Effects of replacing alfalfa hay with Atriplex nummularia on the growth performance, digestibility, and energy usage of six-month old camel calves

BACKGROUND: The use of halophytes as fodder, such as Atriplex, is an appropriate strategy for sustainable agriculture and a promising way to fill the gap in the camel feeding in arid and semi-arid areas. This experiment investigated the effects of feeding Atriplex nummularia instead of alfalfa hay on the growth performance, digestibility, and energy utilization in growing camel calves. METHODS: Eighteen six-month-old male camel calves were employed and divided into three groups (n = 6). Animals received a concentrate feed mixture at 0.9% dry matter (DM) of their live body weight (BW) with different roughage sources at 1.1% DM of their BW. The roughages fed consisted of: alfalfa hay alone (T1), a 50:50 mixture of alfalfa hay and Atriplex (T2), or Atriplex alone (T3). During the growing study, animals were weighed once a week, and the proper concentrates and roughages were computed and applied immediately. At the end of the experiment, the digestibility trial, energy measurements, and rumen and blood metabolite analyses were conducted. RESULTS: Replacing alfalfa hay with Atriplex significantly reduced total organic matter intake and digestibility (P < 0.01), resulting in lower BW changes and average daily gain with a poorer feed conversion ratio. Energy expenditure significantly differed among feeding regimens, with a greater energy balance for those fed alfalfa hay vs. Atriplex. A greater concentration of total protein, globulin, and urea was obtained in camels fed Atriplex (P < 0.05). The inclusion of the Atriplex in the diet decreased serum creatinine, cholesterol, and aspartate aminotransferase (P < 0.05). Replacing alfalfa hay with Atriplex resulted in lower rumen pH (P < 0.01) and higher total volatile fatty acids and ammonia levels (P < 0.05). CONCLUSIONS: In arid environments, Atriplex nummularia can partially or entirely replace alfalfa hay for growing camel calves; however, complete substitution resulted in significant reductions in average daily growth, nutrient digestibility, and feed efficiency. It proposed that Atriplex could be an effective camel fodder for enhancing drought resilience in desert environments.