Data di Pubblicazione:
2014
Citazione:
NUTRITIONAL AND FEEDING STRATEGIES TO REDUCE METHANE EMISSION FROM DAIRY COWS / M. Pirondini ; tutor: G. M. Crovetto ; coordinatore: G. Gandini. DIPARTIMENTO DI SCIENZE AGRARIE E AMBIENTALI - PRODUZIONE, TERRITORIO, AGROENERGIA, 2014 Mar 10. 26. ciclo, Anno Accademico 2013. [10.13130/pirondini-mario_phd2014-03-10].
Abstract:
The general aim of the present thesis was to evaluate the effects of several nutritional and feeding strategies to reduce methane (CH4) production from dairy cows. The thesis includes the results of three experiments conducted with the financial support from EU Research Project LIFE 09 ENV/IT/0214 Gas-Off.
The aim of the first study was to measure total gas and CH4 production from 30 total mixed rations (TMRs) fed to dry and lactating cows in 20 commercial dairy farms of the Po Plain (Italy). Samples were analyzed for chemical composition, in situ 48 h fiber digestibility (NDFD) and in vitro gas production (GP) and CH4 concentration at 24 h of incubation. Neutral detergent fiber digestibility of TMRs from dry and lactating cows was identical (52.1%; P=0.995). The TMRs fed to dry and lactating cows differed for GP (43.0 and 54.4 mL/200 mg DM, respectively; P<0.001) and CH4 (7.24 and 8.85 mL/200 mg DM, respectively; P=0.001), but not for CH4 as percentage of GP (24.3 and 23.7%, respectively; P=0.286). Data were also analyzed dividing the TMRs into quartiles depending on “starch:ADF” ratio; the average ratios of the groups 1, 2, 3 and 4 were 37, 77, 116 and 138, respectively. Increasing “starch:ADF” ratio determined a higher GP: 42.2, 51.4, 55.1 and 56.2 mL/200 mg DM for groups 1, 2, 3 and 4, respectively (P<0.001), whilst CH4 (mL/200 mg DM) was lower (P<0.001) for group 1 (7.12) in comparison with the others (8.82 on average). Acetate, expressed as percentage on total volatile fatty acids (VFA) decreased for increasing “starch:ADF” ratio (P=0.009), whereas butyrate tended to increase (from 8.11 to 9.23% on total VFA; P=0.069) and the “acetate:propionate” ratio to decrease (from 3.35 to 3.09; P=0.082). The lack of a higher CH4 concentration in GP from diets richer in fiber might be attributed mainly to the relatively short time of incubation.
The second trial was aimed to evaluate at first the effects of 18 essential oils, yeast, Quebracho tannin and Quillaja saponin on ruminal methane and gas production (GP) in vitro.
A lactating cow diet was incubated with rumen inoculum. Doses of the additives (mg/L) were: essential oils=500; tannin=67; yeast=8.35 and 16.7; saponin=300.
Lemongrass, estragole, eugenol, geraniol, limonen, thyme oil and thymol produced less gas (overall mean 33.8 mL/200 mg DM) than control (43.6 mL/200 mg DM; P<0.001). Methane produced (mL/200 mg DM) by guaiacol (10.7), lemongrass (9.6), limonene (11.4), thyme oil (10.9) and thymol (2.1) was lower than control (12.5) (P<0.001). Methane percentage on total GP was lower (P<0.001) for cinnamic alcohol (25.4), guaiacol (24.5), thymol (19.7) and vanillin (26.3) than control (28.8).
In the second part of the experiment, thymol, guaiacol and yeast were added to the diet of dry fistulated cows to determine in situ NDF digestibility (NDFD) of six forages and in vivo dietary NDFD. Thymol and yeast decreased in situ NDFD after 24 h (33.9% and 33.5% vs 38.1%; P=0.008). Thymol decreased in vivo total tract NDFD (40.8% vs. 51.4%; P=0.02).
Differences in GP and methane levels were registered within classes of additives. A careful selection of additives may allow for the manipulation of ruminal fermentation.
The third experiment was conducted to evaluate the effects of diets with different starch contents and fish oil (FO) supplementation on lactation performance, in vivo total-tract nutrient digestibility, N balance and methane (CH4) production in lactating dairy cows.
The experiment was conducted as a 4×4 Latin square design with a 2×2 factorial arrangement: two levels of dietary starch content (low vs high), the presence or absence of FO supplement (0.80% DM) and their interaction were evaluated. Four Italian Friesian cows were fed one of the following f
Tipologia IRIS:
Tesi di dottorato
Keywords:
methane ; dairy cow ; additives ; NDF digestibility ; starch ; fish oil
Elenco autori:
M. Pirondini
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