Substitution of maize silage with sorghum silages in cow ration: effect on global warming potential of milk production
Poster
Data di Pubblicazione:
2014
Citazione:
Substitution of maize silage with sorghum silages in cow ration: effect on global warming potential of milk production / L. Bava, S. Colombini, M. Zucali, A. Sandrucci, A. Tamburini - In: Livestock, climate change and food security : conference abstract book : 19-20 May 2014, Madrid, Spain[s.l] : Wordpress, 2014 May. - pp. 20-20 (( convegno Livestock, climate change and food security tenutosi a Madrid nel 2014.
Abstract:
About 45% of Green House Gas (GHG) emission from livestock sector is methane. In cow milk production, enteric
emissions load for nearly 45% on the total GHG emissions and CH4 represents about 50% of GHG from enteric and
manure fermentations. Sorghum is growing in popularity as alternative silage crop for dairy cattle feeding, because of
lower requirements of water and agronomical inputs in comparison to maize. The aims of the study were to estimate
the e ects of replacing maize silage with sorghum grain and sorghum forage silages on the global warming potential
(GWP) of milk production and to compare the results obtained using both estimated and in vivo measured enteric
methane emissions. The study compared three di erent scenarios where cropping systems and cow diets were based
on maize silage (MS), whole plant grain sorghum silage (WPGS) and forage sorghum silage (FS). The GWP (kg CO2
eq. 100-year horizon) of milk production in the scenarios was evaluated through a ”cradle to farm-gate” Life Cycle
Assessment. The emissions related to on-farm activities (forage production, fuel and electricity consumptions, manure
and livestock management), o -farm activities (production of fertilizers, pesticides, bedding materials, purchased feed,
replacing animals, electricity, fuel) and transportation were considered. Functional unit was 1 kg Fat and Protein
Corrected Milk (FPCM). Enteric emission of methane of lactating cows was obtained from in vivo experiment with
respiration chambers or from the equation by Ellis et al. (2007) based on ration DM, NDF, ADF and DMI. Methane
estimated from enteric fermentation and manure storage was the major contributor (46%) to GHG for milk production
and 73.1% of estimated methane produced derived from enteric emission. Daily enteric methane emission per cow
estimated by equation was higher than the average emission measured from in vivo trials with the three diets (363 vs
312 g/d per cow). The average value of GWP using the estimated values of methane was 1.53 g CO2 eq./kg FPCM. The
lowest CH4 emission per kg FPCM was obtained with MS diet, particularly when in vivo CH4 enteric measurements
were used. As a consequence MS diet was the best option, in terms of GWP per kg FPCM. Purchased concentrate feed
showed a great load on GWP (29% on average), especially in the FS scenario, because of the high o -farm purchased
energy feed. Contribution of crop production on-farm to GWP was lower for sorghum scenarios, particularly FS, due
to reduced water and fertilizer use.
Tipologia IRIS:
03 - Contributo in volume
Elenco autori:
L. Bava, S. Colombini, M. Zucali, A. Sandrucci, A. Tamburini
Link alla scheda completa:
Titolo del libro:
Livestock, climate change and food security : conference abstract book : 19-20 May 2014, Madrid, Spain