Four-fifths of Algeria is just desert --which leaves no room for agriculture.  The Algerian economy is mostly powered just by the oil industry, which contain about ~70% of government revenues. Oil and oil related products constitute more than 80% of Algeria's exports. 

For example, Turkey has twice the population of Algeria but it was more than 7.5 times the cattle Algeria has. ([14.2 in Turkey][1] vs [1.6 in Algeria][2]). So the short answer is that Algeria isn't just suited for Agriculture.

  [1]: https://www.google.com/url?q=https://gain.fas.usda.gov/Recent%2520GAIN%2520Publications/Livestock%2520and%2520Products%2520Annual_Ankara_Turkey_8-15-2017.pdf&sa=U&ved=0ahUKEwj55Z_woePaAhWLRY8KHYqcDqQQFggSMAI&usg=AOvVaw27ccAyb6380HDWs5YyTmc0
  [2]: https://www.google.com/url?q=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3647101/&sa=U&ved=0ahUKEwiBnqa6oePaAhXGLI8KHbZnB8wQFggeMAc&usg=AOvVaw2f-bmuntrUmY71hIbg_G1D