عنوان مقاله [English]
Introduction: Early post-hatch feed and water deprivation, as happens practically, may negatively influence the growth performance and health of broiler chickens due to severe dehydration, suppressed mitotic activity of satellite cells, poorer gut health, and development as well as retarded yolk sac (YS) absorption. Decelerated YS absorption may be associated with a higher incidence of YS infection and lower transfer of maternal antibodies from the YS to the chick body. Royal Chick is a nutritious gel providing adequate quantities of water and essential nutrients for newly-hatched chicks. The product also contains probiotic organisms, prebiotic, yeast nucleotides, and natural anti-stress substances. Royal Chick is an innovative nutrient-enriched powder product that forms a jelly mass when mixed with water. As claimed by the manufacturer, the product prevents initial weight loss, alleviates oxidative stress, improves skeletal muscle growth, and stimulates the development of the digestive and immune systems of the newly hatched chicks. This study aimed to evaluate the effect of early feeding with Royal Chick on productive performance, carcass traits, immune system function, and jejunum morphometry of broiler chickens.
Materials and Methods: A total of 420 d-old straight-run Ross 308 broiler chicks were used in a completely randomized design with 5 treatment groups and 6 replicates per each. A group of chicks were deprived of both feed and water for the first 24 h post-hatch and served as control (CON). In the second group, each bird was treated with HRCH gel in two separate 2 g dosages from which the first was given in the chick box and the second was administered immediately after placement in combination with the first meal of the starter diet (T1). In the third group, each bird was treated with a mixture of 2 g HRCH and 2 g starter feed in the chick box (T2). In the fourth group, each bird was treated with a single 2 g dose of HRCH in the chick box (T3). In the fifth group, each bird received a mixture of 2 g HRCH gel and 2 g starter feed immediately after placement (T4). All chicks were held in chick box up to 24 h post-hatch and then were transferred to the associated floor pens and reared for 42 days on standard starter (2 to 10 d of age), grower (11 to 24 d of age), and finisher (25 to 35 d of age) diets. On days 10, 24, and 35 birds of each pen were weighed together. Offered feed and refused feed were also weighed and mortality records were kept for each phase. Then weight gain (WG), feed intake (FI), and mortality-corrected feed conversion ratio (FCR) were calculated. On days 2 and 25, blood samples were taken from 2 birds per replicate to evaluate maternal immunity and humoral immune responses to vaccination against Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and avian influenza virus (AI). The birds from which blood samples were taken on day 2 were killed at the same time to measure residual yolk sac weight. At the end of the experiment, 2 female birds per pen were weighed and decapitated to investigate carcass traits and to sample the mid jejunum for morphometric analysis.
Results and Discussion: Birds in T1 and T2 groups tended to have lighter residual yolk sac than their control counterparts (P=0.076). During the starter phase, T2, T3, and T4 groups had significantly (P<0.05) higher WG and FI compared to those in the control group with no improvement in FCR. During the grower phase, the T4 group consumed more feed than the control one (P<0.05). No treatment effect was detected on performance traits at the finisher phase and throughout the experimental period (P>0.05). Birds in T2 and T3 groups produced the most pronounced antibody responses against IBV. The highest carcass yield was obtained in birds treated with a combination of HRCH and starter feed in the chick box (T2). The same birds also tended to have the highest breast yield (P=0.077).
Conclusion: Administration of hydrated Royal Chick gel in chick box (with or without a starter diet) or immediately after placement (in combination with a starter diet) can bring beneficial effects on the health and productivity of broiler chickens. Further investigations are necessary to identify possible interactions of different EF regimens involving HNG with breeder age, deprivation duration, and pre-placement environmental conditions on subsequent performance and health status in broiler chickens.