The past decade has seen dramatic change in basic and applied reproductive biology. The technical revolution that began with artificial insemination and embryo transfer in the last half of the twentieth century reached new heights with the widely reported cloning of sheep and cattle by nuclear transfer from somatic cells. Similarly, less well publicized technical advances, such as in vitro maturation of oocytes, embryo culture, gene modification and transfer, embryo splitting, identification and isolation of X and Y bearing spermatozoa, sexing of embryos prior to transfer, and early pregnancy diagnosis, may also be used to advantage by cattle and sheep producers to increase productivity and ease of management and improve the health and genetic composition of flocks and herds. Although artificial insemination and embryo transfer have been widely accepted and adopted by the dairy industry, these techniques are less commonly used in the beef cattle and sheep industries. However, the improvement in animal health and productivity in the dairy industry has not gone unnoticed and use of these sophisticated reproductive technologies in the beef cattle and sheep industries is expected to increase dramatically during the next decade. One of the objectives of our work in the W112 project is to provide the scientific and technical expertise that will support and encourage development, acceptance, and application of technology-based management tools that will improve the productivity and profitability of livestock producers in the Western states.

Despite recent advances in reproductive technology, cattle and sheep producers are still faced with the persistent problem of low fertility. Indeed, recent work indicates that the fertility of domestic ruminants, even under optimal conditions, is about 50%. That is, at best only one of every two natural or artificial inseminations results in the birth of a healthy calf or lamb. The poor fertility of domestic species is reflective of cumulative loss due to poor fertilization efficiency, high embryo mortality, and spontaneous abortion.

One must also recognize that these statistical estimates of fertility reflect the response noted in animals maintained under highly controlled conditions. The unique and varied environments facing domestic animals on the range lands of the Western states are likely to reduce the efficiency of fertilization and increase embryonic and fetal loss. Indeed, the Western and Southwestern states included in the W112 project encompass a land mass that represents more than 50% of the US total and includes more than 57 million cattle and calves and 6.5 million sheep. Much of the Western range land is included in the high desert plateau, where limited rainfall and a short growing season make feed a limiting factor in animal production. Seasonal and regional fluctuation in feed quality and quantity, climatic extremes, and other environmental factors can markedly affect the efficiency of reproduction.

As noted in Table 1, the inventory of livestock in the Western states represents a significant fraction of the US total. Indeed, the value of sheep and cattle produced by farms and ranches in W112 member states exceeds 32 billion dollars. These figures indicate that livestock production is a critical component of the economic health of the Western states and, moreover, that the US supply of livestock and products (meat, wool, etc.) is dependent on the production efficiency of Western herdsmen.

Table 1. Cattle and sheep inventory in the Western states and the value of livestock and products sold.

Categorya W112 Member States Fraction of US Total (%)
Number of Beef Cows 20,100,000 60
Number of Feedlot Cattle 21,600,000 80
Value of Cattle and Calves Sold $31.745b 78
Number of Sheep and Lambs 6,550,000 84
Value of Sheep, Lambs, and Wool $583.5c 85

a data from USDA 1997 Census of Agriculture, Tables 28, 30, 38, 41, 46.
b in billions
c in millions

In addition to production of beef cattle and sheep, a phenomenon that has gained momentum in the last decade has been the domestication of exotic ruminant species. This has been particularly true in Texas, Wyoming, Montana, and Alaska, where commercial production of non-traditional species has expanded from bison and white-tailed deer to now include muskoxen, reindeer, elk, and caribou. Management and efficient propagation of these species has added a new challenge to the original mission of our research project.

An additional challenge to livestock producers in the Western states is the changing demographics of our region. Indeed, the unrelenting expansion of our urban populations continues to stretch the boundaries of the urban-rural interface. Issues like air and water quality, waste management, production efficiency, and resource stewardship are becoming of increasing importance as the interface between the rural and urban communities expands. Another issue of concern in the Western states is animal welfare and we are expanding our efforts to develop new management strategies that will improve animal well-being while maintaining or improving productivity.

The members of our research project strongly adhere to the vision of the Regional Research concept. That is, we believe the Western states represent a unique ecosystem that offers opportunities and challenges for producers of domestic ruminants. The challenges that are shared in common among the Western states are best addressed by combining the expertise and resources of representatives from all the states. In addition, we have requested the participation of experts from states outside our region when the advice, experience or knowledge of those experts would enhance our ability to improve the fertility of domestic ruminants in the target region. Thus, membership in the W112 project has not been limited solely to representatives from the Western region, but also includes leading reproductive biologists from Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio and Texas. We have found the contributions from these distinguished colleagues to be particularly valuable.
To effectively address the critical aspects of reproductive biology affecting reproductive efficiency in the Western states the members of the W112 project have divided into research teams or workgroups. These workgroups place particular emphasis on those components of the reproductive process (follicular maturation, ovulation and fertilization, embryo development, implantation, maternal recognition of pregnancy and maintenance of luteal integrity) that limit fertility. Our research teams also examine the role of stress, season and photoperiod and nutritive status on folliculogenesis and ovulation. In addition, our clinical colleagues are developing vaccines and immunologic strategies to lessen the incidence and severity of diseases that reduce the fertility of domestic species in the Western states.

The Ovarian Biology Research Group examines the molecular, cellular, and endocrine mechanisms that control follicular development, ovulation, and subsequent luteal function. The members of this group include representatives from CA, OR, KS, WA, ID, ID [ARS], MT, MT [ARS] WY, CO, NM, AZ, AK, NE [ARS], TX, MN, MI, OH, and MO. The specific charge to this group is to define the endocrine, paracrine and/or autocrine factors that control follicle maturation, with the goal of increasing the number and viability of follicles and improving the synchrony of follicle maturation among animals. The members of this group also examine the cellular and molecular biology of the ovulatory process, with the goal of improving the synchrony between ovulation and estrus. Additionally, members of the Ovarian Biology Research Group examine the process of luteinization, with the goal of reducing the incidence of luteal insufficiency during the post-ovulatory period. The Ovarian Biology Research Group will also examine the effect of stress, photoperiod, season, and nutritive status on follicular development and ovulation.

The Uterine Biology Research Group examines the molecular and cellular aspects of embryo development, implantation and maternal recognition of pregnancy. The members of this group include representatives from CA, WA, ID, ID [ARS], WY, CO, OR, HI, TX, and MO. The specific charge to this group is to define the endocrine, paracrine and/or autocrine factors that regulate conceptus and uterine gene expression, signal implantation and contribute to luteal maintenance and maternal recognition of pregnancy, with the ultimate goal of increasing the efficiency of implantation and reducing embryonic and fetal mortality. The members of this group will also examine the maternal and fetal factors that influence placental development and control fetal growth and maturation.

The Animal Disease Research Group includes representatives from AK, CA, CO, ID, ID [ARS], NV, TX, WA, and WY. The research conducted by this group is concerned with development of immunologic approaches to lessen the incidence and/or severity of diseases endemic to the Western states. In addition, we will continue to develop management strategies to lessen the severity of bacterial, viral and parasitic disease, with concerted focus on mastitis in animals on the Western range.

The Reproductive Technology Research Group includes members from all participating states. The broad membership of this group is reflective of the critical contributions it makes toward attainment of our overall mission; improving fertility of domestic ruminant in the Western region. The charge to this group is the development and optimization of management protocols and treatment regimens that will facilitate and encourage the use of artificial insemination and other novel reproductive technologies by cattle and sheep producers in the Western states. Another issue of concern in the Western states is animal welfare and we are expanding our efforts to improve animal well-being by seeking to develop effective and efficient immunologic alternatives to castration.