doi:10.5455/vetworld.2013.151-155

Aim: The objective of the present study is to know the effect of feeding processed sweet sorghum (Sorghum bicolour (L) moench) crushed residue (SSCR) based complete ration on growth, feeding behavior and cost of gain in Murrah buffalo calves in order to compare the feeding value of SSCR with sorghum straw (SS) and also find out the efficient way of utilization of SSCR in the diets of growing buffalo calves. 
 
Materials and Methods: Experimental complete rations were formulated with SSCR and concentrate in 50:50 ratio and processed in to SSCR chopped and concentrate (SSCRC), mash (SSCRM) and expander extruder pellets (SSCRP). The control ration was SS based complete feed processed in to mash (SSM). 24 Murrah buffalo calves (Average 137 kg body weight and aged 1 year 2 months) were randomly distributed into 4 experimental groups of 6 animals each in a completely randomized design and the experimental rations were offered to 4 groups randomly for a period of 150 days. A 7 day digestion trial was conducted at the end of 150 day growth trial to find out the nutrient digestibility of experimental rations. Eating and ruminating activities were noted every 5 minutes, and each activity was assumed to persist for the entire 5 minutes. Sorting behavior in the calves was observed physically at the time of feeding. The cost of the rations was calculated on the basis of processing cost and the prevailing market prices of the feed ingredients. 
 
Results: The DM intake (g/d), digestibilities of DM, organic matter, crude protein and nitrogen free extract and nitrogen (N) balance were higher (P


Introduction
digestibility of nutrients.Now a day's expanders are being used in feed industry as an alternative for Sweet sorghum (Sorghum bicolour (L) moench), pelleting for processing of livestock feeds [8,9].a dry land crop is more water use efficient and recently The objective of the present study was to know the gaining importance as a feedstock for ethanol production effect of feeding processed SSCR based complete [1].In general, it can produce stalk 54 -69 t/ha [2].The ration on growth, nutrient digestibility, feed efficiency, crushed residue produced after juice extraction from feeding behavior and cost per kg weight gain in Murrah stalks can be used as animal feed [3].The feed value of buffalo calves in order to compare the feeding value of the sweet sorghum crushed residue is not less than the SSCR with sorghum straw (SS) and also find out the value of non-sweet stem that is currently the main stay efficient way of utilization of SSCR in the diets of of feed market in and around Hyderabad [4].Feeding growing buffalo calves. of roughages under complete diet system improved the palatability and utilization of bulky crop residues [5].

Materials and Methods
Various processing methods like grinding [6] and The variety of sweet sorghum used in the present pelleting [7] improved the dry matter intake and calves with uniform body weight (137 kg) and age (1year 2 months) were distributed randomly into four Sorting behavior of the calves observed physically experimental groups of six animals each in a completely during feeding of the calves for last three days of the randomized design.Experimental complete rations growth trial.Statistical analysis of the data was carried were formulated with SSCR and concentrate in 50:50 out according to the procedures suggested [14].The ratio and processed in to chopped SSCR and concentrate costs of the rations were calculated on the basis of (SSCRC), mash (SSCRM) and expander-extruder pellets processing cost and the prevailing market prices of the (SSCRP).The control diet was formulated using sorghum feed ingredients.straw (SS) in the same roughage to concentrate ratio Ethical approval: The study was approved by and processed in to mash form (SSM).The complete th Institutional Animal Ethics Committee on 17 October rations were offered to four groups of buffalo calves 2010 randomly for a period of 150 days.The animals were weighed fortnightly for 3 consecutive days before

Results and Discussion
offering feed and water in the morning.A 7 day digestion Chemical composition of SSCR: SSCR on dry trial was conducted at the end of 150 day growth trial.
matter basis contained 92.5% dry matter (DM), The samples were analyzed for proximate principles 90.75% organic matter (OM), 3.94% crude protein [10] and fibre fractions [11].Metabolizable energy (CP), 1.89% ether extract (EE), 37.58% crude fibre (ME) values were calculated from total digestible (CF), 47.34% nitrogen free extract (NFE), 9.2 % total nutrients (TDN) using factors suggested [12].Eating ash (TA), 74.76% neutral detergent fiber (NDF), and ruminating behavior were monitored visually for a 42.93% acid detergent fiber (ADF), 31.84%cellulose, 24 h period in shifts of 8 hours during the last 3 days of 37.75% hemicellulose and 4.24% lignin.The the growth trial.Eating and ruminating activities were proximate principles of SSCR were comparable with noted every 5 minutes, and each activity was assumed sorghum and maize stovers [15].The CP per cent of to persist for the entire 5 minutes.To estimate the time SSCR was comparable with sorghum stover [16].spent for eating, ruminating and total chewing per kg The NDF and ADF content of sorghum and maize dry matter intake (DMI) and neutral detergent fibre stovers [15] and stripped leaves of sweet sorghum intake (NDFI), the actual intake for that day was used.rations [20].All the buffalo calves showed positive The chemical composition of processed SSCR nitrogen balance.rations were comparable (Table -1

) as the processing does not have any effect on chemical composition
Nutritive value: Higher (P<0.05)DCP (%) content and among mash and pelleted rations [17].
intake in buffalo calves fed SSCRP ration (Table 2) might be due to higher (P<0.05)digestibility and Dry matter intake: The DMI (g/d) was higher (P<0.05)intake of CP due to expander-extruder processing [5]. in buffalo calves fed SSCRP ration, while comparable among SSCRC, SSCRM and SSM rations (Table 2).
The trend of TDN (%) and ME (MJ/kg DM) content This might be due to more palatability of pelleted ration and intake of SSCRP ration was similar to that of DCP resulted into more feed intake of expander-extruder (%) content and intake but the difference among the complete diets [5,18].rations were not significant.All the buffalo calves fed However, no significant difference was found in differently processed complete rations met the DM, water intake among buffalo calves fed different DCP and TDN requirements recommended [21].experimental rations.
Feeding behavior: Eating, rumination and total chewing time (minutes/d, minutes/kg DMI and minutes/kg Nutrient digestibilities: The average DM, OM, CP and NDFI) and number of chews for eating, rumination and NFE digestibilities were higher (P<0.05) in calves fed total chewing (per d, per kg DMI and per kg NDFI) SSCRP ration, but comparable among SSCRC, were higher (P<0.01) in buffalo calves fed SSCRC SSCRM and SSM rations (Table -2).This might be due ration compared to those fed SSCRM, SSCRP and to heat treatment of the complete ration during SSM rations and lower (P<0.01) in calves fed SSCRP expander-extruder processing which might have ration compared to those fed SSCRC, SSCRM and protected protein from ruminal degradation resulted SSM rations.This might be due larger particle size and for higher CP digestibility and might also helps in less dense nature of the SSCRC ration compared to gelatinization of the starch components of the feed and SSCRP, SSCRM and SSM rations.Lower eating and loosening of the bonds between lignin and soluble chewing time in buffalo calves fed SSCRP ration might carbohydrates (hemicellulose, xylose etc.) which in be due to easier consumption of the pellets [19] turn resulted in higher (P<0.05)energy digestibility [8].
resulting on higher intakes [18].The rumination time However, significant difference was not observed per unit DM intake decreased with decreasing dietary in the digestibilities of CF and EE and cell wall particle size [22] in cattle corroborates with the present constituents among the differently processed SSCR findings of lower rumination in SSCRP followed by rations and with control ration corroborating the SSCRM and SSM rations.findings [8,19].
However, the difference in time required and number of chews for eating, rumination and total chewing were Nitrogen balance: The N intake (g/d) and N balance not significant in buffalo calves fed SSCRM and SSM (g/d) were higher (P<0.05) in calves fed SSCRP ration rations (Table -3) because of the similar physical OM, CP and NFE in buffalo calves fed SSCRP ration properties of the complete rations.
than those fed SSCRC, SSCRM and SSM rations Sorting and selection of ration against longer corroborating the findings [17].Even though FCR was particles of SSCR in favour of smaller particles of the not significant in buffalo calves fed either SSM or concentrate portion of the ration was observed in SSCRC and SSCRM rations, the cost/kg gain (INR) calves fed SSCRC ration compared to SSCRP, SSCRM was lower ((P<0.01) in buffalo calves fed SSCRM and and SSM rations.Similar findings were reported in SSCRC rations than those fed SSM ration due to higher Holstein Friesian heifers [23] and cattle [24].However, cost of sorghum straw (INR-4) compared to SSCR sorting was not observed in SSCRP, SSCRM and SSM (INR-1).rations.Sorting of the complete ration can be prevented Conclusion by pelleting and grinding of the feed [25].
Based on the results of the present study it was Growth rate and cost economics: The higher (P<0.05)concluded that SSCR may be used as roughage source feed intake and higher (P<0.01)average daily gain (g) in place of SS in complete feeds for economic growth in buffalo calves fed SSCRP ration (Table-4) might be rate in buffalo calves.Further, expander-extruder processing due to easier consumption of pelleted ration and of the complete ration improved feed intake, growth efficient digestibility of nutrients [8] compared to rate, feed efficiency and decreased sorting behavior chopped form of the ration.Even though the average and cost of feeding compared to mash and chopped daily feed intake (kg/d) among SSCRM, SSCRP and forms of the ration.SSM rations were not significantly different, higher Author's contribution (1.32%) study was SSV 84 developed by ICRISAT (Inter-A period of rumination was defined as at least 5 national Crops research Institute for the Semi Arid minutes of rumination occurring after at least 5 minutes Tropics) and propagated by the farmers in Medak without rumination activity.Total chewing time was District of Andhra Pradesh.The crop was harvested at determined as the sum of total eating and ruminating 135 days after sowing and crushed at the decentralized times.The number of chews per day was calculated by sweet sorghum crushing unit established by ICRISAT the following formulas [13].at Ibrahimbad village of Medak District in Andhra Eating chews (number day)= -5854 + 84.75 X eating time Pradesh.The required quantity of SSCR was procured (minutes/d).Ruminating chews (number per day)= -81 + 71.29 X ruminating from the crushing unit and sundried for the preparation time (minutes/d).ofexperimental rations.Twenty four Murrah buffaloTotal chews (number per d)= -12390 + 80.59 X total chewing time (minutes/d).

Table - 1
. Ingredient and chemical composition of experimental complete rations *Each value is the average of three observations.On dry matter basis except for dry matter

Table - 2
. Effect of feeding differently processed sweet sorghum crushed residue based complete rations on nutrient digestibility (%) in murrah buffalo calves Each value is the average of three observations, a,b: values bearing different superscripts in a row differ significantly (P<0.05)

Table - 3
daily feed intake (kg/d) in buffalo calves fed SSCRP ration was observed compared to SSCRM and CVS, SJR, YRR and DN implemented the study SSM rations.design.CVS and MM recorded and analysed the data.The FCR and cost per kg gain (INR) was lower CVS, SJR, YRR and DN drafted and revised the (P<0.01) in buffalo calves fed SSCRP ration compared manuscript.All author read and approved the final to those fed SSCRC, SSCRM and SSM rations (Tablemanuscript 4).This might be due to efficient digestibility of DM, .Effect of feeding processed sweet sorghum crushed residue based complete rations on eating and rumination in murrah buffalo calves Each value is the average of four observations, a,b: values bearing different superscripts in a row differ significantly (P<0.01)Each value is the average of six observations, a,b: values bearing different superscripts in a row differ significantly (P<0.01)

Table - 4
. Effect of feeding differently processed sweet sorghum crushed residue based complete rations on growth rate, feed efficiency and cost economics in Murrah buffalo calves