Supplementation of Pelleted Hazel (Corylus avellana) Leaves Decreases Methane and Urinary Nitrogen Emissions by Sheep at Unchanged Forage Intake

Abstract

This study is the first to quantify the effects of hazel (Corylus avellana) leaves on methane and urinary nitrogen emissions, digestibility, nitrogen and the energy balance of ruminants. Four experimental pellets were produced with 0, 30% and 60% hazel leaves, the latter also with 4% polyethylene glycol. Hazel leaves gradually replaced lucerne. The diet was composed of the pellets and grass hay (80%: 20%). Six adult sheep were allocated to all four treatments in a 6 × 4 crossover design. Including hazel leaves did not affect the feed intake, but it decreased the apparent digestibility of organic matter and fibre, especially at the high level. Methane emission was reduced by up to 25 to 33% per day, per unit of intake and per unit of organic matter digested. Urinary nitrogen excretion decreased by 33 to 72% with increasing levels of hazel leaves. The treatment with polyethylene glycol demonstrated that tannins in hazel leaves caused significant shares of the effects. In conclusion, the current results indicated a significant potential of hazel leaves as forage for ruminants to mitigate methane and urinary nitrogen emissions. Even high dietary hazel leaf proportions were palatable. The lower digestibility needs to be compensated with easily digestible diet ingredients.

In vitroscreening of temperate climate forages from a variety of woody plants for their potential to mitigate ruminal methane and ammonia formation

“…In a feeding experiment with sheep, Wang et al . (2018) demonstrated that C. avellana leaves also have a clear methane-mitigating effect in vivo . As a sole substrate, L. corniculatus has been reported to reduce CH 4 emissions in vivo (Pinares-Patiño et al ., 2003; Woodward et al ., 2004) and in vitro (Williams et al ., 2011).…”

Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques

“…Urine samples need to be collected with minimal contamination by feces. In sheep, samples of feces and urine can be collected in metabolic crates independent of the sex (e.g., Wang et al, 2018). In cattle, sampling of total urine varies depending on the sex of the experi-mental animal.…”

Examining the Variables Leading to Apparent Incongruity between Antimethanogenic Potential of Tannins and Their Observed Effects in Ruminants—A Review

“…Similarly, in a study conducted on adult sheep, hazel (Corylus avellana) leaves when supplemented at 50% of the total diet were able to reduce CH 4 emissions by 35% (per unit OM intake) compared to the control (ryegrass hay and lucerne pellets). Concomitantly, a substantial decrease in urinary N proportion of total N intake was observed without any negative effects on forage intake, apparent palatability, or body weight of the sheep [111]. However, despite the promising findings indicated by these studies, the antimethanogenic potential of the forages is not clearly linked to the tannin concentration, as evidenced by the high variability in results from different studies (Table 1).…”