Effects of the Marek’s Disease Vaccine on the Performance, Meat Yield, and Incidence of Woody Breast Myopathy in Ross 708 Broilers When Administered Alone or in Conjunction with IIn ovo/I and Dietary Supplemental 25-Hydroxycholecalciferol

• Published in: Animals (Basel) 2024-05, Vol.14 (9)
• Main Authors: Fatemi, Seyed Abolghasem, Mousstaaid, Ayoub, Williams, Christopher J, Deines, Joshua, Poudel, Sabin, Poudel, Ishab, Walters, Elianna Rice, Levy, April Waguespack, Peebles, Edgar David
• Format: Article
• Language: English
• Subjects: Poultry industry; Vaccination; Vaccines; Williams, Christopher J
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani14091308

The second metabolite of vitamin D, 25-hydroxyvitamin D[sub.3] (25OHD[sub.3]), has previously shown promising results on the live performance and meat yield of broilers when it was administered in ovo or in their diet. However, the effects of 25OHD[sub.3] on the posthatch performance of broilers have not been tested in combination with the in ovo administration of the Marek’s disease vaccine (MDV). Therefore, the aim of the current research was to investigate the effects of in ovo and dietary sources of 25OHD[sub.3] in conjunction with the in ovo delivery of the MVD on the broiler meat yield, live performance, and incidence of woody breast myopathy (WBM). In this study, it was shown that both 25OHD[sub.3] sources increased the meat yield and improved the live performance variables of broilers with no measurable negative effects on WBM scoring. It is worth mentioning that the dietary source of 25OHD[sub.3] had greater effects on breast meat yield and posthatch performance throughout the rearing period when compared to its in ovo administration. In conclusion, both the in ovo and dietary administration of 25OHD[sub.3] can be used in combination with the in ovo delivery of the MDV in order to enhance its efficacy on broiler posthatch production. The effects of the Marek’s disease vaccine (MDV) on the live performance, breast meat yield, and incidence of woody breast myopathy (WBM) of Ross 708 broilers were investigated when administered alone or in conjunction with in ovo and dietary supplemental 25-hydroxycholecalciferol (25OHD[sub.3]). At 18 d of incubation (doi), four in ovo injection treatments were randomly assigned to live embryonated Ross 708 broiler hatching eggs: (1) non-injected; (2) commercial MDV alone; or MDV containing either (3) 1.2 or (4) 2.4 μg of 25OHD[sub.3]. An Inovoject multi-egg injector was used to inject a 50 μL solution volume into each egg. The birds were provided a commercial diet that contained 250 IU of cholecalciferol/kg of feed (control) or a commercial diet that was supplemented with an additional 2760 IU of 25OHD[sub.3]/kg of feed (HyD-diet). In the growout period, 14 male broilers were placed in each of 48 floor pens resulting 6 replicated pens per in ovo x dietary treatment combination. Live performance variable were measured at each dietary phases from 0 to 14, 15 to 28, and 29 to 40 d of age (doa). At 14 and 40 doa, pectoralis major (P. major) and pectoralis minor (P. minor) muscles were determined for one bird within each