*3.1. Feed Analysis*

Four experimental diets were formulated (Table 1) to be isocaloric (3080 kcal/kg) and isonitrogenous (18% crude protein). In addition, chemical analysis was performed to determine the crude protein, crude fat, gross energy, and fatty acid profile of the experimental diets (Table 2). As expected, the HOPN dietary treatment had the highest level of oleic fatty acid content relative to the other treatment groups, while the control, PN Skin, and OA dietary treatment groups had the highest levels of linoleic fatty acid content relative to the HOPN dietary treatment (Table 2). Interestingly, the PN Skin dietary

treatment had the greatest percent of omega 3 fatty acid content (Table 2) relative to the other treatment groups.


**Table 1.** Feed formulation of experimental laying hen diets.

1 Four isocaloric, isonitrogenous (18% protein) diets were fed to Hy-Line W36 hens for 8 weeks. 2 Treatments: control = conventional soybean meal and corn mash diet, HOPN = (24%) unblanched high-oleic peanut crumbles and corn mash diet, PN Skin = control diet supplemented with 3.0% ground peanut skins, OA = control diet supplemented with 2.5% food-grade oleic fatty acid oil. 3 High-oleic peanuts = unblanched raw whole high-oleic peanut crumbles. 3 Santoquin® = Feed antioxidant and preservative to prevent fat oxidation in stored feed (Novus International, St. Charles, MO, USA). 4 Mineral premix manufactured by NCSU FeedMill, supplied the following per kg of diet: manganese, 120 mg; zinc, 120 mg; iron, 80 mg; copper, 10 mg; iodine, 2.5 mg; and cobalt. 5 Vitamin premix manufactured by NCSU FeedMill supplied the following per kg of diet: 13,200 IU vitamin A, 4000 IU vitamin D3, 33 IU vitamin E, 0.02 mg vitamin B12, 0.13 mg biotin, 2 mg menadione (K3), 2 mg thiamine, 6.6 mg riboflavin, 11 mg d-pantothenic acid, 4 mg vitamin B6, 55 mg niacin, and 1.1 mg folic acid. 6 Selenium premix manufactured by NCSU FeedMill = 1 mg selenium premix provided 0.2 mg Se (as Na2SeO3) per kg of diet. 7 Metabolizable energy = kcal/kg feed.


**Table 2.** Chemical analysis of experimental laying hen diets.

1 Treatments: control = conventional soybean meal and corn mash diet, HOPN = unblanched high-oleic peanut crumbles (24%) and corn mash diet, PN Skin = control diet supplemented with 3.0% ground peanut skins, OA = control diet supplemented with 2.5% food-grade oleic fatty acid oil. Lipid (crude fat, total cholesterol, fatty acid) and beta-carotene analysis was performed by an AOAC-certified lab, ATC Scientific (Little Rock, AR, USA), using AOAC-approved standard methods. 2 Crude fat content = g crude fat/g total sample weight \* 100, \* fatty acid content = g of fatty acid/g total lipid \* 100. Each value represents the mean ± the standard error for each triplicate sample. 3 Gross energy = kcal/kg feed.

#### *3.2. Hen Performance and Egg Weights*

Hens fed the OA diet had body weights that were significantly less than the body weights of hens fed the control and PN Skin diets (*p* < 0.05), while body weights were similar between the HOPN and OA dietary treatments at week 1 (Table 3). At week 8, hens fed the HOPN diet had significantly smaller body weights relative to the body weights of hens fed the control and PN Skin (*p* < 0.05) diets, while body weights were similar between hens fed the HOPN and OA diets. In addition, hens fed the HOPN experimental diet had significantly reduced feed intake (*p* < 0.001) and fewer dozens of eggs produced (*p* < 0.05) in comparison to the other treatment groups (Table 3). Nevertheless, there were no significant treatment differences in feed conversion ratio over the 8-week feeding trial.

The weekly average egg weights (Table 4) were the smallest in eggs produced from hens fed the HOPN diet relative to the other treatment groups at week 1 of the feeding trial (*p* < 0.05). At week 2, week 4, week 6, and week 8, egg weights from hens fed the HOPN and OA experiment diet were significantly smaller than eggs produced from hens fed the control and PN Skin experimental diets, while egg weights produced from hens fed the OA experimental diet were significantly greater than eggs produced from hens fed the HOPN diet (week 1, week 2, week 4, and week 8; *p* < 0.0001). Egg weights were similar between the control and PN Skin treatment groups at week 1, week 2, and week 4, while egg weights were significantly higher in the PN Skin treatment group at week 6 and week 8 relative to the controls (Table 4).


**Table 3.** Performance of hens fed an unblanched high-oleic peanut or peanut skin diet and housed in battery cages.

Two hundred Hy-Line W36 hens (40 week of lay) were assigned to one of 4 isonitrogenous (18% crude protein) and isocaloric (3080 kcal/kg) treatments (5 replicates per treatment) and fed 8 weeks *ad libitum*. Body weights were collected at week 1 and week 8 of the study. 1 Treatments: control = conventional soybean meal and corn mash diet, HOPN = 24% unblanched high-oleic peanut crumbles and corn mash diet, PN Skin = control diet supplemented with 3.0% ground peanut skins, OA = control diet supplemented with 2.5% food-grade oleic fatty acid oil. 2 Feed conversion ratio (FCR) = kg total feed intake over the 8-week/total dozen eggs produced over 8 weeks for each treatment group. Each value (body weights and feed intake) represents the mean ± the standard error. a,b Means within the same column lacking a common superscript differ significantly (*p* < 0.05). \* *p*-value = differences determined by ANOVA *p* < 0.05.

**Table 4.** Egg weights from hens fed an unblanched high-oleic peanut or peanut skin diet and housed in battery cages.


Two hundred 40-week of lay Hy-Line W36 hens were assigned to one of 4 isonitrogenous (18% crude protein) and isocaloric (3080 kcal/kg) treatments (5 replicates per treatment) and fed 8 weeks *ad libitum*. Body weights were collected at week 1 and week 8 of the study. 1 Weights (g) of eggs were determined daily and weekly for each treatment group. Data represent the weekly (1, 2, 4, 6 and 8 weeks) averages ± standard error for each time point for each treatment group. 2 Treatments: control = conventional soybean meal and corn mash diet, HOPN = 24% unblanched high-oleic peanut crumbles and corn mash diet, PN Skin = control diet supplemented with 3.0% ground peanut skins, OA = control diet supplemented with 2.5% food-grade oleic fatty acid oil. Each value represents the mean ± the standard error. a,b,c,d Means within the same column lacking a common superscript differ significantly (*p* < 0.05). \* *p*-value = differences determined by ANOVA *p* < 0.05.

#### *3.3. Egg Grading and Quality*

All eggs produced in this 8-week feeding trial were graded as USDA Grade AA of superior quality, with thick, firm egg whites and defect-free egg yolks. Moreover, all shells were clean and without defects. There were a minimal number of blood spots or number of meat spots and no statistical difference at the 95% confidence interval between eggs produced from the treatment groups (data not shown). There were no significant differences in 8-week average shell strength or vitelline membrane strength between shell eggs produced from hens fed the four different treatments (Table 5). However, the HU used as a measurement of egg quality was similar between shell eggs produced from hens fed the control, HOPN, and PN Skin dietary treatments, while the 8-week average HU of eggs produced from hens fed the OA diet was significantly lower than shell eggs from the HOPN and PN Skin treatment groups (*p* < 0.05). Of most interest, the 8-week average yolk color was significantly less in eggs produced from hens fed the HOPN experimental diet in comparison to the other treatment groups (*p* < 0.0001).


**Table 5.** Egg quality of eggs produced from hens fed an unblanched high-oleic peanut or peanut skin diet and housed in battery cages.

Two hundred Hy-Line W36 hens (40-week of lay) were assigned to one of 4 isonitrogenous (18% crude protein) and isocaloric (3080 kcal/kg) treatments (5 replicates per treatment) and fed 8 weeks *ad libitum*. Eggs were collected on the day of quality assessment with 15 eggs per treatment, with 3 eggs randomly selected per replicate. Each value represents the average values over the 8-week period ± SEM. **1** Yolk color = Roche Color Fan color index 1–15 (lightest to darkest color intensity). 2 Treatments: control = conventional soybean meal and corn mash diet, HOPN = 24% unblanched high-oleic peanut crumbles and corn mash diet, PN Skin = control diet supplemented with 3.0% ground peanut skins, OA = control diet supplemented with 2.5% food-grade oleic fatty acid oil. \* *p*-value = differences determined by ANOVA *p* < 0.05. a,b is described as items within a column sharing the same superscript are similar, so that means that Control and OA are similar statistically, while HOPN, PN Skin and Control are statistically similar, but OA and HOPN and PN Skin are statistically different.
