Effect of replacing ground corn with Parkia platycephala pod meal on the performance of lactating Anglo-Nubian goats

Abstract

This study tested the hypothesis that Parkia platycephala pod meal can replace ground corn in the diet of lactating goats by evaluating nutrient intake, digestibility, serum parameters, and ruminal fermentation as well as the production, composition and sensorial properties of goat milk. Eight multiparous Anglo-Nubian goats aged ∼4 years, each one approximately 44.5 ± 6.3 kg in live body weight and 50 days into lactation, were randomly distributed in a double Latin square (4 × 4) with four treatments. The experimental treatments were 0 (control), 333, 667 and 1000 (total) g Parkia platycephala pod meal instead of ground corn. Each experimental period consisted of 15 days for adaptation and 5 days for data collection. Except for ether extract (EE) intake, which decreased linearly (P = 0.001), nutrient intake was not affected by Parkia platycephala pod meal inclusion in goat diets. The digestibility of the DM and its total digestible nutrient (TDN) content were also unaffected by the treatments. However, the digestibility of OM (P = 0.02), crude protein (CP) (P = 0.03), EE (P = 0.04) and acid detergent fiber (ADF) (P = 0.04) had quadratic effects, as NDF digestibility decreased linearly (P = 0.005) and non-fiber carbohydrates (NFC) increased linearly (P = 0.0001). The ruminal pH and concentrations of acetic acid (A), propionic acid (P), butyric acid (B), as well as the A:P ratio and methane (mol%), were unaffected by the treatments. Conversely, isobutyric acid (P = 0.01), isovaleric acid (P = 0.006) and branched-chain fatty acids (BCFAs) (P = 0.005) decreased linearly, while valeric acid (P = 0.03) increased linearly. Blood serum concentrations of calcium (P = 0.03) increased linearly, while phosphorus concentration decreased quadratically, with Parkia platycephala pod meal inclusion; the other serum parameters were unaffected. The fat-corrected production (4% fat), total-solids-corrected production, chemical composition and sensorial properties of the milk were unaffected by Parkia platycephala pod meal inclusion. Thus, total (1000 g/kg DM) replacement of ground corn with Parkia platycephala pod meal in the diet of lactating Anglo-Nubian goats is recommended.