Effect of Rhodanese Enzyme Addition on Rumen Fermentation, Cyanide Concentration, and Feed Utilization in Beef Cattle Receiving Various Levels of Fresh Cassava Root

Abstract

Fresh cassava root is not recommended for animal feeding due to high quantities of hydrocyanic acid (HCN), which produces symptoms of poisoning. The purpose of this study was to find out how a rhodanese enzyme addition affects rumen fermentation, HCN content, feed utilization, and blood metabolites in beef calves fed fresh cassava root. Four Thai native beef cattle with an initial body weight (BW) of 95 ± 10.0 kg (1–1.5 years old) were randomly allocated to receive fresh cassava root containing HCN at 0, 300, 450, and 600 ppm according to a 4 × 4 Latin square design. Rice straw was the basal diet. The rhodanese enzyme was combined with concentrated feeds at a concentration of 1 mg/104 ppm HCN. The fresh cassava root was cleaned to remove dirt and chopped into 3 to 5 mm sized pieces before being fed to the animals at their various levels. The total feed intake of beef cattle increased when fed with fresh cassava root (p < 0.05). The digestibility of crude protein (CP) was different among various fresh cassava root levels (p < 0.05). Ruminal ammonia-N levels were measured 4 hours after feeding, and the average concentration declined considerably in animals fed fresh cassava root at 300–600 ppm HCN (p < 0.05). Cyanide concentration in the rumen was linearly increased by 270.6% (p < 0.05) when it was supplemented with a high level of fresh cassava root. Blood urea-N concentration was altered and decreased when supplemented with fresh cassava root (p < 0.01). The blood thiocyanate concentration was altered by the levels of fresh cassava root and rhodanese enzyme, which ranged from 4.1 to 27.9 mg/dL (p < 0.01). Cattle given fresh cassava root showed no influence on total volatile fatty acid, acetic acid, or butyric acid concentrations in the rumen (p > 0.05). However, the concentration of propionic acid increased slightly (p < 0.05) 4 hours after feeding. Supplementing fresh cassava root up to 600 ppm HCN/day improved N absorption, retention, and the proportion of N retention to N intake (p < 0.05). Therefore, increasing the inclusion of fresh cassava root with a rhodanese enzyme addition improves total feed intake, CP digestibility, nitrogen utilization, blood thiocyanate, and propionate concentrations, which may remove HCN without harming animal health.

Effect of cyanide-utilizing bacteria and sulfur on feed utilization, microbiomes, and cyanide degradation in cattle supplemented with fresh cassava root

“…When CR containing HCN at 600 mg/kg DM was supplemented, total intake increased by 14.8% when compared to CR containing HCN at 300 mg/kg DM. In agreement, Supapong et al 31 discovered that when CR levels increased, it also increased the total amount of feed that was consumed by the animals. Fresh cassava roots are typically more palatable and offer a more appealing taste and texture compared to the dried form, resulting in increased feed intake 4 , 6 .…”

“…When animals consume feed with a high NFC content, they can rapidly acquire a significant amount of energy. The improved palatability of the feed can stimulate their appetite, encouraging them to consume more of the NFC-rich feed 4 , 6 , 31 . As a result, nutritional intake varies depending on how much CR was provided.…”

“…Due to the fact that CR contains NFC, which the rumen can easily convert into propionate, beef cattle that were given a higher dose of CR showed higher ruminal propionate concentrations 32 , 33 . Supapong et al 31 discovered that giving animals more CR led to increased amounts of propionic acid after 4 h of feeding. Like with Cherdthong et al 6 , who showed that beef cattle given CR at 1.5% BW may have a 15.4% increase in propionate.…”

“…This could be because the animal received more N in the CR, resulting in increased N intake. Supapong et al 31 found that adding CR increased nitrogen availability in native beef cattle from 33.5 to 40.0 g/day.…”

The isolation of rumen enterococci strains along with high potential utilizing cyanide

“…In ruminants, the levels of rhodanese activity are high in the rumen epithelium, hepatocytes, and kidney cortex, resulting in the production of thiocyanate before its excretion in urine 13 . Previous research has shown that adding rhodanese in the presence of CN improves rumen fermentation characteristics in vitro (e.g., increasing cumulative gas production, in vitro digestibility, and volatile fatty acid concentration) 14 and in vivo (e.g., increasing propionate concentration) 15 .…”