Effect of trace mineral injection in late pregnancy on colostrum quality and plasma parameters of Lori does and their kids

Introduction:  Suboptimal levels of kid survival are the largest contributor to reproductive wastage in goat flocks. This results in substantial loss of production, producer, and industry income, and is increasingly being perceived as poor animal welfare. Improving kid survival is therefore a priority for the industry. Nutrient provision during gestation not only affects maternal status and reproductive performance but also affects prenatal and postnatal offspring growth and health. Although trace minerals (TM) are needed by the body in small amounts, they are essential nutrients for several metabolic functions such as growth, development, reproduction, and immunity. Furthermore, newborn animals are dependent upon their dams for the transfer of these nutrients via the placenta and the mammary gland. The antibodies obtained from colostrum are the only defense mechanism against environmental factors in neonatal ruminants. Inadequate nutrition of the dam, immune system suppression, and stress factors may lead to the production of low-quality colostrum. Management and feeding of high-quality colostrum can reduce kid mortality, strengthen immunity, and increase animal life span. Nutrition affects the development of the mammary gland, the onset of lactogenesis, and colostrum production, either by affecting some of the hormones that control these processes or by contributing nutrients that are in demand at this stage of pregnancy. Selenium plays an important role in preventing impaired function of the immune response. Copper deficiency has been shown to result in lowered bactericidal activities of blood leukocytes in ruminant animals. Zinc sufficiency has also been linked to proper immune functions. Therefore, this study aimed to investigate the effect of TM injection in late pregnancy on colostrum quality and plasma metabolites of Lori does and their kids. Materials and methods: Thirty Lori mature does with an average body weight of 40 kg and an age of 2-3 years were used. One month before the expected kidding, animals were divided into two groups (n=15 does/group) and randomly assigned to experimental treatments. Experimental treatments were no injection of trace minerals (Control; C) and injection of 1 mL of TM at four and two weeks before expected kidding. Blood samples were taken through the jugular vein. Each mL of TM solution contained 2.5 mg of Cu, 1.25 mg of Se, 5 mg of Mn, and 5 mg of Zn. All does were kept in similar nutritional and managerial conditions from mating to one month before kidding. Results and discussion: Results showed that plasma concentrations of glucose and total cholesterol (TC) tended to be higher and lower in the TM group at day 7 before kidding, respectively (P=0.06). Experimental treatments did not affect plasma triglyceride (TG), Ca, and Mg concentrations, and glutathione peroxidase (GPX) activity of does at day 7 before kidding (P>0.05). Whereas, TM injection before mating decreased plasma malondialdehyde (MDA) and increased total protein (TP), BRIX index (BI), superoxide dismutase (SOD), and total antioxidant activity at day 7 before kidding (P<0.05). Colostrum of does received TM had a higher fat, protein, and BI content and a lower lactose content than the colostrum of the C group (P<0.05). Plasma concentrations of glucose and MDA were lower in kids born from does received TM than those born from the C group (P<0.05). Experimental treatments did not affect plasma concentrations of TC, Ca, and Mg concentrations in kids (P>0.05). Kids born from does received TM had higher plasma concentrations of TG, TP, BI and SOD, GPX, and total antioxidant activity than those of the C group (P<0.05). Conclusions: According to the results of the present experiment, injection of a TM solution containing Cu, Zn, Se, and Mn four and two weeks before birth increased the concentrations of TP and BI as well as the activity of antioxidant enzymes (SOD, GPX) and antioxidant capacity and reduced MDA concentration in Lori goat plasma. This improved the quality of colostrum produced by these does. Kids born from does receiving trace minerals had higher plasma concentrations of TP, BI, and activity of antioxidant enzymes (SOD, GPX), higher total antioxidant capacity, and lower concentrations of MDA compared to the C group. Therefore, this strategy may have beneficial effects on the health, viability, and performance of kids before weaning.