Effects of Increasing Levels of Total Tannins on Intake, Digestibility, and Balance of Nitrogen, Water, and Energy in Hair Lambs.

This study aims to evaluate the effects of increasing tannin levels from Mimosa tenuiflora hay on the intake, digestibility, and balance of nitrogen (N), water, and energy in hair lambs. Thirty-two Santa Ines lambs, at an average age of 150 days and body weight of 26.75 ± 2.29 kg, were randomly assigned to four treatments in a completely randomized design. The treatments consisted of four diets: a control diet, tannin-free, and three diets with increasing levels of total tannin, 26.2, 52.4, and 78.6 g tannin/kg dry matter (DM). Including the total tannins in the lambs' diet led to a quadratic increase in the intake of nutrients, N-retention (g/day), water intake, water absorption and retention, energy intake, and energy excretion in feces and gases. However, the digestibility of crude protein, neutral and acid detergent fibers, and total carbohydrates decreased. It was observed that there is a correlation between the variable nutrient digestibility and N-ingested and the N-absorbed, N-urinary, and N-retained. However, the N-excreted in feces did not correlate with any of the variables studied. It is recommended to include 33 g/kg DM of total natural tannins from Mimosa tenuiflora hay in the diet of hair lambs, as it improves intake, energy balance, dietary N, and body water composition while reducing the excretion of N-urinary and gas emissions to the environment.

Resilience of cactus pear genotypes in a tropical semi-arid region subject to climatic cultivation restriction.

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.