Genetics and Genomics Commons^™

Consequences Of Differing Wool Growth Rates On Staple Strength Of Merino Wethers With Divergent Staple Strengths, A. C. Schlink, G. Mata, R. M. Lewis

Department of Animal Science: Faculty Publications

An experiment was conducted to determine the effects of dietary protein intake after a period of weight loss on the wool components of staple strength for sheep with a history of low or high staple strength (18.0 vs 34 Nlktex). After being fed to lose 15% of their liveweight over 10 weeks, sheep within each staple strength group were assigned in equal numbers to either a low or high protein diet designed to re-gain initialliveweight in 8 weeks. Liveweight, feed intakes and the growth, fibre diameter and fibre length characteristics of wool were measured at regular intervals. After the weight …

Relationships Between In Situ Protein Degradability And Grass Developmental Morphology, R. B. Mitchell, D. D. Redfearn, Lowell E. Moser, R. J. Grant, K. J. Moore, B. H. Kirch

Department of Animal Science: Faculty Publications

The objective of this research was to determine the relationships between the morphological development and in situ ruminally degradable protein (RDP), ruminally undegradable protein (RUP), and microbial protein of two cool season grasses (intermediate wheatgrass and smooth bromegrass) and two warm season grasses (switchgrass and big bluestem). The initial growth of grass tillers grown near Mead, Nebraska was clipped at ground level six times during the 1992 growing season and morphologically classified. Mean stage was calculated. Forage was ground to pass a 2-mm screen and was incubated in ruminally fistulated steers for 16 h. The RUP was adjusted for microbial …

Ewe Fertility In The Star Accelerated Lambing System, R. M. Lewis, D. R. Notter, D. E. Hogue, B. H. Magee

Department of Animal Science: Faculty Publications

Effects of environmental factors such as ewe age, season of exposure, and time from lambing to exposure on fertility were evaluated using records on 1,084 Dorset ewes in the STAR accelerated lambing system. The STAR program consisted of five 30-d concurrent breeding and lambing periods per year beginning on January 1, March 15, May 27, August 8, and October 20. Fertility in the flock changed in a cyclic and predictable fashion during the year. Changes in prolificacy were less consistent but also tended to show cyclic variation. Matings that occurred within the typical breeding season (August, October, and January) were …

Adjustment Factors For 120-Day Weaning Weight In Rambouullet Range Lambs, R. M. Lewis, M. Shelton, J. O. Sanders, D. R. Notter, W. R. Pirie, Texas Agricultural Experiment Station

Department of Animal Science: Faculty Publications

Additive and multiplicative environmental adjustments for effects of dam age, lamb sex and birth-rearing type on 120-d weight were derived using data from 819 Rambouillet range lambs. The relationship between mean and variance within environmental effect classes was one criterion for evaluating suitability of adjustment methods. Among lamb sexes and birth-rearing types, larger means were associated with greater variability (P < .01). Variances became homogeneous (P > .10) when data were expressed on a logarithmic scale, suggesting that multiplicative adjustments for these effects are needed. Because variances were homogeneous with respect to dam age (P > .50), additive adjustment factors are suggested for this effect. Validation of a …

Relationship Between Herd Management Practices In The Midwest On Milk And Fat Yield, Jeffrey F. Keown

Department of Animal Science: Faculty Publications

A dairy management survey was conducted in fall 1985 and spring 1986 in the nine-state area served by the Midstates Dairy Records Processing Center in Ames, IA. The questionnaire, consisting of 57 questions with 254 possible choices, was used to survey dairy producers on DHI testing in Arkansas, Illinois, Iowa, Kansas, Missouri, Nebraska, North Dakota, Oklahoma, and South Dakota. The questions covered housing pactices, milking equipment and practices, feeding regimens, calf rearing and feeding, feed additives, various management categories, and artificial insemination usage. The survey responses were merged with the 1985 year end rolling herd production averages from the processing …

Heterosis And Breed Effects In Swine, R. K. Johnson

Department of Animal Science: Faculty Publications

An objective of the NC-103 regional swine breeding project is to evaluate inter-population and intra-population performance of domestic and exotic strains of swine. Several cooperating stations have conducted experiments relative to this objective. Projects were not exact replicates, but sufficient overlap allowed combining the information to yield more precise estimates of heterosis and breed effects than was possible from the analyses of data from any single experiment. This publication summarizes data available from NC-103 cooperating stations on breed and heterosis effects in swine. An extensive crossbreeding experiment has been conducted and results published by Canadian researchers Fahmy and Bernard, 1971 …

Effect Of Graded Levels Of Bambermycins On Turkey Growth Performance, R.J. Grant, P.E. Waibel, T.W. Sullivan, C.L. Quarles

Department of Animal Science: Faculty Publications

Three experiments were conducted in Minnesota, Nebraska, and Colorado to determine the effect on turkey performance of feeding graded levels of bambermycins (Flavomycin ®1) from one day of age to market weight. The body weight and feed efficiency values are averages for 22-week-old males and 18-week-old females. Bambermycins produced significant (P<.001; P<.05) improvements in body weight or feed efficiency in all three experiments. Composite average body weights at 0, 1.1, 2.2, and 4.4 mg bambermycins/kg diet were 10.40, 10.54, 10.59, and 10.64 kg, respectively. Overall, average feed efficiencies from bambermycins at 0, 1.1, 2.2, and 4.4 mg/kg of diet were 2.76, 2.73, 2.72, and 2.71, respectively.

Subjective Evaluation Of Teat Canal Anatomy, R. D. Appleman

Department of Animal Science: Faculty Publications

Since radiographic techniques have shown that streak canals with larger diameters tend to milk-out faster and are more susceptible to new intramammary infections, a practical visual test was sought to provide easier determination of cows with either extremely narrow (slow milking) or extra wide (susceptible to new infections) streak canals.

A subjective teat classification scheme was developed to describe five different teat-end shapes in 159 Holstein and Brown Swiss cows in the University of Nebraska dairy herd. Approximately one-fourth of the cattle had pointed or round teat ends, one-half had fiat or near flat, and one-fourth were either disk or …

Genetic Aspects Of Calving Ease, James S. Brinks

Department of Animal Science: Faculty Publications

Several trends in cattle production and marketing are becoming evident. Leaner and perhaps heavier muscled slaughter cattle will be in demand through the chain from consumers back through retailers, packers, feeders and finally the producers. Emphasis on growth in the feedlot will continue. Thus, the feedlot and carcass characteristics desired point towards fairly large, heavier muscled cattle. At the producer level, increased emphasis is being placed on matching cow size, milk level, and overall biological type to available resources. Thus, the trend for maternal herds in the Great Plains point towards an adapted, probably moderate size, and milking cow that …

Effects Of Management, Strain And Truck Shipment On Albumen Quality Of Eggs, J.L. Adams, J.L. Skinner

Department of Animal Science: Faculty Publications

Very little has been reported on changes in quality of eggs during shipment. Gwin (1952) reported a study involving more than a billion eggs purchased by the Armed Forces of the United States. U.S. Grades were determined by candling and inspection by trained inspectors from the Army Veterinary Corps and the U.S. Department of Agriculture. Quality loss was shown to be related to time in transit, distance or miles in transit and seasonal influences. No data were reported as to the relation of varying physical conditions during transit or position effects within the rail cars. Adams and Milam (1960) studied …