Comment on "Productivity is a poor predictor of plant species richness"

Adler et al. (Reports, 23 September 2011, p. 1750) analyzed the standardized sampling data from 48 herbaceous-dominated plant communities and concluded that "Productivity is a poor predictor of plant species richness" at fine-scale. However, their method was biased toward site-number-dominated plant communities. They also failed to provide enough data for regional analysis and detailed information for within-site analysis.     

Performance of early and late feathering broiler breeder females with different feeding regimens.

1. Growth, reproductive characteristics and immunocompetence were evaluated in a line of broiler breeder females segregating at the sex-linked feathering locus when maintained on three feeding regimens with two forms of food in a factorial design. 2. Long-term obesity but not short-term weight gain had deleterious consequences for reproductive characteristics, response to sheep red blood cell antigen, resistance to Escherichia coli and livability. 3. Reproductive performance of early feathering females was superior to that of late feathering ones. Differences were attributed to an association between the allele for late feathering and an endogenous viral locus ev21, which encodes for avian leucosis virus. 4. Reproductive performance of breeders fed crumbles was superior to that of breeders fed a combination of crumbles and fines.     

Responses of chickens to Streptococcus faecalis: genotype-housing interactions

Hens from lines selected for high and low juvenile body weight were maintained in single-bird wire cages or in litter-floor flocks and inoculated intravenously with Streptococcus faecalis. Responses to the inoculation, as measured by changes in body weight, plasma xanthophyll levels, heterophil/lymphocyte ratios, and mortality, were more severe in the high-body-weight line than the low-body-weight line. The effect of cage vs. floor housing varied according to genetic line. Responses of individuals to Str. faecalis could not be predicted from either plasma xanthophyll levels or numbers of heterophils and lymphocytes before inoculation. Diagnosis of field outbreaks would be difficult, because autopsies performed 14 days after inoculation revealed no lesions, and liver swabs positive for Str. faecalis were rare.     

Colibacillosis of turkeys exacerbated by hemorrhagic enteritis virus. Laboratory studies

Lesions typical of colibacillosis disease were reproduced in laboratory experiments. Mortality resulting from experimentally produced colibacillosis was significantly increased when Escherichia coli O1:K1 was presented to poults that had been orally inoculated with hemorrhagic enteritis virus (HEV) 1 week earlier. These and previous data suggest that HEV infection can exacerbate colibacillosis of older poults. HEV infection apparently damages the poults' defense system enough to account for the observed increase in susceptibility to E. coli.     

The role of supplementary dietary antioxidants on immune response in puppies

The objective of this study was to evaluate the effect of supplementary antioxidants (AOX) and whey protein on the immune function health of puppies. Four groups of 10 puppies were fed a control and 3 different test foods (control + antioxidants (AOX), control + AOX + 1% whey protein, and a grocery brand (low AOX)) for 6 weeks. A standard vaccination protocol with a combination canine parvovirus (CPV) and distemper (CDV) vaccine was carried out at 2 and 4 weeks. The results showed that animals on high AOX foods had significantly increased titers, memory cells and serum E concentrations compared to the control and groc groups respectively.     

Aquatic productivity and the evolution of diadromous fish migration

Diadromous migration, in which some fish species migrate from freshwater and feed in the ocean (anadromous species) and others migrate from the ocean and feed in freshwater (catadromous), has long been perplexing. However, when the distribution of diadromous species is examined with respect to global patterns in aquatic productivity, this apparent paradox is resolved. The contrasting directions of migration can largely be explained by the relative availability of food resources in ocean and freshwater habitats. Oceans are more productive than freshwaters in temperate latitudes, and anadromous species predominate. In contrast, catadromous species generally occur in tropical latitudes where freshwater productivity exceeds that of the ocean.