OBJECTIVES The purpose of this study was to assess whether broiler breeders vaccinated in ovo with a Vaxxitek (HVT&IBD) (Merial) plus an inactivated IBD vaccine prior to the onset of lay had a significantly different humoral IBD antibody response to broiler breeders vaccinated solely with Vaxxitek (HVT&IBD) (Merial) in ovo. In addition, maternally derived antibody (MDA) passed to the progeny of...

While measures to control carcass contamination with Salmonella at the processing plant have been implemented with some success, on-farm interventions that reduce Salmonella prevalence in meat birds entering the processing plant have not translated well on a commercial scale. We determined the impact of Salmonella vaccination on commercial poultry operations by monitoring four vaccinated and fo...

Mole-rat of the genus Fukomys are mammals whose life span is strongly influenced by reproductive status with breeders far outliving nonbreeders. This raises the important question of whether increased longevity of the breeders is reflected in atypical expression of biochemical markers of aging. Here, we measured markers of glycation and advanced glycation end-products formed in insoluble skin c...

The wildlife pet trade has the potential to threaten the viability of free-ranging animal populations. Yet there are potential benefits from the informal biological knowledge produced by breeders and caretakers for these taxa. How the evolution of a species shapes and is shaped by its embeddedness in the unique and changeable spatialities of the pet trade is also of relevance. To convey these p...

Adult individuals that do not breed in a given year occur in a wide range of natural populations. However, such nonbreeders are often ignored in theoretical and empirical population studies, limiting our knowledge of how nonbreeders affect realized and estimated population dynamics and potentially impeding projection of deterministic and stochastic population growth rates. We present and analys...

Unrelated subordinates may invest in costly help to avoid being evicted from groups (the 'pay-to-stay' hypothesis). However, the effectiveness of eviction to enforce help should depend on its being applied accurately and on the costs it imposes on both dominants and subordinates. The relative cost of being evicted is a function of the population frequency of eviction when population growth is l...

Acorn woodpeckers (Melanerpes formicivorus) are cooperative breeders in which groups consist of a variable number of cobreeding males, jointnesting females, and non-breeding helpers of both sexes that are offspring from prior nests. We temporarily manipulated brood size of nests to determine the feeding response of birds in relation to their status (breeder or non-breeding helper) and sex. All ...

In cooperatively breeding species, helpers can alleviate reproductive constraints by assuming the role of primary carers to first-born young, liberating breeders to invest in subsequent broods. However, evidence on how first-born young are transferred to helpers is currently lacking. We propose that breeder-offspring aggression might facilitate inter-brood division and test this idea using data...

The antagonistic pleiotropy theory of senescence postulates genes or traits that have opposite effects on early-life and late-life performances. Because selection is generally weaker late in life, genes or traits that improve early-life performance but impair late-life performance should come to predominate. Variation in the strength of age-specific selection should then generate adaptive varia...