The cactus pear has demonstrated productive potential in arid and semi-arid regions due to its photosynthetic process of crassulacean acid metabolism. Thus, this study aimed to evaluate agronomic characteristics and chemical composition of three genotypes of cactus pear at different locations of a tropical semiarid region classified as non-suitable for cactus pear cultivation. A completely randomized design in a factorial arrangement (3 × 7) (three genotypes of cactus pear [Miúda, Baiana (Nopalea cochenillifera) and Orelha de Efefante Mexicana - OEM (Opuntia stricta)] and seven locations) was used. The climatic conditions characterized an environment that restricts the growth of cactus pear genotypes, mainly due to the air relative humidity values. All morphological characteristics of the cactus pear genotypes were influenced by the interaction genotype x location, with higher expression of the characteristics on the different genotypes under hot semi-arid climate and tropical wet and dry climate. An effect of the interaction genotype x location was observed (p < 0.05) on water use efficiency, water accumulation and carrying capacity, where the highest values were observed for genotype Baiana at location 1. Also, there was influence of the interaction genotype x location over the chemical composition of the cactus pear. The cultivation of cactus pear is recommended under restricted climatic conditions in semi-arid tropical regions, especially the genotype Baiana, based on growth factors, biomass production and chemical composition.

The aim of the present study was to estimate the relationships among water, crude protein (CP), ether extract (EE) and ash in the empty bodyweight (EBW), and the soft tissue and bone and, moreover, to determine an objective method to define weight at maturity in Nellore cattle. A dataset containing carcass and body compositions of 249 animals from 11 experiments was developed. There were 63 bulls, 105 steers, and 81 heifers where all animals were purebred Nellore, aged between zero and 24 months. The contents of water, CP and ash in the EBW were predicted by non-linear regressions, whereas an exponential model was used to predict EE. In addition, the content of CP was predicted on a fat-free dry matter (FFDM) basis, and maturity was defined as the point when no significant accretion of CP in the FFDM was observed. The soft tissue water (STW) was regressed on logistic Gompertz functions, and segmented regression models, whereas the analysis of bone chemical composition in the EBW was conducted using an exponential model. The gender effect was not significant (P > 0.05) for EBW and EE; therefore, this effect was not included in the analysis of FFDM. The exponential model suggests that Nellore cattle reached maturity at ~445 kg and the segmented regression model suggested that maturity was reached at 429 kg. A significant relationship between the concentration of STW and soft tissue EE (STEE) was observed (STEE = 0.920 – 1.147 × STW; r2 = 0.96, mean square error = 1.01), but the soft tissue was not a good predictor of maturity, because it is dependent on the diet. Analysis of bone chemical composition showed that EE, water and ash become constant between 400 and 500 kg of EBW, and that CP in bones was constant at 19.1% of EBW. These data also suggested that bone composition could be a good predictor of maturity; however, with the high variability in our dataset, it was not possible to determine an EBW at which these components became constant with a reliable precision. We concluded that Nellore cattle reach maturity at ~437 kg of EBW and that CP in the FFDM and CP, water and ash in bones are good predictors of maturity, whereas soft tissue composition is not a useful predictor of maturity.

The objective was to evaluate the fermentation parameters, chemical composition and in situ degradability of sesame silage in comparison to usual silages. The losses, fermentation quality and chemical composition of the forages and silages were evaluated using a completely randomised design with four treatments (sesame, corn, millet and sunflower) and four replicates per treatment, the silages were produced in experimental silos. In-situ degradability was evaluated using a completely randomised design with four treatments and three replicates (animals) per treatment. The results were statistically evaluated by analysis of variance and Tukey's test with a level of 5% of probability. Three rumen fistulated non-castrated Santa Inês rams were used. Sunflower and corn silages presented higher percentages of losses through gases (p ¼ .0256). Millet silage presented higher losses by effluent (p < .0001). The dry matter recovery (p < .0001) ranged from 70.0 to 96.5% for sesame and corn silage, respectively. The dry matter content (p ¼ .0002) in the silages ranged from 280.0 to 429.4 g kg À1. The sesame silage presented loss amounts and fermentation parameters similar to those found in corn and sunflower silage. Sesame silage showed moderate dry matter (DM), content, excellent crude protein (CP) and total digestible nutrients (TDN) contents, and low lignin content. Corn silage presented higher concentration of the soluble fraction of DM (p < .0001). The sesame silage presented a high degradability rate of DM and it was similar to corn and millet which have great nutritional potential for ruminants feeding. Sesame has the potential to produce quality biomass and silage for animal feeding. HIGHLIGHTS The sesame can be an option for silage making. Sesame helps to ensure sustainability by promoting lower seasonal risks in this region through the usage of silage as feed for the animals. Sesame also increases the productivity of livestock throughout the year, through the availability of feed for the herd mainly during the dry season of the year.

-The objective of this study was to evaluate the quality of raw milk in different production systems and its variation throughout the year. The data were collected from 943 dairy farms in the South, Central-West and Central regions of the state of Minas Gerais, and in Vale do Paraíba, in the state of São Paulo, Brazil. The data were collected in the period from January 2009 to September 2011, in a total of 18,206 samples. The properties were divided into confinement, semi-confinement and extensive production systems. The evaluated factors were somatic cell count (SCC), total bacterial count (TBC) and protein and fat contents. There was no effect of production system on the contents of protein, fat and SCC. Total bacterial count, however, was affected by production. Seasonal variations were found for SCC, TBC, protein and fat; the highest protein values were found from March to June; the highest fat contents were obtained from May to August; and TBC and SCC, from December to March. The production system does not interfere with the percentage of fat and protein and SCC of the milk. However, confinement systems present a better TBC content. Both month and year are factors that interfere with TBC, SCC, protein and milk fat, and the best patterns are found in the coldest periods of the year.

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The objective of this study was to investigate the rumen fermentation kinetics of 18 by-products from the biodiesel industry exhibiting potential for use in the feeding of ruminants via the in vitro gas production technique. The following feeds were investigated: cottonseed, canudo de pito, crambe, sunflower, castor seed (detoxified with lime) and soybean meals and cottonseed, peanut, babassu, crambe, palm kernel, sunflower, licuri nut, macaúba, forage radish and jatropha cakes. The evaluated parameters were total gas production (VfT), gas production from fibrous carbohydrates (VfFC), gas production from non-fibrous carbohydrates (VfNFC), the degradation rate of fibrous carbohydrates (kdFC), the degradation rate of non-fibrous carbohydrates (kdNFC) and lag time (lag). The feeds were grouped into six different groups according to rumen fermentation kinetic parameters and adopting an R2 of 0.8. Forage radish cake and the meals of cottonseed, soybean, crambe and sunflower composed the first group, while the cakes of babassu and sunflower formed the second group. Canudo de pito and castor seed meals and the cakes of cottonseed, licuri and jatropha I and II formed the third group. The fourth group was composed by the cakes of crambe, palm kernel and peanut I. The fifth group was formed by peanut cake II, while macauba fruit cake formed the sixth group. The VfNFC and VfFC varied from 16.72 to 200.07 mL and from 53.09 to 242.12 mL, respectively. The mean kdFC and kdNFC values varied from 0.002 to 0.039% h-1and from 0.022 to 0.430% h-1, respectively. The mean lag and VfT varied from 0.0001 to 5.2029 hours and 136.94 to 301.44 mL, respectively. A number of the products exhibited the potential to replace soybean meal, especially the forage radish cake and cottonseed, crambe and sunflower meals.

Impact of farm size on milk quality in the Brazilian dairy industry according to the seasons of the year.Ciência Rural, v.47, n.11, 2017. INTRODUCTIONMilk produced in Brazil has been seen as having poor quality because it is associated with the large number of small farms and because of the absence of hygiene practices. However, there are few studies proving or quantifying the lower quality of the milk produced on small properties, as described by ALLORE et al. (1997), where they affirm that smaller herds would be more affected by higher levels of somatic cell count (SCC) than larger ones (BATTAGLINI et al., 2013; FRANÇA et al., 2017). Yet, consultants from several regions report the existence of small farms producing milk with high quality, or no correlation between farm range production and milk quality (BORGES et al., 2013;INGHAM et al., 2011), which reinforces the importance of studies tracing the quality profile of Brazilian dairy farms.

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