The Impact Of Diet Type On Chicken Development
The aim of commercial chicken production is to obtain a high yield level at the lost cost possible, (Lacin, Yildiz, Esenbuga & Macit, 2008). The meat chicken industry has a relatively small history in comparison to other Australian livestock industries, (Poultry Hub, 2019), across Australia there is over 800 meat chicken production, with 80% of that number being operated by contract chicken growers, which are companies that are in contract with mean process businesses, (Poultry Hub, 2019). As of 2018-19, the Australian meat chicken industry as a net worth of almost $3 billion with a retail value of about $7 billion, (Agrifutures Australia, 2019). Before large companies over took the meat chicken industry, majority of the production was being managed by large family owned organisations and backyard producers, it was not till the arrival of Kentucky Fried Chicken in 1968 did the meat chicken industry grow in order to keep up the intake of chicken, (Poultry Hub, 2019). Over the last 50 years, meat chicken nutrition and genetic potential as improved drastically , due to a better understanding of dietary requirements, genetic modification, additives etc. In Australia meat chickens can reach a weight of about 2.2kg in a period of 35 days while only consuming approximately 3.3kg kg feed over the same period, (Poultry hub, 2019), this rapid growth is once again due to genetic improvement in chicken breeds which has been achieved through, “ investment in advanced breeding programs by large well-resourced breeding companies,” (Poultry Hub, 2019) and the short period it takes for chickens to reach sexual maturity ( 20-25 weeks old) which allows for increase in generation production in a short time frame. With in three weeks of reaching sexual maturity hens are able to start producing the next generation of chickens creating up to 150 offspring within the same year of her hatching, (Poultry Hub, 2019).
Over the past ten years the layer chicken industry has shown a strong increase in production in order to keep up with the rising capita of egg consumption with approximately 200 eggs per year per person being consumed by Australians, (Poultry Hib, 2019), layer hens produce approximately 421 million dozen eggs each year, with a majority of this production occurring in three different production systems which includes, free-range, cage or barn systems, (RSPCA, 2019) . In Australia, 55% of egg laying chickens are kept in a cage production system with the rest of egg production occurring in cage-free systems, (Department of Primary Industries, 2019).
The study of nutrient content and dietary requirement for all animal production has been undertaken for so many years in order to increase production rate to keep up with the supply and demand of the ever-growing global population. Within the chicken production industry, nutrition is a fundamental variable within layer and broiler “production, profitability and welfare,” (Ross Aviagen,2018). To produce desired production value, farm manager need to be aware of the nutrition content that they are providing their chickens, this is done with careful balancing and formulation of diet requirements conducted by nutrition specialists, (Ross Aviagen,2018) and then achieved by routine monitoring and analysis of feed intake. By having a clear understanding of feed requirements for performance chickens, production managers are able to determine the right “expected dietary content” and therefore ensure that, consumption and feed levels are providing the appropriate daily nutrient intake to optimise growth performance and health, (Ross Aviagen,2018). The aim of this trial was to try and demonstrate how different diet types effect growth and body weight in chickens and how different breeds of chickens present different growth performances. On day one of the trial each chick was weighed at random. One out of the two types of diets were assigned to each group (Barastoc Chick Starter PP for layer chicks and Barastoc Turkey & Meat Chicken Starter PP). Food placed in feeders and water was given to each cage. Before being placed in the cage the feeder containers were weighed and recorded, the diets were then added to the containers and weighed to find the weight of the feeder and feed as well as the feed by subtracting the feeder and feed weight from the feeder alone. This trial was conducted over total of 21 days were daily monitoring of chicks was done, while data collections occurred on a weekly basis. The data collected was body weight, average daily feed intake, average daily gain and feed conversion ratio, we also had to take into consideration of any chick mortalities. To calculate the required data, multiple calculations where used, these calculations were:In the results, graph one shows the growth performance ( weekly body weight and average daily growth) for the broilers and layers when being fed both diets, as you can see layer chicken had a lower growth performance in comparison to the broilers and in correlation had a lower average daily feed intake (ADFI). This difference in growth is because layers do not require the rapid body growth. Once layer chicks have reached full feathering, their energy requirement is often reduced, (Poultry Hub, 2019). Once developed to the desired stage, layer feed management is formulated to maintain their growth performance that will lead to the layers reaching sexual maturity without become obese, (Poultry hub, 2019). If they become too fat in a small period their body weight will have a negative association with egg production, maintaining correct body weight for layer chickens is important in order to achieve maturity and quality and quantity of egg production, (Lacin et al, 2008). In comparison to layer chickens, Broiler chicken were very efficient in growing big in a short period of time, even though the broilers had a rapid growth rate, they had a lower feed conversion ratio.
Graph 3 which correlates columns three and four in appendix 1, shows the effect of that meat commercial diet (diet 1) and layer commercial diet (diet 2) has on the body weight growth on a weekly basis for both types of chicken. The results showed that when fed on commercial diet 2 (layer diet) the growth performance of both chickens was lower then when they were fed diet 1 (broiler diet). This result is due to the fact that diet 1 contained a higher nutrient content (mainly Crude protein and energy) then diet 1, it shows that regardless of their breed, the feed content plays a significant roll in growth performance. According to Poultry Hub 2019, the daily energy intake for layer chickens should be around 2770-2860kcalkg between the age of 1-32weeks, with crude protein intake being 19.80% (appendix 2). In Comparison, broiler chicken daily energy intake is 3010kcal/kg from the age of 0-10 (appendix 3). In the meat chicken industry, broiler chicken starter feed often contains higher energy because the diet is made-up to contain 22% protein, which is then decreased to 19% protein content in finisher feed, (Poultry World, 2016). The purpose of a diet with a high protein content is to enhance growth development, immunity, environment adaptation and for layer chickens increase egg production quality and quantity, (Ross Aviagen, 2018).
The final columns (interactions) in appendix 1 (graphs 4-7), compared the growth performance of broiler and layer chickens (graph 4 &6) when fed their own specific or the incorrect diet. It was found that meat chickens had a significant growth performance in comparison to layer chicken when fed either the commercial meat diet or the commercial layer diet. With in that the meat chickens that were fed the commercial diet 1 had a higher growth performance then the broilers that were fed the commercial diet 2, once again, this was because commercial diet 1 contained higher concentration in nutrient (energy and crude protein).
Even though this experiment proved the point that diet types does affect the growth performance and body weight on different performance chickens, there was one major fault that effected the experiment. This error was that was that the chickens were weighted at random every week. This result in inconsistent results because when it came to measure chicken 1, 2 etc. their weight would change every week, for example in week one, chicken one could have been the smallest chicken (depending on the group) and by day 7 the smallest chicken could have been chicken three being weighed. In order to keep a consistent each chicken could have been weighed and tagged in the order the were selected.
