Comparative Study of Intake, Apparent Digestibility and Energy and Nitrogen Uses in Sahelian and Majorera Dairy Goats Fed Hay of <i>Vigna unguiculata</i>

This study aimed to compare digestive and metabolic characteristics in Sahelian (S) and Majorera (M) goat breeds. Six lactating females from each breed, with an average weight 27.0 ± 1.93 and 23.7 ± 1.27 kg, respectively, were used. Cowpea hay, variety 58/74, was offered as sole feed ingredient, at a rate of 2 kg of fresh matter per animal per day. The animals were placed in metabolic cages and a digestibility test was conducted according to an adaptation period of 15 days and a collection period of 7 days. The daily chemical components offered and refused and recovered faeces, urine and milk were measured in order to assess energy and nitrogen utilization. The M and S goats had similar levels of dry matter (DM) intake as well as nutrient digestibility. On a metabolic weight basis, dry matter intake, gross energy intake, metabolizable and energy intake, digestible energy and energy lost as methane production were significantly higher (<i>p</i> < 0.01) in M than in S goats. Urinary energy excretion was similar (<i>p</i> = 0.9) between breeds, while faecal energy output was higher in M than in S goats. The milk energy output from the M goats was higher than that the S goats (<i>p</i> < 0.05). However, metabolizable to net energy conversion efficiency (klm) was not affected by breed (<i>p</i> = 0.37), while N intake, milk N yield and faecal N losses, relative to metabolic weight, were significantly higher (<i>p</i> < 0.05) in M than in S goats. Similarly, the percentage of dietary N intake excreted in urine (UNIN) was higher in S than in M breeds. The breed factor had no effect on N retained, N digestibility, urinary N and N use efficiency. In conclusion, the M and S goats were similar in terms of energy and nitrogen use efficiency, despite higher daily milk production and DM consumption in the M goat. This suggests that the M breed is possibly more dependent on a dense nutrition diet than the S breed but requires less maintenance nitrogen.