Performance, rumen fermentation and blood metabolites of dairy calves fed starter mixtures supplemented with herbal plants, essential oils or monensin

Phytogenic feed additives as natural antibiotic alternatives in animal health and production: A review of the literature of the last decade

The use of antibiotics in animal production raises great public safety concerns; therefore, there is an urgent need for the development of substitutes for antibiotics. In recent decades, plant-derived feed additives have been widely investigated as antibiotic alternatives for use in animal health and production because they exert multiple biological functions and are less likely to induce resistance development. This review summarizes the research history and classification of phytogenic feed additives and their main functions, potential modes of action, influencing factors, and potential negative effects. Further, we highlight the challenges in developing sustainable, safe, and affordable plant-derived antibiotic alternatives for use in livestock production.

Effects of castration and eucalyptus oil supplementation on growth performance, nutrient digestibility, and blood-immunity indicators of male Holstein calves

The purpose of this study was to investigate the effects of early castration and eucalyptus oil (EUC) supplementation on dry matter intake (DMI), growth performance, and immune response of Holstein calves. Fifty-six male Holstein calves 52 d old and with an initial body weight (BW) of 63.5 ± 5.27 kg were used. The animals were blocked by BW and randomly assigned into 1 of the 4 treatment groups in a randomized complete block design with a 2 (no castration vs. castration) × 2 (without vs. with EUC) factorial arrangement of treatments. The treatments were (1) uncastrated calves fed without EUC, (2) uncastrated calves fed 0.5 g/d EUC (EUC group), (3) castrated calves (steers) fed without EUC (castrated group), and (4) steers fed with 0.5 g/d EUC (castrated + EUC). The experiment was 8 wk long, including pre- and postweaning (weaned at 72 d). The EUC × castrated interactions were not significant for DMI, growth performance, nutrient digestibility, and immune response. Castration did not affect the DMI, final BW, average daily gain (ADG), or feed efficiency, except that the ADG was greater for bull calves than for steers at postweaning. Supplementation with EUC increased DMI pre- and postweaning and increased the ADG of weaned calves. Digestibility in the total digestive tract was not affected by castration (except for organic matter digestibility), whereas adding EUC improved the digestibility of dry matter, acid detergent fiber, and crude protein. Blood concentration of IL-6 at d 94 was decreased by feeding EUC. These results indicate that the EUC could be fed to either intact or castrated dairy calves to promote growth and health postweaning; castration before weaning may reduce ADG and cause inflammatory stress without affecting feed intake or feed efficiency.

Assessing the In Vitro and In Vivo Effect of Supplementation with a Garlic (Allium sativum) and Oregano (Origanum vulgare) Essential Oil Mixture on Digestibility in West African Sheep

This study assessed the impact of a mixture of garlic (Allium sativum) and oregano (Origanum vulgare) essential oils (EOGOs) on in vitro dry matter digestibility (IVDMD) and in vivo apparent nutrient digestibility. Different EOGO inclusion levels were evaluated to assess the dose response and potential effects of the mixture. Three EOGO inclusion levels (0.5, 0.75, and 1 mL/kg of incubated dry matter) were evaluated in vitro, while four treatments (0.5, 0.75, and 1 mL/day of EOGO and a control group) were tested in vivo on 12 West African sheep. A randomized controlled trial was conducted using a 4 × 4 design. Blood parameters (glucose, blood urea nitrogen, and β-hydroxybutyrate) were measured to observe the effect of EOGO on the metabolism. The results showed that the inclusion of EOGO significantly enhanced IVDMD at low levels (p < 0.052) compared with the highest levels in treatments containing 0.5 and 0.75 mL/kg of EOGO dry matter. A higher intake of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) (p < 0.05) was observed in the in vivo diets with the inclusion of EOGO. In terms of in vivo apparent digestibility, significant differences were found among treatments in the digestibility coefficients of DM, CP, and NDF. EOGO inclusion increased the digestibility of DM. CP digestibility displayed a cubic effect (p < 0.038), with the lowest values of digestibility observed at 1 mL EOGO inclusion. Additionally, NDF digestibility showed a cubic effect (p < 0.012), with the highest value obtained at 0.75 mL of EOGO inclusion. The inclusion levels above 0.75 mL EOGO showed a cubic effect, which indicates that higher concentrations of EOGO may not be beneficial for the digestibility of CP and NDF. Although no significant difference was observed in total digestible nutrients, a linear trend was observed (p < 0.059). EOGO improved the intake of DM, CP, and NDF. EOGO supplementation improved the digestibility of DM and NDF, with optimal levels observed at 0.5 mL/day. No significant effects were observed in the blood parameters. These results suggest that EOGO has the potential as an additive in ruminal nutrition to improve food digestibility and serve as an alternative to antibiotic additives. The use of EOGO potentially improves fiber digestion and may reduce the use of antibiotics in livestock production. Garlic (A. sativum) and oregano (O. vulgare) essential oils effectively modulated fiber digestibility at 0.75 mL/day. Garlic (A. sativum) and oregano (O. vulgare) essential oils have the potential to improve digestibility at low inclusion levels and serve as an alternative to antibiotic additives. The effectiveness of essential oils is greater in a mixture and at lower doses.

Effects of a phytogenic feed additive on weaned dairy heifer calves subjected to a diurnal heat stress bout

The study objective was to evaluate the effects of a phytogenic feed additive (PFA) on dry matter intake (DMI), average daily gain (ADG), inflammation, and oxidative stress markers of heifer calves exposed to a heat stress bout in the summer. A total of18 Holstein and 4 Jersey heifer calves (192 ± 5 kg of body weight at 162 ± 16 d of age) housed in indoor stalls were assigned to 1 of 2 dietary treatments (n = 11; 9 Holstein and 2 Jersey): (1) a basal total mixed ration (CTL), and (2) CTL top-dressed with 0.25 g/d of PFA. Following 7 d of acclimation, baseline measurements were made over 7 d under regular summer conditions [average temperature-humidity index (THI) = 79 from 0900 to 2000 h, and 75 from 2000 to 0900 h]. Calves were then subjected to a 7-d cyclic heat stress bout (HS) by turning on barn heaters and increasing the barn temperature to 33.0°C only during the daytime (the average THI = 85 from 0900 to 2000 h). The study continued for an extra 4-d period after HS ended (post-HS). The HS increased rectal temperature, skin temperature, and respiration rate from the baseline by 1.0°C, 4.0°C, and 49 breaths/min, respectively. The drinking water intake increased by 32% in response to HS, and calves continued to consume more water (44%) than the baseline consumption even after HS ended. The treatment × time interactions were not significant for feed intake, ADG, partial pressure of O2 in the blood, and blood concentrations of inflammation markers such as haptoglobin and lipopolysaccharide binding protein (LBP), and antioxidant markers such as protein carbonyl and thiobarbituric acid (TBARS). The PFA tended to increase daytime DMI (0.24 kg/d) compared with CTL throughout the experiment but did not affect ADG, which decreased from 1.12 kg/d to 0.26 kg/d in response to HS. Both DMI (13%) and ADG (85%) increased during post-HS relative to baseline, indicating compensatory performances that were not affected by the PFA. Serum haptoglobin and plasma LBP concentrations of PFA calves were 44% and 38% lower than that of CTL calves across all time points. The PFA decreased O2 pressure and tended to decrease protein carbonyl concentration in the blood across all time points. The PFA tended to decrease TBARS concentration on the first day of HS and increase and decrease the ratio of reduced to oxidized glutathione in the blood during the baseline and post-HS periods, respectively. Despite the lack of growth improvements, feeding PFA seems to increase O2 levels in the blood and alleviate oxidative stress and inflammation of heifer calve exposed to diurnal heat waves (~7 d) in the summer.

Influence of Anti-Coccidial Compounds and Phytogenic Saponin Extracts on In Vitro and In Vivo Ruminal Fermentation and Methane Production of Cattle

Four experiments were conducted to evaluate sources of anti-coccidial compounds and phytogenic saponin extracts on in vitro and in vivo ruminal fermentation and CH₄ production at multiple inclusion levels. In experiment 1, eight steers were fed either a finishing diet or a finishing diet supplemented with 0.5 mg/kg BW decoquinate (DCQ) and 3.33 mg/kg BW Yucca schidigera extract (YSE), and respiratory gas exchange was measured. In experiment 2, four ruminally-cannulated steers were fed the same treatments as experiment 1, and ruminal fermentation was evaluated. Anti-coccidial sources (experiment 3; monensin, DCQ, amprolium) and saponin sources (experiment 4; YSE, Quillaja saponaria extract) and levels were evaluated for effects on in vitro ruminal fermentation and CH₄ production. DCQ + YSE supplementation did not influence (p ≥ 0.24) in vivo respiratory gas consumption/production, in situ DM degradation, or liquid passage kinetics. Ruminal propionate proportion tended to increase (p = 0.09) with DCQ + YSE. Monensin decreased (p ≤ 0.04) in vitro acetate:propionate and CH₄ production; saponin supplementation linearly increased (p < 0.01) propionate proportion but did not influence (p ≥ 0.38) in vitro CH₄ production. Saponins and non-antibiotic anti-coccidials did not influence in vitro or in vivo CH₄ production with finishing diets.

Changes in the concentration of methane in the ecosystem in vitro against the background of Asteraceae family plants biomass

The assessment of Asteráceae Family Plants (rhizomes and roots of elecampane and wormwood) influence on the process of methane formation in the rumen ecosystem and metabolic processes was carried out. Studies (in vitro) were carried out using ANKOM Daisy II incubator (modifications D200 and D200I) according to a specialized method. Rumen contents were obtained from beef bulls with chronic rumen fistula. Gas analysis of air and volatile fatty acids samples was performed by gas chromatography. The results of the study showed that different dosages of phytobiotic preparations did not significantly affect the characteristics of fermentation in vitro. Phytobiotic preparations of elecampane and wormwood reduce the production of methane in the ruminal fluid, which may be associated with various active components or dosages of their administration.

Pereira LG, R. Tomich T, A. Carvalho W, S. Silva RO, L. Voorsluys A, V. Jacob D, Magalhães Campos M. Effects of a blend of essential oils in milk replacer on performance, rumen fermentation, blood parameters, and health scores of dairy heifers

The aim of this study was to evaluate how the inclusion of a blend of essential oils in milk replacer (MR) affects different outcomes of dairy heifers. The outcomes evaluated: feed intake, performance, body development, blood cells and metabolites, insulin-like growth factor-1 (IGF-1), rumen fermentation, fecal scores, and respiratory scores. All outcomes were evaluated during pre-weaning (4–60 d of age), and carry-over effects during post-weaning (61–90 d of age) periods. The experimental units utilized were 29 newborn Holstein × Gyr crossbred dairy heifers, with genetic composition of 5/8 or more Holstein and 3/8 or less Gyr and body weight (BW) at birth of 32.2 ± 5.2 kg. Experimental units were assigned to either a control (CON, n = 15) or a blend of essential oil supplementation (BEO, n = 14) treatment, maintaining a balance of genetic composition. The BEO was supplemented in the MR with 1 g/d/calf of a blend of essential oils (Apex Calf, Adisseo, China) composed by plant extracts derived from anise, cinnamon, garlic, rosemary, and thyme. During the pre-weaning phase, all heifers were fed 5 L of MR/d reconstituted to 15% (dry matter basis), divided into two equal meals. Water and starter were provided ad libitum. During the post-weaning, animals received a maximum of 3 kg of starter/d, and ad libitum corn silage, divided into two meals. Feed intake, fecal and respiratory scores were evaluated daily. The BW was measured every three days, while body development was recorded weekly. Blood samples were collected on 0, 30, and 60 d of age for total blood cell count, weekly and on the weaning day to determinate ß-hydroxybutyrate, urea and glucose, and biweekly for IGF-1. Ruminal parameters (pH, volatile fatty acids, ammonia-N, and acetate:propionate proportion—C2:C3) were measured on days 14, 28, 42, 60, 74 and 90. A randomized complete block design with an interaction between treatment and week was the experimental method of choice to test the hypothesis of the BEO’s effect on all outcomes. An ANOVA procedure was used for continuous outcomes, and a non-parametric test was used for the ordered categorical outcomes, both adopting a CI = 95%. Results indicated that there was not enough evidence to accept the alternative hypothesis of the effect of BEO in MR on feed intake, performance, body development, and blood metabolites during both pre-weaning and post-weaning periods. However, results indicated that the inclusion of BEO in MR significantly affects the proportion of C2:C3 during pre- and post-weaning (P = 0.05). Similarly, the effect was significant for basophil (P ≤ 0.001), and platelet (P = 0.04) counts pre-weaning. The interaction between week and treatment was also significant for lymphocytes (P ≤ 0.001), revealing a cumulative effect. Lastly, fecal scores were also significant (P = 0.04) during pre-weaning, with lower values for BEO. The BEO contributed to ruminal manipulation in pre-weaning and carry-over effects in post-weaning, immunity improvement, and decreased morbidity of neonatal diarrhea in the pre-weaning phase.

Effect of a Phytogenic Feed Additive on Growth Performance, Nutrient Digestion, and Immune Response in Broiler-Fed Diets with Two Different Levels of Crude Protein

Simple Summary

The rising concerns on antibiotics resistance from using antibiotics in animal production has resulted in an increase in researches on antibiotic alternatives. A phytogenic feed additive from a blend of extracts of oregano, cinnamon, citrus peel, and fructooligosaccharides was evaluated in the present study. The objective of the present study is not only to evaluate the effect of phytogenic feed additive on broiler performance, but also to explore the potential mode of actions through immune response, digestive enzyme activities, nutrient transporter gene expressions and nutrient digestibility. Supplementation of phytogenic feed additives improved broiler FCR through stimulating ileum immunity.

Abstract

The aim of this experiment was to evaluate the effect of a phytogenic feed additive (PFA) on growth performance and nutrient digestibility of broilers fed corn and soybean meal-based diets containing two different levels of crude protein. A 2 × 2 completely randomized factorial arrangement (eight replicates/treatment, 30 birds/replicate) was conducted with a positive control (PC) and negative control (NC) containing crude protein at standard or reduced by 1.5% (equivalent to a reduction of 15 g/kg), respectively, and supplementation of PFA at 0 or 125 ppm of diet. There were no significant interactions found between PFA and CP levels in the current study. Main effect analysis showed that during 0–42 d of age NC diets decreased body weight gain (p < 0.05), but increased feed intake (p < 0.05) and feed conversion ratio (FCR, p < 0.01), whereas supplementation of PFA resulted in a lower FCR (p < 0.01). The ileal nutrient digestibility was reduced (p < 0.05) in the broilers fed a reduced protein diet at 21 d compared to the standard protein level group, but there were no effects for PFA levels. Similarly, supplementing PFAs showed no effects on digestive enzyme (Alkaline phosphatase, amylase, and lipase) activity in jejunal digesta and jejunal brush border enzyme (maltase, sucrase, and aminopeptidase) activity. Supplementation of PFA downregulated (p < 0.05) the mRNA expressions of cytochrome P450 1A and interleukin 6 in the ileum but had no effects on nutrient transporter genes in the jejunum. In conclusion, supplementation of PFA reduced broiler FCR during the whole grow-out period and positively regulated the immune responses in the ileum.

Probiotic effect of Bacillus subtilis B-2998D, B-3057D, and Bacillus licheniformis B-2999D complex on sheep and lambs

Objectives:

Probiotics are well documented for their health benefits by developing a balanced intestinal microbiota and boosting immunity. The present study was conducted to determine the effects of a probiotic preparation Enzimsporin^TM (consisting of spore-forming bacteria Bacillus subtilis B-2998D, B-3057D, and Bacillus licheniformis B-2999D) on the biochemical, hematological, immunological parameters, intestinal microbiota, and growth dynamics of sheep and lambs.

Materials and Methods:

Enzimsporin was fed to lambs and sheep at different doses to determine the bacteria’s probiotic effects. Sheep were divided into three groups (six each), which received 0, 1, and 3 gm of Enzimsporin/per head/day, respectively, and two groups of lambs (10 each), who received 0 gm and 1 gm of Enzimsporin/per head/day for 30 days in addition to their regular ration. On day 30, blood samples were collected, followed by the determination of biochemical, hematological, and natural resistance indicators. Fecal samples were examined to determine the intestinal microflora, and animals were weighed daily to determine their growth dynamics.

Results:

Supplementation of probiotics (Enzimsporin^TM) improved the lambs’ body weight gain by 18.8%. Analysis of the clinical parameters showed improvements in the levels of total protein, globulins, and urea by 5.3%, 10.8%, and 6.2%, respectively, in the blood of probiotic-supplemented lambs. Similarly, an increment in the total protein, albumins, and globulins was observed in the sheep with Enzimsporin^TM supplementation. The decrease in bilirubin and cholesterol levels in the blood and increased bactericidal and phagocytic index in the sheep and lambs with probiotic supplementation indicated a positive influence of Enzimsporin^TM on the liver function and natural resistance. Furthermore, an increase in Lactobacillus and Bifidobacterium and a decrease in the Escherichia coli, Enterococcus, and Yeast in the fecal contents of experimental sheep and lambs indicated the potentiality of Enzimsporin^TM on maintaining good gut health.

Conclusion:

Spore-forming bacteria B. subtilis B-2998D, B-3057D, and B. licheniformis B-2999D can be used in feeding sheep and lambs of 2 months of age to increase body weight gain, improve intestinal microbiota, strengthen the immune system, and maintain normal metabolic processes.

Essential Oils in Livestock: From Health to Food Quality

Using plant essential oils (EOs) contributes to the growing number of natural plants' applications in livestock. Scientific data supporting the efficacy of EOs as anti-inflammatory, antibacterial and antioxidant molecules accumulates over time; however, the cumulative evidence is not always sufficient. EOs antioxidant properties have been investigated mainly from human perspectives. Still, so far, our review is the first to combine the beneficial supporting properties of EOs in a One Health approach and as an animal product quality enhancer, opening new possibilities for their utilization in the livestock and nutrition sectors. We aim to compile the currently available data on the main anti-inflammatory effects of EOs, whether encapsulated or not, with a focus on mammary gland inflammation. We will also review the EOs' antioxidant activities when given in the diet or as a food preservative to counteract oxidative stress. We emphasize EOs' in vitro and in vivo ruminal microbiota and mechanisms of action to promote animal health and performance. Given the concept of DOHaD (Developmental Origin of Health and Diseases), supplementing animals with EOs in early life opens new perspectives in the nutrition sector. However, effective evaluation of the significant safety components is required before extending their use to livestock and veterinary medicine.

Ovarian activity and antioxidant indices during estrous cycle of Barki ewes under effect of thyme, celery and salinomycin as feed additives

This research aimed to examine the effects of thyme, celery and salinomycin on ovarian sex hormones, reproductive traits and antioxidant status during the estrous cycle. Seventy-five mature Barki ewes aged 2-3 years with an average weight of 40 ± 1.5 kg were assigned randomly into five groups (15 head/group). Group 1 was kept as the control; groups 2 and 3 received 20 g/head/day thyme (T) and celery (C) as dried herbs, respectively. Group 4 (T×C) received 10 g thyme + 10 g celery/head/day, and group 5 was treated with salinomycin 1 g/head/day. Blood samples were collected during follicular and luteal phases of the estrous cycle. Thyme and celery and the mixture of T×C increased (P < 0.01) estradiol-17β (E2) during the follicular phase of the estrous cycle, while only the celery group showed a marked (P < 0.001) increase in progesterone (P4) during the luteal phase compared with the control. Salinomycin supplementation decreased (P < 0.05) E2 concentrations during the follicular and luteal phases of the estrous cycle. Supplementation with thyme and celery enhanced (P < 0.001) antioxidant capacity in the luteal phase compared with the follicular stage. The salinomycin group showed increased (P < 0.01) levels of reduced glutathione (GSH) and decreased malondialdehyde (MDA) levels compared with the control group throughout luteal phase. For the interaction between estrous phases and treatments, thyme, celery, and T×C supplementation revealed an increase (P < 0.05) in superoxide dismutase (SOD), GSH, and glutathione disulfide (GSSG) levels compared with the control group during the follicular and luteal phases. Thyme and celery supplementation improved the number of services per conception and fertilization from 1st and 2nd inseminations, respectively. In conclusion, the applied treatment had significant effects on reproductive performance and antioxidant status in ewes throughout the estrous cycle.

Research on the Applications of Calcium Propionate in Dairy Cows: A Review

Calcium propionate is a safe and reliable food and feed additive. It can be metabolized and absorbed by humans and animals as a precursor for glucose synthesis. In addition, calcium propionate provides essential calcium to mammals. In the perinatal period of dairy cows, many cows cannot adjust to the tremendous metabolic, endocrine, and physiological changes, resulting in ketosis and fatty liver due to a negative energy balance (NEB) or milk fever induced by hypocalcemia. On hot weather days, cow feed (TMR or silage) is susceptible to mildew, which produces mycotoxins. These two issues are closely related to dairy health and performance. Perinatal period metabolic disease significantly reduces cow production and increases the elimination rate because it causes major glucose and calcium deficiencies. Feeding a diet contaminated with mycotoxin leads to rumen metabolic disorders, a reduced reproductive rate (increased abortion rate), an increased number of milk somatic cells, and decreased milk production, as well as an increased occurrence of mastitis and hoof disease. Propionic acid is the primary gluconeogenic precursor in dairy cows and one of the safest mold inhibitors. Therefore, calcium propionate, which can be hydrolyzed into propionic acid and Ca2+ in the rumen, may be a good feed additive for alleviating NEB and milk fever in the perinatal period of dairy cows. It can also be used to inhibit TMR or silage deterioration in hot weather and regulate rumen development in calves. This paper reviews the application of calcium propionate in dairy cows.

Impact of a phytogenic feed additive on growth performance, feed intake, and carcass traits of finishing steers

The purpose of this study was to evaluate the effect of a phytogenic feed additive (Digestarom [DA]; Biomin, Getzersdorf, Austria) on growth performance, feed intake, carcass traits, fatty acid composition, and liver abscesses of finishing steers. One hundred twenty Angus × Charolais crossbred steers (488 ± 26.5 kg) were used in a 110-d feeding experiment. Steers were blocked by weight and randomly assigned to 12 pens with 10 steers per pen. Each pen was allocated to one of three diets. Each diet contained 86.5% barley, 10.0% barley silage, and 3.5% vitamin and mineral supplement on a dry matter (DM) basis. The diets contained 0, 0.05, and 0.1 g DA/kg complete diet (DM basis), to achieve average daily DA intakes of 0 (control), 0.5 (LowDA), and 1.0 g (HighDA) per steer. Diets were prepared once daily and provided ad libitum. Two pens per treatment were equipped to record individual feed intake behavior. Steers were weighed every 28 d and carcass traits and liver scores were recorded at slaughter. Dry matter intake (average: 9.34 kg/d) did not differ (P > 0.05) among diets. Average daily gain tended to increase linearly as DA increased (control: 1.82; LowDA: 1.87; and HighDA: 1.95 kg/d; P < 0.09), but gain:feed ratio was not affected. Supplementation of DA affected longissimus muscle area quadratically (P = 0.05) with the largest area observed for LowDA. However, dressing percentage decreased linearly in response to increasing level of DA (P < 0.01). Total abscessed livers were not affected, whereas proportion of severe liver abscesses was numerically lower with DA (30.8% and 42.5% for LowDA and HighDA) compared to the control (50%).

Effect of replacement of antibiotics with thyme and celery seed mixture on the feed intake and digestion, ruminal fermentation, blood chemistry, and milk lactation of lactating Barki ewes

The study investigated the effect of in-feed administration of dried thyme leaf and celery seed mixture (at 1 : 1 w/w) compared with salinomycin ionophore on milk production and milk nutritive value of Barki ewes.

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

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.