The Standardized Performance Analysis (SPA) Program uses a standardized methodology to measure the biological and financial performance of cow calf, pasture and hay production enterprises. The focus of the SPA Program is to help the beef industry separate the various enterprises within a farming operation, for enterprise specific analysis.

Administration of pharmaceuticals and vaccines using traditional methods is laborious and requires animal restraint to be accomplished. There is risk of injury, stress compromises recovery rates, and normal physiological processes can be altered. Researchers have demonstrated that stress associated with transport or venipuncture affects the preovulatory luteinizing hormone (LH) surge (Nanda et al., 1989) and suppresses fertility (Hixon et al., 1981; Kesler and Favero, 1996) in cattle. A new delivery system utilizing needle-less implants has been developed that allows remote delivery of substances via implantation.

Economic pressures to improve production efficiency have prompted the beef cattle industry and researchers to evaluate different production systems. Maintaining pasture productivity and calf gain during midsummer is a problem for most cattle producers. This study was conducted to evaluate the effects of three weaning ages on 1) steer performance and carcass traits, and 2) cow performance, body condition score, and pregnancy rates.

Forage composition is affected by stage of growth and by forage species. The effect of forage species and maturity on digestion and animal performance results mainly from changes in cell wall components, which affects DM intake and digestibility (Van Soest, 1994). However, quantification of different fiber and CP fractions have not been extensively conducted in fresh forages at stages of maturity used in grazing situations. Our objective was to analyze and compare the composition of fiber and CP fractions of the spring growth of alfalfa, bromegrass, and tall fescue endophyte free and infected forages as affected by maturity.

Only a small percentage of beef cattle are currently bred by AI because of the absence of an estrus synchronization procedure that allows for AI at a predetermined time with consistently high pregnancy rates. The concurrent use of melengestrol acetate (MGA) and prostaglandin F(2 alpha) (PGF(2 alpha)) has been successfully used to synchronize estrus in heifers and cows (Brown et al., 1988; Jaeger et al., 1992; Patterson et al., 1995). However, pregnancy rates of females bred at a predetermined time have been variable (King et al., 1994; Larson et al., 1996; Kesler et al., 1996b).

Various procedures have been developed to synchronize estrus in beef cattle. One of the more recently promoted, although not FDA approved, procedures is the use of GnRH and PGF2 (Geary et al., 1998). The procedure involves the administration of GnRH seven day before PGF2 treatment. GnRH is administered to control follicular growth and development.

In addition to its well established role of causing luteolysis, prostaglandin F(2 alpha) (PGF(2 alpha)) has been shown to enhance fertility in cattle (Macmillan and Day, 1982). In a study involving 5,000 dairy cows, Macmillan and Day (1982) reported a higher calving rate (69% vs 60%) in PGF(2 alpha)-treated cows than in untreated cows. PGF(2 alpha) may exert a fertility effect by stimulating a release of luteinizing hormone (LH; Louis et al., 1974) upon demise of the corpus luteum and reduced progesterone concentrations (Hafs et al., 1975).

The future of the livestock industry depends on the production of wholesome, palatable, and nutritious meat products low in fat, as efficiently as possible (Unruh, 1986). Profit in the livestock industry is directly affected by daily gain, cost of gain, and feed efficiency (Schanbacher, 1984). Feed costs are the primary expense in determining cost of gain. Therefore, for a producer to supply the consumer with an affordable and desirable product, the cost of gain must be reduced. To achieve this, beef producers must use management strategies that will allow them to reduce their production costs.

Most cow-calf producers try to maximize longevity of cows to reduce replacement costs. However, the traditional cow-calf production system may not be the most efficient production system for some beef producers. The objective of this experiment was to evaluate the feedlot performance and carcass composition of 30-month-old single-calf heifers which were still lactating and sigle-calf heifers whose calves were weaned prior to entering the feedlot.

Most cow-calf producers seek to maximize the longevity of cows to reduce the costs of replacements. However, the traditional cow-calf production system may not be the most efficient production system for some beef producers. The objective of this research was to evaluate the effects of Finaplix-H® in immature, lactating primiparous females for growth, lactation, and carcass characteristics.

Bovine respiratory disease (BRD) is the most economically important infectious disease of calves in North American feedlots (Jensen et al., 1976; Thomson, 1980; Church and Radostits, 1981; Wohlgemuth and Herrick, 1986; Baker et al., 1986). BRD not only threatens the medical health of cattle but also the financial health of the producers who raise them. Morbidity rates as high as 69% and mortality rates as high as 15% have been reported (Kelly and Janzen, 1986). The high incidence of this disease necessitates that feedlot veterinarians and cattlemen must continually rely on the use of antimicrobial agents to deal with BRD.

Although several estrus synchronization procedures have been developed, none developed yet have been highly accepted by beef producers. Therefore, there continues to be an need for a highly efficacious estrus synchronization procedure. The combined use of a intravaginal progesterone insert and PGF(2 alpha) has been proved highly efficacious and acceptable in New Zealand. This procedure is now being considered for approval in the U.S. This study was part of a larger study to determine efficacy of the procedure for approval in the U.S.

Most of the information about forage digestion and utilization by cattle comes from experiments done with low quality forages. Most of grazing areas in Illinois are suitable for pastures including tall fescue, bromegrass, alfalfa, and red clover which have high qualities depending on time of the year and forage management. However, it is well known that animals grazing high quality forages often perform at levels below expectations. Our goal was to compare the extent of the ruminal DM and CP degradation in different forages (alfalfa, bromegrass, tall fescue endophyte-free, and endophyte-infected) as affected by forage species and period of utilization.

The first therapeutic use for gonadorelin in veterinary medicine, treatment of ovarian follicular cysts in dairy cattle, was reported in 1975; three years before the Nobel prize was awarded to the two scientists that chemically identified it (Guillemin, 1978; Schally, 1978). The objective of these experiments was to determine if the gonadorelin-induced release of testosterone could be developed into a biological assay for quality assurance of gonadorelin after synthesis and/or manufacturing.

Estrus synchronization provides producers a means to utilize AI, improve reproductive management, produce uniform groups of calves, hasten ovarian cycles (Hixon et al., 1981), etc. Syncro-Mate B is an estrus synchronization procedure that provides a high degree of synchrony, thus allowing for a single timed insemination (Kesler and Favero, 1996). Anderson et al. (1982) reported similar pregnancy rates for heifers that exhibited estrus and heifers that did not exhibit estrus after Syncro- Mate B treatment, and mass insemination of females 48 to 52 hours after implant removal is recommended by the manufacturer (Darling, 1993).

Calving rates of cattle bred after estrus synchronization are often lower than desired (Odde, 1990; Kesler and Favero, 1996). Factors that negatively affect the establishment of pregnancy include lack of synchronization (Burns et al., 1993; Kesler and Favero, 1996; Kesler et al., 1997a), subnormal luteal phases (Kesler and Favero, 1996), and embryonic/fetal mortality (Ayalon, 1978; Diskin and Sreenan, 1980; Roche, 1981).

Economic pressures to improve production efficiency have prompted the beef cattle industry and researchers to evaluate the performance of different biological types of cattle and methods to produce cattle that result in higher quality grade. Feeding grain diets to cattle is generally considered to result in meat that is more tender, flavorful, and juicy than forage-fed cattle.

Supplementation of nursing beef calves is commonly referred to as creep feeding and traditionally consists of allowing calves unlimited access to a grain mix. Creep feeding calves has increased weight gains; however, the supplemental feed efficiencies (SFE) have been relatively poor (more than 8 kg of feed per kilogram of gain: Stricker et al., 1979: Faulkner et al., 1994). Creep feeding with corn has been shown to improve carcass merit with little influence on feedlot performance (Faulkner et al., 1994).

A new method of pregnancy detection has been advertised. This method involves the assay of serum samples collected 12 to 48 hours after insemination. The manufacturer (Concepto Diagnostics of Knoxville, TN) reports that it "is a unique immunoassay to identify the open cow within 12-48 hours of breeding. The test is conducted only on serum samples using the monoclonal-polyclonal antibody ‘dip stick' methodology with gold as the indicator. This is not an absolute diagnosis of open cows.

Fresh alfalfa, such as that consumed by grazing ruminants, has a high CP concentration which is inefficiently utilized by the animal. A large portion of the ruminally degraded CP is absorbed as NH3N from the rumen, and excreted in the urine as urea (Wallace, 1994). Increasing the transfer of the forage CP into a form than can be used by the animal would be desirable as a means of maximizing utilization of available nutrient resources.

Fresh alfalfa usually has a high CP content which is highly degradable in the rumen (Dhiman and Satter, 1997). The amount of escape protein provided by alfalfa is often low and ruminal microbes can not utilize all of the amino acids (AA) and ammonia (NH3 N) released and more protein will be degraded than is synthesized (Broderick, 1995). Addition of a source of energy such as corn grain to alfalfa-based diets may increase the proportion of the ruminally degraded CP to be utilized for microbial growth and consequently, increase the flow of AA to the small intestine. Therefore, energy supplementation may enhance the efficiency of utilization of the forage N by providing more AA to the animal and reducing ruminal N losses.

Recently, increased consumer demand for fructose sweetener and the use of ethanol as a fuel additive have resulted in increased wet and dry milling of corn (Schrage et al., 1991). This has resulted in the production of co-products, such as corn gluten feed and a new ethanol co-product, hereafter referred to as modified corn fiber, which may be used as supplemental feedstuffs.