An animal welfare officer has recalled the “pure aggression” he saw in a horse owned by a Suffolk woman accused of mistreating animals.

Jonathan Jackson, field officer for World Horse Welfare, was bitten by a stallion during a raid on Home Farm, owned by Marylin Read, in Benhall, Saxmundham, last May.

Mr Jackson visited the farm a day after attending a nearby field, also owned by 77-year-old Read, where he had been notified of horses being kept “in a poor way”.

He told Lowestoft Magistrates’ Court that the field in Kiln Lane was “horse sick” due to lack of pasture management. Mr Jackson said three of five miniature Shetland ponies he saw were “seriously underweight” and were signed over to the World Horse Welfare by Read, who he said would not allow RSPCA inspectors to revisit her home. A warrant was executed the following day, when Mr Jackson said he found a horse in a pen “two-foot deep in horse muck”.

While standing in an adjoining pen, he said the horse sunk its teeth into his arm with aggression he had never before seen in a stallion. Days after being taken to the charity’s stables, and kept in an environment away from other stallions, he said the horse’s behaviour changed entirely.

A total of 28 horses and 24 dogs were removed from Home Farm, and five horses taken from Kiln Lane.

Defending Read, Nigel Weller said Mr Jackson’s system of relying on memory and photos allowed potential for confusion or forgetting information. Mr Jackson said his role had been as a “facilitator” for the attending vet, but Mr Weller said giving evidence on body condition suggested he was there in a larger capacity.

Referring to Mr Jackson’s initial visit to Kiln Lane, he suggested that the thickness of the ponies’ coats would enable body condition to be calculated on sight alone.

Mr Jackson argued that even someone with poor eyesight would have come to his conclusion, adding that the condition of every animal taken from Read’s property was, in his opinion, “prosecutable”. Mr Weller then argued that Read had actually met the needs of the stallions by keeping them in a herd unit, and that there was no need for them to socialise with humans.

Mr Jackson said conditions contradicted that claim and that he witnessed some horses attacking each other.

The trial continues.