Inclusion Prosopis juliflora Pod Meal in Grazing Lambs Diets: Performance, Digestibility, Ingestive Behavior and Nitrogen Balance

Abstract

Prosopis juliflora is an arboreal legume that concentrates its nutritive value in pods (fruits), constituting a rich source of carbohydrates and with a crude energy concentration comparable to ground corn. Therefore, we aimed to evaluate the effect of inclusion of Prosopis juliflora pod meal (0 or control, 250, 500 and 750 g/kg total DM) as a replacement for ground corn in the diet of lambs on performance, digestibility, ingestive behavior, and nitrogen balance of lambs grazing in the Megathyrsus maximus pasture. Forty Santa Inês uncastrated lambs with an average body weight (BW) of 24.2 ± 0.55 kg were distributed in a completely randomized design. There was a linear increase in the non-fiber carbohydrates (NFC), ether extract (EE) and neutral detergent fiber (NDF) digestibility with Prosopis juliflora pod meal supplementation in the diet of the lambs. Dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) intake, and digestibility and time spent ruminating were not affected by Prosopis juliflora meal supplementation. Prosopis juliflora pod meal inclusion increased time spent feeding and idling of lambs, however, without affecting spent time ruminating. Lambs fed with Prosopis juliflora pod meal presented greater final BW, gain: feed ratio, N-balance, microbial protein production ef-ficiency, N-urea urinary (NUU) and blood urea nitrogen (BUN). However, the average daily weight (ADG), total weight gain and hot carcass yield as well as N ingested, N excreted in feces and urine, total purines, ab-sorbed purines and N microbial production in lambs were not influenced by Prosopis juliflora pod meal inclusion. The Prosopis juliflora pod meal inclusion up to the 750 g/kg level in the concentrate supplement totally replace ground corn in the diet of grazing lambs improving the NFC intake and NDF digestibility, supplement acceptability, microbial protein production efficiency and consequently the performance. The addition of Prosopis juliflora pod meal as a replacement for ground corn in the concentrate does not influence the microbial protein production; however, there was an improvement in the efficiency of microbial synthesis.