Impact of litter and litter amendments on blood variables and immunity of broiler chickens

 Poultry litter is composed of bedding material, excreta, feed, feathers and water. It is currently accepted that litter quality can add to environmental and management problems in the commercial poultry industry. Several studies are available on the impact of litter material or quality on the intestinal health immunity of poultry, but often they focus on particular pathogens, potentially detrimental to humans or other livestock, or on imposed limitations to broilers performance. 

 This study aimed to assess whether the type of bedding materials (sand, wood shaving, and paper) or chemical amendments (lime and bentonite vs. controls) affect blood parameters and immunity of broiler chickens. 

 Two hundred and seventy male Ross broiler chickens were randomly assigned into nine treatment groups with three replicates per each treatment (a total of 30 birds per each treatment). A completely randomized 3 × 3 design was used, with the main effects of bedding materials/subtracts (sand, wood shaving, or paper) and amendments (no amendment (control), bentonite, or lime), in three replicate pens of 10 chicks each, in a total of 27 experimental units. Starting at day one, groups were created according to the combination of beddings and amendments, as follows: Group 1 (Grp 1) - control sand bedding; Group 2 (Grp 2) - sand bedding treated with Bentonite; Group 3 (Grp 3) - sand bedding treated with lime; Group 4 (Grp 4) - control wood shaving bedding; Group 5 (Grp 5) - wood shaving bedding treated with Bentonite; Group 6 (Grp 6) - wood shaving treated with lime; Group 7 (Grp 7) - control paper bedding; Group 8 (Grp 8) - paper bedding treated with Bentonite; and Group 9 (Grp 9) - paper treated with lime. 

 The results showed that different bedding materials (sand, wood shavings, and paper) had not effect on most analyzed traits; though, we detected a small significant increase in the influenza antibody titres at day 36 (P < 0.05) in sand reared groups, and an increase in the total immunoglobulins (Ig) titres (due to increased IgM) on 14 days after challenged with sheep red blood cells (P < 0.05). Treatment of the bedding material with Bentonite or lime mainly affected the humoral immunity traits assessed herein. Lime treatments slightly increased the antibody titres for Influenza at the first challenge, but did not affect them on the second challenge. In contrast, no treatments increased total Ig titres (due to an increase in IgM) at day 38. The comparison of the nine groups (bedding type × amendment) indicated small differences in particular blood parameters and the humoral immunity traits. 

 Although, no deleterious effects were found on broilers, the results suggested that different litter materials with distinct amendments may affect the final quality of carcasses.