Milk restriction or oligosaccharide supplementation in calves improves compensatory gain and digestive tract development without changing hormone levels

Abstract

We estimated the effect of oligosaccharide supplementation and feed restriction on calves. The study was divided into two experimental periods of 28 days each with 20 crossbred calves that had initial body weight of 37 Kg and housed in individual pens. The animals were split in four experimental groups: animals fed 6 L milk/day (CON) in the two periods, animals fed milk restricted (3 L milk/day) in the first period and followed by CON feeding in the second period (RES), animals receiving supplementation of 5 g/day of mannanoligosaccharide (MOS) and animals receiving supplementation of 5 g/day mannan and frutoligosaccharide (MFOS). At the end of the study, all the animals were slaughtered. The average weight gain was lower in the restricted group when compared with CON and MFOS groups in the first period (P < 0.05) and there were no difference among the groups in the second period. Animals supplemented with MOS showed a significant increases in jejunal villus height and rumen papillae, which were not observed for MFOS group (P < 0.05) compared with RES and CON groups. There were no difference in ghrelin and leptin levels among treatments during periods 1 and 2 (P > 0.05). Also, the expression of ghrelin receptors in the paraventricular region of the hypothalamus did not differ among groups. We conclude that milk restriction during the first weeks of life in calves resulted in compensatory gain and did not modify the hormonal profile and expression of the ghrelin receptor in the hypothalamus. Moreover, a prebiotic supplementation changed the development of intestinal and ruminal epithelium.

Fig 1. Calves weight gain and solid food intake.

The average weight gain during periods 1 (day 1–28) and 2 (day 29–56) (Fig 1B and 1C, respectively), the total weight gain at the end of experiments (Fig 1A) and solid food intake during periods 1 and 2 (Fig 1D and 1E, respectively) of calves underwent milk restriction or supplemented with prebiotics. Data are presented as mean ± the standard error of the mean (SEM). * P<0.05; ^# P<0.05 vs. other groups. CON–control calves that received 6 L of milk/day for 56 days. RES–calves received restriction milk (3 L/day) for 28 days (Period 1) followed by 6 L milk/day for 28 days (Period 2). MOS–calves supplemented with 5 g/day of mannanoligosaccharides and same diet of CON animals. MOS calves supplemented with 5 g/day of manan-fructooligosaccharides and same diet of CON animals.

Fig 2. Changes in metabolites of calves underwent milk restriction or supplemented with prebiotics.

Serum levels of lactate (Fig 2A), protein (Fig 2B), triglycerides (Fig 2C), glucose (Fig 2D), creatinine (Fig 2E), urea (Fig 2F) and alkaline phosphatase (Fig 2G) of calves fed milk restricted or supplemented with prebiotics during period 1 (gray bars) and period 2 (black bars). Data are presented as mean ± the standard error of the mean (SEM). *P<0,05. CON–control calves that received 6 L of milk/day for 56 days. RES–calves received restriction milk (3 L/day) for 28 days (Period 1) followed by 6 L milk/day for 28 days (Period 2). MOS–calves supplemented with 5 g/day of mannanoligosaccharides and same diet of CON animals. MOS calves supplemented with 5 g/day of manan-fructooligosaccharides and same diet of CON animals.

Fig 3. Hormone concentrations of calves underwent milk restriction or supplemented with prebiotics.

Ghrelin (Fig 3A) and leptin (Fig 3B) serum levels during period 1 (gray bars) and period 2 (black bars). Data are presented as mean ± the standard error of the mean (SEM). CON–control calves that received 6 L of milk/day for 56 days. RES–calves received restriction milk (3 L/day) for 28 days (Period 1) followed by 6 L milk/day for 28 days (Period 2). MOS–calves supplemented with 5 g/day of mannanoligosaccharides and same diet of CON animals. MOS calves supplemented with 5 g/day of manan-fructooligosaccharides and same diet of CON animals.

Fig 4. Histomorphometry of ruminal papillae and small intestine mucosa of calves.

Representative images of ruminal papillae (Fig 4A–4C), jejunum villi (Fig 4F–4I) and duodenum villi (Fig 4K–4N). Length of ruminal papillae (Fig 4E); height of villi (Fig 4J) of jejunum (gray bars) and duodenum (black bars); Crypt depth (Fig 4O) of jejunum (gray bars) and duodenum (black bars) after 56 days of study of calves that underwent milk restriction or supplemented with prebiotics. Data are presented as mean ± the standard error of the mean (SEM). *P<0,05. CON–control calves that received 6 L of milk/day for 56 days. RES–calves received restriction milk (3 L/day) for 28 days (Period 1) followed by 6 L milk/day for 28 days (Period 2). MOS–calves supplemented with 5 g/day of mannanoligosaccharides and same diet of CON animals. MOS calves supplemented with 5 g/day of manan-fructooligosaccharides and same diet of CON animals.

Fig 5. Gene expression of ghrelin in hypothalamus of calves.

Expression of ghrelin receptor (GHS-R1a) in the paraventricular region of the hypothalamus of calves underwent milk restriction or supplemented with prebiotics. Values are presented as mean ± standard error. CON–control calves that received 6 L of milk/day for 56 days. RES–calves received restriction milk (3 L/day) for 28 days (Period 1) followed by 6 L milk/day for 28 days (Period 2). MOS–calves supplemented with 5 g/day of mannanoligosaccharides and same diet of CON animals. MOS calves supplemented with 5 g/day of manan-fructooligosaccharides and same diet of CON animals.