Growth Performance, Nutrient Digestibility, Nitrogen Utilization and Economic Efficiency of West African Dwarf Rams Fed  Rice Straw, Maize Stovers or Maize Cobs

Technical Summary: Growth Performance and Economic Efficiency of WAD Rams Fed Rice Straw, Maize Stovers, or Maize Cobs

Problem Statement
The study addresses the challenge of optimizing feed resources for West African Dwarf (WAD) rams, a breed of significant economic importance in the region. The core issue involves identifying the most effective basal roughage source among locally available agricultural by-products—specifically rice straw (RS), maize stovers (MS), and maize cobs (MC)—when supplemented with a concentrate diet. The goal was to determine which of these roughages yields superior growth performance, nutrient utilization, nitrogen balance, and economic returns, thereby guiding more efficient livestock management practices.

Methodology
The research employed a completely randomized design involving twenty-four growing WAD rams with an average initial body weight of 18.5 ± 0.6 kg. The animals were randomly assigned to three dietary treatment groups and fed for a duration of 70 days. The experimental diets consisted of the three distinct roughage sources (RS, MS, and MC) offered ad libitum as basal feeds. To ensure adequate nutrition, all groups received a concentrate supplement provided at a rate of 2% of their body weight.

The study monitored several critical parameters:

• Intake and Growth: Dry matter intake (DMI), final body weight, and average daily gain (ADG).
• Digestibility and Utilization: Nutrient digestibility coefficients, nitrogen balance, and nitrogen retention.
• Physiological Health: Serum biochemical metabolites, including total protein, albumin, glucose, urea, and cholesterol.
• Economic Analysis: Net profit and benefit–cost ratios were calculated to evaluate the economic efficiency of each feeding regimen.

Key Results
The dietary treatments exerted a statistically significant influence (P < 0.05) on all measured variables. The group fed maize stovers (MS) demonstrated superior performance across nearly all biological and economic metrics compared to the rice straw and maize cobs groups:

• Intake and Growth: Rams on the MS diet recorded higher concentrate intake, total dry matter intake, final body weight, and average daily gain.
• Efficiency: The MS group exhibited better feed efficiency and higher nutrient digestibility coefficients.
• Nitrogen Utilization: Nitrogen retention was significantly greater in the MS group, indicating more efficient protein utilization.
• Serum Metabolites: Animals fed maize stovers showed enhanced concentrations of total protein, albumin, and glucose. Importantly, urea and cholesterol levels remained within physiological limits across all groups, suggesting no adverse metabolic effects from the diets.
• Economic Viability: The economic evaluation confirmed that the maize stover diet yielded the highest net profit and the most favorable benefit–cost ratio.

Significance and Claims
The paper concludes that among the tested agricultural by-products, maize stovers offer superior nutritional value when used as a basal roughage for WAD rams supplemented with concentrates. The study claims that utilizing maize stovers not only improves biological performance—evidenced by better growth rates, nutrient digestibility, and nitrogen retention—but also significantly enhances economic returns for producers. Consequently, the findings support the adoption of maize stovers as a preferred feed resource to optimize both the productivity and profitability of small ruminant farming systems in the region.