Effect of technical cashew nut shell liquid on rumen methane emission and lactation performance of dairy cows
Abstract
Technical-grade
cashew nut shell liquid (TCNSL) is a by-product of the cashew nut
industry in tropical countries, and is known to exhibit a wide range of
biological activities, including inhibitory effect against gram-positive
bacteria. This study was conducted to investigate the effects of TCNSL
(73.3% cardanol, 16.4% cardol, and 3.0% methylcardol) on rumen methane
emission, nutrient digestibility, dry matter intake, and milk yield and
composition in dairy cows. Eight multiparous Holstein cows were used in a
crossover design trial with two 21-d experimental periods. The diet was
based on corn silage and alfalfa haylage and was formulated to meet or
exceed the energy and metabolizable protein requirements of the cows.
Treatments were control (no TCNSL supplementation) or 30 g/cow per day
of TCNSL. Rumen carbon dioxide emission was not affected by TCNSL.
Treatment had no effect on methane emission (542 vs. 511 ± 35.3 g/cow
per day, respectively) and methane emission intensity (15.0 vs.
13.9 ± 0.58 g/kg of energy-corrected milk, respectively) and tended to
decrease methane emission per kilogram of dry matter intake (20.2 vs.
18.6 ± 1.04 g/kg, respectively). Dry matter intake (average
26.9 ± 1.00 kg/d), milk yield (40.0 ± 1.73 kg/d), and milk composition
were not different between treatments. The TCNSL had no effect on N
losses in urine and feces and total-tract apparent digestibility of
nutrients, except digestibility of neutral detergent fiber tended to be
increased compared with the control. Plasma urea and glucose
concentrations were not affected by TCNSL. Concentration of milk C18:0
tended to be decreased (17%) by TCNSL compared with the control. In this
study, TCNSL did not alter absolute methane emission in the rumen, but
tended to decrease it by 8% per kilogram of dry matter intake. The TCNSL
had no effect on milk yield and composition in dairy cows.
Key words
- cashew nut shell liquid;
- methane;
- dairy cow
