1. Introduction

Poultry farming is one of the most efficient animal husbandry methods as it provides nutritional security to a significant number of the population. With the demand for poultry products ever-rising, poultry farming is among the most profitable businesses today. Hence, it is considered the fastest-growing division of the agricultural sector [1]. Chickens are reared in either commercial farms or backyard farms, and in low- and middle-income countries such as the Philippines, backyard farming is relatively common. Poultry is a big contributor to the agricultural sector of the Philippines, and according to the Philippine Statistics Authority, the total inventory of chicken as of September 30 of 2023 it reached 202.82 million birds which is 1.1% higher than previous year and is still projected to increase.

Broiler production requires fast-growing chickens in a short time. It is an intensive farming system that demands higher production while incurring lower expenses. Moreover, the goal of farming is to have improved feed conversion and animal growth with reduced morbidity and mortality. Environmental stressors during poultry production are major concerns in the industry as they cause severe economic loss due to the detrimental effects on the health and performance of chickens. Stressful events in poultry farming include transportation, changes in environmental conditions, handling of animals, administration of vaccines, and exposure to new surroundings; therefore, it is essential to effectively manage these to have an efficient production system [2]. Broilers are typically raised on a formulated diet that provides the necessary nutrients for rapid growth [3]. Currently, it is being achieved by using subtherapeutic amounts of antibiotics as feed additives, preventives, and as treatment. Due to the convincing effects and ease of use of these veterinary products, this has been a hallmark of modern animal husbandry. However, the mechanism of antibiotics as growth promoters is still unknown, and due to this massive use, it is a major concern due to potential impacts on human health, animal welfare, and the development of antimicrobial resistance (AMR). The indiscriminate use of antibiotics in the poultry industry can result in the deposition of residues in products such as meat and eggs, which is a serious public health concern since it may lead to AMR. Antibiotic-resistant infections can be more difficult to treat, leading to increased morbidity and mortality both in animals and humans.

Furthermore, to combat antimicrobial resistance, there is consumer demand for poultry products that are ‘Raised Without Antibiotics’ or ‘No Antibiotics Ever’ flocks. Furthermore, more countries, such as the Philippines, are employing the ban on the use of antibiotic growth promoters. Hence, the quest for alternative products or approaches has intensified in recent years.

Ethnoveterinary medicine, a subset of traditional or indigenous knowledge, is concerned with treating and managing livestock with the use of more natural and indigenous materials, which includes the use of herbal medicine. The traditional way of preparing medicinal plants is considered laborious, which makes it less convenient for farmers, especially in large-scale farming. The availability of commercially prepared products addresses these challenges. As technology has led to the development of herbal products that are now commercially available, the use of these products in poultry farming has gained attention due to their potential benefits and convenience. These herbal products can be better alternatives to conventional additives and medications, specifically supplementation, to increase growth performance and minimize morbidity and mortality in livestock, including poultry [4]. The acceptance of its medicinal benefits has been growing steadily over the years. Hence, it is significant to study further the potential effectiveness of different herbal supplements in chicken growth and combating diseases faced by the industry. This study was aimed to evaluate the effects of supplementation via the drinking water of two different herbal preparations on the growth performance and profitability of broiler chickens.

2. Materials and Methods

2.1. Ethics Statement

All procedures involving animals were reviewed and approved by the University of the Philippines Los Baños Institutional Animal Care and Use Committee (UPLB-IACUC).

2.2. Animals and Housing

A total of 270 day-old mixed-sex broiler chicks (Cobb 500) were obtained from a certified hatchery. Birds were raised at the LEADS-VTH Poultry Trial Facility at UPLB Veterinary Teaching Hospital, College of Veterinary Medicine, University of the Philippines-Los Banos, under standard commercial husbandry conditions, including controlled temperature, ventilation, lighting, and biosecurity protocols.

2.3. Experimental herbal Supplements

A herbal formulation of Sorbitol (200 g) with Red Ginger extract (5 g) from a private company was used in the study. It is a water-soluble herbal medicine and the dosage from the manufacturer was followed- 2 mL for every 1 liter of water. It was given to chicks assigned to Treatment 1 for the whole experimentation period (day 7 to day 35).

A herbal formulation of Tussilago extract (25 mg) and Thyme extract (25 mg) from a private company was used in the study. It is a water-soluble herbal medicine and the dosage from the manufacturer was followed - 0.5 mL for every 1 liter of water. It was given to chicks assigned to Treatment 2 for the whole experimentation period (day 7 to day 35).

The two hundred seventy (270) 7-day-old broiler chicks were weighed and were randomly assigned to three treatment groups (Control, T1, and T2) following a completely randomized design with 90 chicks per treatment. There are nine chicks per replicate and 10 replicates per treatment. The chicks were caged randomly, and the treatments used are as follows: Control = no supplementation (The birds were given with clean water only); T1 =Gingertol (sorbitol with red ginger, a water-soluble supplement and 2 ml of the solution was added to every 1 liter of the birds' drinking water); and T2 = Respitoran (tussilago and thyme extract, a water-soluble supplement, and 0.5 ml of the solution was added to every 1 liter of the birds' drinking water).

During the brooding period (Day 0 to 7), the chicks were reared together and provided with adequate brooding requirements- such as temperature and lighting. The chicks were fed with a chick booster diet from 0 to 7 days of age. Then on day 7, the chicks were randomly assigned to the different treatment groups and were placed on the cages by batch. Thereafter, a starter diet was provided to birds from Day 7 to 21 and then shifted to a finisher diet until Day 35. The supplementation of the herbal products via drinking water was given from Day 8 until the harvest day. One liter of drinking water containing the supplements is provided daily in the morning and once it is emptied, only plain water is given thereafter. Feeds were provided on an ad libitum basis, and water was available at all times. No antibiotics were given throughout the rearing period for all treatment groups.

2.4. Dietary Formulation

Birds were fed standard booster, starter, and finisher diets formulated to meet or exceed NRC nutrient requirements. Diets were supplemented with essential vitamins, minerals, and amino acids appropriate to each production phase. Feed and water were provided ad libitum.

2.5. Care and management

Birds were managed following standard commercial poultry production practices to ensure optimal growth performance and welfare. Environmental temperature and ventilation were adjusted according to the age and physiological requirements of the birds. Each pen was equipped with appropriate feeders and nipple drinker systems that provided continuous access to fresh feed and clean drinking water. Litter was maintained dry and clean, and routine sanitation procedures were implemented to minimize pathogen load and prevent disease. Biosecurity protocols, including controlled entry, footbaths, and regular facility disinfection, were strictly followed throughout the experimental period.

2.6. Production parameters

Growth and production parameters, including body weight, feed intake, weight gain, feed conversion ratio (FCR), and livability, were recorded at four measurement points: Day 7, Day 21 and Day 35. Mortality was recorded daily and used to compute livability for each treatment group.

The live body weight was measured and recorded on days 7, 21, and 35. Weight was obtained per pen, and the average was recorded from each replicate of all treatment groups.

The amount of feed consumed was calculated by dividing the total feed consumed by the number of birds per replicate for each treatment group.

Feed Intake = (Total feed consumed)/(Number of birds per pen)

The body weight gain was calculated by subtracting the average initial weight from the average final weight of each replicate in all treatment groups at each period of the experiment.

BWG = Average Final Weight - Average Initial Weight

The feed conversion ratio of each treatment group was computed as shown in the equation below:

FCR = (Feed Consumption)/BWG

The number of mortalities and culled birds for each treatment group was recorded throughout the experiment to monitor broiler livability. No intervention was given in cases of mild immune challenges to the flock so as not to interfere with the results. The livability percentage was calculated using the formula below:

Livability % = ((Number of birds sold at the end of rearing period)/(400 birds)) X 100

At the end of the experiment (Day 35), an economic analysis was performed to assess cost-effectiveness. Income over feed and chick cost (IOFCC) and other economic indicators were calculated to determine the financial benefits associated with synbiotic supplementation relative to the control.

IOFCC = (Final Weight in kg x (Market price in Php)/kg)- (Feeds + Medications + DOC Price)

2.7. Statistical analysis

All data gathered was subjected to analysis of variance (ANOVA) using the general linear model procedures of SAS Software with Tukey’s honestly significant difference (HSD) post-hoc test (SPSS v 23). Values were considered statistically significant at p < 0.05.

3. Results and Discussion

The prophylactic use of antibiotics has been extensively employed to promote growth performance and prevent diseases. However, concerns regarding antibiotic resistance, residue accumulation in meat products, and consumer health have compelled the poultry industry to explore alternative approaches. Herbal supplements, derived from natural plant sources, are increasingly regarded as a viable and safe alternative to boost the production performance of broilers. In the present study, two different herbal products were supplemented to broiler chickens via drinking water to investigate the effects on different growth performance parameters and livability.

Herbal supplements can be administered in poultry through various methods such as addition in the drinking water, in the feeds, or by direct oral administration. All methods are effective ways to administer herbal supplements to poultry, but they have different physiological impacts, practical applications, and effectiveness in specific situations. The water supplementation is effective in situations requiring rapid physiological responses, such as periods of stress, disease outbreaks, or post-vaccination recovery. It is because of the faster absorption of bioactive compounds into the bloodstream, providing immediate physiological and immune-boosting effects. Additionally, the performance of broilers in terms of body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) improved when the supplement was provided via drinking water due to a shorter transit time compared to solid particulate feed.

Furthermore, water supplementation is advantageous during heat stress, as birds tend to increase water intake while reducing feed consumption it helps the birds to regulate their body temperature through evaporative cooling; it facilitates heat dissipation, thus ensuring continuous nutrient delivery. Conversely, supplementation via feed mixture has been the conventional way of giving supplements. It is more cost-effective for large-scale operations, as it allows for consistent dosing without the need for daily adjustments. Feed supplementation ensures a consistent and prolonged intake of bioactive compounds that support digestion, metabolism, and gut health. The study conducted by Rahayu et al. [5] investigated the effects of herbal supplementation administered through feed and drinking water on broiler chickens' blood parameters. They have noted that herbal addition through drinking water led to a lower triglyceride (TG), Low-Density Lipoprotein (LDL), and malondialdehyde (MDA) levels which is a positive marker in producing quality chicken meat by having an improved digestion and fat metabolism. They concluded that this is primarily due to water as it plays a significant role in lipid metabolism. According to Orakpoghenor et al. [6], water is vital for poultry health, constituting approximately 70–80% of lean body mass, and is crucial for metabolic processes and maintaining body temperature stability. Lastly, direct oral administration has been widely used for disease treatment and emergency supplementation whenever precise dosing for sick or weak birds is necessary. However, there are several disadvantages in this route as it is highly labor-intensive and time-consuming, making it impractical for large-scale operations where thousands of birds are managed. Further stress is also experienced by the birds as frequent handling will be necessary for this method [7].

The supplementation of natural compounds such as sorbitol and red ginger (Zingiber officinale var. rubrum) has garnered increasing interest in animal nutrition due to their potential physiological benefits and to replace the prophylactic use of antibiotics. There are currently no known studies on the effects of the supplementation of combined Ginger and Sorbitol. However, various studies have supplemented ginger and sorbitol individually, and it has garnered much attention as it can positively influence production performance, immune modulation, and carcass quality in poultry. These improvements can be attributed to the active constituents and biological functions of both supplements, which act through distinct but complementary pathways.

Red ginger (Zingiber officinale var. rubrum) is known by its higher concentrations of gingerols and shogaols. These are bioactive compounds known for their extensive pharmacological properties including antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory activities [8]. In a study conducted by Dosu et al. [9] wherein ginger is feed supplemented in different rations compared with a treatment group receiving a basal diet with antibiotics. The growth performance of the chickens that were given 0.375 g/kg up to 1.5 g/kg ginger in their diet was not different and did not have detrimental effects in comparison to the antibiotics group. The histology revealed that ginger-fed birds had increased intestinal villus height, surface area, and cell mitosis, indicating improved absorptive capacity in the gut. Moreover, this study showed that supplementation resulted in an enhanced immune system and suppressed E. coli while promoting the growth of healthy bacteria. Similar positive effects on production parameters were observed in a study conducted by Sa’aci et al. [10] wherein ginger is supplemented via drinking water. The antioxidant capacity of red ginger further contributes to its efficacy. Oxidative stress, caused by the accumulation of reactive oxygen species (ROS), can impair cellular functions and growth in poultry. Ginger's bioactive compounds enhance endogenous antioxidant enzymes such as glutathione peroxidase (GSHPx), catalase, and superoxide dismutase (SOD). Zhang et al. [11] demonstrated that ginger supplementation significantly increased GSHPx activity and decreased malondialdehyde (MDA) levels, a marker of lipid peroxidation, in broiler plasma. This suggests that ginger not only supports physiological function under normal conditions but also confers resilience during oxidative stress.

On the other hand, Sorbitol is a six-carbon sugar alcohol and plays a notable metabolic role as it is converted to fructose and subsequently into glucose, yielding approximately 2.6 kcal/g of energy [12]. Although Furuse and colleagues reported that sorbitol supplementation did not significantly affect body weight gain, feed intake, or feed efficiency in birds, they observed a significant reduction in both absolute and relative abdominal fat weights. The study by Takahashi et al. [13] explained that sorbitol reduces early inflammatory responses by modulating cytokine responses that resulted to prevention in growth reduction. This immunomodulatory effect is particularly valuable in intensive poultry systems where birds are frequently exposed to environmental and pathogenic stressors.

This chapter presents the findings that were recorded during the experimental procedures and statistical analysis performed in the study. The results are presented through appropriate tables to enhance clarity and arranged to correspond with the objectives and hypotheses previously established. Comparative analyses were stated to highlight significant differences and trends in the parameters among the experimental groups.

The mean body weight of broiler chickens during each experimental stage until the last day of the experiment is presented in Table 1. The initial weights of the week-old chicks, ranging from 181.44 g to 190.00 g, did not vary significantly (P ≤0.05). After two weeks of the experiment, the average body weight ranged from 981.10 g to 1110.56 g. Statistical analysis showed that the body weight of treatment groups supplemented by Sorbitol with Red Ginger (T1) and Tussilago and Thyme Extract (T2) were significantly higher than the Control group. At day 35, average body weights recorded from the Control, T1 and T2 were 1926.32 g, 2016.85 g and 2064.45 g, respectively. Still, statistical analysis revealed that the herbal groups exhibited significantly higher average body weights compared to the control, with the Tussilago and Thyme extract having the heaviest birds at the end.

As demonstrated in Table 2, the mean feed intake did not vary significantly among treatment groups from the production day 7 to 21. On day 21 to 35, finisher feeds were given to chicks, the data analysis showed a significant difference in average feed intake in groups that were supplemented via the drinking water compared with the control, note that the control group had a higher recorded feed intake among the three. Data gathered during the whole experimentation period highlighted that broilers that were given Sorbitol with Red Ginger (T1) and Tussilago and Thyme Extract (T2) consumed less amount of feeds in contrast to the non-supplemented group.

Data on weight gain were recorded, analyzed, and summarized in Table 3. The weight gain of broilers in the Sorbitol with Red Ginger (T1) and Tussilago and Thyme Extract (T2) groups were recorded as 907.50 g and 921.67 g, respectively, both significantly higher than that of the Control group, which only achieved a weight gain of 809.65 g from days 7 to 21. Then during the last two weeks of the experimentation, there were no significant differences among the three treatment groups. Nonetheless, when comparing data from the whole rearing period, day 7 to 35, the mean body weight gain of T2 and T3 were significantly higher than that of the Control.

The feed conversion ratio (FCR) of broilers provides an index of feed efficiency, with lower values indicating more efficient feed utilization. Using the data on feed intake and weight gain, the FCR were computed and recorded in all stages of the experiment and presented in Table 4. At the first two weeks (Day 7-21), both supplemented groups have achieved a lower FCR than the Control group. At the last two weeks, from day 21 to 35, the Tussilago and Thyme Extract supplemented chicks exhibited significantly better performance compared to the chickens under Sorbitol with Red Ginger (T1) and Control groups. Over the entire rearing period (Day 7 to 35), broilers under both supplemented treatments were still recorded to have a lower FCR. Notably, broilers under T3 group recorded an FCR of 1.80, indicating the most efficient in feed utilization among all treatment groups.

The present study assessed the effects of a dietary supplementation combined ginger and sorbitol in comparison with the control group that did not receive any supplementation. The treatment group exhibited a positive impact on production parameters, evidenced by a significantly higher body weight while having a lower feed intake, thus resulting in a better FCR. Sorbitol primarily acts through the metabolic and anti-inflammatory pathways, preserving growth under stress. Red ginger, on the other hand, has benefits across gut health, carcass traits, immune function, and oxidative stress mitigation. These synergistic interaction between the two compounds could have directly affected the bird’s livability as in this study wherein throughout the rearing period the Sorbitol with Red Ginger extract groups percentage of livability was markedly higher than that of the control group.

Furthermore, the improvements in growth performance and feed efficiency observed in the ginger and sorbitol-supplemented group translated into better economic efficiency. The reduced feed intake, in combination with significantly higher final body weights, resulted in a lower feed cost per kilogram of body weight gain compared to the control group. The enhanced livability has also minimized production losses and contributed to a greater overall yield. In the context of the Philippine poultry industry, the supplementation of ginger and sorbitol offers distinct economic advantages, particularly in relation to the country's tropical climate. High temperatures and humidity levels commonly experienced in the Philippines can induce heat stress in broilers, leading to reduced feed intake, thus having poor weight gain and increased mortality [14]. Taking advantage of broilers' natural tendency to increase water intake during periods of heat stress presents an effective route for administering ginger and sorbitol supplementation via drinking water [15]. Ginger’s natural antioxidant and thermoregulatory properties are helpful for poultry during hot weather. It helps birds cope with heat stress by improving their appetite and digestion while also boosting their immune system—supporting their overall health and comfort when temperatures rise. Combined with sorbitol, which aids in nutrient absorption and gut health, the supplementation results in improved feed conversion ratios and higher final body weights, even under suboptimal environmental conditions.

The present study investigated the effects of a combination of Tussilago farfara (commonly known as coltsfoot) and Thymus vulgaris (thyme) extracts on poultry production performance. The birds that received this herbal in drinking water demonstrated superior growth performance, improved feed conversion ratio (FCR), and higher survival rates compared to other treatment groups. The observed improvements in production performance, immune response, and overall health of poultry in the group supplemented with a combination of Tussilago farfara (coltsfoot) and Thymus vulgaris (thyme) extracts can be attributed to the synergistic action of the bioactive compounds found in both herbs. And currently there are no known studies on the effects of the combined Tussilago and Thyme supplemented in animals.

Mortality rates were monitored daily to evaluate the effects of the treatments on birds' livability. During the initial two weeks of rearing, no mortalities were recorded in treatment with Tussilago and Thyme Extract (T2), resulting in a 100% livability rate, whereas the Control group recorded only 75% livability rate. In the subsequent two weeks, four birds died in T2, reducing its livability by 96%. Meanwhile, the Control and T1 reported a livability rate of 87% and 97%, respectively, during the same period. Nevertheless, T2 maintained the highest overall livability and the control group had the lowest livability throughout the entire rearing period, with final computed percentages of 96%, 93%, and 66% for T2, T1, and Control, respectively.

Tussilago commonly known as coltsfoot, is being utilized for human herbal medicine that addresses common respiratory diseases and there is limited scientific research specifically on its effects on chicken. The ethnobotanical value, phytochemistry, pharmacology, and toxicity of coltsfoot were reviewed by Chen et al. [16], and they have highlighted the biological activities such as its anti-inflammatory, neuro-protective, and antimicrobial properties due to its constituents - flavonoids, phenolic acids, triterpenoids, and polysaccharides. According to this review, the antioxidant capacity of coltsfoot is mainly associated with its total phenolic content. It acts as strong free radical scavengers, helping to reduce oxidative stress in living cells. This antioxidant activity is important in poultry, especially under commercial farming conditions, where birds are frequently exposed to environmental and metabolic stressors. While the polysaccharide from coltsfoot is the one responsible for its immuno-stimulating activities. However, a safety concern was seen in a study by Hui et al. [17], where they observed hepatotoxic effects of coltsfoot in rats after 4 weeks of administration due to the presence of pyrrolizidine alkaloids (PAs).

In contrast, thyme has been widely accepted as a supplement for chicken and is used as a growth promoter and immune stimulant. The primary active compound in thyme extract is thymol, which is known for its antimicrobial, antioxidant, and anti-inflammatory properties. Thymol possesses strong antimicrobial properties by disrupting the cell membranes of harmful bacteria, such as E. coli and Salmonella spp. [18]. This helps reduce the microbial load in the gut, allowing for better nutrient absorption and improved growth performance. Moreover, carvacrol, another active property found in thyme, is responsible for its positive effect on the chicken's immunity by enhancing antibody production and supporting the gut health, leading to a higher livability of chicken [19]. These effects were also seen in the study conducted by Almremdhy et al. [20], wherein thyme extract was mixed with the birds drinking water while also measuring the antibody titers against the infectious bursal disease. They have noted that this resulted to a higher antibody titer in the Thyme-supplemented chickens compared with non-supplemented, which were attributed to the flavonoids that extend the activity of vitamin C.

In this study, equal amounts of coltsfoot and thyme extracts were mixed and administered through drinking water, and their synergistic effect were observed. The results in this study were consistent with those reported in previous studies of individual herbs. Results showed significantly highest body weight gain, improved feed conversion ratio (FCR), and increased livability rates over the experimental period. The antimicrobial activity of thymol and carvacrol in thyme likely works in tandem with the anti-inflammatory and expectorant properties of coltsfoot, promoting both gut health and immune system even during the stressful conditions. Additionally, the immunostimulatory polysaccharides from coltsfoot and the immune-enhancing effects of thyme's carvacrol and flavonoids likely contributed to the higher survivability observed in the study. The antioxidants from both herbs, especially phenolic compounds, help reduce oxidative stress, thereby supporting cellular health, growth, and recovery.

The economic analysis presented in Table 6 highlights the impact of herbal supplementation on the production cost and profitability of broilers. Among the three treatment groups - Control, T1 (Sorbitol with Red Ginger), and T2 (Tussilago and Thyme Extract) - T2 consistently demonstrated superior outcomes in terms of both production efficiency and net income. Broilers in the T2 group recorded the lowest total cost to produce at Php173.15 despite incurring the highest medication cost (Php1.55). This is attributable to a lower feed intake cost (Php151.60) compared to both the control (Php160.02) and T1 (Php152.95) groups. Notably, T2 group has the highest average live weight at 2064.45 g, which translated to the highest live weight price among the three-control at Php231.12, T1 at Php241.92, and T3 at Php247.68, based on a farmgate price of 120/kg. The Income Over Feed and Chick Cost (IOFCC) further emphasizes the economic benefit of supplementation. The control group resulted in having the lowest return despite no added supplementation cost (Php51.10), and the broilers in T1 and T2 yielded 40% higher returns at Php67.87 and Php74.53, respectively. Therefore, T2 demonstrated the most favorable return on investment (ROI) indicating superior economic performance.

Economic analysis revealed that this group has the highest profitability by analyzing using income over feed and chick cost (IOFCC). Although there was a slight increase in input cost due to the use of herbal extracts, this is compensated by the improved feed efficiency, heaviest final weight, and reduced mortality. The improved FCR meant that less feed was required per kilogram of weight gain, directly lowering feed-related expenses. The economic return was further reflected in the higher market weight in the treatment group, translating into increased revenue per bird. This finding is especially relevant in the Philippine poultry industry, where broiler farms commonly face respiratory diseases such as Chronic Respiratory Disease (CRD) and Newcastle Disease [21]. For farms that employ vaccination programs against these diseases, there are still post-vaccination reactions, which often manifest as mild to moderate respiratory symptoms, including coughing, sneezing, and nasal discharge, which can lead to temporary reductions in feed intake and growth performance [22]. Moreover, high humidity, fluctuating temperatures, and poor ventilation experienced in many small- to medium-scale operations exacerbate these issues, often resulting in overall poor productivity and higher mortality.

4. Conclusion

The findings of this study demonstrated that dietary supplementation with tussilago-thyme extract had a significant positive impact on the growth performance of broilers. Similar positive effects were also seen in the sorbitol with red ginger supplemented group, but production parameters were just slightly lower when compared to the Tussilago-Thyme extract group. It confirmed that the observed improvements were significant, thereby supporting the efficacy of the tested supplements in promoting optimal broiler performance. Moreover, the results suggest that such dietary interventions given via drinking water can be effectively utilized to enhance productivity in poultry production, particularly towards the end of production and during periods of heat stress. Future research should focus on optimizing dosage levels, evaluating long-term effects, and assessing economic viability under various farming conditions. Additionally, further research should look into the effects of using these supplements on carcass quality, dressing percentage, meat yield, fat deposition, and overall carcass characteristics.