Effect of Dietary Crude Protein on Productive Efficiency, Nutrient Digestibility, Blood Metabolites and Gastrointestinal Immune Markers in Light Lambs

Abstract

This study hypothesized that reducing the level of crude protein (CP) in lambs′ feed may improve nutrient utilization and did not negatively affect their productive efficiency, blood metabolites, oxidative status (OS) or intestinal immune barrier function. A total of 120 weaned male Ripollesa lambs (45–60 days old and 15.0 ± 1.5 kg of body weight) were used. Four feed concentrates were formulated for two different phases (growing and finishing): CP20/19 group (20% and 19% of CP on dry matter basis, for each phase, respectively) and CP18/17 group (18% and 17% of CP on dry matter basis, for each phase, respectively). Lambs were randomly assigned to feeding treatments by balancing initial body weight between groups. The reduction of dietary CP level did not impair their growth performance parameters, while it did improve the apparent digestibility of organic matter. Furthermore, the lambs of the CP18/17 group showed lower plasma urea levels with no effect on OS (malondialdehyde levels) or gastrointestinal immunity markers (gene expression of interleukin 10 (IL10), tumor necrosis factor-α (TNFA) and transforming growth factor-β1 (TGFB)).

The Effects of Pre-weaning and Post-weaning Feeding Periods on Biochemical Parameters in Terms of Metabolic Profile in Dorper and Lacaune Lambs

“…It can be said that the decreases observed intra-group ALP values are related to the decrease in the amount of TP in the blood (Fig 1, panel C,G), protein uptake in the tissues and nitrogen evaluability (Dayıoğlu and Doğru, 1996). It has been stated that feeding a diet containing 17-20% crude protein after the weaning period does not affect the total MDA levels in male lambs (Pelegrin-Valls et al, 2020). An increase was observed in the MDA level of the MD group in the 2 nd and the 5 th period, while a decrease was observed in the transition to the 3rd period (P0.05) (Fig 1 , panel H).…”

Impact of protein supply on the productive performance of growing lambs drinking natural saline water and fed low-quality forage under semi-arid conditions

“…On another note, creatinine is a byproduct of muscle metabolism and is excreted by glomerular filtration; thus, it can be used as an indicator of renal function (Thiet et al 2022 ). Moreover, blood urea is considering to be an indicator of ingested or mobilized protein (Pelegrin-Valls et al 2020 ).…”

Minimum Effects of Sampling Time on the Apparent Digestibility of Nutrients and Blood Protein Catabolites in Light Lambs

“…In a previous study, we reported that CP content of lamb feed can be reduced (10% below the current commercial standards) without a negative effect on growth performance or carcass yield of local Spanish breeds [ 16 ]. However, the impact of a reduction in the amount of dietary protein on metabolism should be carefully evaluated and adequate methods are needed, as many metabolic processes in mammals have been described as being influenced by eating frequency [ 18 ], which could impair the proper metabolic synthesis of proteins, and consequently, the growth of lambs.…”

“…Before the experiment started, lambs were fed standard commercial diets for five days adaptation concentrate containing coccidiostatic (decoquinate at 30 mg/kg). Ingredients and chemical composition of the experimental diets can be found in Pelegrin-Valls et al [ 16 ], and the organic matter (OM), CP, P and AIA contents are reproduced in Table 1 . Briefly, pelleted diets were isoenergetic (1760 kcal of Net Energy for Ruminants/kg of concentrate) and they were formulated with the same ingredients and additives in the same manufacturing batch.…”