Calculating Optimum Daily Gain for Wintering Replacement Beef Heifers

Research has demonstrated that weight of the yearling heifer is an important factor affecting puberty and initiation of the reproductive cycle. Work at several institutions including South Dakota State has demonstrated that rate of gain from weaning to start of the breeding season influences the proportion of heifers that settle. The objective of this project was to provide the producer with an easy way of calculating this desired rate of growth

Preweaning and Postweaning Performance of Crossbred Calves--0, 1 or 2 Ralgro Implants

The preweaning performance of 221 steer and heifer calves given differing numbers of Ralgro implants was evaluated. The steer and heifer calves given one implant had an additional 23 and 33 lb weaning weight compared to those receiving no implant. No additional response was shown by steer calves receiving a second implant 100 days after the first was given. Average daily gains during the 105-day growing period were not significantly faster than those receiving two implants during the 103-day finishing phase. This work supports other studies indicating that implanting calves at weaning time is an economical management practice. The work further indicates to feeders that calfhood implants have little or no effect on subsequent performance in the feedlot

Feedlot Performance of Growing Steer Calves on a High Roughage Ration Supplemented with a High Bypass or an All Natural Protein Supplement

This study was undertaken to compare a urea-based protein supplement containing meat and bone meal and dehydrated alfalfa as the primary by-pass protein source to a protein supplement containing soybean meal and sunflower meal as the protein sources

Effect of Length of Feeding Period of Performance of British and Exotic Crossbred Yearling Heifers

Producers very often question the additional length of time they should feed exotic-cross cattle as opposed to the feeding period required for the traditional British breeds of cattle. Also implied in this question in this question is the additional amount of feed needed for the exotic-cross animal to attain an optimum weight and an acceptable grade. This trial was conducted in an attempt to help answer these basic questions

Comparison of Methods of Producing Slaughter Weight Steers Using Maximum Quantities of Forage and Minimum Quantities of Grain

The objectives of this study were to compare performance and slaughter characteristics of various production systems by which slaughter steers can be produced in the high desert rangeland of eastern Oregon, which is very similar to the semi-arid rangelands of western South Dakota. Economic analysis and taste panel evaluations are also included

Dynamically-Coupled Oscillators -- Cooperative Behavior via Dynamical Interaction --

We propose a theoretical framework to study the cooperative behavior of dynamically coupled oscillators (DCOs) that possess dynamical interactions. Then, to understand synchronization phenomena in networks of interneurons which possess inhibitory interactions, we propose a DCO model with dynamics of interactions that tend to cause 180-degree phase lags. Employing an approach developed here, we demonstrate that although our model displays synchronization at high frequencies, it does not exhibit synchronization at low frequencies because this dynamical interaction does not cause a phase lag sufficiently large to cancel the effect of the inhibition. We interpret the disappearance of synchronization in our model with decreasing frequency as describing the breakdown of synchronization in the interneuron network of the CA1 area below the critical frequency of 20 Hz.Comment: 10 pages, 3 figure

Three unrelated species, 3 sites, same host monogenean parasites of the southern fiddler ray, Trygonorrhina fasciata, in South Australia: egg hatching strategies and larval behaviour

The southern fiddler ray, Trygonorrhina fasciata (Rhinobatidae), is parasitized by 3 monogenean (platyhelminth) species from 3 families on 3 different sites of the host: Calicotyle australis (Monocotylidae) from the cloaca, Pseudoleptobothrium aptychotremae (Microbothriidae) from the skin and Branchotenthes octohamatus (Hexabothriidae) from the gills. Cues that promote egg hatching were investigated for each species and the behaviour of their larvae was also documented. Eggs were laid by parasites in vivo and maintained at 22 °C. Three different egg hatching and host finding strategies were discovered. Calicotyle australis eggs hatched spontaneously with a strong diurnal rhythm that is likely to be under circadian control. The larva is ciliated, photo-responsive and can survive for up to 24 h at 22 °C after hatching. Pseudoleptobothrium aptychotremae may have a ‘bet-hedging’ strategy. Some eggs hatched spontaneously and rhythmically. However, since the hatching success was low, it is possible that other eggs require a different cue provided by the host. The larva is also ciliated but shows no photo-response and was observed to remain active for <4 h at 22 °C after hatching. Branchotenthes octohamatus has a ‘sit-and-wait’ strategy that depends on mechanical disturbance to stimulate hatching. The larva is unciliated, shows no photo-response but may survive for more than 2 days at 22 °C after hatching. The implications of hatching strategy, larval behaviour and morphology in the goal to find a host are discussed for each species.V. Glennon, L. A. Chisholm and I. D. Whittingto

Self-avoiding walks crossing a square

We study a restricted class of self-avoiding walks (SAW) which start at the origin (0, 0), end at $(L, L)$, and are entirely contained in the square $[0, L] \times [0, L]$ on the square lattice ${\mathbb Z}^2$. The number of distinct walks is known to grow as $\lambda^{L^2+o(L^2)}$. We estimate $\lambda = 1.744550 \pm 0.000005$ as well as obtaining strict upper and lower bounds, $1.628 < \lambda < 1.782.$ We give exact results for the number of SAW of length $2L + 2K$ for $K = 0, 1, 2$ and asymptotic results for $K = o(L^{1/3})$. We also consider the model in which a weight or {\em fugacity} $x$ is associated with each step of the walk. This gives rise to a canonical model of a phase transition. For $x < 1/\mu$ the average length of a SAW grows as $L$, while for $x > 1/\mu$ it grows as $L^2$. Here $\mu$ is the growth constant of unconstrained SAW in ${\mathbb Z}^2$. For $x = 1/\mu$ we provide numerical evidence, but no proof, that the average walk length grows as $L^{4/3}$. We also consider Hamiltonian walks under the same restriction. They are known to grow as $\tau^{L^2+o(L^2)}$ on the same $L \times L$ lattice. We give precise estimates for $\tau$ as well as upper and lower bounds, and prove that $\tau < \lambda.$Comment: 27 pages, 9 figures. Paper updated and reorganised following refereein