Choline, a rediscovered Vitamin B4 that largely exists within the sort of phospholipids, plays a vital role in many biological functions in poultry. It is essential for building and maintaining cell membranes and organelles, like mitochondria and microsomes, and for bone maturation. It is also a necessary element of neurotransmitter acetylcholine, the foremost neurochemical within the nervous system concerned within the transmission of nerve impulses across synapses. The specialized structural feature of Choline chloride is its biologically active methyl groups through which it plays a significant role as a labile methyl group donor within the formation of methionine from homo-cysteine once being oxidised to betaine. Choline chloride helps in preventing abnormal accumulation of lipid and development of liver disease.
Unlike different vitamins, Choline is synthesised through de novo synthesis, however, the inability to form a decent quantity will lead to choline deficiency, causing growth retardation and perosis in young chicks. Moreover, the bioavailability of native choline varies mostly and depends on staple sources and bird-related factors like sort, strain, age, feed consumption, dietary crude macromolecule, and essential amino acid. Additionally, the supplementation of dietary methionine or different methyl group donors cannot fully replace the choline demand of chicks as avian species have restricted capability to hold out the initial step in choline synthesis, i.e., methylation of aminoethanol to methyl aminoethanol, that is contradictory to a situation with growing mammals like pigs or rats.
Hence, choline has become an essential feed additive within the ration of broiler chickens because the above-stated issues can be counteracted by adding enough amounts of synthetic choline chloride (SCC).
Choline chloride, a typical sort of Choline added to the animal diets, has some disadvantages like high hygroscopicity, acceleration of oxidative loss of vitamins, and the formation of trimethylamine (TMA) within the duct of the birds. TMA is a short-chain aliphatic amine formed from dietary Choline chloride in a reaction catalysed by microbial enzymes inside the gut. It is found in high concentrations in fish and is to blame for the characteristic odour of food. These drawbacks will influence the organic poultry production and hence, the utilization of Synthetic Choline Chloride in organic farming practices has been investigated.
Due to the importance of Choline chloride in poultry nutrition and production, the researchers have reinvestigated and explored the alternatives for artificial Choline chloride from natural sources. To counteract the drawbacks of Synthetic choline chloride addition, researchers have conjointly worked on the addition of herbal preparations in broiler rations. Numerous natural products and medicinal plants, together with crude extracts and compounds isolated from plants, are used as an alternate to Synthetic Choline Chloride in animal diets. Several researchers believe that these herbs will mimic the choline-like activity in poultry.
The polyherbal formulation (PHF), indexed as Kolin Plus and (M/s Natural Remedies Pvt Ltd, Bengaluru, India), is a combination of tree nilotica (A. nilotica) and herb (C. longa) belonging to the families of Mimosaceae and family Zingiberaceae, respectively. The hepatoprotective, inhibitor and lipophilic properties of extracts of those plants have been reported separately. However, there isn’t any scientific information demonstrating their Choline chloride-like activities in combined form in a choline deficiency model (CDM) in poultry.
There are not any applicable models for studying Choline chloride deficiency using weight gain as the major response criterion in broiler chickens. Similarly, many attempts to judge the importance of Choline chloride in poultry production have met with failure, as commercial ration had decent Choline chloride content and no distinction was ascertained with or without synthetic choline chloride. Therefore, an acceptable basal diet can permit the researchers to judge the issues of Choline chloride deficiency in broiler chickens.
SBM or soybean meal may be a principal supply of Choline chloride that satisfies the Choline chloride requirements in poultry diets. Therefore, once intact SBM is substituted by defatted SBM (i.e., soy macromolecule isolate [SPI]), a process to get rid of a part of the Choline, the sole distinction within the basal and Choline chloride-deficient diets would be the quantity of choline present. This modification overcomes the matter of adding contradictory factors aside from Choline chloride with the test ingredient.
Hence, the current study was planned to develop a CDM that might elicit the weight gain distinction in broiler chickens by feeding a basal diet with SBM or SPI. The induced CDM compared the impact of the newly developed PHF and SCC on growth performance, serum biochemistry, liver histopathology, and carcass traits of broiler chickens.
The study was designed to establish choline deficiency model (CDM) in broilers for evaluating efficacy of polyherbal formulation (PHF) in comparison with synthetic choline chloride (SCC). A total of 2,550 one-day-old Cobb 430 broiler chicks were randomly assigned to different groups in three experiments.
In experiment 1, G1 and G2 served as normal controls and were fed a basal diet with 100% soybean meal (SBM) as a major protein source supplemented with and without SCC, respectively.
In G3, G4, G5, and G6 groups, SBM was replaced at 25%, 50%, 75%, and 100% by soy protein isolate (SPI) to induce a graded level of choline deficiency.
In experiment 2, PHF (500 and 1,000 g/ton) in comparison with SCC (1,000 g/ton) were evaluated.
In experiment 3, dose-response of PHF (200, 400, and 500 g/ton) with SCC (400 g/ton) was determined.
Replacement of SBM by SPI produced a linear decrease in body weight gain (BWG) with a poor feed conversion ratio (FCR). 25% SBM replacement by SPI yielded an optimum negative impact on BWG and FCR;
In experiment 2, PHF (500 and 1,000 g/ton) and SCC (1,000 g/ton) showed a similar performance in BWG, FCR and relative liver weight.
In experiment 3, PHF produced an optimum efficacy at 400 g/ton and was comparable to SCC in the restoration of serum aspartate aminotransferase activity, abdominal fat, breast muscle lipid content and liver histopathological abnormalities.
Carcass characteristics: PHF vs SCC
Histopathological changes taking place in CDM
Replacement of SBM by SPI caused choline deficiency characterised by worsening of BWG, FCR, elevation in liver enzymes and histopathological changes indicating fatty liver. CDM was found valid for evaluating SCC and PHF.
In conclusion, choline deficiency could cause the growth of depression in meat broiler chickens. In this study, CDM was successfully induced and established using 75% SBM+25% SPI as a source of protein, which is suitable to measure the characteristic symptom of choline deficiency, i.e., growth performance in broiler chickens. CDM was found valid in the screening of products possessing choline-like activities. Also, it was confirmed that PHF has the potential to replace the function of 1 kg/ton of synthetic choline (choline chloride 60%) at 400 g/ton inclusion rate in broiler diets; this was reflected by the improved growth performance and feed efficiency.
For further reference kindly follow,
Evaluation of polyherbal formulation and synthetic choline chloride on choline deficiency model in broilers: implications on zootechnical parameters, serum biochemistry and liver histopathology Asian-Australas J Anim Sci. 2018 Nov; 31(11): 1795–1806.
Authors: Ramasamy Selvam, Marimuthu Saravanakumar, Subramaniyam Suresh, CV Chandrasekeran, and D’Souza Prashanth
Dr Ananth Krishna and Dr Mohita Gautam