Since 1972, when Mr Ruddenklau founded the Newhaven Perendale stud, there had been many highlights, but the best part was the people he and his wife Robyn had met.
And it was very satisfying to hear about the "gains and the wins" of their clients.
There had been clients in hoof and hook competitions, national Golden Fleece awards, and national ewe hogget competitions, to name a few; and that was the most rewarding part of ram breeding, he said.
During a client focus field day at Newhaven Farms, there were representatives from all three of Mr Ruddenklau's original ram clients: Doug Blanchard's son Graeme, Jim Hutton's sons Mark and David, and Michael Moynihan.
Looking back to the sheep and beef farming scene in the late 1970s and early 1980s, it was "just so different" to the present day.
In those days, it was quite usual for farmers to almost live with their ewes during lambing, and ewe and lamb deaths were quite high.
During the 1970s, probably more than 60% of all sheep farm income was derived from wool.
Mr Ruddenklau recalled articles about "progressive" farmers who chose not to put their rams out, as they were solely farming wool. As for lamb production, getting up to 13kg "nearly got bragging rights".
"Things have moved an awful long way in the last 40 years," he said.
There had been many trends in sheep breeding and the introduction of a lot of crossbreeding and exotic genetics, but he believed the Perendale would continue to excel.
As the new generation of breeders and new technology came through, the future was looking very exciting.
Mr Ruddenklau is chairman of the Perendale New Zealand national progeny trial, an initiative which was exciting both for the breed and the industry, he said.
He paid tribute to his wife and family for their commitment, saying it had been a team effort.
One of their daughters, Jane, and her husband, Blair Smith, started operational management of Newhaven Farms, alongside Mr and Mrs Ruddenklau, in 2008.
Mr and Mrs Smith were the supreme winners of the Otago Ballance farm environment awards this year, and a field day will be held at Five Forks on Friday.
Mr Ruddenklau believed it was vital to remain focused on what opportunities there were within the sheep industry.
It was important to remember there were always climatic challenges and the industry also had to keep costs under control.
Mr Ruddenklau was particularly concerned about district and regional councils and the way the rating system worked.
"It's really an asset tax that we're getting hammered with now."
He had some concerns about the direction of corporate ownership, saying he was still a very strong believer in family-owned operations. It was also important to have passionate people involved in ram breeding.
Mr Smith outlined a joint venture that Newhaven had embarked on in Victoria, Australia, with Mount Monmot Perendales and which had been launched last year.
Newhaven sent over 33 ewes and the first crop of rams would be available for sale in Australia in December.