Effect of different levels of hatchery wastes on growth performance, nutrients digestibility, ruminal and blood parameters in fattening lambs

Processing and treatment of agricultural residues and by-products is a good economical solution for reusing them into the product cycle specially in animal feeding. The production a huge quantity of hatchery waste (HW) in the poultry industry has raised concerns about environmental pollution. Nutrients and energy in wastes, litter of broiler and hatchery after eliminating of their pathogens, can be recycled and used in livestock diets. Therefore, the purpose of this experiment was to investigate of the effect of feeding different levels of HW as the main source of dietary protein on lamb’s performance, nutrients digestibility, rumenal fermentation and blood parameters.

Twenty-four Kermani male lambs with an average initial weight of 23±0.33 kg and six months’ age, were used in a completely randomized design. The experimental diets included control diet and diets containing 3 and 6% of HW. To estimate of feed intake, the remaining feed of lambs collected and weighed daily before the morning meal. At the end of every two weeks the lambs are weighed for calculation of daily weight gain. Nutrients digestibility measured by acid insoluble ash marker method. Rumen liquid samples taken from lambs before and 3 and 6 h after feeding for NH3-N, pH and volatile fatty acids measuring. Blood samples were collected at the end of period and 3 h post morning feeding for determination of blood biochemical factors. At the end of main period, all lambs were slaughtered following an overnight fast and skinned. Empty body were weighted and stored at 4 °C for 24 hours (for determination of cold carcass weight).

In the present study, performance and dry matter intake in lambs fed with 6% hatchery waste powder were significantly higher than the control group (P<0.05). Dry matter, organic matter and crude protein digestibility was not affected by HW. But, neutral and acid detergent fiber digestibility decreased (P<0.05) by adding of HW in lamb’s diet. Adding of HW in lambs’ diet, increased warm and cold carcass weights linearly (P<0.05). The pH, protozoa population and NH3-N concentration in the rumen were not affected by the experimental diets. The HW in diet caused to decreasing (P<0.05) and increasing acetic and propionic acids concentration in lambs, respectively. Blood cholesterol and glucose level in lambs fed HW were significantly higher than other groups (P<0.05). but other factors such as BUN and total protein were not different among the experimental diets.

The chemical composition of the HW indicates that this by-product is relatively appropriate nutritious. Because of increase in feed intake and performance and too alter in ruminal fermentation characteristics, this waste can be used as part of a concentrate in the diet of lambs.