Effect of Azolla pinnata Feeding on Linear Type Traits and its Relation to Economic Feasibility in Sahiwal Calves

Most farmers suffer from problem of unavailability of animal health accessing and their growth measurements tools so they make use of linear body measurements for estimating them (Ulutas et al. 2002). Simple linear measuring tools will be easy to manage and will help to pick the animals to become next-generation parents (Essien and Adesope 2003). Morphometric/Linear type traits (LTT) can be used in farm animals to determine growth rate, body weights, feed use and carcass characteristics. Body measurements can be used in cattle as selection criteria for the growth traits. In addition to increasing their milk production level, enhancement of these (LTT) traits will enhance the herd life of dairy cows (Atkins and Shannon 2002).
       
The most expensive part of livestock farming is the feed expense (Goh and Rajion, 2007). Concentrate is the most vital element in animal diet, prepared primarily from traditional protein sources such as groundnut cake, cotton seed cake and soybean meal. All these protein sources are very expensive and responsible for reducing the income and act as a major constraint for poor farmers. Protein is the costliest component of the diet (Mederos et al. 2002). The prices of traditional sources of protein are increasing day by day. Human beings and animals end up competing for protein sources either for consumption or industrial use. Besides this heavy price of these feed resources, their seasonal availability also restricts their inclusion in formulating feed for livestock. Also, Agbede et al., (2008) and Agbede et al.,(2009) indicated that assessing unconventional feed resources in conjunction with other strategies would reduce the load on traditional feed resources and accelerate the achievement of feed safety in tropical animal. Scientists have recently researched more on the use of local protein resources, which have no nutritional and economic value to man. Various research have been done on the use of maggot cassava leaf protein concentrate by Fasuyi, (2000), cassava leaf meal Okonkwo et al. (2010) cassava peel by Tewe, (1985) winged bean seed by Igene (1999) and Leucaena leaf protein concentrate by Agbede, (2000) at different times to replace conventional protein feed ingredients in the formulation of livestock feeds. Therefore, in order to create dairy farming as a profitable venture for farmers, it is hourly necessary to develop cheap protein feed sources.
       
With this context, Azolla pinnata can act as the best source of protein substitution. So, the present study was conducted with an objective to evaluate the effect of Azolla pinnata feeding on different linear type traits (LTT) and to explore the viability and financial feasibility of Azolla pinnata as a partial protein substitute for concentrate in Sahiwal calves.
 

The present study has been conducted at Livestock Research Centre (LRC) of National Dairy Research Institute (NDRI), Karnal, Haryana. The experiment was performed to evaluate the different linear type traits (LTT) and evaluate its relationship with cost economy of Azolla pinnata feeding in calves by substituting the protein content of concentrate at 15 per cent and 30 per cent level. Sahiwal female calves (n=18) were randomly divided into three treatment groups with six animals in each one. The average weight and age in each groups was 56 kg and 4 months. The research was conducted at LRC, NDRI herd, Karnal.
       
Azolla was propagated at the Azolla production unit established at NDRI, Karnal. A rectangular pit having dimension of 11.0*4.5 feet (L*B) and 90 cm depth was prepared (total 22 pits). The calves were kept on the adaptation period of two weeks. Afterwards an experiment of 13 weeks (90 days) was carried out during which the groups were fed with three treatments. The animals were fed as per the ICAR feeding standard 2013. The 1^st group (T0) was a control group and fed as per ICAR 2013 feeding standard. The 2^nd group (T1) was fed by replacing the 15% protein content of the concentrate with the Azolla pinnata and the 3^rd group (T2) was fed the same but by replacing the 30% protein content of concentrate with the Azolla pinnata. All the groups were fed as per ICAR feeding standard 2013 by balancing the CP intake, TDN intake and DM intake for each animal. The iso-nitrogenous and iso-caloric diets were formulated for all the groups.
 
Data collection and sampling
 
Feed intake and body measurements like body length (BL), heart girth (HG), height at withers (HAW), head to shoulder length (HS), chest depth (CD), Hip height (HH) and abdominal girth (AG) were measured fortnightly. The LTT variables were used to measure growth, feed usage and its relationship to economic Azolla feeding. The LTT have been measured using inch tape and represented in centimetres as per the recommended procedures.
       
The LTT traits were used for estimating the body weight of animals. The body weights at various age groups of calves were estimated by using Schaeffer’s formula as outlined below:
 
 
 
Where,
Length and girth is measured in inches.
       
The resulted body weight in pounds was converted into Kilogram (Kg) unit for easy assessment and relating it with economic parameters calculation.
       
Data were collected from the local market about the prevailing price of all the inputs used in the production of Azolla. The cost of roughage and concentrate supplied by the fodder section and the cost of cultivating Azolla were considered together for calculating the cost of the feed. On cost analysis, feed cost per kilogram weight gain was calculated by multiplying the cost of feed intake by the feed consumed and divide by the weight gain (kg). It is mathematically expressed as: 
 
 
 
 
The unit cost of Azolla production is calculated as:
 
 
 
The percentage reduction in feed cost over control group (%) is calculated as:



Statistical analysis
 
The various LTT traits and body weight measurements at fortnight interval were analysed using the SPSS statistical package (version 20.0) and are presented as means and pooled standard errors (SEM). The dietary treatment effects were explored using a General linear model (GLM) for repeated measures analysis of variance (ANOVA) with dietary treatments (D= T0, T1 and T2) and considering the sampling time (S) as the repeated measure and their interactions (D×S) according to the model:
 
 

Where,
Υik is the dependent variable, μ is the overall mean, Di is the effect of dietary treatment (i=3), (DxS) is the interaction between dietary treatments and sampling time and eik is the residual error. Post hoc analysis was performed using LSD multiple range test and for all tests, the level of significance was set at 0.05.
 
 

Azolla pinnata yield
 
Azolla has been harvested daily from all the pits. The average yield of Azolla was 0.021 kg/ft2/day. The total Azolla pinnata yield has been presented below in Table 1. The resulting regrading unit cost of production of Azolla was Rs. 1.36 which was higher than the values obtained by (Pillai et al., 2002; Cherryl et al., 2013; Sireesha et al., 2017) and the value obtained by them was Rs. 0.65, Rs. 0.56 and 0.66 respectively. This could be due to the inclusion of the silpauline sheet expense as compared to earlier studies that did not include it when measuring the unit cost of production of Azolla.


 
Economics of Azolla pinnata production
 
In the experimental period it was observed that Rs. 2472.79 was the total expenditure required for Azolla production. The amount was determined by adding all expenditures such as the cost of silpauline sheets, cow dung, super phosphate, labour costs, insecticide etc. The economics of Azolla pinnata production has been presented below in Table 2.


 
Linear type traits
 
The mean linear type traits (LTT) of different groups have been presented in the Table 3. Post-hoc analysis revealed that there was no significant difference in height at withers, body length, chest depth, hearth girth, hip height, abdominal girth and head to shoulder length (cm) among all the three groups (P<0.05). There was a significant effect of time (trial) but there was no significant interaction between time and variable interaction (LTT Traits) (P<0.05). The average heart girth (cm) has shown no significant difference in all the groups in the experiment. In the T2 group, numerically higher value was reported for head to shoulder length (cm), compared to control one. The other LTT parameters like hip height, abdominal girth and head to shoulder length (cm) have shown no significant difference in between the groups.  The higher average value for body length was obtained for T2 group in comparison to T0 group. Similar results were obtained by (Paul et al., 2012; Milla et al., 2012; Bhagat et al., 2017). Azolla is rich in essential amino acids, vitamins (vitamin A, vitamin B12, beta carotene), promoters and minerals such as calcium, phosphorus, potassium, zinc, etc. (Lumpkin 1984; Bhatt et al., 2020). This may have led to improved growth and thus increased body length. Since Azolla have better mineral profile, growth promoters and contributed to better growth (Lumpkin 1984; Bhatt et al., 2020). The higher value for height at withers (cm) was observed in treatment group in comparison to control one. Since Azolla leaves also contain anthocyanins that have antioxidant property Katyamaa et al. (2008). All of this may have led to faster growth, better bone and muscle development in Azolla fed groups and thus the height was highest in 30 per cent replaced fed groups. Similarly the higher value for body length, chest depth, hearth girth, hip height, abdominal girth and head to shoulder length (cm) was observed in treatment groups. Similar results for various body measurements were obtained by (Otto et al., 1991; Prasad et al., 1994). 


 
Body weight
 
The body weight of calves (in pounds) at different fortnights has been mentioned in Table 4.  The body weight of calves (in Kg) at different fortnights has been mentioned in Table 5. Post hoc analysis using GLM model showed that there was no significant difference in body weights in between the groups at different fortnights. There was a slight significant interaction between time and variables (Body weights) (P<0.05).




 
Cost economics of Azolla feeding
 
The concentrate ration cost per kilogram used was Rs. 23.4. The cost of ration in T0, T1 and T2 groups with inclusion of Azolla as protein substitute with concentrate at 15 per cent and 30 per cent level respectively has been shown in Table 6. The total cost/day/group in different groups that is T0, T1 and T2 group was Rs. 181.86, 174.42 and 165.84 respectively. There was a significant difference observed for total cost/day/group in between the T0 and T2 groups and the non-significant results were obtained for the same between the T0 and T1 and T1 and T2 groups. Compared to the control group, the total feed cost reduction/day in T1 and T2 group was Rs. 7.44 and 16.02 respectively. The total reduction in feed costs in the T1 and T2 group compared to the control group over the whole 90-day period was Rs.669.6 and 1441.8 respectively. All the cost economics of Azolla pinnata feeding has been presented below in Table 5. The significant difference was observed for feed cost per day/calf in a 30 per cent substituted group in comparison to control one (P<0.05). Such findings suggested that a total quantity of Rs. 1.24 was saved in T1 groups per day per calf, while a bit higher quantity of Rs. 2.67 was saved in T2 groups per calf compared to control groups. It was concluded that in the T1 groups, the cost of feed was reduced by Rs. 7.44 per day per group. It was also found that in the T2 groups the cost of feed was reduced by Rs. 16.02 per day per group. The significant difference was observed for feed cost per day/calf in T2 group in comparison to control one (P<0.05). Similar results were obtained by (Bhagat et al., 2017; Lupmkin et al. (1984)) who found significantly higher values in the Azolla feed groups. Therefore it was concluded that Azolla has a major role to play in lowering feed costs and also being able to fasten the growth of the body due to the growth promoter in them.  


 
Body weight and feed cost analysis
 
The average initial body weights for different groups were recorded before the start of experiment for grouping and their values has been presented in Table 6. The overall average increase in body weight along with the average daily weight gain (ADG) has been presented in the Table 6. The non-significant results were obtained for the average body weight of different groups at each fortnight. However the average body weight gain was highest in the T2 group in comparison to the T0 groups. There was a significant difference in the ADG in between the T0 and T2 groups (P<0.05). However, ADG of calves in T1 did not differ significantly from other groups. In the T0, T1 and T2 group, feed cost/kg weight gain was Rs. 77.32, 70.04 and 62.81, respectively. The lowest values for feed cost/kg weight gain were obtained in the T2 groups, reflecting the reduced amount invested for the same body weight gain. The reduction in the T1 and T2 group feed cost/kg weight gain compared to the control group was Rs.7.28 and 14.51 respectively. The percentage decrease in feed costs over control group (per cent) in the group T1 and T2 is Rs 9.41 and 18.76 respectively. The feed cost analysis has been represented in the Table 6. There was a significant difference seen among all the three groups in feed cost/kg gain (Rs). In the T2 group the feed cost/kg gain (Rs) was significantly lower compared to the T0 groups. The percentage reduction in feed costs over the control group (per cent) in T1 and T2 groups is 9.41% and 18.76%. The lowest values for feed cost/kg weight gain were obtained in the T2 groups, reflecting the reduced amount invested for the same body weight gain. There was a significant difference seen among all the three groups in feed cost/kg gain (Rs). In the T2 group the feed cost/kg gain (Rs) was significantly lower compared to the T0 groups. It reflects the low cost of using Azolla as a substitute for the protein concentrate. In the groups treated with Azolla the growth rate was also higher. In the T2 group the feed cost/kg gain (Rs) was significantly lower compared to the T0 groups. It reflects the low cost of using Azolla as a substitute for the protein concentrate. In the groups treated with Azolla the growth rate was also higher. After proper cleaning, Azolla is eaten by animal in desired quantity. So it lowers the cost of feed and increases profit. The feed cost in the T2 group was significantly reduced as compared to control one. This is due to improved Azolla diet adaptability in replacing the concentrate and reducing the cost of raisings.
 

From the present research, it was found that Azolla has a positive impact on LTT traits. All the parameters were under the normal range and in some cases there was better growth seen. The total feed cost and feed cost per kg gain was less in the Azolla fed groups. Highest profit and growth was seen at 30% replacement level, indicating it has highly economical. Thus in the nearby future, the inclusion of fresh Azolla pinnata as an unconventional natural protein source in Sahiwal calves ration up to 30% level will be highly beneficial  and recommended.
 

The authors declare that there is no conflict of interest.