An Energy-Rich Diet Causes Rumen Papillae Proliferation Associated with More IGF Type 1 Receptors and Increased Plasma IGF-1 Concentrations in Young Goats

Abstract

We tested the hypothesis that the dietary energy-dependent alterations of the rumen papillae size are accompanied by corresponding changes in systemic insulin-like growth factor (IGF)-1 concentration and in rumen papillary IGF type 1 receptors (IGF-1R). Young male goats (n=24) were randomly allocated to two groups (n=12) and fed a high level (HL) metabolizable energy [1200 kJ/(kg(0.75).d)] or a low level (LL) [500 kJ/(kg(0.75).d)] diet for 42 d. The concentration of ruminal total SCFA did not differ between the groups, but the molar proportion of butyric acid was enhanced by 70% in the HL group (P<0.05). Both the length and width of the papillae were greater (P<0.05) in the HL group, and the surface was 50-100% larger (P<0.05) in the tissue sampled from the artrium ruminis, the ventral ruminal sac and the ventral blind sac. Transport of Na+ across the rumen epithelium, which is amiloride sensitive, was higher (P<0.05) in the HL than in the LL group. Furthermore, the plasma IGF-1 concentration was about twofold higher in the HL group (P<0.05), and the maximal rumen epithelial IGF-1R binding was also higher in the HL (P<0.05) than in the LL group. IGF-1R mRNA and IGF-1 mRNA were detected in rumen papillae; however, they were unaffected by dietary treatments. DNA synthesis and cell proliferation of cultured rumen epithelial cells were higher (P<0.05) after IGF-1 treatment (25 or 50 microg/L) compared with those in the medium without IGF-1. Thus dietary energy-dependent alterations of rumen morphology and function are accompanied by corresponding changes in systemic IGF-1 and ruminal IGF-1R.

Identification of differentially expressed proteins in ruminal epithelium in response to a concentrate-supplemented diet

“…The response of the ruminal epithelium to an increase of energy (and protein) has been previously studied in sheep, cattle, and goats (19,47,55).…”

“…Hence, supplementation of forage-fed ruminants with sufficient amounts of energy and protein is necessary and significantly improves milk production or daily weight gain (41), but, particularly, a surplus of easily fermented carbohydrates or low-fiber intake will place the animals at risk. Such a change in the diet is a challenge for rumen microbes (31) and especially for the ruminal epithelium with respect to adaptation to the new fermentation pattern (47,55). Insufficient adaptation to diet may result in disintegration of the epithelium (22), translocation of lipopolysaccharides (30), and disturbed transport mechanisms (22) and can further cause subacute ruminal acidosis (14, 49).…”

“…The phenotypic effects of diets, particularly of concentrate supplementation on rumen morphology and physiology, have been well investigated (38,55) and reviewed (7). In particular, feeding a diet containing highconcentrate rations increases the number and/or size of papillae in the rumen and influences the transport properties of the ruminal epithelium (19,26).…”

Cattle genomics and its implications for future nutritional strategies for dairy cattle

“…The rumen has to develop efficiently in early life to ensure animal health, productivity and economic benefit for the farmer. To understand changes in energy metabolism of developing ruminal epithelium various aspects of metabolism have been explored including ketogenesis (Lane et al, 2002), volatile fatty acid absorption (Shen et al, 2004;Koho et al, 2005), butyrate and glucose oxidation , propionate metabolism (Weigand et al, 1972), LCFA metabolism and cell proliferation (Shen et al, 2004). Large-scale transcriptional adaptations during growth or in response to nutrition have only recently been explored.…”

Avaliação morfológica do abomaso e ceco-cólon de bovinos

“…Myers et al (1967), ao isolar o ceco de carneiros e fazer infusões de AGV através de uma cânula, implantada cirurgicamente, observaram alterações na taxa fracional de absorção quando houve alterações no pH do fluido e nas concentrações de AGV. A influência da dieta e de infusões diretas de AGV no IM, no peso de mucosa e no tamanho das criptas já foi demonstrada no ceco e APCA de ratos (Sakata e Engelhardt, 1983;Sakata, 1987;Edwards et al, 1992;Ichikawa e Sakata, 1997) (Sakata et al, 1980) e IGF-1 (Shen et al, 2004). Daniel e Resende Júnior (2012), ao trabalharem in vitro com fragmentos de estômago de bovinos, encontraram correlação positiva e alta entre IM e taxa fracional de absorção no omaso, mas não no rúmen.…”