In vitro rumen fermentation kinetics of diets containing oldman saltbush hay and forage cactus, using a cattle inoculum

Abstract

In vitro rumen fermentation kinetics of diets containing oldman saltbush hay and forage cactus, using a cattle inoculum [ ABSTRACTThe aim of this experiment was to evaluate, by means of the semi-automated in vitro gas production technique, fermentation kinetics of carbohydrates and degradability of dry matter (DM) and organic matter (OM) of diets containing oldman saltbush hay levels (8.4; 18.8; 31.2 and 48.3%) associated to forage cactus in natura. Pressure readings of the gases were done with a pressure transducer at 2, 4, 6, 8, 10, 12, 17, 20, 24, 28, 34, 48, 72 and 96h post-inoculation. The rumen kinetics was described by the following parameters: maximum potential of gas production, lag time and production rates of gas (k), fibrous carbohydrates (FC) and nonfibrous carbohydrates (NFC). It could be observed that the addition of oldman saltbush hay to the diets promoted a quadratic effect in the production of gases originated from NFC. However, there was no significant effect on the production of gases originated from FC and on production rates of gases from NFC and FC. The degradability of DM and OM did not differ due to the addition of oldman saltbush hay. The use of 8.4% hay and 74.9% forage cactus promoted the maximum potential of production of gases from the fibrous fraction of diets containing cactus and oldman saltbush hay.

Divergence in nutrient concentration, in vitro degradation and gas production potential of spineless cactus genotypes selected for insect resistance

“…The opposite occurred with the genotypes Miuda and IS since their greater NFC concentration resulted in a greater amount of fermentable substrate at any time, and consequently contributed positively to increasing IVDMD, B and c . These results are in agreement with other studies, where c for spineless cactus ranged from 0.06 to 0.3/h (Abidi et al , 2009; Luz et al , 2014; Tosto et al , 2015).…”

“…This is probably related to the low ADF concentration observed in all genotypes. In agreement with the current results, Batista et al (2003 b ) and Tosto et al (2015) reported Vf 1 of 195–222 ml for different spineless cactus. High gas production and DM degradation of cacti are likely due to their high non-structural carbohydrate and low lignin concentrations, which probably explains the high degradation rate of the slowly degradable DM fraction.…”

“…This characteristic of low NDF and ADF concentrations is associated with high non-structural carbohydrate concentration, making the spineless cactus a valuable source of fermentable carbohydrates for ruminants. On average, cactus TC concentration ranged from 62 to 84 g/kg DM, while NFC range from 31 to 58 g/kg DM (Tegegne et al , 2007; Costa et al , 2013; Tosto et al , 2015). Results from the current study were within these ranges.…”

In vitro and in situ digestibility of annual ryegrass silage from distinct phenological growth stages and pre-dehydration times

“…With the increase of the NDF content, there is a decrease in the rate of degradation of DM (Figure 1) due to the difficulty of the rupture of these molecules by the bacteria, which affects, mainly, the rate of degradation. In general, this also affects the rate of passage of the feed because, the lower the rate of degradation, the longer the dwell feed retention time in the rumen, (MUNIZ et al, 2012;TOSTO et al, 2015).…”

Spineless cactus associated with Tifton hay or sugarcane bagasse may replace corn silage in sheep diets

“…The high degradability of cactus organic matter (Tosto et al 2015;Siqueira et al 2017), which comprised 35% of DM of the TH and SB diets, may have increased the synthesis of organic acids (Lins et al 2016) and microbial protein in the rumen of the sheep, which explains the greater gain in weight. In a recent review, Boval et al (2015) verified that the weight gain increases as the digestible dry matter intake increases too.…”