Physiological and Behavioral Responses of Heifers that Graze Tall Fescue Infected by Wild-type or Novel Endophytes

Fescue toxicosis presents serious challenges and huge economic losses to the beef industry in the U.S. Replacing tall fescue (TF) infected by wild-type endophyte (WE) with TF infected by novel endophyte can eliminate this problem but adoption of this technology has been limited. We aimed at demonstrating the physiological and behavioral responses of heifers that grazed either WE or NE TF using relatively non-invasive techniques. Angus or Angus cross heifers (n = 24) were assigned to either WE or NE pastures for a 56-d grazing period during the summers of 2020 and 2021. Heifer ADG and hair retention scores were recorded once every 4 weeks and intravaginal temperatures were recorded for two consecutive days at this interval. Extremity temperatures were determined using thermographic imaging and hair was collected from the left rump for cortisol analysis. Animal behavior was detected using time-lapse trail cameras. The overall ADG of heifers that grazed NE was greater (p = 0.0160) compared to heifers that grazed WE in 2020, but not in 2021 (p = 0.9623). Hair retention was greater for heifers that grazed WE compared to heifers that grazed NE (p = 0.0029). Heifers that grazed WE TF had lower (p ≤ 0.0075) temperatures at ears, tails, and hooves and 0.3-0.9 °C greater intravaginal temperatures than heifers that grazed NE, especially during daytime. Hair cortisol levels of heifers that grazed WE were greater (p \u3c 0.0001) compared to heifers that grazed NE. From 1200h-1700h each day, heifers on WE pasture spent 1.5 more (p = 0.0003) hours loafing and 0.9 fewer (p = 0.0402) hours lying down than heifers on NE pastures. These results suggest that heat stress and other physiological changes in heifers grazing WE could be mitigated by renovating pastures with NE TF

Prolonged Elevated Concentrations of Estradiol Do Not Affect Conception Rates in Beef Cattle

Following treatments causing either prolonged elevated concentrations of estradiol associated with development of persistent follicles or inhibited elevated concentrations of estradiol and development of persistent follicles, conception rates were compared. Beef females received either four norgestomet implants for 9 days (day 0 = treatment initiation; n=59) or one norgestomet implant for 7 days and three additional norgestomet implants for 2 days (n=60). All implants were removed on day 9 followed by estrous detection and AI for 7 days. Treatment and day interacted to affect estradiol concentrations from day 0 to day 9 with elevated estradiol in females treated with one norgestomet implant for 7 days. Conception rates to AI were similar across treatments. Prolonged elevated concentrations of estradiol associated with development of persistent ovarian follicles do not affect fertility when persistent ovarian follicles are not allowed to ovulate

Carcass Trait Trends for Steers and Heifers Finished Through the Tri-County Steer Carcass Futurity Cooperative from 2002 Through 2018

Objective: The objective was to evaluate trends in carcass characteristics for steers and heifers finished through the Tri-County Steer Carcass Futurity Cooperative. Study Description: Data analyzed included 74,207 steers and 33,529 heifers finished at the Tri-County Steer Carcass Futurity Cooperative (Lewis, IA) and harvested from 2002 through 2018. Steers and heifers were harvested at liveweights of 1,235.0 +/- 119.8 lb and 1,124.2 +/- 106.7 lb, respectively. Carcass trait trends evaluated for steers and heifers included calculated yield grade score, backfat thickness, hot carcass weight, kidney, pelvic, heart, fat percentage, marbling score, and ribeye area. Results: Calculated yield grade scores increased from 2002 through 2018 for steers and heifers. Fat thickness increased 0.08 in for steers and 0.07 in for heifers, both peaking in 2017 at 0.55 and 0.59 in, respectively. Hot carcass weights ranged from 727 to 780 lb for steers and increased over the 17-year period. Hot carcass weights for heifers ranged from 671 to 711 lb and increased slightly from 2002 through 2018. Kidney, pelvic, heart, fat percentage did not change for steers and heifers. Marbling score increased from 422 to 456 for steers and 449 to 493 for heifers. Ribeye area increased slightly for steers while decreasing slightly for heifers over the 17-year period. The Bottom Line: Corresponding with increases in fat thickness and minimal to no improvement in ribeye area, yield grade scores increased over the past 17 years. Genetic selection pressure on marbling within the beef industry is evident from these data

Antioxidative Activities of Alfalfa and Timothy Varieties

The term functional foods is often used as a generic description for the beneficial effects of ingested foods that go beyond their traditional nutritive value (Bauman et al., 2001). Milk and dairy products are important dietary sources of nutrients, providing energy, high quality protein, and a variety of vitamins and minerals. Recent research has focused on altering the fat and protein content of milk and other dairy products in order to improve their nutrient content to more aptly reflect current dietary recommendations and trends. As a result, additional focus is being given to designing foods that have beneficial effects on human health. This study was carried out to investigate the antioxidative activities of forages grown in Korea

Decline in Brahman Breed Influence of Beef Calf Lots Marketed by Video Auction from 1995 to 2015

Brahman cattle are widely known for their ability to tolerate hot and humid climates as well as for their insect and parasite resistance. An estimated 40% of all beef cows in the United States are located in the southern region, which has a relatively hot climate. Historically, many of these beef cows have had at least some Brahman influence. The opportunity to evaluate potential changes in the influence of the Brahman breed on beef calves produced in the United States was available through lots of beef calves marketed through a video auction service. The objective was to characterize the potential change in the percentage of lots of beef calves with Brahman influence among calves originating from various regions of the United States marketed through summer video auctions from 1995 through 2015

Sale Price of Holstein Feeder Steer Lots Relative to Other Breed Descriptions Sold Through Superior Livestock Video Sales from 2010 Through 2018

Objective: The objective of this study was to determine the relative value of Holstein feeder steer lots compared to steer lots of other breed descriptions sold through video auctions while adjusting for all other factors that significantly influenced sale price. Study Description: Data were analyzed from 14,075 lots of feeder steers sold via 211 livestock video auctions from 2010 through 2018. All lot characteristics that could be accurately quantified or categorized were used to develop a multiple regression model with backwards selection. A lot was categorized into one of four breed descriptions: 1) English, English crossed; 2) English-Continental crossed; 3) Brahman influenced; and 4) Holstein. The Bottom Line: The relative price discount for Holstein feeder steer lots compared with other breed descriptions appears to have increased from 2010–2018, and thus is likely indicating lessening interest in the feedlot sector to feed Holstein steers to harvest

Factors Affecting the Sale Price of Bred Heifers and Bred Cows Sold Through Superior Livestock Video Auctions

Objective: The objective of the study was to evaluate potential factors influencing the sale price of bred heifers and bred cows sold through video auctions while adjusting for all other factors that significantly influenced prices. Study Description: Descriptive characteristics of lots offered for sale were obtained through a livestock video auction service (Superior Livestock Auction, Fort Worth, TX). Data were available on 1,870 lots of bred heifers sold through video auctions from 2010 through 2018 and 1,237 lots of bred cows sold through video auctions from 2011 through 2018. Two separate multiple regression models were developed to determine the factors influencing the sale price for each. The Bottom Line: Understanding the various factors influencing the sale price of bred heifers and bred cows will allow producers to make more informed investment decisions

Breed and gender interact to affect the sale price of beef calves sold through video auctions from 2010 through 2014

Citation: McCabe, E. D., King, M. E., Fike, K. E., Hill, K. L., Rogers, G. M., & Odde, K. G. (2016). Breed and gender interact to affect the sale price of beef calves sold through video auctions from 2010 through 2014. Journal of Animal Science, 94, 29-29. doi:10.2527/msasas2016-063The objective of this study was to quantify the effect of the potential interaction of breed and gender on the sale price of beef calves marketed through video auctions while adjusting for all other factors that significantly influenced price. Information on descriptive characteristics of lots of beef calves were obtained from a livestock video auction service. Data were available on 20,007 lots of steer calves and 13,804 lots of heifer calves (2106,181 total steer calves and 1239,645 total heifer calves) that sold in 116 video auctions from 2010 through 2014. All lot characteristics that could be accurately quantified or categorized were used to develop a multiple regression model that evaluated the effects of independent factors on the sale price using a backward selection procedure. A value of P < 0.05 was used to maintain a factor in the final model. Breed description of the calves in the lots was 1 of 19 factors included in the original model and was characterized into 6 groups: English, English crosses (EX), English–Continental crosses (ECX), Black Angus sired out of dams with no Brahman influence (AN), Red Angus sired out of dams with no Brahman influence (AR), and Brahman influenced (BR). Breed and gender of the lot interacted (P < 0.0001) to affect the sale price of calves. Lots of AR and AN steer calves had similar sale prices (P = 0.9540; $379.08 and$378.14 per 100 kg BW, respectively) and sold for significantly higher prices than all other steer breed groups. English cross and ECX steer lots had similar sale prices (P = 0.2588; $376.24 and$374.92 per 100 kg BW, respectively) but were greater (P < 0.05) than BR steer calves ($365.61 per 100 kg BW). Among heifer calves, lots of AR heifers sold for the highest price (P < 0.05;$356.02 per 100 kg BW). The AN heifer calves sold for the second highest price at $345.95 per 100 kg BW, and this price was greater (P < 0.05) compared with ECX ($341.50 per 100 kg BW) and EX heifers ($341.14 per 100 kg BW). Brahman-influenced heifer calves sold for the lowest (P < 0.05) price at$334.64 per 100 kg BW compared with heifers of all other breed descriptions. Breed and gender composition of the lots of beef calves interacted to affect the sale price of calves selling through video auctions. The value of the specific breed composition of beef calves is influenced by gender and may be related to buyers purchasing certain breeds of heifer calves as replacements for the breeding herd

Region of Origin in the United States Affects Price Premiums Associated with Value-Added Health Protocols of Beef Calf Lots Sold Through Summer Video Auctions from 2010 Through 2018

Objective: The objective was to evaluate the effects of value-added calf health protocols within various regions of the United States on the sale price of beef calf lots sold via summer video auction. Study Description: Information describing lot factors was obtained through a livestock video auction service (Superior Livestock Auction, Fort Worth, TX). Descriptive characteristics were available over nine years (2010-2018) representing 43,242 lots of beef calves. Data were evaluated to investigate participation in various health programs across regions. A multiple regression model was developed for each region to determine the value associated with health protocols throughout regions of the United States. The Bottom Line: While variation in the sale price of beef calves across regions suggests evident differences in the recognized value by buyers, results indicate the value associated with the vaccination and management of calves with potentially larger transportation distances from origin to delivery