Utilization of Purple Napier Grass Silage on Milk Quality and Blood Antioxidant Activity in Lactating Dairy Goats

In this study, our subjects were 18 female crossbred Saanen lactating goats; the goats weighed approximately 43.25 ± 2.35 kg and had been producing milk for 14 ± 2 days. They were assigned to three equally sized experimental groups based on the cycle of the lactation period. In accordance with the randomized complete block design (RCBD), six animals were randomly assigned to the treatments in each block. There were three treatments: (1) control = Napier Pakchong-1 grass silage (NPS); (2) = sweet grass silage (SGS); and (3) = purple Napier silage (PNS). Our findings show that the goats fed with purple Napier grass silage had a higher DM intake (1805.97 g/day) than those that underwent a different treatment (1312.76 and 1443.43 g/day). The goats fed with purple Napier grass silage had higher protein digestibility (79.85) than those fed with Napier Pakchong-1 and sweet grass silage. There were significant differences in the ruminal ammonia nitrogen and blood urea nitrogen. Nevertheless, purple Napier grass silage significantly increased butyric acid 2 and 4 h after feeding and increased the number of microorganisms. In the dairy goats fed purple Napier grass silage, we observed a reduction in protozoa and methanogen populations. The levels of antioxidants shown by the plasma indices differed in the goats fed with purple Napier grass silage and showed enhanced milk composition, higher levels of total antioxidants, superoxide dismutase and glutathione peroxidase in the plasma, reduced protozoa methanogen, and a decreased level of malondialdehyde in the plasma. This study highlights that purple Napier grass silage has the potential to be a beneficial source of roughage for lactating dairy goats.