Performance Testing Beef Cattle

Guide to performance testing beef cattle discusses keeping records, birth weights, weaning weight records, adjusting individual weights, sex adjustments, yearling or 365-day weights, and weight ratios or index values

Annual Crossbreeding Report for South Dakota Livestock Production Records Association

Each year since 1970 weaning weight records from member herds of the Production Records Association have been used to prepare a crossbreeding summary for use by members and other cattlemen in the formulation of individual breeding programs. This report presents the five year summary which includes the 1974 calf crop

Weaning Weight Summary for South Dakota Livestock Production Records Association Member Herds Using Crossbreeding

The primary objective of this study was to provide members of the Production Records Association an analysis of the weaning weights of various crossbreds produced in member herds. The results should form an important part of the total information needed by members and other cattlemen to formulate individual breeding programs

Beef Production of Simmental-Angus and Hereford-Angus Crossbred Cows

In recent years there has been increased utilization of exotic cattle to increase production in beef herds. Crossbreeding European breeds with domestic British breeds has resulted in larger calves at weaning and slaughter due to increased milking ability of the dams and gaining ability of the crossbred calves. Crossbreeding beef cows with European breeds has resulted in larger cows having higher nutrient requirements than the domestic breeds or crosses. Hereford-Angus crossbred cows have been used extensively in South Dakota and have performed well under local conditions. This study was designed to compare reproductive performance and calf production of Sinnnental-Angus (S x A) and Hereford-Angus (H x A) crossbred cows under range conditions. Feedlot performance, carcass beef production and economics of calf production have also been evaluated

Preconditioning Feeder Calves

Each year more than million quality feeder calves are sold in South Dakota. These sales contribute significantly to agricultural income in the state, the sale of cattle and calves comprising about 50% of the total. Under the leadership of the South Dakota Beef Cattle Improvement Association (BCIA) and the South Dakota Extension Service, an organized, certified feeder calf preconditioning program has been initiated and is available as an optional management/marketing tool for South Dakota cow-calf producers. The program is designed to assure the highest standards of quality, health and performance once South Dakota feeder calves reach the feedlot

A differential method for bounding the ground state energy

For a wide class of Hamiltonians, a novel method to obtain lower and upper bounds for the lowest energy is presented. Unlike perturbative or variational techniques, this method does not involve the computation of any integral (a normalisation factor or a matrix element). It just requires the determination of the absolute minimum and maximum in the whole configuration space of the local energy associated with a normalisable trial function (the calculation of the norm is not needed). After a general introduction, the method is applied to three non-integrable systems: the asymmetric annular billiard, the many-body spinless Coulombian problem, the hydrogen atom in a constant and uniform magnetic field. Being more sensitive than the variational methods to any local perturbation of the trial function, this method can used to systematically improve the energy bounds with a local skilled analysis; an algorithm relying on this method can therefore be constructed and an explicit example for a one-dimensional problem is given.Comment: Accepted for publication in Journal of Physics

Necrotic tumor growth: an analytic approach

The present paper deals with a free boundary problem modeling the growth process of necrotic multi-layer tumors. We prove the existence of flat stationary solutions and determine the linearization of our model at such an equilibrium. Finally, we compute the solutions of the stationary linearized problem and comment on bifurcation.Comment: 14 pages, 3 figure

Steady states in a structured epidemic model with Wentzell boundary condition

We introduce a nonlinear structured population model with diffusion in the state space. Individuals are structured with respect to a continuous variable which represents a pathogen load. The class of uninfected individuals constitutes a special compartment that carries mass, hence the model is equipped with generalized Wentzell (or dynamic) boundary conditions. Our model is intended to describe the spread of infection of a vertically transmitted disease, for example Wolbachia in a mosquito population. Therefore the (infinite dimensional) nonlinearity arises in the recruitment term. First we establish global existence of solutions and the Principle of Linearised Stability for our model. Then, in our main result, we formulate simple conditions, which guarantee the existence of non-trivial steady states of the model. Our method utilizes an operator theoretic framework combined with a fixed point approach. Finally, in the last section we establish a sufficient condition for the local asymptotic stability of the positive steady state

So, You Want to Use Next Generation Sequencing In Marine Systems? Insight from the Pan Pacific Advanced Studies Institute

The emerging field of next-generation sequencing (NGS) is rapidly expanding capabilities for cutting edge genomic research, with applications that can help meet marine conservation challenges of food security, biodiversity loss, and climate change. Navigating the use of these tools, however, is complex at best. Furthermore, applications of marine genomic questions are limited in developing nations where both marine biodiversity and threats to marine biodiversity are most concentrated. This is particularly true in Southeast Asia. The first Pan-Pacific Advanced Studies Institute (PacASI) entitled Genomic Applications to Marine Science and Resource Management in Southeast Asia was held in July 2012 in Dumaguete, Philippines, with the intent to draw together leading scientists from both sides of the Pacific Ocean to understand the potential of NGS in helping address the aforementioned challenges. Here we synthesize discussions held during the PacASI to provide perspectives and guidance to help scientists new to NGS choose among the variety of available advanced genomic methodologies specifically for marine science questions