Effect of different genotypes of

Abstract

Tithonia diversifolia (Mexican sunflower) is a shrub used for animal feed that has outstanding agronomic and chemical characteristics. Its potential to modify the dynamics of fermentation and improve the supply of nutrients to ruminants has received considerable attention. This study was designed to determine the effect of different genotypes of T. diversifolia on ruminal fermentation and degradation of dry matter (DM), concentration of volatile fatty acids, and production of methane (CH4) when mixed with a low-quality tropical grass, Urochloa brizantha (palisade grass). In a randomised complete block design, mixtures of seven genotypes of T. diversifolia with U. brizantha cv. Marandú were evaluated by using the in vitro gas production technique. The effect of fertilisation was also evaluated for each genotype. Inclusion of T. diversifolia significantly (P < 0.05) increased the supply of nutrients and modified fermentation parameters. DM degradation of biomass after 72 h was greater in the presence of T. diversifolia than for feeds based only on U. brizantha (68.0% vs 63.4%; P < 0.01). CH4 production was lower (P < 0.05) during fermentation with some T. diversifolia genotypes (25.3 vs 27.7 mg CH4 g–1 incubated DM), and the acetic:propionic acid ratio was also lower. Fertilisation of T. diversifolia genotypes increased DM degradation, increased the content of certain nutrients (e.g. crude protein) and modified CH4 production. Therefore, inclusion of T. diversifolia in mixtures based on low-quality tropical grasses such as U. brizantha increases the supply of nutrients (crude protein, minerals, energy) and can modify the products of enteric fermentation, with some genotypes decreasing enteric CH4 emissions.

Tithonia diversifolia Improves In Vitro Rumen Microbial Synthesis of Sheep Diets without Changes in Total Gas and Methane Production

“…Unfortunately, there is not much work in the literature describing the IVGP kinetics of TD inclusion in concentrate diets, although some authors have described its kinetic behavior in forage diets. Firsoni et al [46] reported a gas production rate of 0.038 h −1 for a substrate using 75% T. diversifolia and 25% rice bran, values similar to our highest TD inclusion, and Rivera et al [47] reported that B. brizantha, in association with different genotypes of TD, had a specific gas accumulation rate between 0.09 and 0.1 h −1 , values higher Some authors argue that the only really valuable information gained from gas production alone is the fermentation rates [44,45]. In the present study, no major differences were observed in the gas production rates (k) between the different substrates; nonetheless, the tendency in the increasing k and the differences in µ 0.5 are consistent with the results obtained in the IVDOM, discussed later, granted that the latter results were more conclusive.…”

“…Unfortunately, there is not much work in the literature describing the IVGP kinetics of TD inclusion in concentrate diets, although some authors have described its kinetic behavior in forage diets. Firsoni et al [46] reported a gas production rate of 0.038 h −1 for a substrate using 75% T. diversifolia and 25% rice bran, values similar to our highest TD inclusion, and Rivera et al [47] reported that B. brizantha, in association with different genotypes of TD, had a specific gas accumulation rate between 0.09 and 0.1 h −1 , values higher than those obtained in the present study.…”

“…These isoacids are products of the ruminal degradation of amino acids, which could suggest that the TDOM in the diets was associated more strongly with the protein content (R = 0.56; p < 0.001) rather than with the fiber content (NDF) (R = 0.34; p > 0.05) (Figure 3). Regarding the IVDOM of TD, some authors have mentioned that the incorporation of TD into substrates results in greater IVDOM [47,65,66], while others did not report significant differences [14,60,67]. In most of these cases, the IVDOM differences were explained by changes in the proportion of soluble carbohydrates within the substrates.…”

CH4 and N2O Emissions From Cattle Excreta: A Review of Main Drivers and Mitigation Strategies in Grazing Systems

“…Since N 2 O emissions are traditionally higher in urine, this may be a mitigation pathway. Silvopastoral systems use forage species such as Leucaena leucocephala, Tithonia diversifolia, and Gliricidia sepium, which contain significant amounts of tannins in their leaves and stems (Barahona et al, 2006;Rivera et al, 2021). Rivera et al (2018) compared an iSPS and a traditional system and found reductions in emission factors (N 2 O) of 23% and 10 times less for feces and urine, respectively.…”

Understanding the impacts of intensity and harvest frequency on Tithonia diversifolia for use in tropical silvopastoral systems

“…T. diversifolia has been used as forage source in silvopastoral arrangements or as cut-and-carry forage (Mauricio et al 2014;Palmer 2014). It exhibits greater biomass production and nutritional value compared to tropical grasses and demonstrates broad adaptability to different edaphoclimatic conditions, with the potential to enhance animal productivity by improving fermentative e ciency and reducing enteric methane (CH 4 ) emissions (Rivera et al 2021(Rivera et al , 2022Mahecha et al 2022).…”