Chemical composition, fractionation of carbohydrates and nitrogen compounds, ruminal degradation kinetics, and in vitro gas production of cactus pear genotypes

Abstract

The aim of this study was to evaluate the chemical composition, fractionation of carbohydrates and nitrogen compounds, degradation parameters, and in vitro ruminal fermentation of cactus pear genotypes. The experiment was conducted in a completely randomized design with 4 cactus pear genotypes and 4 replicates. The evaluated cactus pear genotypes were: Miúda (Nopalea cochenillifera Salm Dyck), IPA Sertânia (Nopalea cochenillifera), Gigante (Opuntia ficus indica Mill), and Orelha de Elefante Mexicana (Opuntia stricta Haw), all in natura. Samples were randomly collected at different points in the experimental area. Whole plants were collected 24 months after field crop establishment. N. cochenillifera Salm Dyck presented the highest dry matter, acid detergent insoluble protein, non-fibrous carbohydrate, total digestible nutrients, digestible energy, total carbohydrates, and fractions A + B1 (P<0.05), while presenting lower neutral detergent fiber corrected for ash and protein, acid detergent fiber, and cellulose in relation to the other genotypes studied (P<0.05). The in vitro true digestibility of neutral detergent fiber was high for the genotypes N. cochenillifera Salm Dyck and N. cochenillifera Dyck, which also presented high in vitro total gas production (P<0.05). The cactus pear genotypes show adequate chemical characteristics to be composed part of diets offered to ruminants. However, supplementation is necessary to increase the dry matter and fiber contents. The Nopalea cochenillifera Salm Dyck genotype presented the highest proportions of total digestible nutrients, non-fibrous carbohydrates, non-protein nitrogen, unavailable nitrogen fraction total, and high gas production in relation to the other analyzed genotypes 24 months after field crop establishment.

Mineral profile, carbohydrates fractionation, nitrogen compounds and in vitro gas production of elephant grass silages associated with cactus pear

“…With this information, it is possible to develop nutritional strategies to improve nitrogen use, both by ruminal microorganisms and by the ruminant, improving their product performance and reducing losses to the environment. Due to the absence of studies that evaluated the nitrogen compounds in elephant grass silages containing cactus pear in its composition, we can observe that the values obtained in this study are close to the findings by Magalhães et al (2021) when evaluating the fractionation of nitrogen compounds from cactus pear in natura. The authors found values of A-90.9 g/ kg CP; B1 + B2-53.4 g/kg CP; B3-173 g/kg CP and C-200 g/kg CP.…”

“…In general, forage plants rich in non-fibrous carbohydrates, such as cactus pear, have higher gas production (Magalhães et al 2019). A fact observed by Magalhães et al (2021) who, when evaluating the in vitro gas production of cactus pear genotypes observed that the cactus pear Opuntia stricta Haw presented a gas production of 193.2 mL/g of dry matter, while when analyzing the in vitro gas production oof elephant grass genotypes of different sizes under irrigation, observed that elephant grass cv. Iri 381 presented a gas production of 120.92 mL/g of dry matter.…”

“…The Gompertz two-compartment model was chosen, assuming that the gas production rate is proportional to the microbial activity, but the proportionality decreases with the incubation time, which can be attributed to the loss of efficiency in the fermentation rate with time (Magalhães et al 2021).…”

Palma forrageira: Adubação orgânica e mineral

“…Existem três espécies encontradas no Nordeste do Brasil, a palma gigante (Opuntia fícus indica), palma redonda (Opuntia spp.) e palma miúda (Nopalea cochenilifera), são cactáceas sem espinhos, de crescimento rápido e teor de umidade superior às outras cactáceas (Magalhães et al, 2021).…”

“…É uma espécie de grande importância para o Semiárido, principalmente, como recurso forrageiro devido ser de fácil propagação (Cavalcante et al, 2017), ter alto rendimento de biomassa fresca (163 ton/ha) e de matéria seca (12.46 ton/ha), essa capacidade produtiva ocorre devido ao seu metabolismo fotossintético MAC (Metabolismo Ácido das Crassuláceas), que captura CO2 à noite, tornando a palma forrageira eficiente no uso da água (100-150 kg água/kg matéria seca) (Nascimento Junior et al, 2022). Além disso, a palma forrageira apresenta alta tolerância ao déficit hídrico, e apresenta em sua composição alto valor energético (66-74% de nutrientes digestíveis totais) e carboidratos não fibrosos (59 -73 %; Magalhães et al, 2021), alta digestibilidade (69-78%), grande reserva de água (80% com base na matéria seca) (Silva et al, 2022). Pode ser incluída na dieta de ruminantes na forma de farelo desidratado, pastejo ou picada e servida no cocho (Marques et al, 2017).…”