Effects of replacing soybean meal with rubber seed meal on digestive enzyme activity, nutrient digestibility and retention in tilapia (Oreochromis niloticus × Oreochromis aureus)

Abstract

A feeding trial was conducted to evaluate the effects of replacing soybean meal (SBM) with rubber seed meal (RSM) on digestive enzyme activity, nutrient digestibility and retention in juvenile tilapia (Oreochromis niloticus 9 Oreochromis aureus). Five isonitrogenous and isoenergetic diets were formulated with 0 (control), 100, 200, 300 and 400 g kg À1 RSM replacing graded levels of SBM respectively. Each diet was randomly assigned to triplicate groups of 30 fish (initial average weight 5.2 g) per aquarium in a rearing system maintained at 29 AE 1°C for 8 weeks. The hepatic protease and lipase activities gradually decreased with increasing dietary RSM level, but no significant differences were observed among the low inclusion level (0-200 g kg À1 ) groups. The apparent digestibility coefficients of dry matter, crude protein, crude lipid and ash showed a similar trend as the hepatic protease and lipase activities. The retentions of protein and individual essential amino acid (except lysine, threonine and leucine) in fish fed diet with 200 g kg À1 RSM were similar to those in fish fed the control diet. These results indicate that dietary RSM inclusion level up to 200 g kg À1 did not markedly affect the digestive enzyme activity, nutrient digestibility and retention in tilapia, whereas these were depressed by the inclusion of 400 g kg À1 RSM.

Effect of processing techniques on chemical composition and hydrogen cyanide content in rubber seed (Hevea brasiliensis) meal

“…The crude fibre value was similar to the findings of and Khatun and Khan (2015) [26] but higher than the values reported by Sharma et al (2014) [13] , Suprayudi et al (2014) [14] , [16] , Deng et al (2017) [18] , Aguihe et al (2017) [1] , Udo et al (2018) [20] , Ahaotu (2018) [19] and Farr et al (2019) [23] and lower than the values reported by Hossain et al (2015) [15] . In the present study, the total ash in RSM was found to be similar to the findings of Sharma et al (2014) [13] , Suprayudi et al (2014) [14] , Hossain et al (2015) [15] , Khatun et al (2015) [16] , Khatun and Khan (2015) [26] , Pha-obnga et al (2016) [17] and Farr et al (2019) [23] but lesser than the observation made by Chanjula et al (2011) [25] , Deng et al (2017) [18] , Oluodo et al (2018) [22] , Udo et al (2018) [20] , Aguihe et al (2017) [1] and Ahaotu (2018) [19] . The NFE value was similar to the values reported by Udo et al (2018) [20] and Deng et al (2017) [18] and contradicts with Suprayudi et al (2014) [14] , Hossain et al (2015) [15] , Khatun and Khan (2015) [26] and Aguihe et al (2017) [1] .…”

“…They found the crude protein content as 11.50, 14.94, 12.19 and 10.30% respectively. However, the crude protein value in the present study contradicts with Sharma et al (2014) [13] , Suprayudi et al (2014) [14] , Hossain et al (2015) [15] , Khatun et al (2015) [16] , Pha-obnga et al (2016) [17] , Aguihe et al (2017) [1] , Deng et al (2017) [18] , Ahaotu (2018) [19] , Udo et al (2018) [20] , Kouakou et al (2018) [21] , Oluodo et al (2018) [22] , Farr et al (2019) [23] , who reported higher values in their experiments. The ether extract of RSM was similar to the observation made by Tean et al (2002) [11] , Samkol et al (2002) [24] , Aguihe et al (2017) [1] , Oluodo et al (2018) [22] and Kouakou et al (2018) [21] but lesser than the values observed by Chanjula et al (2011) [25] , Sharma et al (2014) [13] , Suprayudi et al…”

“…(2014) [14] , Pha-obnga et al (2016) [17] and Udo et al (2018) [20] , and higher than the values observed by Hossain et al (2015) [15] , Khatun et al (2015) [16] , Khatun and Khan (2015) [26] Deng et al (2017) [18] , Ahaotu (2018) [19] and Farr et al (2019) [23] . The variation in the crude protein and ether extract content can be attributed to rubber tree varieties, or may be climatic condition.…”

“…In the present study, the total ash in RSM was found to be similar to the findings of Sharma et al (2014) [13] , Suprayudi et al (2014) [14] , Hossain et al (2015) [15] , Khatun et al (2015) [16] , Khatun and Khan (2015) [26] , Pha-obnga et al (2016) [17] and Farr et al (2019) [23] but lesser than the observation made by Chanjula et al (2011) [25] , Deng et al (2017) [18] , Oluodo et al (2018) [22] , Udo et al (2018) [20] , Aguihe et al (2017) [1] and Ahaotu (2018) [19] . The NFE value was similar to the values reported by Udo et al (2018) [20] and Deng et al (2017) [18] and contradicts with Suprayudi et al (2014) [14] , Hossain et al (2015) [15] , Khatun and Khan (2015) [26] and Aguihe et al (2017) [1] . After processing the seeds, there was no such change in the crude protein content of soaked, boiled and oven-dried rubber seed meal.…”

Upgrading low-quality feeds for tilapia by enzyme and probiotic supplementation

“…The starch fraction of the diet is considered highly digestible with apparent digestibility coefficients (ADC) of 90%, up to 99% in Nile tilapia (Amirkolaie et al, 2006;Haidar et al, 2016;Leenhouwers et al, 2007a). The ADC of the total carbohydrate fraction has been found to be as low as 30-60% (El-Saidy and Gaber, 2003;Deng et al, 2016) and as high as 80-2 90% for Nile tilapia (Tran-Ngoc et al, 2016;Sintayehu et al, 1996). The large variation in the digestibility of the total carbohydrate fraction is mainly caused by differences in the total dietary fibre fraction.…”