EXTENSION EDUCATION SYMPOSIUM: reinventing extension as a resource--what does the future hold?

The mission of the Cooperative Extension Service, as a component of the land-grant university system, is to disseminate new knowledge and to foster its application and use. Opportunities and challenges facing animal agriculture in the United States have changed dramatically over the past few decades and require the use of new approaches and emerging technologies that are available to extension professionals. Increased federal competitive grant funding for extension, the creation of eXtension, the development of smartphone and related electronic technologies, and the rapidly increasing popularity of social media created new opportunities for extension educators to disseminate knowledge to a variety of audiences and engage these audiences in electronic discussions. Competitive grant funding opportunities for extension efforts to advance animal agriculture became available from the USDA National Institute of Food and Agriculture (NIFA) and have increased dramatically in recent years. The majority of NIFA funding opportunities require extension efforts to be integrated with research, and NIFA encourages the use of eXtension and other cutting-edge approaches to extend research to traditional clientele and nontraditional audiences. A case study is presented to illustrate how research and extension were integrated to improve the adoption of AI by beef producers. Those in agriculture are increasingly resorting to the use of social media venues such as Facebook, YouTube, LinkedIn, and Twitter to access information required to support their enterprises. Use of these various approaches by extension educators requires appreciation of the technology and an understanding of how the target audiences access information available on social media. Technology to deliver information is changing rapidly, and Cooperative Extension Service professionals will need to continuously evaluate digital technology and social media tools to appropriately integrate them into learning and educational opportunities.

Effects of locoweed on serum swainsonine and selected serum constituents in sheep during acute and subacute oral/intraruminal exposure.

A study was conducted to evaluate the effects of acute and subacute locoweed exposure on serum swainsonine concentrations and selected serum constituents in sheep. Thirteen mixed-breed wethers (BW = 47.5 +/- 9.3 kg) were assigned randomly to 0.2, 0.4, or 0.8 mg of swainsonine x kg BW(-1) x d(-1) treatments. During acute (24 h) and subacute (19 d) exposure, serum swainsonine was detected in all treatments and was greatest (P < 0.03) in the 0.8 mg treatment. Serum alkaline phosphate (ALK-P) activity was increased (P < 0.01) for the 0.8 mg treatment compared with baseline (0 h) by 7 h and continued to increase throughout the initial 22 h following acute exposure to locoweed. A linear increase (P < 0.01) in serum ALK-P activity was noted, with the rate being 3.00 +/- 0.56 U x L(-1) x h(-1). Serum ALK-P activity was increased (P < 0.05) across treatments on d 7 over d -19, -12, 0, 1, 21, and 26; on d 14 over d -19, -12, 0, and 26; and on d 19 over d -19, -12, 0, 1, 21, and 26. By d 20, approximately 48 h after last exposure to swainsonine, serum ALK-P activities were no longer different (P = 0.13) than baseline (d -19, -12, and 0), and by d 26 values had generally returned to baseline. No linear (P = 0.98), quadratic (P = 0.63), or cubic effects of swainsonine with time from exposure were noted for serum aspartate aminotransferase. Similar to serum ALK-P activities, serum aspartate aminotransferase activities were increased (P < 0.05) across treatment levels on d 7, 14, 19, 20, 21, and 26 over those on d -19, -12, 0, and 1. Total serum Fe was decreased (P < 0.05) within the initial 22 h following the swainsonine exposure. On d 21 (48 h after swainsonine feeding ended), serum Fe increased to 472 mg/L. Concentrations of ceruloplasmin were lower (P < 0.10) on d 14 and 19 following exposure to locoweed. Recovery of ceruloplasmin levels coincided with similar changes in serum Fe. There was a linear (slope = 0.33 mg x dL(-1) x d(-1); P < 0.01) effect with time of exposure to locoweed (i.e., swainsonine) on serum triglyceride concentrations. Rapid changes in serum ALK-P and Fe concentrations without parallel changes in other damage markers indicate that acute exposure to swainsonine induces metabolic changes that may impair animal production and health before events of cytotoxicity thought to induce clinical manifestation of locoism.

Effect of lonophore supplementation on selected serum constituents of sheep consuming locoweed.

The effects of ionophore supplementation on selected serum constituents of sheep consuming locoweed were investigated. Sixteen sheep were allotted by weight to a 2x2 factorial arrangement of treatments: 1) no locoweed, no lasalocid, 2) no locoweed, 0.75 mg lasalocid/kg BW, 3) 0.5 mg swainsonine/kg BW, no lasalocid, 4) 0.5 mg swainsonine/kg BW, 0.75 mg lasalocid/kg BW. Swainsonine was provided by locoweed (Oxytropissericea), and sheep were fed a blue grama based diet at 2.5% BW for a 35 d treatment period. Diets were formulated to be isocaloric and isonitrogenous. Blood samples were collected on d 1, 7,14, 21, 31 and 35 to determine serum swainsonine concentration, alkaline phosphatase, total iron, aspartate aminotransferase, g-glutamyltransferase, and lactate dehydrogenase activity and total cholesterol, and triglyceride concentrations. No lasalocid by locoweed interaction (P > 0.4) was noted for any response variable measured. Average daily gains (P = 0.4) and orts (P = 0.7) were not affected by the treatments. No lasalocid treatment (P = 0.7) or day (P = 0.1) effect of serum swainsonine was observed. A locoweed by day interaction (P < 0.0001) of serum alkaline phosphatase was detected. Alkaline phosphatase levels were elevated (P < 0.01) for locoweed treated sheep at 24 h following initial exposure and remained elevated throughout the trail. Total iron was suppressed (P < 0.08) in locoweed fed sheep. A day effect (P < 0.02) was observed for serum iron. However, no linear, quadratic, or cubic effects of day were noted (P >0.2). A locoweed by day interaction (P < 0.0001) of serum aspartate aminotransferase and g-glutamyltransferase was detected. Aspartate aminotransferase levels were elevated (P < 0.0001) by d 7 for locoweed treated animals and remained elevated throughout the trial. g--Glutamyltransferase levels were suppressed (P < 0.0001) by day 7 for locoweed treated animals and remained suppressed throughout the trial. A locoweed by day interaction (P = 0.06) of serum cholesterol was detected. However, no linear, quadratic, or cubic effects of day were detected (P = 0.2). Lasalocid treatment had no effect on any serum constituent measured. Use of lasalocid in grazing animals should not increase the likelihood of locoweed intoxication.

Phosphorus requirement of finishing feedlot calves.

Dietary P supplied to feedlot cattle is important because an inadequate supply will compromise performance, whereas excess P may harm the environment. However, P requirements of feedlot cattle are not well documented. Therefore, 45 steer calves (265.2+/-16.6 kg) were individually fed to determine the P required for gain and bone integrity over a 204-d finishing period. The basal diet consisted of 33.5% high-moisture corn, 30% brewers grits, 20% corn bran, 7.5% cottonseed hulls, 3% tallow, and 6% supplement. Treatments consisted of 0.16 (no supplemental inorganic P), 0.22, 0.28, 0.34, and 0.40% P (DM basis). Supplemental P was provided by monosodium phosphate top-dressed to the daily feed allotment. Blood was sampled every 56 d to assess P status. At slaughter, phalanx and metacarpal bones were collected from the front leg to determine bone ash and assess P resorption from bone. Dry matter intake and ADG did not change linearly (P > 0.86) or quadratically (P > 0.28) due to P treatment. Feed efficiency was not influenced (P > 0.30) by P treatment and averaged 0.169. Plasma inorganic P averaged across d 56 to 204 responded quadratically, with calves fed 0.16% P having the lowest concentration of plasma inorganic P. However, plasma inorganic P concentration (5.7 mg/dL) for steers fed 0.16% P is generally considered adequate. Total bone ash weight was not influenced by dietary P for phalanx (P = 0.19) or metacarpal bones (P = 0.37). Total P intake ranged from 14.2 to 35.5 g/d. The NRC (1996) recommendation for these calves was 18.7 g/d, assuming 68% absorption. Based on performance results, P requirements for finishing calves is < 0.16% of diet DM or 14.2 g/d. Based on these observations, we suggest that typical grain-based feedlot cattle diets do not require supplementation of inorganic mineral P to meet P requirements.