Source: Tribune India [edited]https://www.tribuneindia.com/news/amritsar/fungal-hit-barseem-strikes-cattle-232458
A fungal disease in the seasonal green fodder, barseem, is causing illness among cattle in the district. The diseased fodder crop was causing losses from many aspects, and animal deaths too had been reported from certain villages. Some of the farmers have harvested their fodder crops in advance by more than 2 months.
According to the information collected from Rasulpur Kalan, Raspulpur Khurd, Alawalpur, Dugalwala, Benwalipur and other villages, the same disease appeared last year  as well. Satnam Kaur, sarpanch of Rasulpur village, said her cow was infected on 27 Mar 2021. In spite of treatment given to the cow, it died on 28 Mar 2021. She said the infected cattle stop taking fodder, and milk production too sharply decreased.
Sarwan Singh, Dharam Singh and Dilbag Singh, secretary of the Raspulpur area, said they had tilled their fodder crops months in advance and had destroyed the crops.
The frightened farmers said that infected cattle started showing signs of the disease a few days ago, including secretion of froth from mouth.
Dr Harinderpal Singh Chandi, Deputy Director, Animal Husbandry Department, said that as he had not been informed by any of the animal farmers before now, he was going to instruct the staff of the department working in the field to collect information regarding the disease, and treatment would be provided to the infected animals.
The Deputy Director said that this disease is often seen at the change of season when fodder crops grow quickly, and the lower part of the standing crop becomes shaded, which allows the fungal disease to develop and sicken the animals.
[Byline: Tarn Taran]
- A yellowish-flowered annual clover (_Trifolium alexandrinum_) native to the Mediterranean region and Asia and grown for forage in warm areas.
- The Alexandrian or Egyptian clover (_Trifolium alexandrinum_) the principal forage-plant and soil-plant of Egypt.
- An Egyptian clover (_Trifolium alexandrinum_) extensively cultivated as a forage plant and soil-renewing crop in the alkaline soils of the Nile valley, and now introduced into the southwestern United States. It is more succulent than other clovers or than alfalfa, also called Egyptian clover." Source: https://www.wordnik.com/words/berseem
Fungal diseases on plants can be quite harmful to animals. They can cause a variety of illnesses, affecting the skin, the gait, and the overall health of the animal. Fungal-infected plants may be difficult to identify visually, thus making these infected plants easy to harvest along with the non-infected plants. Sometimes fungus can be seen on the seed head, and sometimes it is not obvious on the harvested plant. The fungus may not have profound effects on the host plant but can have severe consequences for the animal(s) ingesting it.
Various types of mold on the clover can produce different toxins. Based on the description above of frothy, slobber/secretions on the mouth, I would investigate the clover for the toxic agent slaframine.
"Slaframine is an indolizidine alkaloid [produced by the fungus _Slafractonia (previously _Rhizoctonia) leguminicola_, http://www.speciesfungorum.org/GSD/GSDspecies.asp?RecordID=552677
. - Mod.DHA] recognized as the toxic principle, and it is stable in dried hay and probably in silage. Horses are highly sensitive to slaframine, but clinical cases occur in cattle as well. Profuse salivation (salivary syndrome) develops within hours after 1st consumption of contaminated hay; signs also include mild lacrimation, diarrhea, mild bloat, and frequent urination. Morbidity can be high, but death is not expected, and removal of contaminated hay allows recovery and return of appetite within 24-48 hours. A related alkaloid, swainsonine, produced by _R. leguminicola_, has caused a lysosomal storage disease from prolonged exposure, but its importance in the salivary syndrome is not confirmed. Diagnosis is tentatively based on recognition of the characteristic clinical signs and the presence of "black patch" on the forages. Chemical detection of slaframine or swainsonine in forages helps to confirm the diagnosis. There is no specific antidote to slaframine toxicosis, although atropine may control at least some of the prominent salivary and GI signs. Removal of animals from the contaminated hay is essential.
Prevention of Rhizoctonia infection of clovers has been difficult. Some clover varieties may be relatively resistant to black patch disease. Reduced usage of red clover for forages or dilution with other feeds is helpful."
Another example specifically calls out horses, but the likelihood of it occurring in cattle is very high:
"White clover (_Trifolium repense_) is a glabrous perennial with trifoliate leaves which is widely distributed in moist temperate zones, Mediterranean areas and some cool subtropical parts of the world.
It was originally introduced from the Mediterranean. During the long daylengths and high temperatures of summer, the axillary buds on the stolons produce inflorescences rather than vegetative stolon branches. Most leaves have a white "V" mark, and are shiny on the underside, with white flowers. It is accompanied by white florets at the end of long peduncles that are often tinged pink, becoming deflexed with age.
Toxic components [_Trifolium repense_ slobbers in horses]: White clover contains cyanogenic glycosides. In young leaves, the cyanogen levels may reach 350 mg of HCN per 100 g of tissue. Cyanogenesis is controlled by 2 independently inherited genes in white clover. Only plants possessing at least one dominant functional allele of both genes liberate HCN when damaged. Some cultivars are capable of liberating HCN and others are not. White clover can also occasionally become infested with the mold _Rhizoctonia leguminicola_, which appears as a rust color seen on the top side of the clover leaf. This mold produces slaframine, which is an indolizidine alkaloidal mycotoxin that causes a condition known as slobbers in horses that ingest it. It appears in pastures during periods of hot and humid weather." Source: http://www.horsedvm.com/poisonous/white-clover/
We hope for the best for these animals and their owners. Hopefully, this event will be resolved soon. - Mod.TG