Dietary protein influences the life‐history characteristics across generations in the African striped mouse Rhabdomys

Abstract

The level of dietary protein determines the onset of reproduction, affects offspring growth and maturation, and hence influences life-history traits and fitness. However, to date, the long-term life-history consequences of protein deficiency are not well understood. We studied the transgenerational effects of different levels of dietary protein on the life-history and level of maternal behavior of the striped mouse Rhabdomys dilectus chakae in captivity. Breeding pairs were assigned to three treatments based on the percentage of dietary protein: baseline (BP; 19%); high protein (HP; 24%); and low protein (LP; 10%). Reproductive output and offspring ontogeny was diminished in the LP treatment compared to the other treatments. Transgenerational effects were studied by breeding F2 females raised on the LP or HP diets on the same (HP-HP, LP-LP) or altered diets (HP-LP, LP-HP). The LP-LP treatment had no reproductive success, while reproductive capacity in the remaining treatments was determined mainly by the diet of mothers at breeding. Pups from protein-restricted females (LP, HP-LP) showed post-weaning compensatory growth. Timing of sexual maturity was age-dependent in female and mass-dependent in male offspring. Females fed low protein diets during breeding (LP, HP-LP) displayed lower levels of maternal behavior than females from the other treatments. This study demonstrates that the level of dietary protein influences the life-history of R. d. chakae in predictable ways. The taxon responds to changes in dietary protein at breeding, largely regardless of its nutrition during rearing. Such phenotypic flexibility in life-history parameters allows Rhabdomys to adaptively respond to unpredictable environmental changes.

Protein deficiency decreases stereotypic behavior frequency and prevalence and activity in the striped mouse Rhabdomys dilectus chakae

“…Stereotypic behavior is associated with present or previous (historical) stress and is often viewed as an indicator of poor welfare (Mason, , ; Mason & Rushen, ; Mason & Veasey, ). Low protein (10% digestible protein) suppresses reproduction in striped mice (Nel et al, ), and here we showed that their activity and body mass are also reduced. Therefore, protein deficiency, through its potential effects on energy deficiency and neurological changes, negatively affects striped mice and poses a concern for their welfare in captivity.…”

“…Secondly, protein‐restricted rats apparently utilize more energy from brown adipose tissue than non‐restricted rats, thus gaining less body mass (Donald, Pitts, & Pohl, ). Therefore, protein‐restricted individuals typically have a lower body mass compared to non‐restricted individuals (Alamy & Bengelloun, ; Almeida & De Araújo, ; Kehoe, Mallinson, Bronzino, & McCormick, ; White et al, ), as also occurred in striped mice in our study and in an earlier study (Nel et al, ). Together with reduced energy availability, a lower body mass may explain why LP striped mice showed reduced levels of activity and potentially reduced levels of stereotypic behavior.…”

“…The food was highly palatable, with consumption comparable to the standard mouse cubes (5–8 g per day for both diets). Moreover, the post‐weaning growth rate in body mass of striped mice was similar on the formulated baseline diet (0.02–0.07 g/day; Nel et al, ) and the standard mouse cube diet (0.02–0.05 g/day; Pillay, ).…”

“…Protein is a limiting factor in Rhabdomys biology, shaping, for example, the onset of reproduction and reproductive performance (Perrin, ; Nel et al, ) and behavioral ecology (Schradin & Pillay, ). Here, we show that dietary protein also influences general activity and locomotory stereotypic behavior in striped mice, provided that stereotypic behavior already exists.…”

Density feedbacks mediate effects of environmental change on population dynamics of a semidesert rodent

“…These findings are consistent with other studies that found food availability to be the main driver of population fluctuations of rodents in semiarid environments (Brown & Ernest, ; Lima, Ernest, Brown, Belgrano, & Stenseth, ; Previtali et al., ), as well as primary consumers in general (Hunter & Price, ; Kagata & Ohgushi, ). In the case of striped mice, opportunistic breeders displaying a high degree of plasticity in reproductive timing (Nel et al., ; Raynaud & Schradin, ), the population increases following elevated food availability are likely the results of prolonged reproductive seasons with many young animals starting to breed early, potentially followed by “out‐of‐season” reproduction due to more favourable conditions.…”