Proteolysis and in situ ruminal degradation of lucerne ensiled with Cistus ladanifer tannins

Abstract

The effects of ensiling lucerne with graded inclusion of Cistus ladanifer condensed tannins (CT) on in silo fermentative parameters, in vitro organic matter digestibility (IVOMD) and on in situ rumen degradability of dry matter (DM) and crude protein (CP) were studied. Lucerne forage (Medicago sativa subsp. sativa) was sprayed with different solutions of C. ladanifer CT extract in 60 ml of water in order for dose 0 (control), 40 (L40), 80 (L80) and 120 (L120) g of CT per kg of lucerne DM and was ensiled in lab‐scale silos. After 35 days, the silages were analysed for chemical composition, and the in situ ruminal degradability was determined in rams. The inclusion of CT in the silages caused an important dose‐dependent reduction in soluble‐N, NH3‐N and a large increase in true protein content and N bound with neutral detergent fibre (NDF‐N), which indicates an effective proteolysis reduction during ensiling. Also, the rumen undegradable protein (RUP) increased linearly (P < 0.01) with CT inclusion. However, a linear decrease (P < 0.02) of 5%, 13% and 22% of IVOMD was observed for the silages L40, L80 and L120 respectively. The results obtained suggest that C. ladanifer CT can be used as silage additives to reduce proteolysis of high‐protein forages during ensiling. A level of CT of 40 g/kg DM seems to be the best compromise between the gains achieved by the protection of CP degradation in silo and in the rumen and the losses associated with the depression of the digestion and absorption.

Ruminal degradation of Panicum grasses in three post-regrowth ages

“…Reductions in the degradation rate of nitrogen fractions from 34 days can reduce the amount of ammonia nitrogen available to rumen microorganisms, which use it for the synthesis of amino acids, cell structures, and growth (25) , which negatively impacts the DM degradability (Table 2). In tropical grasses, a reduction in the protein degradation rate is expected with advancing age, associated with factors such as climate, water availability, and temperature, with the incorporation of this fraction in the less soluble components of the forage (1,13) .…”

“…The level of rumen degradability of CP can be variable between different forage species, which determines the availability of ammonia nitrogen in the rumen, and the proportion of amino acids from the diet and microbial protein, that reach the intestine, which are directed to tissue protein synthesis (25) . The concentration of crude protein is higher at the vegetative stages of forages and decline at the flowering stage, which may vary depending on differences between species, initial level of protein in the plant, stem and leaf proportions, content of fiber components in the cell wall and ambient temperature (15,21) .…”

Additives Altered Bacterial Communities and Metabolic Profiles in Silage Hybrid Pennisetum

“…AN is produced by clostridial fermentation, and one of the criteria for good silage is AN < 100 g/kg TN ( Mu et al, 2020 ). NPN is an important product of proteolysis, and the utilization rate of NPN in ruminants is lower compared with that of TP due to rapid degradation ( Dentinho et al, 2019 ; Wang et al, 2021 ). The present study suggested that the addition of malic acid and cellulase had positive effects on inhibiting proteolysis, and low pH was speculated to inhibit the activities of proteases ( He et al, 2020 ).…”

Effects of Malic Acid and Sucrose on the Fermentation Parameters, CNCPS Nitrogen Fractions, and Bacterial Community of Moringa oleifera Leaves Silage

“…Here, one of the most important biochemical reactions is proteolysis, which transforms proteins into NPN (such as small peptides, free amino acid, and AN) under the activities of microorganisms and proteases [ 43 ]. The conversion of TP to NPN (PA fraction) reduces the N utilization in ruminants, further increasing urinary and fecal N losses and causing environmental pollution [ 44 ]. Thus, the application of malic acid may have a good effect in terms of nutrient preservation.…”