Melatonin implants in late pregnancy increase yield and enhance milk quality in dairy goats

This study investigated the effects of melatonin implants in pregnancy on milk production and composition, and the quality of colostrum in dairy goats. Thirty days before kidding, 92 goats (group MEL) received one melatonin implant, and the remaining 177 goats (group CON) did not. Three monthly milk evaluations included milk yield (kg/day), composition (%Fat, %Protein, % Lactose), daily yield (Fat, g/day Protein, g/day Lactose). A sample of colostrum was obtained from 165 goats, from which its composition, and IgG concentration were measured. MEL had a significantly ( P < 0.01) higher milk yield in the second month (3.16 ± 0.10 kg/day) than CON (2.78 ± 0.07 kg/day). In the three milk samplings, fat concentrations were significantly higher ( P < 0.05) in the MEL than in the CON does. In the second milk sampling, does that had received a melatonin implant produced higher ( P < 0.05) daily milk yield components than did non-implanted (Fat: 144 ± 6.0 vs. 115 ± 3.4; Protein: 104 ± 3.4 vs. 91 ± 2.5; Lactose: 148 ± 5.8 vs. 131 ± 4.3 g/day). In conclusion, melatonin implants administered 30 days before kidding increased milk production, the amounts of milk daily components in the second month of lactation, and the concentration of fat milk.