Enviado por davaro el Lun, 01/09/2023 - 11:35
Aloe Vera For Dairy Cows: A Guide to Improving Feed Digestibility, Milk Production and Methane Emissions
Introduction to the Problem
Methane is a major cause of climate change. It’s the second biggest contributor, after carbon dioxide, and responsible for about half a degree of warming. A single cow emits up to 100 kg of methane per year. A Food and Agriculture Organization of the United Nations (FAO) report showed that total emissions from global livestock are 7.1 Gigatonnes of Co2-equiv per year, representing 14.5 percent of all anthropogenic GHG emissions.
Cattle (raised for both beef and milk, as well as for inedible outputs like manure and draft power) are the animal species responsible for the most emissions, representing about 65% of the livestock sector’s emissions. In terms of activities, feed production and processing (this includes land use change) and enteric fermentation from ruminants are the two main sources of emissions, representing 45 and 39 percent of total emissions, respectively. Manure storage and processing represent 10 percent. The remainder is attributable to the processing and transportation of animal products.
Just to understand the size of the emissions, cutting across all activities and all species, the consumption of fossil fuel along supply chains accounts for about 20 percent of the livestock sector’s emissions.
On a commodity-basis, beef and cattle milk are responsible for the most emissions, respectively, contributing 41 percent and 20 percent of the sector’s overall GHG outputs.
In general, 44% of livestock emissions are in the form of methane. The remainder is shared almost equally between nitrous oxide at 29% and CO2 at 27%.
This means that livestock supply chains emit:
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Gt CO2-eq of CO2 per annum, or 5 percent of anthropogenic CO2 emissions (IPCC, 2007)
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3.1 Gt CO2-eq of CH4 per annum, or 44 percent of anthropogenic CH4 emissions (IPCC, 2007)
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2 Gt CO2-eq of N2O per annum, or 53 percent of anthropogenic N2O emissions (IPCC, 2007)
And while CO2 is the most prevalent greenhouse gas in the atmosphere, methane is estimated to be 26 times more potent when it comes to global warming.
Methane reduction is one of the objectives to reach to keep the goal of limiting warming to 1.5 C within reach.
Our Solution
As most people know, aloe vera is a widely prevalent plant in the tropics, which has been used for its medicinal properties since ancient times.
Aloe vera grows naturally in arid regions of Africa, Asia, Central and South America, as well as in Australia and some U.S. States. But today Mexico is the leading place for commercially grown aloe vera for different uses and several industries.
Aloe has applications across a variety of fields including food, beverages, cosmetics, pharmaceuticals, agrochemicals, veterinary, animal nutrition and more. In this article we will focus on the use of aloe vera for cattle feed to improve feed digestion and milk production in dairy cows. But even more, along with these effects Aloe Vera can also help reduce methane emissions by improving the digestibility of the pelleted feed and decreasing methane produced during rumen fermentation.
It means excellent news for climate change efforts, since livestock farming is known as one of the major drivers of climate change, due to the substantial contribution of greenhouse gas (GHG) emissions including methane and nitrous oxide to the environment. In short, Aloe Vera can help dairy cattle reduce enteric methane production and consequently carbon footprint of milk production.
Some authors suggest that for any sustainable adoption of methane mitigation methods by farmers in the ruminant production system, methane mitigation strategies should improve animal production without animal health issues and residues in food products (Patra et al., 2017).
A recent study demonstrates that feeding of aloe vera at 20 g/kg dry matter intake to dairy cows increased milk production and decreased methane production, which combinedly decreased methane production per unit of milk production substantially without health effects. Thus, feeding of aloe vera could be beneficial for sustainable and cleaner milk production decreasing environmental burdens of residue disposal problems and ruminal methane production.
This research concluded that aloe vera feeding mixed to daily ration given to dairy cows increased milk production by 25% and simultaneously reduced methane production by 15%. Furthermore, it decreases methane emission from animal origins without compromising production.
There are many benefits of aloe vera for dairy cattle. The benefits of aloe vera include improving feed digestion, milk production, and decrease methane emissions from the rumens of dairy cows. These benefits are due to several factors, one of them being the presence of aloe based compounds that improve the digestibility in the diet of dairy cattle.
Inclusion of aloe vera not only decreases methane production, but increases feed digestibility and total volatile fatty acid concentration. Nutrient digestibility and concentrations of fat, protein, and lactose in milk are not affected, but yields of these milk components increase due to aloe vera feeding. Feeding of aloe vera improves delayed type of hypersensitivity without affecting other blood variables adversely.
Improvement in Digestibility of Pelleted Feed
In order to improve milk production, dairy cattle are fed a diet consisting of untreated pelleted feed. This feed makes up most of the diet of low and medium milk production animals. The types of feed available for dairy cattle vary from feedlot to feedlot, across organic and non- organic soils, and in the climate of the feedlot.
Most of this feed is made up of corn, soybeans, and other animal feeds. In some areas, feedlot practices use feed made from corn, soybeans, or other industrial stocks. As mentioned above, inclusion of aloe vera increases feed digestibility and total volatile fatty acid concentration.
Improvement in Milk Production in Dairy Cows
As noted above, the type and amount of feed provided to dairy cattle varies from feedlot to feedlot. This is due to a number of factors, including the type of feed being provided, the weather, space and environment conditions, the milk yield of the animals produced, and the health of the animals. While organic feedlots provide higher milk production rates than non-organic feedlots, these feedlots also have a higher incidence of diseases and mechanical problems.
The supplementation of plant extracts or their secondary metabolites as feed additives alters the ruminal biohydrogenation of dietary fatty acids by showing an antimicrobial effect on certain bacterial species involved in the rumen biohydrogenation process and by increasing the useful intermediates, thereby boosting the milk fatty acid profile (Joseph et al., 2010).
A unique opportunity to enhance milk’s antioxidant properties has been provided by increasing evidence of the transfer of secondary metabolites into milk and milk fat. Aloe vera is rich in plant secondary metabolites and positively alters biohydrogenation process in rumen to augment nutraceutical value of milk (Patra, 2016).
Reduced Methane Emissions from Rumen Fermentation
It is believed that the diet of dairy animals includes milk from heifers and winter calves.
The unique digestion of milk from heifers and winter calves is accomplished via the action of two enzymes: luteinizing hormone (LH) synthase and steatid hormone. These enzymes are believed to be responsible for the efficient breakdown of milk idols into lutein and sucrose. When feed is provided to dairy cattle that contains ervatives and other substances that increase the production of lutein and thus increase milk yield, it is known as the “milk supply”. When feed is provided that protects the animals from danger and diminishes the amount of lutein being produced, it is known as the “defense”.
Polyphenols, especially tannins, inhibit ruminal microorganisms at greater doses (>40 g/kg diet) depending upon the type of chemical structures and molecular weights (Patra et al., 2012). The phenolic compounds present in aloe vera may likely increase the activities of some categories of microbiota, preferably, fiber-degrading populations, which was further substantiated from increased microbial biomass production (MBP) in the in vitro study of the mentioned study.
The antioxidant activities of aloe vera may be responsible for the increased microbial activities (Tagliapietra et al., 2013). Also, tannins at a low concentration may stimulate the growth of bacteria by interacting with the cell surface proteins of bacteria, which facilitates cell transport functions or improves enzyme activities (Mole and Waterman, 1985; Krause et al., 2005). Therefore, a low concentration of phenolics and antioxidant compounds may be useful in improving ruminal fermentation, whereas high concentration of polyphenols, in particular tannins, may be detrimental for microbial activities. Total volatile fatty acid (VFA) concentrations increased at the lower doses (10 to 30 g/kg), which was due to increases of both acetate and propionate production by the ruminal microbiota. Degradability of neutral detergent fiber (NDF) increased in the in vitro study, and acetate is mainly produced from NDF digestibility by the cellulolytic bacterial populations. Propionate concentration and proportion, particularly, increased, which may likely be due to rechanneling of greater metabolic hydrogen towards propionate metabolic pathways as a result of inhibition of methanogenesis by aloe vera (Patra et al., 2017). Increased propionate production is stoichiometrically beneficial not only for decreasing methane acting as a hydrogen sink, but this fermentation pathway does not produce carbon dioxide. Therefore, feeding of aloe vera may also decrease carbon dioxide production arising from the ruminal fermentation.
Conclusion
For ruminants -cows, mainly- the greatest promise involves improving animal and herd efficiency. This includes using better feeds and feeding techniques, which can reduce methane (CH4) generated during digestion as well as the amount of CH4 and nitrous oxide (N2O) released by decomposing manure.
To diminish the belching problem, farmers are turning to feed additives that interrupt the microbial processes in a cow's gut that produce methane.
Reducing the amount of methane produced by the livestock industry offers economic benefits to producers in addition to the environmental benefits. At the heart of methane production is the microbes that reside within the rumen. Diet can be used to modify microbial populations in the rumen and thus reduce methane emissions and improve animal performance.
The use of aloe as natural digestive aid to mix with the daily ration to feed cattle is an attractive option.
In this article, we described some benefits of aloe vera for dairy cattle, such as its ability to improve feed digestion, which allows for less waste to be generated and for less energy to be released into the atmosphere. The overall benefits of aloe vera for dairy cattle include reduced methane emissions, improved feed digestion, milk production.
