The objective of this study was to characterize the milk yield (MY) and milk composition of relevant sheep and goat breeds raised around the world to be used with nutrition models for diet formulation and nutrient balancing. A 2-step approach was used. First, a database developed by the Food and Agriculture Organization was used to identify relevant breeds (i.e., frequently raised) by comparing the occurrence of transboundary breed names across countries. We selected transboundary breeds that occurred more than 3 times and other relevant breeds obtained from the specialized literature that had milk production information (e.g., MY, days in milk, and milk fat, protein, and lactose). The majority of sheep breeds were classified as nondairy (76%) because they lacked milk production information. Karakul and Merino accounted for up to 2.4% of sheep breeds raised around the world, whereas the other individual breeds accounted for less than 1%. In contrast, nondairy breeds of goats accounted for 46.3% and of the remaining 53.7%, Saanen, Boer, Anglo-Nubian, Toggenburg, and Alpine accounted for 6.5, 5, 4.4, 4, and 3%, respectively, of the transboundary breeds. Second, a database compiled from published studies for the selected sheep (n = 65) and goats (n = 78) breeds were analyzed using a random coefficients model (studies and treatments within studies as random effects). For sheep breeds, the average and SD were 1.1 ± 0.3 kg/d for MY, 6.9 ± 1% for milk fat, 5.4 ± 0.4% for milk protein, 5 ± 0.3% for milk lactose, 17.7 ± 1.4% for milk total solids, and 1,073 ± 91 kcal/kg of milk energy. Lacaune had the greatest MY compared to Comisana and Tsigai (1.65 versus 0.83 and 0.62 kg/d; respectively, P < 0.05), but milk components were not different among breeds. For goats breeds, the average and SD across breeds were 1.7 ± 0.6 kg/d for MY, 4.2 ± 0.9% for milk fat, 3.3 ± 0.4% for milk protein, 4.4 ± 0.4% for milk lactose, 12.7 ± 1.1% for milk total solids, and 750 ± 75 kcal/kg of milk energy. Alpine had similar MY to Saanen (2.66 versus 2.55 kg/d, respectively; P > 0.05), but greater (P < 0.05) than other breeds. The Boer breed had the greatest milk fat, protein, lactose, and total solids than several other breeds, leading to the greatest milk energy content (907 kcal/kg). Because there are many factors that can alter MY and milk composition, averages provided in this study serve as guidelines, and nutritionists must obtain observed values when using nutrition models.

Inadequate management in recent times has been considered the main factor contributing to pasture degradation. A major reason for this is related to gross errors of grazing management as a consequence of the lack of knowledge of ecophysiological limits of forage. This review aimed to approach the importance of organic reserves for grasses under grazing. Therefore, the predominant effect of animal grazing is the reduction of leaf area which impacts on carbohydrate and nitrogen reserves and consequently the growth of tillers, leaves and roots. Grass growth after defoliation is related to organic reserves and rate of photosynthesis. The latter is affected by the level of canopy light interception of and by the reminiscent leaf area index. When grazing management is carried out with respect to the physiological limits of grass growth, the rate of dry matter accumulation will be quick and constant. In this aspect, grazing management consists of seeking an efficient balance between plant growth and consumption which will reflect on animal productivity. Therefore, a balance point among frequency and intensity of defoliation must be found to achieve greater animal production concerning the ecophysiological limits of the forage plants. So the challenge will be to find a balance between frequency and intensity of grazing to achieve greater production of animals respecting the eco-physiological limits of forage plants for each forage grass individually.

This experiment was carried out to evaluate management strategies for Piatã grass grown in the soil-climatic conditions of the south region of Mato Grosso State, Brazil. The treatments corresponded to four management strategies determined by the following pre- and post-harvest heights: 30/10, 30/15, 35/20 and 40/15. A completely randomized design with five replications was employed totaling twenty experimental units. The highest number of harvests was observed in the plots subjected to strategies 35/20 and 30/15, which allowed for two additional harvest cycles when compared with strategies 40/15 and 30/10. The strategies that provided plants with the greatest pre-harvest heights, 40/15 and 35/20, resulted in lower leaf elongation rates, stem elongation rates, and leaf senescence. Because of the lower post-harvest height, strategy 30/10 resulted in the largest tiller population, an average of 829 tillers m2. The highest herbage accumulation value, 18.600 kg ha-1 DM, was observed with management strategies 40/15 and 30/15. The management of Piatã grass based on the harvest target of 30/15 associates elevated herbage production with a favorable pasture structure for grazing.

The objective of this study was to evaluate the effect of including common-bean residue in diets for feedlot sheep on the intake and digestibility of nutrients by these animals. Sixteen intact male sheep were allotted in a completely randomized design with four treatments and four replicates. Treatments consisted of the inclusion of 0, 11, 22, and 33% of the common-bean residue (dry matter basis) in the experimental diets, which corresponded to the substitution levels of 0.0, 33.3, 66.7, and 100.0% of cottonseed cake for the bean residue. Data of the studied variables were subjected to analyses of variance and regression, adopting a significance level of 5%. The model was chosen based on the significance of the regression parameters, evaluated by the t test (P<0.05), and on the coefficients of determination. The levels of inclusion of the common-bean residue in the diet influenced (P<0.05) the intakes of dry matter (DM), crude protein, organic matter, ether extract, and indigestible neutral detergent fiber, expressed in g animal -1 day -1 , percentage of body weight (%BW), and metabolic weight (BW 0.75 ), which decreased linearly. However, the inclusion of the different levels of common-bean residue did not change (P>0.05) the intakes of neutral detergent fiber, non-fiber carbohydrates, or total digestible nutrients by the feedlot sheep. Every 1.0% of inclusion of the common-bean residue in the sheep diet led to a reduction of 4.93, 0.01, and 0.20 in DM intake when expressed in g animal -1 day -1 , %BW, and BW 0.75 , respectively. Every 1.0% of inclusion of the bean residue resulted in the reduction of 2.73% in the intake of indigestible neutral detergent fiber by the feedlot sheep. Sheep displayed a linear increase (P<0.05) in water intake with the levels of common-bean residue in the experimental diets. The inclusion of 0, 11, 22, and 33% of the residue in the diet caused the digestibility of dry matter, crude protein, organic matter, and neutral detergent fiber to increase linearly (P<0.05). It is concluded that the inclusion of up to 22% of commonbean residue in diets for feedlot sheep provides balanced and adequate values between the intake and digestibility of nutrients. ResumoObjetivou-se avaliar o efeito da inclusão do resíduo de feijão na dieta de ovinos confinados sobre o consumo e a digestibilidade dos nutrientes. Foram utilizados 16 ovinos, machos inteiros, distribuídos em um delineamento inteiramente casualizado, com quatro tratamentos e quatro repetições. Os tratamentos foram constituídos pela inclusão de 0; 11; 22 e 33% na MS do resíduo de feijão nas dietas experimentais, as quais corresponderam aos níveis de substituição de 0,0; 33,3; 66,7 e 100,0% da torta de algodão pelo resíduo de feijão. Os dados das variáveis estudadas foram submetidos às análises de variância e de regressão, adotando-se o nível de significância de 5%. A escolha do modelo foi baseada na significância dos parâmetros de regressão, testada pelo teste t (P<0,05), e nos valores dos coeficientes de determinação. Os n...

This study aimed to evaluate the effects of different levels (0, 10, 20 and 30%) of starch or glucose associated with marandu palisadegrass (Urochloa brizantha cv. Marandu) on its kinetic parameters and fiber digestion by the in vitro gas production technique. The experiment was arranged in a completely randomized design, with four treatments and six replications for each energy source. The marandu palisadegrass associated with nonfiber carbohydrate levels was incubated in 120 ml bottles, with McDougall buffer and rumen fluid from two rumen-cannulated sheep. Readings were taken of gas pressure within the bottle, and two vials were removed at 24, 48 and 96 hours (h) to assess residual neutral detergent fiber (NDF). The one-pool logistic model was used to estimate the kinetic parameters for pure forage and forage associated with starch, however it was necessary to use the two-pools model when glucose was added. Each 1% of added starch promoted a linear increase in total gas production of 0.2254 ml and a decrease in lag time of 0.2451 h, but did not affect the digestion rate. Glucose levels had a quadratic effect on digestion rate and lag time, with a minimum estimated value for digestion rate of 0.01689 h-1 at a glucose level of 10.07% and a minimum lag time of zero. Starch levels caused a linear reduction in NDF digestion of 0.296% only at 24 h, while glucose levels linearly reduced the NDF digestion in all evaluated times (0.3269, 0.4171 and 0.2340% at 24, 48 and 96 h, respectively). Glucose levels promoted different effects on the in vitro gas production kinetic parameters of marandu palisadegrass compared to starch supplementation, highlighting the prolonged negative effects on NDF digestion.