Custom Heifer Raiser ‐ We Define Quality!

Meet Our Team

Who's On Our Team?

  • Family Managers: Marty & Mary Weiss and Bronson & Louise Weiss

  • Employees: Juan Carlos Diaz, Manuel Rodriquez, Juan Flores, Fransisco Morales, Fransisco Rivas, Harlee Barth, Hector Vazquez, and Jesus Casarez

In-House Breeder

JUAN CARLOS DIAZ grew up in the small community of Yuma Colorado and has had the opportunity to work in the dairy industry for 12 plus years. He started as a farm hand on a 600 cow dairy where he was able to grow along with the farm to becoming dairy manager and milking 2500 cows. Having started from the bottom he was able gain experience and knowledge in all the areas of dairy, from maternity and raising calves to treating sick cows and artificial insemination.

He understands succesfull nutrion and herd management practices at a calfs early age play a crucial role in the health and productivity of the cow. Juan is bilingual and possesses excellent reproductive, herd health, and nutritional skills. Juans passion for working with cows and his natural leadership skills paved the way for his success in the industry. Juan is ready to be a leader for your team and is eager to use his abilities and knowledge to bring success to your farm. His goal is to deliver quality, loyalty, and trust.

In his spare time Juan enjoys spending time with his family, wife Brenda Ivone, daughter Adahli (11), and sons Jadiel (7), and Liam (1). They are of Christian religion and are very involved with the community church Centre of New Hope. Juan also enjoys sports, fishing, and the outdoors.

Select Sires Breeding Team

JAY HILL was raised on a high mountain cattle ranch in western Colorado. He attended Northeastern Junior College in Sterling, Colorado. After graduation in 1995, he started working for Colorado Cattle Services, an independent select sires distributer. He attended CSU with a major of Animal Science while working full time in the heavily beef area of eastern Colorado.

In 2000, Colorado Cattle Services sold to Cache Valley Select Sires, at which time he began servicing southwestern Nebraska. Over the last 15 years the business has evolved from a primarily beef tank delivery area into a beef technician area. In the last ten years the dairy business has grown to being the primary focus. He lives in Sterling, Colorado with his wife of 20 years Jill and their 3 boys Bryce, 17, Bryan, 15 and Brandyn, 13.


AARON SHIFLETT is a Reproductive Specialist for Select Sires Mid-America. Aaron grew up on a dairy and beef operation in the Shenandoah Valley of Virginia. He studied Dairy Science for two years at Virginia Tech before moving to Colorado in 2005 to work with a veterinarian who specialized in the management of reproduction on dairies. While working with this practice, he learned how to utilize ultrasound in the reproductive management of dairies as well as how to implement different synchronization protocols and breeding strategies.

While working with the veterinary practice he finished his undergraduate degree in Animal Science from Colorado State University. In 2011 Aaron began work as a herdsman at a dairy in Berthoud, CO, where he took care of the dairies breeding needs as well as employee management and fresh/sick cow responsibilities. In 2013 he started with Select Sires Mid-America and now works together with the sales staff, technicians, and clients in Colorado, Wyoming and Nebraska to best serve each client’s reproductive needs.

Senior Dairy Specialist

TIM THOMPSON is a Senior Dairy Specialist with Provimi – NA – a division of Cargill Premixes and has been with the company since 1995. He is responsible for Nutrition Tech support to their dealer network throughout Minnesota, Wisconsin, Iowa, North & South Dakota, Colorado, Texas, and Kansas. Currently, he services about 200,000+ cows on numerous herds – approximately 5-600 or so. He also works with 40-45 outside salesman/consultants and over sees their accounts. In addition, he personally handles the ration work to some 8000 cows and 6000 heifers on 18 herds.

He has played an intricle part in the development of the AAMPS program over the last 21 years, making it user-friendly as well as developing a true working model to be used to least cost diets in the field.

Over the last 10+ years, his responsibilities have included providing dairy nutrition and management tech support to one of the larger feed companies in Canada (Hi Pro Feeds) as well as the largest feed company in Japan (Feed One).

He is currently an active member of the American Registry of Professional Animal Scientists.