This study investigates the growth performance of Large White Yorkshire (LWY) pigs under two feeding systems: a conventional concentrate-based diet (T1) and a swill feeding system (T2). Over a period of 373 days, twelve male weaned piglets were randomly assigned to each treatment group. Weekly measurements of body weight, average daily weight gain, feed intake, and feed conversion ratio were recorded. While both feeding systems generally resulted in similar growth trends, significant differences were observed at certain intervals, particularly in weeks 13 and 49, where T1 displayed higher body weight and more efficient feed conversion compared to T2. These findings suggest that both feeding systems can yield high-quality pork and lard, with T1 showing a slight advantage in terms of efficiency. However, the swill feeding system presents an environmentally friendly approach by utilizing food waste. Overall, this study provides valuable insights into the potential of swill feeding as a sustainable alternative for pig farming, contributing to the optimisation of pork production in India.

Pig farming in India has vast untapped potential to meet the non-vegetarian population's food and nutritional needs. Pigs offer advantages like high prolificacy, efficient feed conversion and low initial investment, making it beneficial for rural farmers. They provide a valuable source of protein-rich food, manure, bristles, and fat. The 20th Livestock Census revealed a pig population of 9.06 million, constituting 1.7% of India's total livestock. Pork production accounts for 9% of animal protein sources, primarily concentrated in North-Eastern states and backyard farming (BAHS, 2022). The Census states that Kerala has witnessed a surge in pig farming, with a notable increase in population across all districts. Pigs have traditionally served as food waste recyclers, and swill-feeding facilitates the conversion of food waste into high-quality pork, providing benefits to farmers and the environment by reducing land demand and greenhouse gas emissions. Swine production has emerged as a financially lucrative livestock venture over the years.

The study was carried out utilising the facilities of the Department of Livestock Production Management, School of Bioenergy and Farm Waste Management, Department of Animal Nutrition, Department of Veterinary Pharmacology and Toxicology and Pig farm, ILFC, CVAS, Pookode.

The study was carried out on from January 2021 to August 2022. The animals were reared from 31st January 2021 to 21st December 2021. The experiment was carried out on twelve male weaned Large White Yorkshire (LWY) piglets. The piglets were weaned at 49 days of age and were randomly allotted to two treatments (T1 and T2) as uniformly as possible with respect to their age and body weight of six each. The animals were maintained under similar housing on different feeding systems. Other management practices prevailing in the farm were followed uniformly to both groups throughout the experimental period.

To ensure uniformity between the groups, split weaning was carried out. Heavier piglets were removed from their mothers on the 35th day. So that almost uniform body weight could be obtained at weaning on the 49th day.

After complete weaning, the two groups were fed different diets as detailed below. Treatment 1 (T1) was fed a grower ration upto 60 kg body weight, followed by finisher ration (as per ICAR feeding standards 2013) until slaughter. Treatment 2 (T2) was fed with swill feed collected from hostels and canteen of the College of Veterinary and Animal Sciences Pookode until slaughter. Standard management practices adopted at ILFC, Pookode were followed for both the groups.

Table 1: Type specification of different types feeds.

Data pertaining to feeding such as daily feed intake were recorded and average daily gain, feed conversion efficiency were worked out. Growth rate in the two different systems were analysed by recording the body weight at weaning and thereafter at fortnightly intervals. Weight of each piglet were recorded in fortnight intervals to get growth performance of the piglets in both treatment groups. The body weight of all the piglets were recorded using a digital weighing machine at the time of weaning. There after fortnightly body weight were recorded up to the twelfth month.

The animals were fed twice daily, in the morning and in the evening. Weighed quantity of feed was provided in group feeding system and the residue was weighed after feeding to calculate the Average Daily Feed Intake (ADFI). 

Body weight. The comparison of bodyweight between two groups, concentrate-fed (T1) and swill-fed (T2) pigs, over different weeks generally revealed similar bodyweights. Notably, in week 13, a significant difference emerged, with T1 displaying higher body weight, while other weeks showed no substantial disparities. 

This finding corresponds with the research conducted by Muthuramalingam et al. (2011), which investigated the effects of heat-treated swill feed on the performance of Large White Yorkshire pigs. The study found no significant differences in weight gain, feed intake, or feed conversion ratio between pigs fed heat-treated swill and those fed commercial concentrate feed.

This contradicts the findings of Ramesh et al. (2010); Muthulakshmi et al. (2015), who reported that swill-fed pigs had significantly higher body and carcass weights compared to those fed concentrate.

Body weight gain. When comparing the biweekly bodyweight gain of two groups, namely concentrate-fed (T1) and swill-fed (T2) pigs, both groups generally displayed similar growth trends with statistically non-significant variations. 

Table 2: Comparison of bodyweight at different weeks between two groups.

                                  * Significant at 0.05 level (P<0.05); ns non-significant (P>0.05)

This finding agrees with the study of Muthuramalingam et al. (2011), where they examined pigs fed concentrate feed, untreated swill feed, and heat-treated swill feed, finding no significant differences in weight gain among the groups.

However, in contrast, both Ranjan et al. (2003); Ramesh et al. (2010) reported significantly higher weight gain and greater final body weight in pigs fed concentrate feed compared to those on a mixed diet or locally available feed in their respective studies.

Average daily weight gain. Both groups generally exhibited similar patterns in their daily growth, with variations that were not statistically significant. These results highlight weeks 11, 13, and 49 as periods where significant differences in average daily weight gain between the groups were observed, while the other weeks showed comparable daily growth trends with no notable disparities.

In contrast, both Ranjan et al. (2003); Ramesh et al. (2010) reported significantly higher average daily gain in pigs fed a concentrate feed compared to those receiving a mixed diet or locally available feed in their studies.

Feed intake. In this study, we observed variations in biweekly feed intake between Treatment 1 (T1) and Treatment 2 (T2) over the weeks, with T2 consistently consuming more feed than T1. These findings align with previous research conducted by Giamouri et al. (2021); Akdağ et al. (2008), where the impact of swill feed versus concentrate feed on pig feed intake was investigated, and no significant differences were noted.

Table 3:  Biweekly feed intake in two treatment groups.

Furthermore, Saikia and Bhar (2010) conducted an experiment demonstrating that pigs fed with food waste had a noticeably lower daily dry matter intake compared to a control group fed a standard ration. However, the food waste-fed pigs showed significantly higher average daily gain, suggesting that the nutritional value of food waste as a pig feed source exceeded that of the concentrate mixture-based diet utilized in the control group.

In contrast, Adebiyi et al. (2017) explored the influence of food waste on weaned pig performance and hematological profiles. They found that incorporating food waste into the diet significantly improved feed intake in weaned pigs compared to diets comprising only concentrate. This improvement was attributed to the palatability and nutrient density of the concentrate. 

Table 4:  Comparison of feed conversion ratio at different weeks between two groups.

** Significant at 0.01 level (P<0.01); * Significant at 0.05 level (P<0.05);  ns non-significant (P>0.05)

Feed conversion ratio. In this study, T1 and T2 displayed varying feed efficiency over the observation period, with each group outperforming the other at different times. However, on the whole, T2 consistently exhibited a significantly higher feed conversion ratio (FCR) compared to T1, indicating substantial differences in feed efficiency between the two groups.

These findings align with previous research conducted by Ramesh et al. (2014), who investigated the impact of different feeding regimes on the growth performance of piglets. Their study revealed that the group exclusively fed a 100% concentrate diet demonstrated superior feed conversion efficiency compared to other groups.

Similarly, Kumar et al. (2010) conducted an experiment involving indigenous growing pigs fed different feed types over 135 days. They noted that the group receiving 100% kitchen waste exhibited significantly higher feed conversion efficiency compared to other dietary groups.

Furthermore, a study conducted by Kayastha et al. (2013) compared the performance of grower pigs fed various feed types. The group receiving a diet consisting of kitchen waste and supplements demonstrated the highest body weight gain, average daily gain, and the most efficient feed conversion. Conversely, the group exclusively fed kitchen waste exhibited the lowest body weight gain, average daily gain, and the least efficient feed conversion.

Future scopes of this study include further analysis of pork's nutritional composition under different feeding systems, comprehensive assessments of the environmental impact and cost-effectiveness of swill feeding, investigations into health and food safety aspects, initiatives to promote adoption among farmers, and policy recommendations for sustainable agricultural practices.

Vijin V.L., John Abraham, Balusami Chinnappan, Sabin George, Biju Chacko and Namratha Valsalan  (2024). Growth Performance of Large White Yorkshire Pigs in Swill and Concentrate Feeding Systems. Biological Forum – An International Journal, 16(3): 04-08.