Journal Issue:
Animal Industry Report: Volume 657, Issue 1

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Evaluation of Egg Production in Layers Using Random Regression Models
( 2011-01-01) Wolc, Anna ; Arango, Jesus ; Settar, Petek ; O'Sullivan, Neil ; Dekkers, Jack

The objectives of this study were to estimate genetic parameters for egg production over the age trajectory in three commercial layer breeding lines, which represent different biotypes for egg production, and to validate the use of breeding values for slope as a measure of persistency to be used in the selection program. Egg production data of over 26,000 layers per line from six consecutive generations were analyzed. Daily records were cumulated into biweekly periods. Data were analyzed with a random regression model with linear polynomials on period for random additive genetic and permanent environmental effects. In all lines, a nonzero genetic variance for mean and slope and a positive genetic correlation between mean and slope were estimated. Breeding values for slope well reflected the shape of the egg production curve and can be used to select for persistency of egg production. The model proposed in this study appealing for implementation in large and multiple populations under commercial conditions by breeding companies or other breeding organizations.

Evaluation of Teat Condition Using Liquid or Powder Dips in Winter
( 2011-01-01) Knutson, Kia ; Timms, Leo ; Lopez Benavideg, Mario ; Henderson, Mark ; Hemling, Tom

Objective of this study was to compares a 0.5% iodine aqueous teat dip vs 0.5% chlorhexidine gluconate powdered teat dip under winter conditions on overall teat end and teat skin condition and health. Under the conditions of this trial there were slight non-significant decreases in teat end condition associated with colder temperatures and temperature changes in both groups, with no differences between groups in TE change. Both groups saw some decreases in teat skin condition with powder dipped teats showing a 2 fold increased hazard of dry teat skin. Results of this trial show teat changes (skin and end condition) associated with cold temperature changes even under ideal (minimal wind) housing and different teat dips. Producers need to realize changes will occur, assess their own farm condition (housing, weather, wind) and be judicious in determining conditions requiring switches to winter dip products and practices.

Evaluation of Drying Methods on Nitrogen and Energy Concentrations in Pig Feces and Urine, and on Poultry Excreta
( 2011-01-01) Jacobs, Brandy ; Patience, John ; Dozier, William ; Stalder, Kenneth ; Kerr, Brian

Drying method was evaluated based on the impact it had on gross energy and nitrogen concentration of swine feces and urine, and nitrogen in poultry excreta, Twelve individually penned growing pigs were fed one of three diets and 16 pens of 10 growing broilers were fed one of four diets that differed in NDF and CP. Feces, urine, and excreta were collected after diet adaptation and were assumed to vary widely in nutrient composition. Following collection, samples were dried using one of four methods: UD-undried, FD-freeze dried, OD55-oven dried at 55°C for 48 h, or OD100-oven dried at 100°C for 48 h, after which dry matter gross energy, nitrogen, carbon, and sulfur were determined. In swine feces, drying resulted in a loss of GE and S, but among the various drying methods, there was no difference for dry matter, gross energy, nitrogen, carbon and sulfur concentrations. There were no differences in urinary gross energy due to drying or among drying methods; however urinary dry matter was highest for FD compared to OD and higher for OD55 compared to OD100. In poultry excreta, gross energy, nitrogen, and S were reduced by drying, but there were no differences among the drying methods. Regardless of drying method, some loss of gross energy and nitrogen appears to be inevitable, but there is no apparent advantage between freeze drying and oven drying.

Next Generation Sequencing to Discover Genetic Markers for Pacific White Shrimp
( 2011-01-01) Du, Zhi-Qiang ; Rothschild, Max

Recently, a new method of sequencing called next generation sequencing has been widely applied due to its lower cost per sequencing output compared to traditional sequencing technologies. Genomic regions of Pacific white shrimp have been selected to construct materials for sequencing using the Illumina Solexa technology. We then used de novo techniques to assemble the sequences into 8,007 contigs, and identified ~ 256K genetic markers. Due to the potential complex genome structure of Pacific white shrimp, we had a success rate of validating about 2/3 of the genetic markers chosen. This important resource could be used for the improvement of growth rate and disease resistance by the shrimp industry

Lameness and Welfare of Cattle: Extension Program Activities and Accomplishments
( 2011-01-01) Shearer, Jan

Lameness of dairy and beef cattle continues to be an extension program priority. Over the previous 12 month period, we conducted 10 training programs (under the heading of the ISU Master Hoof Care Program) on foot care and claw trimming to trimmers and dairy farm managers throughout the United States. Most of these programs are conducted in Spanish to address the needs of the dairy industry’s multi-cultural workforce. Similar programs were provided to veterinary students at Iowa State University, the University of Minnesota and the University of Florida. These programs consist of approximately a half day of classroom and 1 to 2 days of claw trimming on cadavers and live animals. Beyond these, multiple on-farm visits were conducted to review lameness problems and/or foot care programs in Iowa and elsewhere in the US. Lameness of cattle has also been the subject of presentations delivered at Iowa Dairy Days and multiple other conferences in Iowa and beyond.