Small intestinal growth measures are correlated with feed efficiency in market weight cattle, despite minimal effects of maternal nutrition during early to midgestation1

Abstract

We hypothesized that gestational nutrition would affect calf feed efficiency and small intestinal biology, which would be correlated with feed efficiency. Multiparous beef cows (n = 36) were individually fed 1 of 3 diets from d 45 to 185 of gestation: native grass hay and supplement to meet NRC recommendations (control [CON]), 70% of CON NEm (nutrient restricted [NR]), or a NR diet with a RUP supplement (NR+RUP) to provide similar essential AA as CON. After d 185 of gestation, cows were managed as a single group, and calf individual feed intake was measured with the GrowSafe System during finishing. At slaughter, the small intestine was dissected and sampled. Data were analyzed with calf sex as a block. There was no effect (P ≥ 0.33) of maternal treatment on residual feed intake, G:F, DMI, ADG, or final BW. Small intestinal mass did not differ (P ≥ 0.38) among treatments, although calf small intestinal length tended (P = 0.07) to be greater for NR than NR+RUP. There were no differences (P ≥ 0.20) in calf small intestinal density or jejunal cellularity, proliferation, or vascularity among treatments. Jejunal soluble guanylate cyclase mRNA was greater (P < 0.03) for NR+RUP than CON and NR. Residual feed intake was positively correlated (P ≤ 0.09) with small intestinal mass and relative mass and jejunal RNA content but was negatively correlated (P ≤ 0.09) with jejunal mucosal density and DNA concentration. Gain:feed was positively correlated (P ≤ 0.09) with jejunal mucosal density, DNA, protein, and total cells and was negatively correlated (P ≤ 0.05) with small intestinal relative mass, jejunal RNA, and RNA:DNA. Dry matter intake was positively correlated (P ≤ 0.09) with small intestinal mass, relative mass, length, and density as well as jejunal DNA and protein content, total cells, total vascularity, and kinase insert domain receptor and endothelial nitric oxide synthase 3 mRNA and was negatively correlated (P = 0.02) with relative small intestinal length. In this study, calf performance and efficiency during finishing as well as most measures of small intestinal growth were not affected by maternal nutrient restriction during early and midgestation. Results indicate that offspring small intestinal gene expression may be affected by gestational nutrition even when apparent tissue growth is unchanged. Furthermore, small intestinal size and growth may explain some variation in efficiency of nutrient utilization in feedlot cattle.

Liver morphometrics and metabolic blood profile across divergent phenotypes for feed efficiency in the bovine

“…Interestingly, a study by Colnot et al [37] on glucose absorption in the small intestine of neonatal calves demonstrated the primary role of the mucosal growth to trigger the intestinal metabolism of glucose. In another study in calves, Meyer et al [17] demonstrated the relevance of intestinal growth to the variation in feed efficiency.…”

“…Interestingly, Montanholi et al [15] observed an increase in the small intestine crypt cellularity in cattle with improved feed efficiency. Such histological and functional evidence is associated with increased metabolic rate of the digestive tract in snakes [16] and also associated with variation in feed efficiency in beef cattle calves [17]. …”

The relationship of residual feed intake and visceral organ size in growing lambs fed a concentrate- or forage-based diet

“…Conversely, another study observed greater liver and empty GIT masses in high RFI compared with low RFI steers (Basarab et al, 2003). In addition, recent data from our lab in feedlot cattle demonstrated a positive relationship between RFI and small intestinal mass and negative relationships between RFI and small intestinal mucosal density and DNA concentration (Meyer et al, 2014). This suggests that more efficient cattle may have smaller intestinal size with a more dense mucosa.…”

Effects of maternal protein supplementation and inclusion of rumen‐protected fat in the finishing diet on nutrient digestibility and expression of intestinal genes in Nellore steers

“…Although nutrient inadequacies generally lead to reduced SI length in several species (Meyer, Hess, Paisley, Du, & Caton, ; Wang, Huo, Shi, Xu, & Hutz, ), progeny from restricted dams and fed the diet without RPF had the longest SI. Rodrigues (), using the same cows and calves in a cow/calf trial until weaning, also reported longer SI in calves from restricted dams.…”

“…Therefore, nutritional restriction during mid to late gestation has long‐term effects on SI length when low lipid diet was used. On the other hand, progeny from restricted cows and fed RPF diet had decreased SI length, a response probably associated to their low DMI, since positive correlation ( r = .32) between intestine length and DMI was found in feedlot steers and heifers (Meyer et al, ). This fact demonstrates the plastic nature of SI, influenced not only by maternal nutrition but also by recent nutritional and environmental stimuli.…”