescimento & desenvolvimento , Carneiro Doméstico/fisiologia , Carneiro Doméstico/crescimento & desenvolvimento , Fenômenos Fisiológicos da Nutrição Animal , Gases de Efeito Estufa/análiseRESUMO
We aimed to evaluate the effects of different drying methods for banana residues on the energy metabolism and respirometry of growing lambs. Twenty Santa Inês x Dorper lambs were fed five experimental diets: Tifton 85 grass hay (Control), shade-dried banana leaf hay (LH Shade), shade-dried pseudostem banana hay (PH Shade), sun-dried banana leaf hay (LH Sun), and sun-dried banana pseudostem hay (PH Sun). Nutrient intake and digestibility were assessed in metabolic cages, whereas O2 consumption and CO2, methane, and heat production were measured in a respirometry chamber with animals fed at maintenance and ad libitum levels. Nutrient and energy intake was not influenced by diet. Pseudostem hay had higher apparent digestibility of dry matter (71.5%), organic matter (72.4%), and neutral detergent fiber (58.0%). However, this led to greater energy loss in the form of methane (12.1%). The banana residue hays and drying methods did not alter oxygen consumption, CO2 production, or heat production of animals fed ad libitum or during maintenance. On the other hand, the use of leaf hay resulted in a reduction of 24.7% in enteric methane production of animals fed ad libitum. The inclusion of pseudostem hay is recommended in sheep feedlot diet. This residue provided greater use of DM, however promoted a greater loss of energy in the form of methane, resulting in similar energy consumption. The drying methods did not reduce the availability of nutrients and the sun drying method is recommended, since it is a faster drying method.