Feeding and Economic Considerations for Baleage Use in Cow-calf Diets

Recent years of drought and suboptimal hay-making conditions have left many cattlemen in Iowa and much of the country with either reduced or poorer quality forage supplies, thus resulting in sharp forage price increases over the past 2 years. Feed costs in the cow-calf sector are often greater that 60% of total production costs, with a large proportion of that 60% derived from forage expenditures. Thus, evaluating harvested forage management practices and adopting new schemes that may increase forage quality, as well as reduce dry matter (DM) losses and feed wastage, are essential to minimizing wintering feed costs and maintaining profitability

Incidence of Ovulation to GnRH at Onset of 5-d CO-Synch + CIDR Protocol and Impact on Reproductive Responses

The objective of this study was to determine howresponse to GnRH at the onset of the 5-d CO-Synch +CIDR protocol (5dCO) affected estrous response, follicular dynamics, and pregnancy success to timed-AI (TAI) beefcows that had calved. On 359 cows, GnRH response at theonset of the synchronization protocol was 54.6%. Estrous response prior to TAI was greater in cows that failed to ovulate after GnRH administration than those that ovulated. However, dominant follicle diameter at TAI was not influenced by GnRH response. Timed-AI pregnancy rates were greater in cows that did not respond to GnRH (65.0%) than those that did (51.5%). These results cannot be interpreted as removing GnRH at the beginning of the 5dCO would affect TAI pregnancy responses. These results, however, warrant subsequent field studies to determine the necessity of GnRH administration at CIDR insert in the 5-d CO-Synch + CIDR protocol

Effect of Excess Dietary Crude Protein from Corn Gluten Meal or Soybean Meal on Reproductive Function of Beef Cows Consuming Low Quality Forage

Coproducts of the ethanol industry are a concentrated package of crude protein (CP) which can be fed to beef cows in conjunction with low quality forage to make economical diets that meets nutrient requirements. With this pairing, having excess dietary CP is likely; however the effects of these excessive CP diets on beef cow reproduction have not been made clear. In addition, the effects of excess dietary CP from feedstuffs that differ in rumen degradability are not known. In the present study, we studied the effects of diets containing 150% of metabolizable protein (MP) requirements from a moderately high (corn gluten meal) or low (soybean meal) rumen undegradable protein (RUP) fraction on reproductive function around the time of ovulation. We observed that excess dietary RUP enhanced dominant follicle growth and ovulatory parameters, while excess dietary rumen degradable protein (RDP) improved circulating progesterone concentration post ovulation. Based on these data, source of CP when fed to excess may have differential impacts on reproductive function in mature beef cows. However, the mechanisms by which these physiological alterations occur are unknown at this time. Thus, more research is warranted to elucidate how source and amount of CP, when supplemented in low quality forage-based diets, may influence reproductive function in beef cows

Opportunities and Challenges in a Changing Beef Industry: Results of a Statewide Needs Assessment in Iowa

The U.S. beef industry is poised for growth following increased contraction over the past decade that has resulted in the lowest cattle inventory in over 60 years. However, sustainable, long term growth of the industry is dependent upon early identification of issues that may inhibit profitability. A series of seven listening sessions conducted across Iowa in November and December of 2013 by the Iowa Beef Center identified land access, farm transition, production efficiency, marketing, genetics, data management, feedstuffs, and animal health as “mega-issues” facing producers. Specific issues under each of these overarching categories will guide future extension programming efforts within the Iowa Beef Center

Effects of Supplementing Excess Amounts of Metabolizable Protein from a Moderately Abundant Rumen Undegradable Source on Ovarian Function of Beef Cows Consuming Low Quality Forage

The effects of pairing a low quality forage with excess amounts of metabolizable protein (MP) supplementation from a moderately abundant rumen undegradable protein (RUP) source (corn gluten meal; 62% RUP) on ovarian function of beef cows was evaluated in a 60-day trial. Non-pregnant, non-lactating cows (n = 16) were offered ad libitum access to cornstalks and fed 1 of 2 isocaloric diets (0.48 NEm/lb) and supplemented primarily with corn gluten meal to provide 125% MP requirements (MP125) or 150% MP requirements (MP150). It was observed that cows offered MP at 150% in the diet from a moderately abundant RUP source had increased ovulatory follicle diameter, average antral follicle count and corpus luteum (CL) development compared to 125% MP. Therefore, excess dietary CP supplementation from a RUP source at 150% of MP requirements appears to enhance ovarian parameters of beef cows when fed with low quality forage compared to supplementation at 125% of MP requirements

Efficacy of the 5 Day CO-Synch Estrous Synchronization Protocol with or without the Inclusion of a Controlled Internal Drug Release Device in Beef Cows

To increase utilization of artificial insemination by beef producers, estrous and ovulation synchronization protocols must be re-evaluated in an attempt to reduce labor, cost, number of handlings, or a combination thereof without negatively impacting pregnancy rates. One potential way to reduce cost in these systems is through the strategic removal of hormones, such as the controlled internal drug release device (CIDR), from the protocol. While this concept has been tested in a 7 day synchronization protocol, it has not been evaluated in the newer 5 day synchronization protocols. The objective of this study was to compare TAI and overall breeding season pregnancy rates in primiparous and multiparous cows synchronized with the 5 d CO-Synch protocol with or without the inclusion of a CIDR. We hypothesized that use of a CIDR would improve timed-artificial insemination (TAI) and overall breeding season pregnancy rates. Results from this study indicate that while overall breeding season pregnancy rates are not impacted by removal of a CIDR in a 5 d CO-Synch protocol (90.3%; P = 0.94), TAI conception rates are improved when a CIDR insert is utilized (62.3 vs. 50.7%; P \u3c 0.001). Based on these data, use of a CIDR in the 5 d CO-Synch program is still recommended to optimize pregnancy success in an AI management system

Effect of Excess Metabolizable Protein Supplementation from Corn Gluten Meal or Soybean Meal on Plasma Amino Acid Concentrations of Beef Cows Consuming Low Quality Forage

With increased availability of fractionated (de-oiled) coproducts, supplementing excess dietary CP is likely when utilizing these high protein and energy coproducts as an energy source. At this time, the effects of these excessive CP diets on beef cow reproduction have not been extensively studied. In addition, the effects consuming excess dietary CP from feedstuffs that differ in rumen degradability with low quality forage on plasma amino acid concentrations of cows have not been extensively characterized. As part of a larger study analyzing the effects of diets containing 150% of metabolizable protein (MP) requirements from a moderately high (corn gluten meal) or low (soybean meal) rumen undegradable protein (RUP) fraction on ovarian function around the time of ovulation, blood samples were taken near ovulation to evaluate the effects of excess MP on circulating plasma amino acid (AA) concentrations. We observed that cows supplemented with excess CP from sources differing in rumen degradability had similar total circulating AA profiles; however, the relative proportions of each AA were different based on protein source. Based on these data, supplementing excess dietary MP from sources differing in degradability differentially affects circulating plasma AA profiles. However, the mechanisms by which these different AA profiles will alter biological, and specifically, reproductive processes are unknown at this time

Effects of Increasing Supplementation of Rumen Undegradable Protein on Plasma Essential Amino Acid Concentrations in Beef Cows Consuming Low Quality Forage

The effects of pairing a low quality forage with increasing metabolizable protein (MP) supplementation from a moderately abundant rumen undegradable protein (RUP) source (corn gluten meal; 62% RUP) on essential plasma amino acid (AA) concentrations were evaluated in a 60-day trial. Non-pregnant, non-lactating cows (n=24) were offered ad libitum access to cornstalks and fed 1 of 3 isocaloric diets (0.48 NEm/lb) and supplemented primarily with corn gluten meal to provide 100% MP requirements (CON), 125% MP requirements (MP125), or 150% MP requirements (MP150). It was observed that increasing concentrations of MP in the diet from a moderately abundant RUP source increased the percent of essential AA, ketogenic AA, branched-chain AA and urea cycle AA in plasma. Also, as a percent of total AA, glycogenic AA were decreased with increased MP supplementation. Therefore, increasing supplementation of MP can the shift essential AA profiles of beef cows when fed with low quality forage

Utilization of Pelleted Corn Stover/DDG Feed as Primary Source of Roughage and Protein in Beef Feedlot Rations

High feed prices and abundant corn stalk residue have created growing interest in the utilization of corn stalk residue or corn stover as a component of beef feedlot rations