Effects of dietary optimization on milk production and emission of greenhouse gas in Holstein cows
| Autor: | Marielena Moncada Laínez, 馬蓮娜 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 The objective of this study was to evaluate the effect of different supplementations (yeast, tea leaves, red sorghum, soybean oil, and Chinese soapberry) on the reduction of methane (CH4) in vitro and in vivo conditions. In the first stage, 5 different supplementations were added to the ruminal liquor of a cow fed Total Mixed Ration and incubated for 24hrs. Results show that all the supplementations significantly decreased CH4 concentration compared to the control treatment (P≤0.05). CH4 concentration tended to be higher during the first hours of incubation in the control treatment compared to all supplementations. However, the supplementations reduced CH4 concentration during the first part of the incubation. This demonstrates that the supplementations used in this experiment are very effective to reduce CH4 concentration as early as 2hrs after supplemented. All the supplementations, but especially soybean oil, have the potential to diminish greenhouse gas (GHG) production in vivo and may be alternatives for the mitigation of global warming. In a second stage of research, the effect of tea leaves and soybean oil supplementation on milk composition of low yield dairy cows in a tropical climate. Three ruminally cannulated dairy cows during their first lactation were used. Results show that soybean oil supplementation increased milk fat percentage without affecting milk yield or protein, lactose or solid nonfat content in milk. The acetate to propionate ratio was lower after soybean oil supplementation since, under heat stress, an extra boost of energy may have greater effect over milk fat production than the volatile fatty acid profile. On the other hand, a positive effect of tea leaf supplementation on milk yield was found, due to the caffeine content in the tea and an increase in rumen butyrate and propionate. These results suggest that soybean oil supplementation is an alternative for solving a negative energy balance in Holstein cows due to heat stress in tropical countries, while also decreasing GHG emissions. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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