RESUMO
OBJECTIVE: Broilers show clear preference towards red color light (RL). However setting of an optimum light intensity is difficult since dim intensities that favor growth reduce welfare. This experiment was conducted to test the most effective RL intensity regimen (Dim [5 lux; DI] vs high [320 lux; HI]) in combination applied at different growth stages that favors for both performance and welfare. METHODS: Complete randomize design was adopted with 6 replicates. Treatments were; T1 = early DI (8-21 d)+latter HI (22-35 d); T2 = early DI (8-28 d)+latter HI (29-35 d), T3 = early HI (8-21 d)+latter DI (22-35 d), T4 = early HI (8-28 d)+latter DI (29-35 d) and T5 = control (white light; WT) (8-35 d) at medium intensity (20 lux). Body weight (BW), weight gain (WG), water/feed intake and ratio, feed conversion ratios (FCR) were assessed. Common behaviours (15) were recorded by scan sampling method. Lameness, foot pad dermatitis, breast blisters, hock burning damage were assessed as welfare parameters. Fear reactions were tested using Tonic Immobility Test. Ocular and carcass evaluations were done. Meat and tibiae were analyzed for fat and bone ash respectively. RESULTS: On 35 d, the highest BW (2,155.72±176 g), WG (1,967.78±174 g) were recorded by T2 compared to WT (BWWT = 1,878.22±155, WGWT = 1,691.83±160). But, application of RL, either DI, or HI during early/latter stage had no significant effect on FCR. Under HI, birds showed much higher active behaviours. DI encourages eating. Though LI changed from DI to HI, same trend could be seen even under HI. The highest leg strength (218.5±120 s) was recorded by T2. The lowest leg strength (64.58±33 s) and the highest ocular weight (2.48±1 g) were recorded by T1. Significantly (p<0.05) the highest skin weight (162.17±6 g) but the lowest fat% in meat (13.03%±5%) was recorded by T2. CONCLUSION: Early exposure to DI-RL up to 28 days followed by exposure to HI-RL is the most favorable lighting regimen for optimizing production, better welfare of broilers and improving health benefits of meat.
RESUMO
Red light (RL) marked higher weight gain (WG) and preference of broilers compared to other light colors. This study aimed to investigate how different intensities of RL affect the performance, behavior and welfare of broilers. RL treatments were T1 = high intensity (320 lux), T2 = medium intensity (20 lux); T3 = dim intensity (5 lux), T4 = control/white light at (20 lux) provided on 20L:4D schedule and T5 = negative control; 12 hours dark: 12 hours day light. Cobb strain broilers were used in a Complete Randomize Design with 6 replicates. WG, water/feed intake, feed conversion ratio (FCR), mortality, behavior and welfare were assessed. At 35 d, significantly (p<0.05) highest body weight (2,147.06 g±99) was recorded by T3. Lowest body weight (1,640.55 g±56) and FCR (1.34) were recorded by T5. Skin weight was the only carcass parameter showed a significant (p<0.05) influence giving the highest (56.2 g) and the lowest (12.6 g) values for T5 and T1 respectively. Reduced welfare status indicated by significantly (p<0.05) higher foot pad lesions, hock burns and breast blisters was found under T3, due to reduced expression of behavior. Highest walking (2.08%±1%) was performed under T1 in the evening during 29 to 35 days. Highest dust bathing (3.01%±2%) was performed in the morning during 22 to 28 days and highest bird interaction (BI) (4.87%±4%) was observed in the evening by T5 during 14 to 21 days. Light intensity×day session×age interaction was significantly (p<0.05) affected walking, dust bathing and BI. Light intensity significantly (p<0.05) affected certain behaviors such as lying, eating, drinking, standing, walking, preening while lying, wing/leg stretching, sleeping, dozing, BI, vocalization, idling. In conclusion, birds essentially required provision of light in the night for better performance. Exposed to 5 lux contributed to higher WG, potentially indicating compromised welfare status. Further researches are suggested to investigate RL intensity based lighting regimen that favors for both production and welfare of Broilers.
RESUMO
The objective of this study was to compare the emission of NH(3) from 3 types of broiler litters. Three litter materials (refused tea, RT; sawdust, SDT; and paddy husk, PH) were randomly assigned into 18 cages. Twenty-day-old broiler chicks (n = 216) were randomly allocated into cages and were fed a commercial broiler finisher diet from 21 to 42 d. Three litter samples were taken from each cage on 36 and 42 d. Three subsamples taken from each cage were pooled and analyzed for moisture, pH, and N. Litter samples were incubated for 5 h, and the emitted NH(3) was trapped with boric acid and then titrated with HCl to determine the NH(3) emissions. The emission of NH(3) from RT litter (13.2 mg/kg of litter per h) on d 36 was 61% less than that from SDT and PH. The NH(3) emission rate of RT litter on d 42 (13.0 mg/kg per h) was very similar to that on d 36 (13.2 mg/kg per h). However, emission rates of SDT and PH on d 36 increased by 57.8 and 33%, respectively, when determined on d 42. Emission of NH(3) from RT litter on d 42 (13.0 mg/kg per h) was significantly (P < 0.05) less than that from SDT (54 mg/kg per h) and PH (44 mg/kg per h) litters. When the emission rate was computed as grams of NH(3)/hour/animal unit (AU), the emission rates of RT litter on d 36 (3.4 g/h per AU) and 42 (5.1 g/h per AU) were significantly (P < 0.05) less than that of SDT and PH. The N contents of the RT litter on 36 and 42 d were 6.6 and 6.7%, respectively, and were significantly (P < 0.001) greater than the respective values of SDT and PH. It was concluded that emission of NH(3) from poultry houses could be reduced substantially by using RT as a litter material.