You may write off cow urine as a mere excreta, but a Birsa Agricultural University (BAU) study has proved that it can help increasing reproductive capacity of hens and harden the outer shell of eggs.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/bau-study-reveals-uses-cow-urine
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/telegraph-ranchi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/animal-care
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cattle
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pigs
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/birds
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/jharkhand
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ranchi-d