Urate crystals are especially common during a baby's first few days of life when she might still be losing weight while breastfeeding, though they may be found in babies who are gaining weight as well. (verywellfamily.com)
Around 400,000 «bobby» calves are sent to an abattoir for slaughter and a further large (but unknown) number of male calves are killed on farm in their first few days of life. (animalsaustralia.org)
Although meconium can produce this color in the first few days of life, after this black poop could be a sign of bleeding. (momtricks.com)