Dietary poultry fat, phytase, and 25-hydroxycholecalciferol influence the digestive and reproductive organ characteristics of commercial layers inoculated before or at the onset of lay with F-strain Mycoplasma gallisepticum.

Effects of 2 supplemental concentrations of dietary poultry fat (PF) and the combination of PF, phytase (PHY), and 25-hydroxycholecalciferol [25(OH)D] on the gross digestive and reproductive organ characteristics of commercial layers inoculated with F-strain Mycoplasma gallisepticum (FMG) were investigated in 2 trials. Sham and FMG inoculations were administered at 12 wk (before lay) or 22 wk (onset of lay), dietary treatments [basal control diet (BCD); BCD with 0.75% supplemental PF (LPFD); BCD with 1.50% supplemental PF (HPFD); HPFD additionally supplemented with 0.013% PHY and 0.025% 25(OH)D] were initiated at 20 wk of age, and organ characteristics were determined at 58 wk of age. In proportion to small intestine weight, jejuna were heavier in birds inoculated at 22 wk rather than at 12 wk of age. In hens inoculated at 22 wk of age, percentage of infundibulum weight was increased by FMG. The proportional length of infundibula in birds fed HPFD with PHY and 25(OH)D was longer than in those fed LPFD. In birds inoculated with FMG at 22 wk of age, BW was greater in those fed HPFD with or without added PHY and 25(OH)D in comparison with those fed LPFD, whereas LPFD increased percentage of oviduct and magnum weights when compared with the HPFD and BCD groups, respectively. Percentage of duodenum weight in birds that were fed HPFD with PHY and 25(OH)D was greater compared with those fed LPFD in the wk 22 sham and wk 12 FMG inoculation groups, but was also greater than in those fed BCD in the wk 12 FMG inoculation group. Conversely, percentage of duodenum weight was greater in birds fed LPFD compared with those fed HPFD after a wk 22 FMG inoculation. However, despite the effects of the supplemental combination of 1.50% PF, PHY, and 25(OH)D on the oviduct and small intestine structures, it did not result in a subsequent influence on layer performance, as indicated in a previous companion report.

Influence of supplemental dietary poultry fat, phytase, and 25-hydroxycholecalciferol on the egg characteristics of commercial layers inoculated before or at the onset of lay with F-strain Mycoplasma gallisepticum.

The effects of supplemental dietary poultry fat (PF), phytase (PHY), and 25-hydroxycholecalciferol (D3) on the egg characteristics of commercial layers inoculated with F-strain Mycoplasma gallisepticum (FMG) were investigated in 2 trials. Sham and FMG inoculations were administered at 12 (before lay) and 22 (onset of lay) wk and 4 dietary treatments [basal control diet (BCD); BCD with 0.75% supplemental PF; BCD with 1.50% supplemental PF; BCD with 1.50% supplemental PF, 0.013% PHY, and 0.025% D3] were initiated at 20 wk of age. Percentages of albumen, yolk, and eggshell weights; yolk:albumen ratio; yolk moisture and lipid concentrations; and eggshell weight per unit of surface area were determined at 24, 34, 44, 50, and 58 wk of age. Inoculation with FMG reduced yolk lipid concentration at wk 24 and increased yolk moisture concentration at wk 58. In birds inoculated on wk 22, percentage of yolk weight was lower in those inoculated with FMG compared with those that were sham-inoculated. Yolk:albumen ratio was lower in birds that were FMG-inoculated at 22 wk of age compared with those that were sham-inoculated at the same age or that were FMG-inoculated at 12 wk of age. Percentage of yolk weight was greater in birds inoculated at wk 22 and fed the BCD with 1.50% supplemental PF treatment compared with those inoculated at wk 22 and fed the BCD or BCD with 1.50% supplemental PF, 0.013% PHY, and 0.025% D3 treatments and compared with birds inoculated at wk 12 and fed the BCD with 0.75% supplemental PF treatment. In conclusion, inoculation with FMG before or at the onset of lay caused a decrease in yolk lipid content early in lay but an increase in yolk moisture late in lay, and FMG reduced percentage of yolk weight in birds inoculated on wk 22. Furthermore, when used in combination with added 1.50% PF in birds inoculated on wk 22, supplementary PHY and D3 prevented an increase in percentage of yolk weight that occurred in response to diets supplemented only with 1.50% PF.

Influence of supplemental dietary poultry fat, phytase, and 25-hydroxycholecalciferol on the performance of commercial layers inoculated before or at the onset of lay with F-strain Mycoplasma gallisepticum.

The effects of 2 levels of supplemental dietary poultry fat (PF) and the combination of PF, phytase (PHY), and 25-hydroxycholecalciferol (D(3)) on the performance of commercial layers inoculated with F-strain Mycoplasma gallisepticum (FMG) were investigated in 2 trials. Sham and FMG inoculations were administered at 12 (before lay) and 22 (early in lay) wk and dietary treatments [basal control diet (BCD), BCD with 0.75% supplemental PF, BCD with 1.50% supplemental PF, and BCD with 1.50% supplemental PF, 0.013% PHY, and 0.025% D(3)] were initiated at 20 wk of age. Hen BW, egg weight, and egg production (EP) were determined every 4 wk between 24 and 58 wk of age. Feed consumption (FC) and feed conversion were determined in 4-wk intervals beginning on wk 25 and ending on wk 58, and total mortality and mean EP were determined over the entire 24 to 58-wk period. The addition of 0.75 and 1.50% PF increased BW at wk 48 and 58, respectively, and supplemental PF at the 1.50% level increased the BW of hens that had been inoculated (sham or FMG) on wk 22 and reduced the FC of hens inoculated on wk 12. Feed conversion was decreased in the 25 to 28- and 57 to 58-wk age periods and increased in the 45 to 48-wk age periods by an FMG inoculation. In birds inoculated at 22 wk of age, FMG increased egg weight. Although EP was reduced at wk 24 and was increased at wk 58 by FMG, total EP was not affected. In conclusion, an inoculation of FMG at either 12 or 22 wk of age can result in a relative shift in EP from the early to late stage of lay without affecting total EP, and although the BW and FC responses of hens to added dietary PF were influenced by their age and the age of inoculation, use of the supplemental combination of PHY and D(3) had no additional effect on performance when provided in conjunction with 1.50% PF.

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

Effects of F-strain Mycoplasma gallisepticum (FMG) inoculation and 1.5% supplemental dietary poultry fat (PF) on the egg yolk characteristics of commercial layers at 24, 34, 44, 50, and 58 wk of age were investigated. Sham and FMG inoculations were administered at 12 and 22 wk of age and dietary treatments (basal control and basal control with 1.5% supplemental PF) were initiated at 20 wk of age. Yolk lipid concentration was reduced on wk 24 in birds that had been inoculated at 12 or 22 wk of age with FMG. The use of 1.5% supplemental PF increased percentage of yolk weight and yolk:albumen ratio across age and inoculation treatment. At 58 wk of age, concentrations of yolk palmitic acid increased and those of oleic and linolenic acid decreased when sham inoculations were given at 22 rather than at 12 wk of age. However, FMG inoculations given at 22 rather than at 12 wk increased palmitoleic acid and decreased stearic acid yolk concentrations. At 12 wk of age, FMG inoculations decreased yolk palmitoleic, oleic, and linolenic acid concentrations while causing increased yolk stearic and arachidonic acid levels when compared with sham inoculations. Furthermore, 1.5% supplemental PF decreased concentrations of palmitic and oleic acid and increased those of linoleic acid in the yolk at 58 wk of age. Despite the interaction of 1.5% supplemental PF with the prelay inoculation of FMG on early (18 to 26 wk) layer performance noted in a previous report, the effects of a prelay FMG inoculation and 1.5% supplemental PF on the egg yolk characteristics examined in the current study were independent of each other. This suggests that 1.5% supplemental PF is not effective in modulating the effects of an FMG inoculation at 12 wk of age on hen egg yolk characteristics between 24 and 58 wk of age and that the combined effects of PF supplementation and FMG inoculation on performance do not influence egg yolk characteristics.

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.

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.