The annual per capita consumption of meat in Rwanda has been increasing by approximately 8% between 2005 and 2010 (NISR, 2011). Beside, poultry, pigs and fish consumption has also been increasing. However, beef is still the most important meat in Rwanda (MINAGRI, 2012). A recent study has indicated that in response to population and increasing per capita consumption, change breed composition the national cattle herds’ size will have to increase from the current estimate of approximately  1.1  million  (FAO,  2015)  to  more  than  2 million heads by 2020. However, due to expansion of arable agriculture, the availability of conventional grazing land for fodder is steadily getting exhausted and alternative feed resources are necessary. Despite their fibrous nature, cereal straws and agro-industrial by products are ubiquitous biomass that have been used and perceived to be cheap sources of the feed for ruminant livestock. In developing countries, urea treatment is perceived to be the most appropriated treatment  method   for   quality  improvement  of  fibrous materials (Wanapat et al., 2013). Experience in India has revealed that adoption urea treated straw technology among dairy farm holdings was subjected to availability of fodder, cost effectiveness of inputs for straw treatment, price incentives of products and the economy scale associated with the unit of production (Chander, 2010) and as well as organizational capacity of extension service delivery (Walli, 2010). In Rwanda, Crop Intensification Program (CIP) and the cooperative paradigm for development provides the organizational premise for extensions service and the economy of scale for success in straw based feedlots. The existing land pressure and policy support for crop-livestock integration leaves cost-effectiveness as the major key information required to promote straw-based feedlots for crop-livestock integration. Therefore, the objective of this study was to determine effects of cattle genotypes and levels of concentrate supplements on cost effectiveness of feedlot beef production using urea-treated rice straw (UTRS).

 

 

 

Location, animals and feeds

The study was carried out at Rwanda Agriculture Board, Songa Research Station in Southern Province of Rwanda (02° 25' 255''S, 029° 48' 004''E). The station is located in the mid-altitude zone (1471 m asl) with an average annual temperature of 25.5°C; an average annual rainfall of 1087 mm and relative humidity of 77%. Rice, maize and cassava are the major crops cultivated in the area. The animals were steers of three cattle genotypes viz: purebred Ankole (A×A), Ankole × Friesian (A×F) and Ankole × Sahiwal (A×S) steers. The feeds were UTRS (4%, w/w) and concentrates made from decorticated cottonseed cake (dCSC) (66%)  and  maize  bran (MB) (34%).

Use of proxy indicators

Proxy indicators were used to determine enterprise profitability and likelihood of economic viability. The GM analysis was used to estimate enterprise profitability. Net Present Value (NPV) and Internal Rate of Return (IRR) were used to estimate the likelihood of economic viability. The cost of the feed was computed from the price of items (Table 1) and the composition of feed ingredients (Table 2).

 

 

 

Daily cost of feed per steer was the product of final price and daily intake. Total feed cost over 90 days of feeding was cumulative sum of daily feed cost per steer. Purchase cost of the steers was taken as the farm gate price of carcass at the beginning of the trial. Revenue at the beginning was the product of abattoir price and estimate of carcass weight. Carcass weight was the product of live weight and dressing percentage. The dressing percentage was adapted from similar study using the similar breeds (Asizua, 2010) because procurement protocol did not allow for slaughter of the steers (Table 3).

 

 

Total cost of production was the sum of cost of carcass at the beginning of the feeding trial and cumulative cost of feed per steer. GM was the difference between carcass value at 90 days and carcass value at the beginning of the feeding trial. What-if Analysis (Microsoft Excel, 2010) was used to estimate Breakeven Cost (BEC) at existing price; Breakeven Price (BEP) at existing cost; and competitive cost of production. Competitive cost was the highest cost, below which the price of beef could be reduced below the current price without incurring losses. The GM associated with these costs and prices were also recorded.

Data analysis

Data entry was done using Microsoft Excel and the analysis of data was  done  by  Statistical  Analysis  Software  (SAS)  version   9.00.

 

 

 

Weights and value of carcass

The initial weight (IWT) did not differ (p>0.05) by genotype. The final weight (FWT) at slaughter differed by genotypes (p<0.05) and levels of supplement (p<0.05). The interaction effect was not significant (p>0.05). The FWT were higher (p<0.05) in A×A and A×S than A×F steers. They were also higher in steers fed UTRS with 500 g/day (p<0.05), 1000 g/day (p<0.001) and 2000 g/day (p<0.001) of concentrate. The weights did not differ (p>0.05) among steers fed UTRS with concentrate (Table 5).

 

 

 

Carcass weight

Estimates of carcass weight (ECW) differed by genotype (p<0.05) and highly across dietary treatments (p<0.0001) without significant interaction effect (p>0.05). The ECW was higher (p<0.05) in A×A and A×S than in A×F steers. It was lower in steers fed UTRS without supplements than in those fed 500 g/day (p<0.001); 1000 g/day (p<0.0001) and 2000 g/day (p<0.0001) of concentrates. The weight did not differ between steers fed 2000 and 1000 g/day of concentrates and between steers fed 1000 and 500 g/day of concentrate (Table 5). The interaction effect was not significant (Table 5).

Initial value and final value of carcass

The initial value (INV) of the carcass differed (p<0.05) only by genotype of steers. It was higher (p<0.01) in A×A and tended also to be higher (p=0.0673) in A×S than in A×F steers (Table 5). Linear, quadratic and cubic trends were not significant. The final value of carcass (FNV) differed (p<0.05) by genotype of steers. The FNV were higher in A×S and A×A than A×F steers. Linear, quadratic and cubic trends were significant.

Feed and total costs

Feed cost differed by genotype (p<0.01) and levels of concentrate supplements (p<0.0001). The effect of supplement had a strong tendency to vary (p=0.0569)  by genotype. The cost was higher in A×S than in A×A and A×F steers. All levels of concentrate supplement increased feed cost in all steers significantly (p<0.0001) with strong linear and curvilinear trends (Table 6).

 

 

Successive levels increased cost above the previous level quite significantly (p<0.0001). The cost did not differ (p>0.05) across genotypes when UTRS was fed without supplement or UTRS with 500 g/day concentrates. At 1000 g/day, the cost of feeding was higher (p<0.05) in A×S than in A×A steers and tended to exceed (p=0.0689) feed costs in A×F steers.

The tendency for significance of interaction effect was associated with difference in costs at 1000 and 2000 g levels of supplementation. Cost did not differ (p>0.05) across genotypes when steers were fed either UTRS without supplements, or UTRS with 500 g/day supplements. At 1000 g/day of concentrate allowance, cost of feed was higher (p<0.05) in A×S than in A×A and tended to be higher (p=0.689) than in A×F steers as well (Table 6).

Total cost differed by genotype (p<0.05) and levels of concentrates offered (p<0.0001). The effects of supplementation were not depended (p>0.05) on genotype. The prices were lower with steers fed UTRS with 1000 g/day (p<0.05) and UTRS with 500 g/day (p<0.001) of concentrate than steers fed UTRS without supplement; or UTRS with 2000 g/day of concentrate (Table 7). Investments in purchasing and fattening the steers on UTRS without supplements were lower when the steers were fattened on UTRS without supplements than when they were fattened on UTRS with 500 g/day concentrate (p<0.01) and 1000 or 2000 g/day concentrates (p<0.0001). The trends of these differences were highly linear and curvilinear (p<0.0001; Table 6). The highest and lowest TC were recorded when the steers were fattened on UTRS with 2000 g/day concentrates and UTRS without supplements respectively. The costs did not differ (p>0.05) in steers fed UTRS with 500 and 1000 g/day (Table 6).

Break-even price at experimental cost

What-if analysis revealed that the prices of beef would be cost effective at the experimental cost and did not differ (p>0.05) by genotype; but they differed (p<0.05) by dietary treatment. However, there was a tendency for the BEP to be higher (p=0.0871) with A×F than with A×A steers. Despite lack of interaction, the BEP was significantly lower with A×A steers fed UTRS with 500 g/day of concentrates than with A×A steers fed UTRS without supplement (Table 7). Otherwise, there were significant differences (P<0.05) across genotype at all levels of supplementation with concentrates.

 

 

Break-even cost at current price of beef (RwF 1800)

BEC at RwF 1800 kg^-1 of beef were highly depended (p<0.001) on dietary treatment and not steers (p>0.05). However, there was a tendency for the cost to be high with A×A steers than A×F steers (p=0.0572). It also tended to be higher (p=0.0885) in A×S than in A×F steers. The costs were higher in steers fed UTRS with supplements than in those fed UTRS without supplements (Table 7). The cost did not differ (p>0.05) at the same level of concentrates across steers (Table 8).

 

 

Threshold cost at current price of beef (RwF 1800)

The threshold cost was the cost below which the farmer could reduce the price of beef that could be gain a competitive edge in the existing market. This cost was highly influenced (p<0.001) by the dietary level of concentrate supplements and steers and the interaction with dietary treatments did not have significant (p>0.05) effect. However, there were tendencies for threshold cost to differ between A×A and A×F (p=0.0564) and A×S and A×F (p=0.0904) steers. The threshold costs were lower in UTRS than in UTRS with 500 g/day concentrate (p<0.01), 1000/day concentrate (p<0.001) and 2000 g/day concentrate (p<0.0001). The threshold price did not differ (p>0.05) in diets with concentrate supplements (Table 8).

Gross margins at experimental cost

Levels of concentrate supplements was the only factor that significantly influenced (p<0.0001) margins that would be realized from carcass sales under the experimental conditions of the trial. GM did not differ (p>0.05) among steers and neither were the effects of levels of concentrates dependent on the steers. Mean GM were negative across all genotype of steers. However, the GM values were not significantly different (p>0.05) from zero except in A×F steers (p<0.01). Gross margin values were negative in steers fed on UTRS without supplements and in those fed on UTRS with 2000 g/day. At other levels (500 and 1000 g/day), GM values were positive but not significantly different (p>0.05) from zero (Table 9).

 

 

Gross margin at breakeven price

GM at BEP depended on dietary treatment (p<0.05) and not (p>0.05) on genotype of steers. At 0, 1000, and 2000 g/day supplement the GM at BEP did not differ (p>0.05) significantly (Table 10). Despite lack of significant interaction, the GM was higher (p<0.05) in A×A steers fed UTRS with 500 g/day concentrate than in A×S steers on the same dietary treatments (Table 10).

 

 

Gross margin at minimum cost at break-even price

Levels of concentrate supplementation highly affected (p<0.001) the GM that would be realized at minimum cost at BEP. This effect applied across all genotype of steers because the interaction effects were not different; and the GM did not differ (p>0.05) among genotypes. Nevertheless, the GM associated with A×S steers were higher (p<0.05) than the GM associated with A×F steers.

The UTRS without supplements had lower GM at minimum cost for the BEP than UTRS with 500 g/day concentrate (p<0.05); UTRS with 1000 g/day concentrate (p>0.01) and UTRS with 2000 g/day concentrate (p<0.0001). This GM did not differ (p>0.05) between UTRS with 500 g/day concentrate and UTRS with 1000 g/day concentrate; and between 1,000 and 2000 g/day concentrate.  It tended to be higher (p=0.0731) in UTRS with 2,000 g/day concentrate than UTRS with 500 g/day concentrate.

Gross margin at maximum cost at break-even price

GM at maximum cost for BEP did not differ (p>0.05) by cattle genotype and dietary treatment levels. The GM was not significantly greater (p>0.05) than zero in A×A steers but it tended to be significantly greater (p=0.0907) than zero in A×F and it was significantly greater (p<0.01) than zero in A×S steers. Across dietary treatments the GM tended to be higher (p=0.0963) in UTRS plus 2,000 than 500 g/day concentrate feeding.

Break-even cost and margin at current abattoir price of beef

Levels of concentrate offer affected (p<0.001) the BEC at the prevailing abattoir price of beef. However, there was a strong tendency for the cost to be higher (p=0.0885) in A×S than in A×F steers. The BEC was lower in UTRS rations than in UTRS+500 g/day (p<0.01), UTRS+1000 g/day (p<0.001) and UTRS+2000 g/day (p<0.0001). The cost did not differ (p>0.05) among dietary treatments with concentrate supplements. The GM associated with the BEC at current price of beef was not affected (p>0.05) by cattle genotypes and dietary treatments. The GM for cost for competitive price adjustment were not dependent (p>0.05) on genotype of steers. However, they strongly tended to be higher in A×A (p=0.0657) and A×S steers (p=0.0698) than in A×F steers (Table 4). They differed highly significantly (p<0.001) with levels of concentrates. The GM in steers fed UTRS with 2,000 g/day (p<0.0001), 1,000 g/day (p<0.001) and 500 g/day (p<0.01) were higher than the GM in steers fed UTRS without supplement. But the GM did not differ (p>0.05) among steers fed UTRS with supplements (Table 10). They were highly influenced (p<0.001) by dietary treatment.

 

 

 

 

 

 

 

 

 

Cattle genotype  did  not  affect  growth,  expected carcass weight, and values of steers feed UTRS. Concentrate supplements significantly improve growth, and expected carcass weight and value. UTRS-based feedlots beef is marginally acceptable under current market prices with concentrate supplement at 500 g/day. Highly levels of supplements are acceptable with a policy incentive that increases abattoir to farmers. However, these results need confirmation with actual results from slaughtered cattle to determine carcass yields.

 

The authors have not declared any conflict of interests.