Influence of supplemental dietary poultry fat on the performance of commercial layers inoculated before or at the onset of lay with F-strain Mycoplasma gallisepticum

Abstract

The effects of F-strain Mycoplasma gallisepticum (FMG) inoculation and 1.5% supplemental dietary poultry fat (PF) on the performance of commercial layers between 20 and 58 wk of age were investigated. Sham and FMG inoculations were administered at 12 (before lay) and 22 (early in lay) wk and dietary treatments (basal control diets and basal control diets with 1.5% supplemental PF) were initiated at 20 wk of age. Mortality at wk 47 and 53 was greatest in birds inoculated with FMG at 22 wk. Feed consumption from 20 to 23 and from 52 to 55 wk of age was greater in birds that were inoculated with FMG (12 or 22 wk). However, feed consumption decreased in birds that were inoculated at 12 wk (sham or FMG) when 1.5% supplemental PF was added to the diet. Percentage of total egg production (EP) between 22 and 58 wk of age was highest in hens that were inoculated with FMG at 22 wk. Furthermore, weekly EP increased at wk 27 and 58 and decreased at wk 47 after birds had been inoculated with FMG (12 or 22 wk), and increased at 22 wk and decreased at 54 wk when inoculations (sham or FMG) were given at 22 wk. Egg weight was increased at wk 29, 31, 39, 40, 42, 44, 53, and 58 in birds that were inoculated with FMG (12 or 22 wk); however, there were no coherent treatment effects on eggshell quality. An FMG inoculation at 22 wk may promote total EP through 58 wk, whereas the inoculation of commercial layers with FMG (12 or 22 wk) may increase subsequent feed consumption during the early and late stages of EP and increase egg weight throughout lay. However, the supplementation of hen diets with 1.5% PF beginning at 20 wk of age may reduce subsequent feed consumption throughout lay in birds having experienced a prelay (12 wk) inoculation.

Mycoplasma gallisepticum in the commercial egg-laying hen: A historical perspective considering the effects of pathogen strain, age of the bird at inoculation, and diet on performance and physiology

“…Although Peebles et al [50] observed no effect of HpFMG eye drop inoculations at either 12 or 22 wk of age on subsequent hen mortality, in these same birds, Peebles et al [51] reported that the inoculation of HpFMG (across the 12 and 22 wk of age inoculation periods) decreased EP on wk 22 and 23 by an average of 5.4% (% of hen-day EP), but increased EP on wk 45 by 3.4% (% of henday EP) without affecting total EP, egg weight, eggshell quality, relative weights of the yolk and albumen, or yolk moisture and lipid concentrations. In other work, Park et al [52] noted in commercial laying hens that feed consumption from 20 to 23 wk and from 52 to 55 wk of age was greater, but that percentage EP on wk 27 and 58 was higher and that on wk 47 was lower in response to the inoculation of HpFMG at either 12 or 22 wk of age. Nevertheless, total EP between 22 and 58 wk of age was highest in hens that were inoculated with HpFMG at 22 wk of age.…”

“…However, the benefit of the supplemental PF on feed consumption was lost if the birds had been inoculated with HpFMG at 12 wk of age. Park et al [52] further showed that this same type and timing of diet supplementation reduced feed consumption throughout lay in birds that experienced an inoculation procedure (sham or HpFMG) at 12 wk of age. Although Park et al [52] reported that the 1.50% supplemental PF did not augment the eggshell quality of the hens subjected to inoculation (sham or HpFMG), in a report in which the same birds were used, Park et al [53] found that the use of 1.50% supplemental PF increased percentage of yolk weight and the yolk:albumen ratio across hen age, inoculation type (sham or HpFMG), and inoculation age (12 or 22 wk of age), and decreased yolk concentrations of palmitic and oleic acid while increasing those of linoleic acid at 58 wk of age.…”

“…Park et al [52] further showed that this same type and timing of diet supplementation reduced feed consumption throughout lay in birds that experienced an inoculation procedure (sham or HpFMG) at 12 wk of age. Although Park et al [52] reported that the 1.50% supplemental PF did not augment the eggshell quality of the hens subjected to inoculation (sham or HpFMG), in a report in which the same birds were used, Park et al [53] found that the use of 1.50% supplemental PF increased percentage of yolk weight and the yolk:albumen ratio across hen age, inoculation type (sham or HpFMG), and inoculation age (12 or 22 wk of age), and decreased yolk concentrations of palmitic and oleic acid while increasing those of linoleic acid at 58 wk of age. Park et al [53] concluded that despite the interaction of 1.50% supplemental PF on the prelay (12 wk of age) inoculation of HpFMG on hen performance during early lay observed by Peebles et al [48], the effects of 1.50% supplemental PF and a prelay inoculation of HpFMG on the egg yolk characteristics of commercial layers are independent of each other.…”

“…Although no effects on eggshell quality were attributable to HpFMG at 12 or 22 wk of age, egg weight was increased up to 1.7 g throughout lay in response to HpFMG administered at either 12 or 22 wk of age, and inoculations given on wk 22 (sham or HpFMG) caused EP to be increased on wk 22 and decreased on wk 54. In a companion study that tested the same birds that were used by Park et al [52], Park et al [53] further showed that total yolk lipid concentration was reduced by 3.7% on wk 24 in hens that were inoculated at 12 or 22 wk of age with Hp-FMG. In addition, the inoculation of HpFMG at 12 wk of age decreased yolk palmitoleic, oleic, and linolenic acid concentrations while increasing yolk stearic and arachidonic acid concentrations.…”

“…In a later report, Peebles et al [77] showed that 0.75 and 1.50% supplemental PF in the diets of laying hens had no effect on their hematocrit, plasma protein, or serum cholesterol, triglyceride, and calcium concentrations throughout lay, regardless of the type (sham or HpFMG) or age (12 or 22 wk of age) of inoculation. Although 1.50% added dietary PF failed to modulate the weight [52] and yolk characteristics [53] of the eggs from the birds inoculated with HpFMG, Park et al [83] later reported that 1.50% supplemental PF influenced the effects that the type (sham vs. HpFMG) and age of bird at inoculation (12 vs. 22 wk of age) had on the weights and lengths of various oviductal segments from these birds. More specifically, Park et al [83] noted on wk 58 that when provided throughout lay, 1.50% supplemental PF decreased the proportional isthmus length in all birds, decreased the proportional infundibulum length in birds sham-inoculated on wk 12, increased the proportional infundibulum length in birds sham-inoculated on wk 22, increased the magnum weight as a percentage of total oviduct weight in birds inoculated at 22 wk of age (sham or HpFMG), decreased the isthmus weight as a percentage of total oviduct weight in layers that were sham-inoculated (12 or 22 wk of age), and increased the isthmus weight as a percentage of total oviduct weight in birds that were inoculated with HpFMG (12 or 22 wk of age).…”