Effect of lemon leaves on energy and C N balances, methane emission, and milk performance in Murciano-Granadina dairy goats

[EN] The objective of this experiment was to find out the effect of lemon leaves on energy and C-N balances, methane emission, and milk performance in dairy goats. Lemon leaves were used to replace alfalfa as forage in a diet for Murciano-Granadina goats. Ten Murciano-Granadina dairy goats (44.1 +/- 4.47 kg of BW) in late lactation (185 +/- 7.2 d) were selected in a crossover design experiment, where each goat received 2 treatments in 2 periods. One group was fed a mixed ration with 450 g of pelleted alfalfa per kilogram of DM (ALF diet) and, the other group replaced alfalfa with 450 g of pelleted lemon leaves per kilogram DM (LEM diet). The concentrate was pelleted, being the same for the two groups (forage to concentrate ratio was 45/55). The goats were allocated to individual metabolism cages. After 14 d of adaptation, feed intake, total fecal and urine output, and milk yield were recorded daily over a 5-d period. Then, gas exchange measurements were recorded individually by an open-circuit indirect calorimetry system using a head box. Higher dietary lipids in LEM diet reduced DMI (200 g/d) and energy intake (251 kJ/kg of BW0.75), although no differences between treatments were observed for ME intake (998 kJ/kg of BW0.75, on average) and oxidation of nutrients (64% and 25% for carbohydrates and fat oxidation, respectively, on heat production from oxidation basis). Greater (P < 0.05) milk fat values for C18:2n6t and CLA 9c11t + 9t11c were found in LEM compared with ALF diet. Goats fed LEM diet produced significantly fewer CH4 emissions than ALF diet (18%). Likewise, the use of lemon leaves as forage reduced the amount of CH4 in 2.7 g/kg of milk. Results suggest that lemon leaves are effective in reducing CH4 emission without detrimental effect on milk yield.This study was supported by HELIOTEC S.A., Vall de Uxo, Castellon de la Plana, Valencia, Spain, through LIFE Ecocitric Project, and LIFE LOW CARBON FEED PROJECT reference LIFE16/CCM/000088.Fernández Martínez, CJ.; Martí Vicent, JV.; Pérez Baena, I.; Palomares Carrasco, JL.; Ibáñez-Sanchis, C.; Segarra, JV. (2018). Effect of lemon leaves on energy and C N balances, methane emission, and milk performance in Murciano-Granadina dairy goats. Journal of Animal Science. 96(4):1508-1518. doi:10.1093/jas/sky028S1508151896