Evolution of the peripheral blood lymphocyte populations in multiparous rabbit does with two reproductive management rhythms

Abstract

The emergence of epizootic rabbit enteropathy is leading to changes in weaning protocols in 25 commercial rabbitries. Traditional weaning protocols are being replaced with late weaning, 26 beyond 35 days postpartum (dpp). The main objectives of this study were to compare the 27 peripheral blood lymphocyte populations of multiparous rabbit does under two reproductive 28 rhythms (insemination at 11 dpp and weaning at 28 dpp, insemination at 25 dpp and weaning 29 at 42 dpp), and to assess the influence on those of kits. Samples of peripheral blood were taken 30 in 22 adult females and 44 of their kits at different critical times, and several lymphocytic 31 populations were evaluated by flow cytometry. Additionally, the perirenal fat thickness of does 32 was also measured at partum and weaning to observe if body condition correlates with 33 lymphocyte populations. During whole lactation, counts of total, T, CD4 + and CD8 + 34 lymphocytes of females were generally lower with weaning at 42 dpp compared to 28 dpp. 35Moreover, counts of total, B and T lymphocytes in rabbit does weaned at 42 dpp correlated to 36 their body condition (+0.60 to 0.82; P<0.05), contrary to that observed in rabbit does weaned 37 at 28 dpp. Some correlations between lymphocyte counts in both does and weaning rabbits 38 were observed. At weaning, those young rabbits weaned at 42 dpp had a significantly lower 39 number of CD4 + lymphocytes than those weaned at 28 dpp (P<0.01). In conclusion, longer 40 lactation periods and major accumulated wear under prolonged reproduction rhythms could be 41 interpreted as a minor immunological level for adult rabbit does.

How selection for reproduction or foundation for longevity could have affected blood lymphocyte populations of rabbit does under conventional and heat stress conditions

“…As reported in a previous study (Guerrero et al, 2011), where a similar methodology was used, several imbalances appear in the results obtained in the present study: (1) the sum of the CD5+ and B lymphocyte percentages is lower than 100 and (2) the sum of the CD4+ and CD8+ lymphocytes is lower than the number of T CD5+ lymphocytes.…”

“…Although rabbits have been traditionally used as experimental models for many years, data about their blood lymphocyte populations are scarce. This lack of information is more evident in commercial rabbits (Guerrero et al, 2011) where it is vital to characterise and to evaluate rabbit genetic lines and their responses to different challenges, like heat stress, which is the case in this study.…”

“…A flow cytometry analysis was carried out as previously described (Guerrero et al, 2011). Blood samples were processed 1 h after sampling.…”

Resources allocation in reproductive rabbit does: a review of feeding and genetic strategies for suitable performance

“…These results would reflect the importance of not moving too far from the appropriate body status to ensure reproduction and reduce the risk of culling. Thus, Guerrero et al (2010) and Ferrian et al (2012) observed a positive correlation between the body status of the rabbit does and the population of B lymphocytes (from +0.40 to +0.82) and that there is a positive correlation between the lymphocyte populations of the does and their litters (e.g. T CD5+: +0.35).…”

Impact of rearing mangement on health in domestic rabbits: a review

“…Chronic exposure to such a stressor could have immunosuppressive effects (von Holst, 1998). Indeed, such a relationship between extended lactation and alterations in immune status has been shown in the domestic rabbit (Guerrero et al, 2011). In addition, injury of the teats and related diseases are also common.…”