Early feed access may improve broiler growth performance

The study looked to evaluate early feed access and algal extract on growth performance, organ development, gut microbiota and vaccine-induced antibody responses.

Hatching concepts such as on-farm hatching provide an opportunity to supply newly hatched birds with optimal nutrition that support growth and development of a healthy gut. Brown algae contain bioactive compounds, especially laminarin and fucoidan that may boost intestinal health and immune responses.

The study

A total of 432 Ross 308 chicks were allotted to 36 rearing pens in a 2×3 factorial design with 2 hatching treatments and 3 dietary treatments.

• During chick placement, half of the pens were directly provided access to feed and water (Early) while half of the pens were deprived of feed and water for 38h (Late).
• The chicks were feed 3 different started diets until day 6:
  – a wheat-soybean meal-based control diet,
  – a diet with low inclusion of algal extract (0.057%)
  – and a diet with high inclusion of algal extract (0.114%).
• Feed intake and Body Weight (BW) were registered on pen basis at placement, days 1, 6, 12, 19, 26, 33 and 40.
• To induce antibody responses, all chicks were vaccinated against avian pneumonia on day 10.
• 3 chicks per pen were selected as focal animals and used for blood sampling on days 10 and 39.
• On days 6, 19 and 40, 2 birds per pen were killed and used for organ measurement and caecal digesta sampling for gut microbiota analysis using the Illumina Miseq PE250 sequencing platform.

Results

The results showed that although the algal extract did not influence gut microbiota or vaccine-induced antibody responses, they showed that during the first 38 hours, early-fed chicks consumed an average of 19.6g of feed and gained 27% in BW, while late-fed chicks lost 9.1% in BW which lowered BW and feed intake throughout the study (P<0.05).

Late chicks also had longer relative intestine, high relative (g/kg BW) weight of gizzard and proventriculus but lower relative bursa weight on day 6 (P<0.05%). No effects of hatching treatment on microbiota or antibody response was detected. The microbiota was affected by age, where alpha diversity increased with age.

In conclusion, the study showed that early access to feed but not algal extract improved the growth performance throughout the 40-day growing period, and stimulated early bursa development.

The research, published in the journal Animal was carried out by researchers at the Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala; the Department of Microbiology, National Veterinary Institute, Uppsala and the Department of Marine Sciences, University of Gothenburg – Evaluation of early feed access and algal extract on growth performance, organ development, gut microbiota and vaccine-induced antibody responses in broiler chickens – ScienceDirect