Assessing Ram Fertility

Hello, Reed Redden here, Texas A&M Sheep and Goat Extension. I'm going to talk to you today about ram fertility and with me we have Jordan Moody. Jordan is starting her Ph.D. program here at the AgriLife Center in San Angelo and Jordan's main focus for her Ph.D. work is going to be on ram fertility. Often within the research world we've kind of focused on ewes and how to improve fertility in the ewes but maybe we've overlooked some things in the rams and some needed research is out there but just on the basic level what should ranchers do to start assessing ram fertility or infertility? So I think the first thing that they can do is conduct a breeding soundness exam so they can walk up to their rams evaluate them for body condition score feet and legs as well as teeth because all of these things are going to be really important so that ram can maintain condition throughout the breeding season do his job and cover as many ewes as possible. All right so if a rancher feels uncomfortable with this who would they go out to and what kind of services would they expect if they're reaching out to their veterinarian to do this for them? So you go to your veterinarian and your veterinarian is going to do the same visual assessment that you do at home but then they initially might take a spiral circumference measurement and then they also might take a semen sample and evaluate that sample for the morphology or the shape of the sperm and the motility or how well it moves. Okay so you take your rams in and a few of the rams test poorly what are common causes that would relate to a ram that's going to have a poor semen test? So a big cause of ram infertility especially here in the west is B. ovus or brucella ovus. Okay so brucella ovus tell us a little bit more about that one. So brucella ovus is a bacterial infection it primarily affects rams and it causes inflammation in the epididymis which is located in the bottom part of the testicle. So it's transmitted from ram to ram and sometimes from ram to you. Okay so rams are giving them to other rams and can really mess up that that ram battery. So if a person is concerned about this how do they test for B. ovus? So B. ovus can be in really advanced cases if you palpate the testicles you might feel a swollen or inflamed epididymis that could be an indicator of B. ovus but really the only way you can test for sure is to take a blood sample and send that into a veterinary diagnostic lab for an antibody test. Okay now you said this is common in the west what you know do you have a number on research that's been published or studies that have been done on the actual prevalence rate across you know western flocks? So there's a study done in Wyoming that looked at several different flocks and it showed that the larger operations had a higher prevalence of B. ovus and some of those flocks had upwards of 30 percent of their rams infected with B. ovus. Okay yeah so commonly they're buying rams from a ram sale that tests for B. ovus and they get the large battery but you know there might be a deal their neighbor's got a ram an extra ram and you pick one up unfortunately if those have B. ovus they're going to spread it to the rest of the ram battery in there so that can be a serious problem. While we're on this ram fertility side of things I also get a lot of questions about you know how many rams should I be using to breed say 100 ewes? What's a general recommendation and what are the things that go into kind of adjusting that recommendation? So I think the standard recommendation is about three to four rams per 100 ewes especially in the west but things to consider are the size of the pasture that you're breeding in the total number of sheep or number of ewes that you're going to have in that pasture and how many other rams you're going to have and if you're going to test before you turn out rams. Okay so if y'all have been following our YouTube channel or Facebook page you may have seen some of the research that Jake Thorne who's another PhD candidate at the lab has been doing with parentage testing of lambs and one of the things that we're finding out is you know sometimes 75% of the lamb crop was sired by 25% of the sires. What do you think's going on there and you know what can you share our audience about that? I think a few contributors to that are going to be infertility of some of your ram battery and lack of testing and lack of breeding soundness exams before the breeding season. Additionally libido can play a role and competition between other rams can also play a role. Okay so libido tell us a little bit more about libido and kind of how that factors into this scenario because you know a lot of these studies that he's done these rams were checked beforehand and it wasn't an infertility so what is libido and is there a test for that? So libido is basically a ram's drive to breed ewes and a ram's drive to compete with other rams to breed ewes. So sometimes you might just get a ram that's a dud and he just doesn't want to go out and cover ewes and that could cause that could be a huge money suck for you and it could cause him to sire a fewer amount of lambs than the rest of the ram battery. All right well good deal. Well thanks for tuning in and watching this video on ram fertility or infertility for that so stay tuned and we'll see you at the next video.