The maximum and minimum temperature (!) data signifies that birds remained in stress throughout the trial (Table 2). THI varied from 84.01-86.68 and 86.54-89.35 in morning and afternoon, respectively. Morning THI values depicted that birds were in moderate heat stress during 1
st and 3
rd week, severe heat stress in 2
nd week and very severe heat stress in 4
th, 5
th and 6
th week. Whereas, in afternoon, birds experienced very severe heat stress throughout the trial. Similar scale of THI was used for stress classification of poultry by
Habeeb et al., (2018).
Feed intake (FI; g) of quail was not influenced on supplementing AV in feed and/or drinking water (DW) at different concentrations (Table 3). Similar observations were reported by
Amini and Vali (2016) on supplementing 0.2, 0.4 and 0.6% AV powder in Japanese quails. Likewise, earlier researchers too reported similar observations on supplementing AV in graded levels or single dose in feed or DW in different poultry species
(Barman et al., 2019; Islam et al., 2020; Amber et al., 2021). A positive correlation was observed between FI and THI in all groups, indicating no beneficial effect of AV on FI (Table 4).
Body weight gain (BWG) of starter and finisher phase were statistically similar, but for entire trial, it was statistically higher (P<0.05) in T
4 than T
1 and C with intermediate values for T
2 and T
3 (Table 3). It may be attributed to antimicrobial, antioxidant, antistress and/or growth promotor properties of AV
(Nalge et al., 2017). Besides above-mentioned properties, AV is also rich in nutrients (protein, vitamins, enzymes,
etc.) which could have added to the nutritional composition
(Surjushe et al., 2008). These results are in line with the findings of earlier researchers that AV supplementation in graded levels or single dose in feed or DW resulted in higher BWG in broilers (
Sakadzo and Chibi, 2020;
Amber et al., 2021). In contrast,
Barman et al., (2019) found no difference in BW of broilers on AV supplementation due to different species and climatic conditions. Feed conversion ratio (FCR) of entire trial was significantly better (P<0.05) in T
4 (3.76) than C (3.98) and T
1 (3.96). Thus, it may be inferred that AV intake through DW is more effective than feed supplementation. The present results corroborate with the findings of
Islam et al., (2020); Amber et al., (2021) and
Gowri et al., (2022), who too found improved FCR on AV supplementation. FCR and THI showed positive correlation, signifying that with the increase in environmental temperature, there is rise of FCR values (Table 4).
Protein efficiency ratio (PER) values were similar (Table 3) and negative correlation was observed between PER and THI, showing no beneficial effect of AV supplementation on protein utilization (Table 4). Also, water intake (WI) and water feed ratio showed no significant difference (Table 3). A similar result has been shown by
Islam et al., (2017) on supplementing AV extract in DW of broilers. A positive correlation was observed between WI and THI in C, T
1, T
2 and T
3, but T
4 had non-significant positive correlation with THI (Table 4). It signifies that 0.6% AV supplemented group was not in extreme stress.
The plasma glucose (mg/dl) values and liver function indices (SGOT, SGPT; IU/L) of quails showed no significant difference with the control group, suggesting no deleterious effect of AV supplementation on vital organs of quail birds (Table 5). Similarly,
Amini and Vali (2016) reported similar glucose values of Japanese quails on supplementing 0.2, 0.4 and 0.6% AV powder. Concurrent with the present study,
Amber et al., (2021) stated that broilers given AV gel had no SGOT and SGPT changes. As far as the lipid profile is concerned, cholesterol (mg/dl) was significantly reduced in T
4 than C with intermediate values in rest of the groups. But no significant difference was observed for triglycerides (mg/dl). In line with the present study,
Amber et al., (2021) illuminated that poultry supplemented with 1.5% AV gel in drinking water had reduced cholesterol. AV has acemannan, a polysaccharide that can modify blood cholesterol by regulating fat metabolism in the liver
(Beppu et al., 2006). AV also enhances the sensitivity of cells to insulin, leading to reduction of free fatty acids released from fat tissue to the blood
(Misawa et al., 2012). However, cholesterol values obtained in present study were in normal physiological range (33.33-266.67 mg/dl;
Agina et al., 2017).
Hb (g/dl) and PCV (%) values were statistically similar and within the range as reported by
Agina et al., (2017) for Japanese quails (8.61-20.57 g/dl and 25.00-66.00% for Hb and PCV, respectively). Similarly,
Islam et al., (2020) reported no change in Hb and PCV of broiler chicken when AV was administered @ 0.5 and 1% in drinking water.
Different carcass traits (as % live weight) and dressing percentage showed statistically similar values (Table 6).
Amini and Vali (2016) and
Shokraneh et al., (2016) also reported similar carcass traits on supplementing AV powder and/or gel in poultry.
