September 21, 2022

 

Plant extracts beneficial for China's dairy cows but use is limited

 

The population of Holstein dairy cows in China had dropped by more than half from 10 million in mid-2010 to 4.71 million in 2019, before rebounding to 5.76 million last year.

 

The total milk production of Holstein dairy cows exceeded that in 2012 due to the substantial increase in their annual yield, a sign that the nutritional technology and breeding management level of Chinese dairy cows have greatly improved.

 

With most antibiotics for use in feed banned in China, it is necessary to source more functional additives as alternatives. Functional additives that promote the growth of rumen microorganisms, modify the rumen microbial flora, stabilise the rumen's PH value, prevent rumen poisoning and improve the rumen's methane emission are the key functions of additives for dairy cattle.

 

Yeast and Aspergillus oryzae have been widely used as functional additives to increase milk production. However, the application of plant extracts in dairy cattle has only been introduced in the past five to six years.

 

Plant extract products have revealed good application prospects in Europe as they produce no drug residues. But their inadequate use in diets, coupled with poor mixing uniformity of total mixed ration (TMR), has resulted in the inconsistent efficacy of plant extract products.

 

Currently, the only plant extract product approved for use in European dairy farming is Pancosma's XTRACT range, which contains three main plant extracts (cinnamaldehyde, eugenol and chili oleoresin). Such extracts are also widely used in China. Additionally, yucca extract products have been promoted recently. One active ingredient in yucca, saponins, can indirectly reduce the production of ammonia in the rumen through its anti-protozoal ability.

 

As for plant essential oils, the efficacy of cinnamaldehyde is officially recognised while compounds of the terpenoid group are also commonly used in feed additives. However, the effect of these products on dairy cattle remains unclear, hence their limited usage.

 

Plant extracts like flavonoids, tannins and eucalyptus oil have been studied in dairy cattle breeding. Yet, these products have no known advantages compared with other additives having the same function.

 

In China's "Catalogue of Feed Raw Materials", 117 kinds of natural plants with medicinal properties can be used in livestock feed. Nonetheless, not many are used in dairy cows and among these varieties, extracts of motherwort, astragalus and hay are only used in small quantities.

- Shi Tao, eFeedLink