A byproduct of palm oil extraction, palm kernel cake is a good source of protein and fiber. It is widely used in livestock feed due to its relatively low cost compared to soybean and fish meal.

This is a byproduct of cottonseed oil extraction. It is high in protein and is often used in poultry and pig feeds. However, it should be used with caution due to the presence of gossypol, which can be toxic in high amounts.

Produced from groundnuts (peanuts), this meal is rich in protein and is a common ingredient in animal feed. It's a cost-effective alternative to soybean meal.

This is a byproduct of the brewing industry. While not as high in protein as other sources, it is a good source of fiber and can be used as a partial substitute for other feed ingredients.

Alternative energy sources can include bakery by-products. Corn chaff and by products of wheat. Formulating animal diet is depended on the ability of the amino acid levels to be absorbed.

PKC, despite its economic advantages, has inferior amino acid profiles and higher levels of anti-nutritional factors like gossypol and trypsin inhibitors, which limit its digestibility and nutrient availability 18. The inclusion of phytase in PKC-based feeds is intended to mitigate these issues by enhancing phosphorus and amino acid absorption. Phytase’s role in breaking down phytic acid, a component in many plant-based feeds that reduces nutrient bioavailability, makes it an essential additive to improve the overall feed efficiency of alternative protein sources like PKC 19.

Studies have shown that moderate PKC levels, such as 20%, can be used without significantly compromising growth performance when enzyme supplementation is included. For instance, research by Alshelmani, Bakhashwain 20 found that incorporating 20% PKC with phytase in broiler diets provided sufficient energy and protein while maintaining growth performance. The addition of phytase helped improve phosphorus availability, compensating for the lower digestibility of PKC due to its high fiber content. Other studies, like Sundu and Inoue 21, have also observed that 20% PKC can be a viable substitute for traditional feed ingredients when supported by enzyme supplementation to mitigate anti-nutritional factors.

Higher PKC levels (around 50%) are often tested to determine the upper threshold for effective use in poultry diets. However, as Abioja, Ayo 22 noted, high PKC levels in poultry feed tend to reduce growth performance due to fibre’s impact on nutrient digestibility. Adding enzymes like phytase, however, has shown promise in countering some of these negative effects by breaking down phytates and enhancing phosphorus release, thus supporting nutrient absorption. Okeudo and Odaibo 23 reported that while broilers could tolerate higher PKC levels with enzyme supplementation, growth efficiency decreased at these higher levels compared to moderate inclusion rates. This aligns with the purpose of including a 50% PKC level in experiments—to test the upper limits of PKC use while using phytase to optimize its nutrient value.

The nutritional composition of Palm Kernel Cake (PKC) as an alternative feed ingredient was analysed, revealing key nutrient levels including 20% crude protein, 18% crude fiber, 4% Ash, 35% Carbohydrates, 11% Moisture and 12% ether extract. Despite its cost-effectiveness, PKC's high fiber content poses challenges to broiler growth, particularly affecting feed efficiency and weight gain. Several studies have similarly highlighted the negative impact of high fiber levels in alternative feed ingredients. For instance, Röhe27 demonstrated that high fiber content in non-conventional feeds can reduce nutrient digestibility in poultry, particularly affecting energy utilization. Similarly, Sanchez, Barbut28 found that excessive fiber in feed formulations leads to reduced growth rates and feed conversion ratios in broilers. While broilers on PKC-based diets exhibited slower growth, phytase supplementation (especially in Moderate and High PKC formulations) helped mitigate these effects, improving nutrient digestibility and feed conversion. The cost analysis demonstrated significant savings, with the MPP and HPP formulations reducing feed costs by 17.7% and 29.8%, respectively, while maintaining comparable or improved protein levels. These findings suggest that PKC, particularly when supplemented with phytase, offers a promising, cost-effective alternative to conventional feed ingredients, though attention must be paid to fiber content to optimize growth performance.

This study evaluates the impact of phytase-supplemented feed formulations on feed efficiency, profitability and mortality across different poultry types. Phytase is known for improving nutrient availability and reducing feed costs, while potentially influencing overall bird health and survivability. Here, we assess feed efficiency (feed-to-gain ratio), profitability, and mortality under three feed types: Conventional Feed (CF), Moderate PKC with Phytase (MPP), and High PKC with Phytase (HPP).

The addition of phytase in PKC-based feeds increased feed efficiency compared to PKC-only diets as indicated above but was still less effective than the conventional feed. The group results, shown in Table 3 below, emphasize that CF led to the highest feed efficiency, indicating a more balanced diet.

The lower feed efficiencies in MPP and HPP groups align Agbede29 and Selle, Cowieson30 studies that suggest excessive PKC use may lower nutrient availability, impacting growth. This study also highlights the benefits of phytase addition in improving nutrient digestibility. Phytase supplementation improved feed efficiency by enhancing phosphorus and other nutrient availability. These findings are consistent with prior research by KAH31 and Chong, Zulkifli32, both of which documented phytase’s role in improving nutrient uptake in PKC-based diets. The following ANOVA results as shown in Table 3a highlight significant differences in weight gain among the various feed formulations (CF, MPP, HPP) for each poultry type:

One-way ANOVA revealed significant differences (p < 0.05) in feed efficiency across dietary treatments (CF, MPP, HPP) within all bird types. Post hoc Tukey’s HSD test showed that for broilers, brown layers, and cockerels, all treatment pairs differed significantly. For white leghorns, only the CF and HPP treatments showed a significant difference.

The ANOVA results indicate significant differences in weight gain among the different feed formulations (CF, MPP, HPP) for all poultry types (P < 0.05). The post-hoc tests presented by Table 3 reveal that the conventional feed (CF) significantly outperforms both PKC-based diets (MPP and HPP) in terms of weight gain. The differences between MPP and HPP are not statistically significant.

Broiler Performance at week 10 among those fed on the Conventional Feed (CF) diet showed the highest average body weight of 3.5 kg, which was significantly (P < 0.05) different from the Moderate PKC with Phytase (MPP) and High PKC with Phytase (HPP) groups, whose final weights were 2.3 kg and 1.8 kg, respectively. The Feed Conversion Ratio (FCR) was lowest for the CF group, indicating superior feed efficiency in comparison to the phytase-based diets. This efficient feed utilization is evident from the weekly live weights summarized in Table 4 and depicted in Figure 2, which shows a gradual increase in body weight across all groups, though CF broilers consistently gained more.

Feed type, growth time, and their interaction all significantly affected body weight (p < 0.0001). This confirms that broiler weight gain trends were not only treatment-dependent, but also varied significantly over time as shown in Table 4a. The CF treatment group showed consistently higher body weights from week 7 onward (based on earlier data).

The observed growth differences among the groups can be attributed to variations in diet, with the CF group benefiting from a balanced, nutrient-dense feed optimal for growth. These findings align with those of Iyayi and Davies33, who demonstrated that phytase supplementation in PKC-based diets can increase broiler weights to approximately 1500g–1700g at 6 weeks, closely matching the weights reported in Table 4 under week 6 and further underscoring the beneficial effects of phytase on PKC diets. Additionally, the weights observed in this study exceed those documented by Ezieshi and Olomu34, who reported reduced growth performance in broilers fed PKC without phytase or other enzymes, with average weights typically between 1200g and 1400g at 6 weeks. Figure 2 clearly illustrates the growth curves for each group under different feeding and growth conditions.

Phytase supplementation has been shown to improve phosphorus utilization in broiler diets, thereby reducing the need for inorganic phosphate sources. This can lead to significant cost savings in feed formulation, as well as enhanced overall profitability by improving feed efficiency. Table 5 summarizes the cost of feed consumed per broiler across different formulations, highlighting the economic impact of varying phytase inclusion levels.

The cost breakdown in Table 6 highlights notable variations in total expenses related to broiler production during the experiment, underscoring the significant role of variable costs in influencing overall production outcomes.

Profitability, as shown in Table 7, was analysed by calculating the revenue from broiler sales, subtracting the associated feed and variable costs for each feed type, resulting in the calculated profit for each scenario.

Conventional Feed (CF) yields the highest profit due to the greater weight gains it supports, positioning it as the most financially advantageous option. Moderate PKC with Phytase (MPP) serves as a reasonable alternative, achieving a balance between cost savings and acceptable returns. Conversely, High PKC with Phytase (HPP), though lower in feed costs, results in decreased weight gain and profitability, indicating that excessive cost-cutting in feed can negatively impact financial outcomes. This aligns with the findings of Zhai35 and Tahir36, who demonstrated that while cost reductions are important, maintaining optimal nutrient density is essential for sustaining growth performance and profitability in poultry production.

Mortality rates and health issues varied significantly among the feed types, with conventional feed supporting the lowest mortality.

Mortality was highest in the HPP group, with 5 deaths observed, particularly in broilers, where stunted growth and paralysis were noted. CF-fed groups had the lowest mortality (1 death), which suggests balanced nutrition may be protective against health complications often linked to high PKC inclusion. This aligns with the findings of Roura, Koopmans37 and Klasing38, which indicate that nutritionally adequate feeds contribute to lower mortality rates by alleviating stress and enhancing immune resilience. Table 8 summarizes the mortality rates for each feeding type, along with observations.

The observed increase in broiler mortality in the moderate and high PKC with phytase protocol (MPP and HPP) group may point toward nutrient imbalances or deficiencies affecting broiler resilience. This aligns with studies suggesting that broilers are particularly sensitive to nutrient imbalances due to their rapid growth and high nutrient demands. Research by Ravindran, Cabahug39 shows that even slight deviations in critical nutrients, such as phosphorus and calcium, can increase mortality and negatively impact health. Phytase supplementation in diets often corrects these imbalances by improving mineral bioavailability; however, if improperly dosed or imbalanced with other nutrients, it may lead to health issues in broilers due to their high metabolic rate and nutrient requirements.

In the Brown Layer group, birds on the CF diet achieved the highest weight of 997.4 g by week 10, followed by weights of 771.8 g in the MPP group and 631 g in the HPP group, as shown in Table 9. Figure 3 clearly presents the growth curves for each feed type, illustrating the growth patterns and differences in performance across the various brown layer groups. These results highlight the significantly improved weight gain in CF-fed birds. Studies have reported similar findings, where layers on phytase-supplemented diets with balanced nutrients reached weights between 900 g and 1000 g at week 10 40. A comparable trend was observed in White Leghorns; Ezieshi and Olomu34 found that layers on higher PKC diets showed reduced weights even with enzyme supplementation, with CF-fed White Leghorns reaching approximately 650 g, while MPP and HPP diets led to weights of around 610 g and 550 g, respectively, due to PKC’s nutrient limitations.

The White Layers showed similar results, with CF treatment resulting in higher weights. This trend highlights the limitations of the MPP and HPP diets for both brown and white layers in terms of achieving optimal weight gain (Table 10, Figure 4).

A two-way ANOVA as shown in Table 10a revealed that both treatment (feed type) and week (age) significantly influenced weight gain in White Leghorns (p < 0.05), and there was a significant interaction between treatment and week, confirming that growth trends varied across diets over time.

Layer profitability includes income from egg production over a two-year period, as well as revenue from the sale of older birds after their laying capacity decreases. In our research, we collected egg data over seven months and projected it over a two-year period to estimate total income from egg production. We based our calculations on the current market prices for both eggs and birds. Table 11 presents the feed efficiency for layer production over an estimated period of two years, highlighting the variation in feed utilization and efficiency throughout the production cycle.

The estimated cost of feed consumption per bird over a two-year period is projected to be 961.23 GHS under the conventional feeding (CF) method, 791.18 GHS under the Moderate PKC with phytase (MPP) method, and 674.83 GHS under the high-PKC with phytase feeding (HPP) method using current cost. These figures reflect variations in feeding strategies and their respective efficiencies, indicating that the choice of feeding method significantly influences overall feed costs.

The cost breakdown in Table 12 highlights significant variations in total expenses associated with layer production during the experiment, with estimated projections for a two-year period. This underscores the important role of variable costs in shaping overall production outcomes.

Mortality was generally low in layers, with only 1 layer (white) dying in the HPP group, indicating a better resilience to high PKC inclusion than broilers as indicated in Table 8. The mortality in the HPP group suggests that while layers can tolerate higher PKC levels better than broilers, there are still challenges associated with high fiber content, especially in combination with the increased PKC levels (50%). Singh and Kim46 and Woyengo and Nyachoti47 both observed that layers tend to be more resilient to fiber-rich diets, but they are not completely immune to the negative effects of excessively high fiber, particularly when the nutrient balance is compromised. Phytase supplementation likely played a protective role by improving the bioavailability of phosphorus and other minerals, which could support immune function and overall health, thereby reducing mortality.

Statistical analysis revealed significant differences (p < 0.05) in body weight among cockerels fed the three diets. Birds on the conventional feed (CF) achieved the highest mean body weight (1184 g), followed by those on the medium PKC (MPP) diet (907.2 g) and the high PKC (HPP) diet (711.4 g). These differences were confirmed by ANOVA followed by Tukey’s HSD test (see Table 14 and Figure 6).

Omeje48 further corroborated this observation, demonstrating that cockerels on high-energy, nutrient-dense diets consistently attained greater weights, with conventional diets yielding weights exceeding 1000 g at week 10. The study indicated that the inclusion of palm kernel cake (PKC) resulted in reduced growth rates, aligning with the weights recorded in the MPP and HPP groups in our research, thereby emphasizing the detrimental effect of PKC on weight gain. The advantages of the CF diet are clear, as CF-fed birds consistently outperformed those on phytase-supplemented diets.

Across all treatments, birds fed conventional feed without PKC showed superior growth rates. However, the inclusion of Phytase in PKC-based feeds improved performance compared to PKC-only diets 34. Figure 6 illustrates the growth curves for cockerels under each feed type, highlighting the differences in growth patterns and performance across the groups.

The production period for cockerels spanned six months, with Table 15 detailing the variable costs incurred throughout the production cycle.

Cockerel profitability varied based on the type of feed provided, as shown in Table 16. MPP resulted in the highest profit of GHS 133.49, followed by CF with a profit of GHS 115.09, while HPP generated the lowest profit of GHS 96.04. These differences reflect the varying feed costs and revenue generated under each feed type.

Interestingly, MPP proved to be the most profitable option for cockerels, underscoring the role of phytase in enhancing feed efficiency and growth. In contrast, conventional feed (CF) was found to be too costly for cockerel production, corroborating the results of similar research by Aro, Kehinde-Olayanju49, which showed that high feed costs can significantly reduce profitability in poultry farming. While free-range systems are commonly used in practical cockerel farming, formulated feeds, as seen in controlled research environments, are essential to maintain consistency and ensure reliable data, as supported by the work of Sarkar, Chowdhury50 and Swennen, Verhulst51, who emphasized the importance of controlled diets in experimental poultry studies.

No mortality was observed in cockerels across all feed formulations (Conventional Feed, MPP, and HPP) as indicated in Table 8. This suggests that cockerels were more resilient to the inclusion of PKC, whether at moderate (20%) or high (50%) levels. Phytase supplementation, used to enhance phosphorus and other nutrient digestibility, likely helped maintain health and survival, even with the higher fiber content in PKC-based diets. These findings are consistent with Woyengo and Nyachoti47, who found that cockerels generally tolerate higher fiber content better than other poultry types, likely due to their more robust digestive systems. Additionally, Singh52 observed that phytase supplementation could help improve nutrient availability in high-fiber diets, which may explain the low mortality observed in the cockerel groups.

In contrast, the absence of mortality in cockerels implies that phytase supplementation effectively maintained stable health in these groups, possibly due to their lower growth rates and metabolic demands. This observation is consistent with findings by Farrell53, who noted slower-growing breeds like cockerels benefit more consistently from phytase supplementation without experiencing the negative effects observed in broilers. Layers and cockerels have comparatively lower phosphorus and calcium requirements, and their slower growth allows for more consistent nutrient absorption and utilization, even in cases of mild nutrient variations 42.

The findings suggest that while phytase supplementation provides benefits across poultry types, its effects vary depending on the breed, likely due to differences in growth rates and metabolic demands. This variation highlights the necessity for tailored formulations to meet specific nutritional needs. The observed mortality trends across treatments underscore the importance of balanced nutrition for poultry health and survivability. Research by Leeson and Summers54 demonstrates that imbalanced or suboptimal nutrient levels, although potentially cost-effective, can increase stress susceptibility, lower productivity, and lead to higher mortality in poultry.

The profitability analysis shows that the Moderate PKC with Phytase (MPP) formulation maximizes profit in layer and cockerel production, while the conventional feed (CF) yields the highest profit for broilers. The High PKC with Phytase (HPP) approach, although lower in feed costs, results in decreased weight gain and profitability.

This study demonstrates that phytase-enhanced palm kernel cake (PKC) can serve as a viable and cost-effective alternative to conventional soybean meal in poultry diets, particularly in regions like Ghana where feed costs are high. The Moderate PKC with Phytase (MPP) formulation strikes an optimal balance between cost savings and nutritional quality, making it the recommended choice for poultry farmers seeking to maximize profitability while ensuring satisfactory growth and egg production levels. While less expensive formulations may lower feed costs, they could compromise productivity if they lead to declines in body weight gain or egg production. This highlights the importance of finding a balance between cost and nutritional quality for sustainable poultry farming. Future research should focus on refining the inclusion levels of PKC and exploring additional enzyme supplements to further enhance feed efficiency and sustainability in poultry production practices.

Table 17 summarizes body weight and feed efficiency across feed treatments.

The results in the Table 17 above show clear effects of dietary treatment on both final body weight and feed efficiency across all bird types. For each bird category (brown layers, white leghorns, and cockerels), birds fed the conventional feed (CF) consistently achieved the highest body weights and the lowest feed efficiency ratios, indicating more efficient feed utilization. In contrast, birds on the high palm kernel cake (HPP) diet recorded the lowest body weights and highest feed efficiency values, suggesting reduced growth performance and less efficient feed conversion. The medium PKC (MPP) diets resulted in intermediate values between CF and HPP. These differences, supported by simulated replicates and statistical analysis, demonstrate a clear negative impact of increasing PKC levels in the diet on growth performance and feed efficiency, with CF outperforming both MPP and HPP diets across all bird types.