Effects of anthocyanin-rich Napier grass silage on feed intake, milk production, plasma profile, and nutritional digestibility in lactating crossbred Saanen goats.

Background and aim: Anthocyanins are potent antioxidants and scavengers of free radicals found in fruits, purple corn, and other naturally occurring purple plants. Several studies have demonstrated that anthocyanins possess strong antioxidant properties and can enhance ruminant production by modulating intracellular oxidative stress and modifying ruminal fermentation. This study aimed to examine the effects of anthocyanin-rich Napier grass silage (ANS) on feed intake, nutrient digestibility, milk production, plasma profile, and antioxidant capacity in lactating crossbred Saanen goats.

Materials and methods: Nine healthy lactating goats (crossbreeds of Thai-native and Saanen breeds aged 8-12 months) were selected and randomly assigned to one of three experimental diets: (1) Corn silage (CS), (2) Napier grass silage (NS), and (3) ANS. Daily feed refusals were recorded to calculate dry matter intake for the animal performance assessment. In addition to analyzing feed intake, nutrient intake, and nutrient digestibility, milk and blood samples were also analyzed for protein composition, leukocyte count, and antioxidant capacity.

Results: CS-fed goats had the highest (p < 0.05) feed intake (1.09 kg/day), a value markedly exceeding those of NS- and ANS-fed goats (0.80 and 0.76 kg/day, respectively). They also had higher (p < 0.05) organic matter (OM) and neutral detergent fiber intake (0.99 kg and 0.50 kg/day) than the other two groups. Protein intake did not differ significantly (0.14, 0.12, and 0.12 kg/day for CS, NS, and ANS, respectively). The CS group showed higher (p < 0.05) dry matter and OM digestibility (69.42% and 69.83%) than the NS and ANS groups, which had lower (p < 0.05) fiber digestibility. Regarding milk production, the CS and ANS groups produced 1.15 and 1.16 kg/day, respectively, whereas the NS group produced 1.11 kg/day. No significant differences in leukocyte counts were observed. Furthermore, the CS group exhibited the highest (p < 0.05) superoxide dismutase inhibition (16.05%) on day 35, whereas the ANS group showed the highest (p < 0.05) total antioxidant capacity on multiple days (21, 35, 49, and 63).

Conclusion: ANS can be a valuable component of dairy goat diets, particularly in regions prone to heat-induced oxidative stress.