NUTRITION ▶▶▶
Fly larvae improve leg health
BY MATTHEW WEDZERAI S
tudies show that in 2017 approximately 90-95% of European fast-growing broilers obtained a weight of 2-2.5 kg within six weeks. What we see is that rapid growth and leg problems have a serious impact on
activity and behaviour, as fast-growing broilers are mostly in- active. Fast growth promotes the development of broiler lameness, directly by impairing leg bone development and indirectly through limiting broiler activity. As moisture and ammonia accumulates in the litter over time, broilers that spend more time resting are prone to develop contact der- matitis. Environmental enrichment that triggers intrinsically motivated behaviours can potentially promote activity and reduce leg problems, thereby improving broiler welfare.
Scattering larvae The study investigated the effect of scattering fly larvae in the litter on broiler behaviour, contact dermatitis, lameness and performance. Broilers received either 5% or 10% of the esti- mated daily dietary DM intake as BSF larvae (hereafter re- ferred to as A5 and A10, respectively), either twice or four times a day (F2 and F4, respectively) which, apart from the control treatment, resulted in treatments A5F2, A5F4, A10F2 and A10F4. Broilers received BSF larvae at set times each day (08:00 and 14:00 hours for the F2 treatments and 08:00, 11:00, 14:00 and 17:00 hours for the F4 treatments). The lar- vae were provided by scattering them across the litter throughout the pen.
Leg health Both foot pad dermatitis and hock burn were scored using a five point scale, with 0 equal to no lesions and 4 representing severe lesions, while gait (indicative of lameness) was scored on a scale ranging from 0 (normal, dextrous and agile walk) to 5 (incapable of walking). The prevalence and severity of hock burn and lameness was significantly less in broilers re- ceiving 10% of their dietary DM as BSF larvae compared to controls, and the severity of lameness was lower in broilers receiving 5% of the dietary DM as larvae four times a day compared to controls. Foot pad dermatitis was also reduced in all the larvae groups. Since leg problems can be painful and inhibit natural behaviour, this suggests that the BSF broilers experienced improved welfare. The study researchers
▶ POULTRY WORLD | No. 10, 2020 25
A recent study at Wageningen University and Research used live black soldier fly larvae as an environmental enrichment tool. This enrichment triggered intrinsically motivated behaviours that can potentially promote activity and reduce leg problems, thereby improving broiler welfare.
expect to see more beneficial effects on leg health from pro- viding larvae under commercial conditions where broilers can benefit more from enrichment. However, the applicability of providing BSF larvae in commercial settings remains to be investigated.
Behaviour Several studies have indicated that promoting activity from a young age onwards promotes leg bone development and even increased activity levels later in life, where prolonged elevated activity levels indicate improved leg health. In ad- dition, increased activity means better litter mixing which helps the litter to dry more easily. A drier litter reduces the risk of contact dermatitis. Thus, environmental enrichment that facilitates activity in broilers may help to improve broiler welfare. The researchers found that all broilers receiving BSF larvae increased the amount of time spent walking, standing idle,
Fly larvae pro- vide an endless resource that can be grown on both food and farm waste.
PHOTO: DENNIS WISSE
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
