# Factors Influencing the Effects of Triticale on Laying Hens' Performance: A Meta-Analysis
## 1 Introduction  
Corn and wheat are frequently incorporated into the creation of poultry feed formulations. However, multiple new feed ingredients have recently been used in replacement of these conventional energy sources within the field of poultry production. Many factors such as global warming, the high price of these cereals (maize, wheat, etc. ), and the current competition to improve animal productivity are the sources of this trend [1]. Indeed, finding alternative cereals able to adapt to difficult weather, with lower production costs and similar nutritive values to common energy sources is of great importance in the present era. The first steps of this process started with the inclusion of other cereals such as sorghum and barley showing promising outputs in poultry nutrition [2, 3]. Nevertheless, the use of these ingredients in human diets limited their utilization [4, 5]. This context led several researchers to elaborate on new feed ingredients having most of the characteristics of interest to be used as an alternative energy source [6, 7]. Among these human-made plants, tritticale stands out as a hybrid cereal derived from crossing wheat and rye and employed as a substitute for maize [8] and wheat [9] in the nutrition of layers and broilers. Additionally, this crop is distinguished by its low cost and favorable protein (10.5 to 14.6%) and energy (63.8 to 67.6%) content when compared to other cereals [8, 10]. Furthermore, tritticale is less used in human nutrition than conventionalcereals [11; 12], has demonstrated a great ability to grow even under hard conditions, and might be a good choice to increase the cereal's production in the world [9]. Regarding the laying hen industry, numerous articles have explored the impact of varying levels of triticale inclusion on egg production. However, these papers underscored a range of conflicting outcomes regarding the effects of triticale on layer production parameters. The results of [PERSON] [13] and [PERSON] [14] suggested that triticale decreased hens' performance when it replaced 100% of wheat, milo, and maize. Moreover, other articles [15; 16; 17] reported that higher incorporation of triticale grain in the diet could decrease egg production. On the other hand, some scientists found that there was no significant difference with control diets (based on other cereals) in laying hens' productivity, even when the feed formula was based only on triticale [18; 19; 20]. The conflicting results highlight the need for a more thorough investigation to gain a clearer understanding of triticale's impact on laying hens' production parameters. In this context, aggregating the findings across all published papers is crucial to ultimately identify the factors that influence the impact of triticale on layer nutrition. Utilizing meta-analysis, a statistical tool to obtain an unbiased evaluation from multiple articles [21], is indeed the appropriate approach to achieve these objectives. Meta-analysis can appropriately combine study findings and ascertain the genuine impact of an intervention, considering the sources of heterogeneity among studies and increasing the sample size [22]. As previously asserted, a huge number of articles have examined the effect of triticale on the production parameters of laying hens. Yet, none of them have explored the impact of various levels of triticale inclusion on the production parameters of layers through the utilization of meta-analysis. To bridge the existing knowledge gap, this study sought to obtain precise insights into the impact of triticale on hens' performance and identify the factors that influence triticale's effect on laying hens' production parameters via the application of meta-analysis. Considering the nutritive value of triticale, we hypothesized that it would induce an overall similar impact to conventional cereals (corn, wheat, etc.) on laying hens' performance.