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The objectives of these experiments were to determine the optimal dose of copper oxide wire particles (COWP) necessary to reduce gastrointestinal nematode (GIN) infection in young and mature goats naturally infected with Haemonchus contortus or a mixed infection and to determine whether the effectiveness could be enhanced through feeding management. Two experiments were conducted during cooler months in Georgia, and 4 experiments were conducted during warmer spring or summer months in Arkansas. Meat goats received 0 up to 10 g of COWP under a variety of management conditions. In all experiments, blood and feces were collected every 3 or 7 d from 6 to 42 d to determine blood packed cell volume (PCV) and fecal egg counts (FEC) to estimate the degree of GIN infection. In mature goats grazing fall pasture, mean FEC of 0 g of COWP-treated goats increased, and those of 4 g of COWP-treated goats remained low on d 0, 7, and 14 (COWP x d, P < 0.03), and FEC decreased on these days (P < 0.001). In 5 and 10 g of COWP-treated goats, PCV increased (P < 0.001), but FEC and PCV remained unchanged over time in control goats. Fecal egg counts were similar among all low doses (0.5, 1, 2, 4 g) of COWP administered to weaned kids for all dates examined (P > 0.10), which were lower on d 7 through 21 (COWP x date, P < 0.05) but similar by d 28, compared with FEC of 0 g of COWP-treated kids. Packed cell volume was lower in 0 g compared with all COWP-treated kids by d 14 (COWP x date, P < 0.05). Feeding management in combination with COWP for GIN control had little effect compared with COWP alone for these short-term studies. In conclusion, a dose of COWP as low as 0.5 g, which was considered optimal to reduce the risk of copper toxicity, was effective in reducing FEC in young goats, and 5 g of COWP was effective in older goats. Copper oxide does not appear to be effective in controlling newly acquired L4 stage (preadult) larvae, which also feed on blood, leading to decreased PCV in newly infected goats. Key words: copper oxide, goat, gastrointestinal parasite, sericea lespedeza

Red clover (Trifolium pratense L.) is a forage legume with considerable economic importance in world agriculture. Knowledge of the amount and distribution of genetic variability within a species is vital to breeders and geneticists when selecting breeding germplasm. The objectives of this study were to assess genetic diversity in 34 North American red clover cultivars by means of isozymes. Isozymes assayed were esterase, Β-glucosidase, phosphoglucomutase, peroxidase, diaphorase, phosphoglucoisomerase, and superoxide dismutase. Eleven of the 13 loci (84.62%) were polymorphic in at least one cultivar. Percentage polymorphic loci within cultivar ranged from 61.54% in cv Morred, Persist, and Redland II to 84.62% in cv Arlington, Ram, and Red Baron, with an overall mean of 73.98%. At the species level, the number of alleles per polymorphic locus was 2.55 and effective number of alleles per locus was 1.64. Within-cultivar averages were 2.71 and 1.59, respectively. Genetic diversity was 0.292 at the species level and 0.285 for within populations. Most of the genetic diversity (98.4-99.7%) was distributed within the cultivars. Grouping the 34 cultivar on the basis of genetic distance indicated that their isozyme variability could be represented by a few cultivar of each of four groups plus the cv Morred and Redon., RED CLOVER is a short-lived herbaceous forage crop thought to have originated in southeastern Europe and Asia Minor near the Mediterranean Sea (Taylor and Quesenberry, 1996, p. 1). It is [...]

Previous investigations of genetic correlation ([r.sub.G]) indicate that [r.sub.G] is sensitive to sampling error. A nonparametric bootstrap method provides an alternative for estimating standard error and confidence intervals. Using the bootstrap method in a half-sib red clover (Trifolium pratense L.) population, we evaluated the effect of sample sizes on the point estimate, its sampling error, and confidence interval of re. We conducted separate analyses for varying numbers of replications, families, and plants per family using a seedling data set. Precision of [r.sub.G] was affected by sample sizes and traits measured. To achieve a reasonable standard error and a small confidence interval of [r.sub.G], a minimum of 42 half-sib families each having nine plants in four replications would be required. Although this study was limited to seedling traits in a greenhouse, similar results may occur when measuring other traits., A genetic correlation coefficient ([r.sub.G]) measures the degree of genetic association between parent and offspring (Reeve, 1955) or between two quantitative characters within and between groups of relatives (Kempthorne, 1957; [...]

Transfer of the low-tannin trait to otherwise desirable sericca lespedeza high-tannin lines produced genotypes with considerably lowered forage yield. It is not known if low-tannin sericeas are proportionally less productive than high-tannin sericeas in high yielding environments. If so, low-tannin senceas would be less desirable to grow in more productive environments. Regression analysis was used to partition GE interactions between regressions and the residuals after regression and to measure the response to changing environments. SHUKLA's stability-variance parameters were used to measure genotype stability. Variance and coefficient of variation were calculated across environments for each genotype and rank correlated to determine their usefulness in the early stages of cultivars testing. Stability analysis was carried out on the day forage yield of 10 genotypes grown in 10 environments in Alabama. The only low-tannin genotype that consistently responded to environmental fluctuations like 'Serala' was 74 100 5. Low-tannin sericeas were found to be proportionally less productive than high-tannin sericeas in high-yielding environments. However, it is possible to select low-tannin lines with an environmental response similar to high-tannin sericeas. Rank correlations among stability parameters indicated that EV is a stability parameter which is easy to calculate and could be used in the early stages of cultivar testing. [ABSTRACT FROM AUTHOR]