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Most milk replacers (MR) contain more lactose compared with whole milk, which, when fed at a large meal size, could influence gut barrier function in calves. This study evaluated how replacing lactose in MR with fat (on a wt/wt basis) affects intestinal histomorphology and permeability in neonatal dairy calves. Thirty-four Holstein-Friesian bull calves were blocked by dam parity and randomly assigned to 1 of 2 treatments (n = 17): a high-lactose (46.1% lactose, 18.0% crude fat, and 23.9% crude protein of dry matter) or a high-fat MR (HF; 39.9% lactose, 24.6% crude fat, and 24.0% crude protein of dry matter). Calves were individually housed and fed pooled colostrum at 1.5 h and 12 h postnatally, at 18 and 9% of metabolic body weight (BW0.75), respectively. From 24 h postnatally until the end of the study (d 7), calves were transitioned to be fed MR (prepared at 15% solids) at 18% of BW0.75 twice daily at 0700 and 1900 h. During postprandial sampling on d 6, intestinal permeability was assessed by mixing lactulose (1.03 g/kg of BW0.75) and d-mannitol (0.31 g/kg of BW0.75) into the morning meal without altering total meal volume. Sequential blood samples were collected via jugular catheter, and total urine was collected for 12 h to measure the marker content. Calves were euthanized 3 h after the morning meal on d 7, and gastrointestinal tract tissues and digesta were collected for analysis of histomorphology, digesta osmolality, and gene expression. The empty gastrointestinal tracts of HF calves were heavier, although length did not differ and differences in histomorphology were minor. Digesta osmolality changed along the tract without differences between treatments. Plasma lactulose was greater in HF, although plasma d-mannitol and the recovery of both markers in urine were unaffected. No significant differences were detected in gene expression, although HF calves tended to have lower expression of TJP1 and CLDN2 and higher expression of proinflammatory cytokine IL1B in ileum tissue. In conclusion, partially replacing lactose in MR with fat resulted in a heavier and more permeable gut, with minor histomorphological differences.

Dairy calf nutrition is traditionally one of the most overlooked aspects of dairy management, despite its large effect on the efficiency and profitability of dairy operations. Unfortunately, among all animals on the dairy farm, calves suffer from the highest rates of morbidity and mortality. These challenges have catalyzed calf nutrition research over the past decade to mitigate high incidences of disease and death, and improve animal health, growth, welfare, and industry sustainability. However, major knowledge gaps remain in several crucial stages of development. The purpose of this review is to summarize the key concepts of nutritional physiology and programming from conception to puberty and their subsequent effects on development of the calf, and ultimately, future performance. During fetal development, developmental plasticity is highest. At this time, maternal energy and protein consumption can influence fetal development, likely playing a critical role in calf and heifer development and, importantly, future production. After birth, the calf's first meal of colostrum is crucial for the transfer of immunoglobulin to support calf health and survival. However, colostrum also contains numerous bioactive proteins, lipids, and carbohydrates that may play key roles in calf growth and health. Extending the delivery of these bioactive compounds to the calf through a gradual transition from colostrum to milk (i.e., extended colostrum or transition milk feeding) may confer benefits in the first days and weeks of life to prepare the calf for the preweaning period. Similarly, optimal nutrition during the preweaning period is vital. Preweaning calves are highly susceptible to health challenges, and improved calf growth and health can positively influence future milk production. Throughout the world, the majority of dairy calves rely on milk replacer to supply adequate nutrition. Recent research has started to re-evaluate traditional formulations of milk replacers, which can differ significantly in composition compared with whole milk. Transitioning from a milk-based diet to solid feed is critical in the development of mature ruminants. Delaying weaning age and providing long and gradual step-down protocols have become common to avoid production and health challenges. Yet, determining how to appropriately balance the amount of energy and protein supplied in both liquid and solid feeds based on preweaning milk allowances, and further acknowledging their interactions, shows great promise in improving growth and health during weaning. After weaning and during the onset of puberty, heifers are traditionally offered high-forage diets. However, recent work suggests that an early switch to a high-forage diet will depress intake and development during the time when solid feed efficiency is greatest. It has become increasingly clear that there are great opportunities to advance our knowledge of calf nutrition; yet, a more concentrated and rigorous approach to research that encompasses the long-term consequences of nutritional regimens at each stage of life is required to ensure the sustainability and efficiency of the global dairy industry.

Compared with Holstein whole milk, commercial milk replacers (MR) for calves deliver relatively high levels of lactose and low levels of fat, and protein levels are rather comparable, resulting in a lower energy density and energy-to-protein ratio of the diet. Thus, the objective of this study was to determine the effects of partially exchanging lactose with fat in MR on voluntary feed intake, growth performance, and feeding behavior. Thirty-two male Holstein calves (2.1 ± 0.16 d of age, 46.4 ± 0.77 kg of body weight; BW) were assigned to 16 blocks of 2 calves per block based on arrival date and serum IgG. Within each block, calves were randomly assigned to 2 treatments: a high-lactose MR (HL; 17% fat; 44% lactose), or a high-fat MR (HF; 23% fat; 37% lactose). Lactose was exchanged by fat on a weight per weight basis, resulting in a 6% difference in metabolizable energy density per kilogram of MR. The experiment was divided into 3 phases: preweaning (P1; 0-35 d), weaning (P2; 36-56 d), and postweaning (P3; 57-84 d). For the first 2 wk of P1, calves were individually housed, fed their respective MR ad libitum through teat buckets, and provided access to water. At 14.2 ± 0.5 d of age, calves were group-housed (4 blocks/pen, 8 calves) and housed in group pens for the remainder of the study. In the group pens, calves were fed ad libitum MR, starter feed, chopped wheat straw, and water via automated feeders. During P2, calves were gradually weaned until complete milk withdrawal by 57 d and then monitored until 84 d (P3). Measurements included daily intakes and feeding behavior (rewarded and unrewarded visits), weekly BW and body measurements, and biweekly blood samples. Increasing fat content at the expense of lactose decreased MR intake during P1 by 15% (HL = 1.32 ± 0.04; HF = 1.17 ± 0.04 kg of dry matter per day), whereas total starter intake was not affected by MR composition. Once MR was restricted during P2, HL calves were reported to have more unrewarded visits to the automatic milk feeder than HF calves (11.9 ± 0.95 vs. 8.4 ± 1.03 visits/d, respectively). Crude protein intake was higher for HL calves during P1 (352.1 ± 11.2 vs. 319.6 ± 11.6 g/d), which was attributed to the higher intake of MR during that period, and metabolizable energy intake and protein-to-energy ratio remained comparable between treatments. Plasma cholesterol and nonesterified fatty acids levels were higher in HF calves as a consequence of the diet. Nevertheless, final BW (84 d) did not differ between treatments. Overall, calves fed ad libitum seemed to regulate their intake of MR based on its energy density, without significant effects on solid feed intake and overall growth.

Milk replacers (MR) formulated to contain more lactose than whole milk could potentially reduce insulin sensitivity in dairy calves. This study evaluated how partially replacing lactose in MR with fat on a weight/weight basis affects glucose-insulin kinetics in neonatal dairy calves fed high quantities of MR. Thirty-four Holstein bull calves were blocked by dam parity (1.6 ± 0.3) and randomly assigned to 1 of 2 treatments (n = 17): a high-lactose MR (HL; 46.1% lactose, 18.0% crude fat, and 23.9% crude protein on a dry matter basis) or a high fat MR (HF; 39.9% lactose, 24.6% crude fat, and 24.0% crude protein on a dry matter basis). Calves were individually housed and fed pooled colostrum at 1.5 h and 12 h postnatal at 18 and 9% of metabolic body weight (BW0.75), respectively. From 24 h postnatal until the end of the study (d 7), calves were transitioned to MR (prepared at 150 g/L) at 18% of BW0.75 twice daily at 0700 and 1900 h. On d 4, an insulin-modified intravenous glucose tolerance test was conducted 8 h after the morning meal by intravenous infusion of glucose (0.54 g/kg of BW0.75, min 0) and insulin (3.9 µg/kg of BW0.75, min 20). During postprandial sampling on d 6, abomasal emptying was assessed by dosing acetaminophen (0.13 g/kg of BW0.75) with MR and measuring its appearance within plasma. Sequential blood samples were collected and analyzed for plasma glucose, insulin, and acetaminophen concentrations. Calves were killed on d 7 and liver and pancreatic tissues were collected for histomorphological analysis. Partially replacing lactose in MR with fat increased body weight gain (679.6 vs. 462.0 ± 69.68 g/d) and gain:metabolizable energy intake (186.6 vs. 120.5 ± 20.21 g of body weight/Mcal) compared with feeding HL MR. Furthermore, abomasal emptying rate was reduced in calves fed HF MR. Calculated variables based on postprandial glucose and insulin concentrations, such as maximum concentration or area under the curve, were or tended to be lower in HF than in HL calves. Postprandial insulin sensitivity tended to be reduced in HL compared with HF, although insulin sensitivity estimated from the insulin-modified intravenous glucose tolerance test was not different. Calves fed HF MR showed enhanced glucose-stimulated insulin secretion. In conclusion, partially replacing lactose in MR with fat resulted in smaller fluctuations in postprandial glucose and insulin concentrations and tended to increase postprandial but not fasting insulin sensitivity in neonatal dairy calves.

The effect of replacing lactose with glucose on the gastrointestinal system of young calves at levels above 20% diet inclusion in milk replacer (MR) is not well described. The aim of this study was to determine tolerance to glucose inclusion at the direct expense of lactose on glucose metabolism, health, and growth performance in Holstein male calves. In total, 110 Holstein male dairy calves (16 ± 2.5 d and 50.3 ± 0.2 kg) were acquired from a commercial collection center. After an adaptation period of 3 d, 100 calves were selected for the study based on health parameters. Calves were blocked based on body weight measured on d 4 after arrival. Within each block, calves were randomly assigned to 1 of 5 levels of glucose inclusion (replacing lactose): 0% (L1, n = 20), 10% (L2, n = 20), 20% (L3, n = 20), 30% (L4, n = 20), and 40% (L5, n = 20), leading to an estimated osmolality range from 417 (L1) to 586 mOsm/kg (L5). Carbohydrates were exchanged based on hexose equivalents, and glucose delivery was standardized across treatments, while the rest of the formula (60%) remained unchanged. Calves received L1 during the adaptation period of 3 d and were then exposed to their respective treatment until d 47 after arrival. Milk replacer was provided daily in 2 equally sized meals. Meal size was 2.0 L during the 3-d adaptation period and gradually increased to 4.0 L until weaning (d 35 after arrival). During weaning, meal size decreased from 4.0 to 2.0 L on d 36, and MR was withdrawn on d 48 after arrival. Straw and concentrates were offered ad libitum from d 25 onward. Calves had ad libitum access to water throughout the study. Measurements included daily feed intakes, weekly body weight, and weekly spot feces sampling in all calves. Blood samples were collected on d 18. Additionally, postprandial responses of insulin and glucose were measured in 6 calves per treatment on d 19, 20, and 21. Increasing glucose inclusion (at the direct expense of lactose) in MR did not affect growth but linearly increased mortality, which was as high as 25% (5/20) in L5. Mortality was primarily associated with gastrointestinal disorders (6/11). At higher glucose levels, calves needed greater serum insulin concentrations to control glycemia, as shown by a linear increase in the area under the curve for insulin. Furthermore, calves needed more time to control glycemia, as indicated by a linear increase in the maximal concentration of insulin. Consequently, there was a linear increase in area under the curve for glucose. Even though calves needed more time and higher insulin concentrations for 30% glucose inclusion and higher, the glucose-to-insulin ratio did not differ across treatments. However, high glucose inclusion levels in MR affected calf mortality and is not a suitable strategy for lactose replacement.

Recommendations for composition of oral rehydration solutions (ORS) for calves, particularly concerning Na+, glucose, and their combined effect on tonicity, are not in line with guidelines for humans. Thus, this study aimed to determine the effect of ORS tonicity on water, mineral and acid–base balance. Seventy‐two calves were selected based on the severity of dehydration and blood base excess (BE) on day 0. Five calves that did not develop diarrhoea were removed post‐inclusion from the study. Calves were allocated to blocks of four animals based on blood BE on day 1. Within each block, calves were randomly assigned to one of four treatments: (a) hypotonic ORS with low Na+ and lactose (HYPO); (b) isotonic ORS with low Na+and glucose (ISO); (c) hypertonic ORS with high Na+ and glucose (HYPER); and (d) control consisting of warm water including 5 g/L of whey powder (CON). Treatments were administered twice daily over a 3‐day period, in which calves were offered 2.0 L of treatment at 1300 and 2100 hr. Calves were fed 2.5 L of milk replacer at 0700 and 1630 hr from day 1 to 3 and 3.0 L from day 4 to 5, and had access to water. Calves were monitored for 5 days in which measurements included intakes, BW, blood sampling and collection of faeces on day 1 and urine from day 1 to 3. All ORS treatments maintained normal serum Na+, whereas CON did not. Calves in the HYPER group had lower blood pH and greater faecal Na+ losses than HYPO and ISO. Plasma expansion relative to baseline was higher in low tonicity ORS (+4.8%) when compared with CON (+1.0%). Urine osmolality was 30% higher in HYPER calves. In this experiment, low tonicity ORS were more effective at restoring water, mineral and acid–base balance than the hypertonic ORS.

BACKGROUND Supranutritional supplementation of lamb diets with α‐tocopherol is an effective method to reduce lipid oxidation and colour deterioration in meat products. However, alternative antioxidant sources have been proposed to replace the supranutritional vitamin E applications. RESULTS Indoor concentrate‐fed Rasa Aragonesa male lambs (n = 480) were supplemented with increasing levels of all‐rac‐α‐tocopheryl acetate (0.25, 0.5, 1.0 g kg−1 compound feed), rosemary extract (0.20, 0.40, or 0.80 g kg−1 compound feed), or rosemary extract embedded in a fat matrix (0.20, 0.40, or 0.80 g kg−1 compound feed) for 14 days before slaughter. The longissimus thoracis et lumborum muscle from three lambs per pen (18 lambs per treatment) were modified‐atmosphere packaged (70% O2 + 30% CO2) and maintained under retail conditions for 14 days. Supranutritional supplementation with antioxidants had no effect (P > 0.05) on average daily weight gain, feed intake, and feed efficiency. Rosemary extract supplementation (with or without fat embedment) had no effect on lipid oxidation, myoglobin forms, or colour stability parameters, regardless of the dose. All vitamin E supplementation levels significantly affected lipid oxidation, colour stability (L*, C*, and h), myoglobin forms, and meat discoloration parameters compared with non‐supplemented lambs. CONCLUSIONS This study demonstrates that, unlike vitamin E, neither dose nor protection of the rosemary extract had an effect on lipid oxidation or meat colour stability of lambs during the 14 days of storage under retail conditions. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Objective Altering energy supply and the relative proportions of energy source in the first weeks of life of dairy calves may influence glycemic and insulinemic responses. The objective of this study was to assess the metabolic responses to high-lactose or high-fat milk replacer. Materials and Methods Forty male calves were fed 7 L of milk replacer per day in 2 meals given 10 h apart, considered either high lactose (44% lactose, HL) or high fat (37% lactose, HF), from the first week of life to 30 d of age. Postprandial blood plasma glucose, insulin, and acetaminophen (an abomasal emptying marker) concentrations were measured up to 420 min and used to fit a mathematical model of abomasal emptying and glucose–insulin dynamics. Additionally, an i.v. glucose tolerance test was used to assess glucose tolerance and insulin sensitivity. Results and Discussion Insulin sensitivity remained unchanged; however, glucose maximal concentration and change from baseline tended to be greater for HL in response to an i.v. glucose challenge. Postprandial glucose was elevated at 30 min for HL and HF at 60 and 90 min. Model parameterization showed no difference in abomasal emptying; however, intestinal glucose absorption tended to be faster with HL. Potentiation of insulin action was greater with HL, and pancreatic responsiveness tended to be greater with HF. Implications and Applications These results suggest HL increased early-phase postprandial glucose appearance, which may influence insulin action. In this study, modifying milk replacer composition to more closely resemble cow’s milk did not negatively affect glucose metabolism.

Current calf milk replacer (CMR) compositions significantly differ from whole milk in their levels of energy, protein, and minerals. Energy source is one of the major differences, as CMR contains high levels of lactose, whereas whole milk contains higher levels of fat. The aim of this study was to determine the effect of partially exchanging lactose for fat on performance, digestibility, and gut permeability in calves fed twice daily on a high feeding plane. Lactose and fat were exchanged in the CMR formulation on a weight–weight basis. The CMR were isonitrogenous but not isoenergetic. A total of 60 male Holstein-Friesian calves were assigned to 1 of 30 blocks based on serum IgG, body weight, and date of collection after birth. Within each block, calves were randomly assigned to 1 of 2 treatments: high fat and high lactose. The CMR was provided twice daily until 49 d of age, followed by a gradual weaning period of 14 d. Starter, straw, and water were available ad libitum throughout the complete study. Exchanging lactose for fat did not affect growth; intakes of starter, straw, water, crude protein, or total energy; or apparent total-tract digestibility of nutrients. Gastrointestinal permeability was assessed by measuring the recovery of lactulose and Cr in 24-h urine and the Cr concentration and lactulose:D-mannitol ratio in serum following an oral pulse dose. Urinary recoveries of Cr and lactulose were generally low in both treatments but were higher in calves fed the high-fat CMR. Accordingly, the serum lactulose:D-mannitol ratio and serum Cr concentrations were higher in calves fed the high-fat CMR. In wk 1 and during the weaning transition, calves fed the high-fat CMR had significantly fewer abnormal fecal scores. In conclusion, exchanging lactose for fat in the CMR did not affect growth performance, total feed intake, or nutrient digestibility. The high-fat CMR was associated with an increase in permeability markers but positively influenced fecal scores in calves.

The increasing availability of automated milk dispensers on dairy farms facilitates ad libitum milk supply but weaning calves from high milk allowances is challenging. This study evaluated effects of gradual weaning methods on starter intake, growth, selected blood parameters and weaning distress in ad libitum fed dairy calves during weaning and early post-weaning periods. Thirty-six male Holstein (n = 30) or crossbred (n = 6) calves were individually housed from days 2 to 14 of age and had ad libitum access to milk replacer (MR) from teat buckets. From days 15 to 84 of age, calves were grouped and had ad libitum access to MR, starter, straw and water from automated feeders. At day 35, calves were blocked (age and breed), and randomly assigned to a weaning method: (1) linear fixed (LIN), MR supply was stepped down to 6 l/day on day 36, and linearly reduced between days 36 to 63 from 6 to 2 l/day. (2) Step-down (STEP), MR supply was stepped down to 6 l/day from days 36 to 48, 4 l/day from days 49 to 56 and 2 l/day from days 57 to 63. (3) Dynamic (DYN), at day 36, MR supply was reduced for each individual calf to 75% of the average voluntary consumption between day 29 and 35, then maintained for 9 days, reduced to 50% for 10 days, and to 25% for 9 days. The DYN calves received more MR during weaning than LIN calves, whereas STEP calves had intermediate MR intake. Starter intake was not affected by weaning method. The DYN calves (1.33±0.08 kg/day) grew faster and were heavier than STEP calves (1.10±0.08 kg/day) during post-weaning period, whereas no difference was observed between LIN calves (1.23±0.08 kg/day) and others. At days 70 and 84, concentrations of β-hydroxybutyric acid were higher in LIN calves compared to STEP and DYN calves. Hair cortisol concentrations were not affected by weaning method. During the gradual weaning process CP intake seemed to recovered earlier than metabolizable energy (ME) intake in all treatments, suggesting that ME rather than CP could be the first limiting factor for growth during weaning. These results highlight the post-weaning benefits of DYN and LIN weaning methods when compared with more abrupt step-down strategies.

When supplementing lamb diets with vitamin E, an equivalence factor of 1.36 is used to discriminate between RRR-α-tocopheryl acetate and all-rac-α-tocopheryl acetate. However, more recent studies suggest a need for new equivalence factors for livestock animals. The current study aimed to determine the effect of RRR- and all-rac-α-tocopheryl acetate supplementation on α-tocopherol deposition in lamb tissues. A total of 108 Rasa Aragonesa breed lambs were fed increasing amounts of all-rac-α-tocopheryl acetate (0.25, 0.5, 1.0 and 2.0 g/kg compound feed) or RRR-α-tocopheryl acetate (0.125, 0.25, 0.5 and 1.0 g/kg compound feed) by adding them to a basal diet that contained 0.025 g/kg feed of all-rac-α-tocopheryl acetate as part of the standard vitamin and mineral mixture. The diets were fed for the last 14 days before slaughtering at 25.8±1.67 kg BW. Within 20 min after slaughter samples of muscle, heart, liver, brain and spleen were frozen at −20°C until α-tocopherol analysis. Increased supplementation of either vitamin E sources led to a significant increase (P

The recent trend in the dairy industry towards elevated planes of milk feeding of young calves requires reconsideration of calf milk replacer (CMR) formulations. The fat:lactose ratio in CMR is typically lower than that of whole milk and effects of increasing fat inclusion at the expense of lactose in CMR on nutrient metabolism and gut function of rearing calves are not sufficiently understood. Therefore, the current study aimed to determine the effect of increasing replacement of lactose by fat on growth performance, nutrient digestibility and metabolism, and glucose/insulin sensitivity. A total of 40 male calves (1.7 ± 0.10 days of age, 46.7 ± 0.76 kg BW) were blocked based on arrival date and randomly assigned to one of four treatments containing differing levels of fat and lactose (18F: 18.8% and 47.6%; 22F: 22.3% and 42.8%; 26F: 26.0% and 38.6%; 30F: 30.1% and 33.8%, fat and lactose DM, respectively). Calves were individually housed for the duration of the 11 week study and received their CMR (150 g/L) twice a day (0700 and 1600 h) from a teat bucket. The CMR feeding schedule consisted of 6 L/d from d 2 to 14, 7 L/d from d 15 to 56, and then 4 L/d during gradual weaning from 56 to 63 days. Pelleted starter, chopped straw, and water were available ad libitum throughout the study. Measurements included feed intake, growth, nutrient digestibility, fecal composition, and blood parameters. A glucose tolerance test (GTT) was performed between 28 and 32 days of age. By design, metabolizable energy intake from CMR increased linearly with fat level, but this did not result in a difference in BW, ADG, or concentrate intake. Fecal composition remained unaffected by treatment except for higher fat content in 22F compared to 26F. Also, plasma non-esterified fatty acids and total bilirubin differences were limited to 22F having the highest values whereas 26F had the lowest values. Regarding the GTT, total area under the curve (AUC) for glucose was highest in 22F and 26F and lowest in 18F whereas the AUC between 30 and 60 min for glucose was highest in 26F and lowest in 18F and 22F. Overall, altering the lactose:fat ratio in CMR did not affect growth performance while having minor effects on nutrient metabolism, but future investigation should focus on physiological consequences and effects in adult life to understand biological impact of fat and lactose levels in CMR for rearing calves.

Male Holstein calves commonly receive minimal quantities of milk replacer (MR) to speed up weaning and reduce costs. Studies with Holstein female calves show that early life feed restriction affects energy metabolism later in life. Aiming to test this hypothesis, 120 Holstein bull calves (48.4 ± 2.2 kg of BW and 20 ± 3.2 d of age) housed in 24 pens were blocked and randomized to two treatments: A low calf MR allowance (LP) (two daily doses of 2 l each, 582 g/d of DM), or a high MR allowance (HP) (two daily meals of 4 l each, 1164 g/d of DM). Calves were weaned at day 49 of the study and slaughtered at 32.8 ± 0.5 weeks of age. Throughout the study, animals had ad libitum access to a common compound feed, straw, and water. Twenty-four animals were randomly selected for an intravenous glucose tolerance test (IVGTT). The IVGTT was performed at week 6 and 12 of the study and consisted of an intravenous glucose infusion and sequential blood sampling up to 90 min after glucose infusions. Calves were heavier for HP until week 12, after which the difference disappeared. By design, the MR intake was higher in the HP group resulting in a higher energy intake and a higher average daily gain in the preweaning phase. Blood glucose curves were not different at week 6, but at week 12, 5 min after the infusion, glucose was higher in HP calves. Insulin curves were not different at week 6. Nevertheless, in week 12, a higher insulin concentration was observed for HP 5, 10, 15, 20, 30, 35, and 45 min’ postinfusion, indicating a higher requirement of insulin to control glycemia. Differences between HP and LP calves were also observed for the quantitative insulin sensitivity check index, maximum insulin concentration, and insulin delta at week 12. Blood glucose reached maximum concentration within 5–10 min of the IVGTT test, and the concentration was, on average, 8.58 and 10.80 mmol/l at weeks 6 and 12, respectively. Insulin reached maximum concentration within 10–15 min of the IVGTT, and concentrations were, on average, 33.32 and 32.61 μUI/ml at weeks 6 and 12, respectively. Doubling MR supply improved animal growth up to weaning, but these differences disappeared by the end of the feeding period. Despite similar responses to glucose infusions preweaning, higher milk supply seemed to decrease insulin sensitivity after weaning.

The objective of this study was to evaluate the effect of inclusion of an extruded high-fat pellet mixed with a conventional pelleted calf starter on energy intake and performance around weaning in calves. To this end, 75 female Holstein newborn calves (41.0 ± 4.98 kg) were randomly assigned to 1 of 5 iso-nitrogenous solid feed treatments consisting of 4 levels of fat inclusion by mixing a low-fat highly fermentable control pellet with 3 different levels of inclusion of an extruded high-fat pellet [control (100:0), 90:10, 80:20, and 70:30], and a high-fat single pellet (HFSP). The HFSP was equivalent iso-energetic and iso-nitrogenous, although it had almost 1 percentage point difference in fat relative to the 80:20 treatment, to contrast the effect of the dual-component pellet mixture. The extruded high-fat starter feed contained a high proportion of fat (38%), mainly from hydrogenated palm fatty acids. Calves were offered a milk replacer up to 900 g/d, and then pre-weaned at 49 d of age by halving milk allowance until 56 d when calves were weaned. Calves had ad libitum access to the starter diets, chopped straw, and water. Individual milk replacer and starter intakes were recorded daily and BW was determined weekly. A glucose tolerance test was performed at 49 and 84 d of age to evaluate blood glucose homeostasis. Apparent total-tract digestibility was determined from 70 to 75 d of age. Calves on the 90:10 treatment had greatest starter feed intake mainly due to a marked increase in solid feed intake around weaning. Metabolizable energy intake was increased when the extruded pellet was included in the starter. No differences were present in digestibility of ether extract among solid feed treatments. The area under the curve of blood glucose concentration after the glucose tolerance test was greatest in 80:20; intermediate in 70:30, HFSP, and control; and lowest in 90:10 calves. No differences were observed for insulin or other parameters related to blood glucose homeostasis. Delivering dietary fat by mixing an extruded high-fat pellet with a conventional highly fermentable pellet to reach a total fat content of 7% results in increased starter intake, energy intake, and body weight gain until 84 d of age compared with a conventional low-fat pellet, or a single pellet with increased fat content.

Supra-nutritional vitamin E supplementation is a commonly used approach to delay lipid oxidation and colour deterioration in lamb and beef meat marketed under modified atmosphere packaging. However, these applications lack a precise calibration of dose for the desired effect and, in addition, limited information is available regarding the use of natural vitamin E for this purpose.; Results: Three hundred and sixty Rasa Aragonesa lambs were fed diets supplemented with all-rac-α-tocopheryl acetate (250, 500, 1000 and 2000 mg kg-1 compound feed), RRR-α-tocopheryl acetate (125, 250, 500 and 1000 mg kg-1 compound feed) and a basal diet without vitamin E supplementation for 14 days before slaughter at 25.8 ± 1.67 kg body weight. Vitamin E supplementation had no effect (P > 0.05) on average daily weight gain, feed intake and feed efficiency. Display time had larger effects on lipid oxidation, colour stability, myoglobin forms and meat discolouration parameters compared to vitamin E supplementation. However, vitamin E source and dosage significantly extended meat shelf-life as indicated by lipid oxidation, redness, hue angle, metmyoglobin formation, deoxymyoglobin formation, A580-630 and ISO2 .; Conclusion: The quantification of these effects demonstrated that the biological activity value of 1.36 used to distinguish both vitamin E sources is not appropriate for meat quality enhancing properties. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

The benefits of feeding elevated quantities of milk to dairy calves have been well established. However, there is a reluctance to adopt this method of feeding in commercial dairy production because of concerns around growth, health, and ruminal development during weaning. The objective of this study was to characterize the effect of an abrupt (0 d step-down) or gradual (12 d step-down) feeding scheme when calves are fed an elevated plane of nutrition (offered 1.35 kg of milk replacer/d). For this experiment, a total of 54 calves were randomly assigned to an abrupt or a gradual weaning protocol before weaning at 48 d of life. Calves were housed and sampled in individual pens for the duration of the experiment, and milk, starter, and straw intake were measured on a daily basis. Body weight was measured every 6 d, whereas blood, rumen fluid, and fecal samples were collected on d 36 (pre-step-down), 48 (preweaning), and 54 (postweaning) of the experiment. Although the growth rates of the step-down calves were lower from d 37 to weaning (0.62 ± 0.04 vs. 1.01 ± 0.04 kg/d), the postweaning average daily gain was greater compared with the group that was abruptly weaned (0.83 ± 0.06 vs. 0.22 ± 0.06 kg/d). Total ruminal volatile fatty acid was greater in the step-down group on the day of weaning (d 48; 59.80 ± 2.25 vs. 45.01 ± 2.25 mmol), whereas the fecal starch percentage was lower during postweaning compared with the abruptly weaned calves (d 54; 3.31 ± 0.76 vs. 6.34 ± 0.76%). Analysis of the digestive tract of bull calves on d 55 revealed minimal differences between gross anatomy measurements of gut compartments as well as no morphological differences in rumen papillae development, yet the total mass of rumen when full of contents was larger in the step-down calves (7.83 ± 0.78 vs. 6.02 ± 0.78 kg). Under the conditions of this study, the results showcase the benefits of a step-down feeding strategy from an overall energy balance standpoint, due to increased adaptation of the gastrointestinal tract preweaning.

The recent trend in the dairy industry toward ad libitum feeding of young calves merits reconsideration of calf milk replacer (CMR) formulations. Additionally, feed intake regulation in young calves provided with ad libitum milk and solid feeds is insufficiently understood. This study was designed to determine the effect of exchanging lactose for fat in CMR on voluntary feed intake and growth performance. Lactose was exchanged for fat on a weight/weight basis, resulting in different energy contents per kilogram of CMR. Thirty-two male calves (1.7 ± 0.12 d of age, 47.6 ± 0.83 kg of body weight) were assigned to 1 of 16 blocks based on arrival date. Within each block, calves were randomly assigned to 1 of 2 treatments. The experimental period was divided into 4 periods. In period 1, until 14 ± 1.7 d of age, calves were individually housed, restricted-fed their assigned CMR treatments at 2.5 to 3 L twice daily, and provided with unlimited access to water, chopped straw, and starter. In period 2, calves were group-housed with 8 calves per pen and received ad libitum access to their assigned CMR treatments, starter feed, chopped wheat straw, and water. During period 3, from 43 until 63 d of age, calves were weaned by restricting CMR allowance in 2 steps, maintaining access to all other feeds. All calves were completely weaned at d 64 of age and were monitored until 77 d of age (period 4). Measurements included the intake of all dietary components, body weight gain, and a selection of blood traits. Increasing fat content at the expense of lactose decreased CMR intake by 10%, whereas total calculated metabolizable energy intake and growth remained equal between treatments. Total solid feed (starter and straw) consumption was not affected by CMR composition. These data indicate that calves fed ad libitum regulate their CMR intake based on energy content. High-fat CMR increased plasma phosphate, nonesterified fatty acids, triglycerides, and bilirubin, whereas plasma glucose remained unchanged. Despite the limited animal numbers in the present experiment, there was a significant decrease in the total number of health events (mainly respiratory) requiring therapeutic intervention and in the total number of therapeutic interventions in calves fed high-fat CMR. Calves appeared to consume CMR based on energy content, with a difference in ad libitum intake proportional to the difference in energy content of the CMR, maintaining equal body weight gain and solid feed intake.

A major goal in treatment of calves with diarrhea is to restore hydration and to correct metabolic acidosis. This can be achieved by the administration of oral electrolyte solutions (OES). However, the composition of OES products and the administration protocols in practice vary widely, which can potentially compromise the efficacy and safety of these treatments. In particular, administration of OES in milk replacer (MR) and the absence of water supply in young calves are not unusual and these conditions could compromise calf health. In this light, the objective of this study was to evaluate the efficacy and safety of OES administered in MR and in water without access to water. Forty-five male Holstein calves (16.6 ± 1.6 d of age and 45.4 ± 2.2 kg at arrival) were purchased from a collection center located in the Netherlands. After arrival, calves went through an adaptation period of 4 d. Calves that developed diarrhea within 6 d after the end of the adaptation period were enrolled in the study, and the remaining calves were sold after being weaned. Upon morning detection of abnormal fecal scores (d 1 starting point), calves were blocked based on initial BW. Within each block, calves were randomly assigned to 1 of 2 treatments, including a control consisting of a small dose of whey (CON; n = 12) and an OES treatment (OES; n = 14). Treatments were blinded to the farm staff by randomly assigning a letter to each treatment. Treatments were simultaneously administered for 4 d in MR (2.5 L at 0800 and 1730 h) and in water (3 L at 1300 and 2200 h). Calves had no supplemental access to plain water. Blood samples were taken at 0600 h for 4 d, and fecal scores (0 = normal; 1 = watery feces) were assessed daily at 0900 h for 15 consecutive days. Additionally, skin turgor and degree of enophthalmos were assessed at 1000 h from d 1 to 4 using a 3-level scoring system. Calves fed OES had a higher prevalence of diarrhea on d 3, 4, and 5 as well as higher prevalence of delayed skin turgor and increased degree of enophthalmos over the 4 monitoring days. Diarrhea duration was longer in calves receiving OES than in calves receiving CON (4.2 d vs. 2.1 d, respectively). The OES treatment resulted in hypernatremia (serum Na+ >145 mmol/L) within 48 h after the first OES administration. Hypernatremia was linked with higher serum Cl− and urea concentrations and thus higher serum osmolarity in OES calves compared with CON calves. Administered under these conditions, OES resulted in various degrees of hypernatremia and a delayed recovery from diarrhea, thus defeating the purpose of OES administration.

BACKGROUND: Due to the growing public concern regarding the addition of chemical antioxidants to foods, focus has shifted towards natural alternatives. Because of their antioxidant potential, culinary herbs and spices have long been used to extend the shelf-life of foods. However, a better understanding of the fate of these products following intake is required to assess their use in lamb diets. RESULTS: Two hundred and eighty-eight Rasa Aragonesa male lambs (70 days old) were supplemented (5.0 g kg −1 compound feed) with bay, marjoram, oregano, rosemary, thyme, turmeric, cumin, caraway, dill, cinnamon and nutmeg extracts for 14 days before slaughter. Dietary supplementation with plant extracts had no effect on intake, growth performance or antioxidant activity in blood (TEAC values). In muscle, nutmeg supplementation increased (P < 0.05) the radical-scavenging capacity (TEAC), whereas a decrease in the radical-scavenging capacity was found for lambs supplemented with oregano, dill, cinnamon and nutmeg (ORAC values). In liver, nutmeg supplementation increased (P < 0.05) the antioxidant capacity (TEAC), whereas bay (ORAC), turmeric, cinnamon and nutmeg (DPPH • values) decreased (P < 0.05) the radical-scavenging capacity of the tissue. In kidney, a lower (P < 0.05) radical-scavenging capacity (TEAC values) was found in lambs supplemented with oregano, cumin and caraway, whereas, turmeric, cumin, caraway, cinnamon and nutmeg increased (P < 0.05) the antioxidant capacity (ORAC values) in kidney. CONCLUSION: Supplementation of lamb diets with plant extracts affected radical-scavenging activity in muscle, liver and kidney. However, due to the divergent results of the different assays for the same tissue, it is not advisable to discriminate plant extracts using this approach.

The objective of this study was to analyze the mammary gland transcriptome to determine how preweaning nutrient supply alters the molecular mechanisms that regulate preweaning mammary development. Holstein heifers were fed via milk replacer (MR) either an elevated level of nutrient intake (ELE; on average, 5.9 ± 0.2 Mcal of ME in 8.4 L of MR/d, n = 6) or a restricted amount of nutrients (RES; 2.8 ± 0.2 Mcal of ME in 4 L of MR/d, n = 5) for 54 d after birth, at which point they were slaughtered and samples of mammary parenchyma tissue were obtained. Parenchymal mRNA was analyzed, and the fold change (FC) of 18,111 genes (ELE relative to RES) was uploaded to Ingenuity Pathway Analysis (IPA) software (Qiagen Bioinformatics, Redwood City, CA) for transcriptomic analysis. Using a threshold of P < 0.05, IPA identified that the FC of 1,931 of 18,811 differentially expressed genes (DEG) could be used for the analysis. A total of 18 molecular and cellular functions were relevant to DEG arising from the treatments; the 5 functions most associated with DEG were cell death and survival, cellular movement, cellular development, cellular growth and proliferation, and lipid metabolism. Based on the directional FC of DEG, the mammary gland of ELE heifers was predicted to have increased epithelial-mesenchymal transition (Z = 2.685) and accumulation of lipid (Z = 2.322), whereas the synthesis of DNA (Z = −2.137), transactivation of RNA (Z = −2.254), expression of RNA (Z = −2.405), transcription (Z = −2.482), and transactivation (Z = −2.611) were all predicted to be decreased. Additionally, IPA predicted the activation status of 13 upstream regulators with direct influence on DEG as affected by ELE feeding that were ligand-dependent nuclear receptors (n = 2), enzymes (n = 1), or transcription regulators (n = 10). Of these, 6 were activated (Z > 2) and 7 were inhibited (Z < −2). In summary, feeding ELE preweaning altered the mammary transcriptome of Holstein heifers, affecting cell functions involved in the morphological and physiological development of the mammary gland.

The objective of this study was to investigate how preweaning plane of milk replacer intake and age can affect insulin and glucose kinetics as well as abomasal emptying rate in dairy calves fed twice a day. A total of 12 female Holstein Friesian calves were blocked by cow parity, paired by colostrum origin, and were randomly assigned to a high plane of milk replacer intake (8 L/d, 1.2kg of milk replacer/d; n=6) or a low plane of nutrition (4 L/d, 0.6kg of milk replacer/d; n=6). All calves received 4 L of colostrum over 2 meals (1 and 6h after birth) and were then directly transferred to their assigned feeding plans until they were stepped-down from milk by 50% during wk 7 and weaned on wk 8. Milk replacer (24% crude protein, 18% crude fat) was fed at 150g/L twice daily (0700 and 1700h) and all calves had ad libitum access to pelleted calf starter, chopped wheat straw, and water. Jugular catheters were placed in all calves at 4, 7, and 10wk of age. Then, postprandial response to plasma glucose, insulin, and acetaminophen (supplied with the meal) were determined to measure abomasal emptying. The next day, a glucose tolerance test was conducted by infusing glucose via the jugular catheter. At 4 and 7wk of age, the rate constant (%/h) for abomasal emptying of the meal was lower in high calves (0.21±0.02 in wk 4; 0.27±0.02 in wk 7) compared with low (0.34±0.02 in wk 4; 0.47±0.02 in wk 7). The postprandial plasma insulin area under the curve over 420min was greater in high calves (18,443±7,329; low=5,834±739 µU/mL) compared with low. We found no differences in glucose tolerance test kinetics between the high and low dairy calves at 4, 7, or 10wk of age. The findings from this study suggest that feeding dairy calves an elevated plane of nutrition in 2 meals of milk replacer per day does not decrease insulin sensitivity.

Most milk replacers (MR) contain a higher lactose:fat ratio compared to whole milk, potentially affecting nutrient absorption and use by the calf. This study evaluated how body composition and intestinal development were affected when lactose was replaced with fat in MR. Thirty-four calves (43.3 ± 0.8 kg) were blocked (BW and dam parity), and randomly assigned to a high-lactose (43.8% lactose and 17.1% crude fat) or high-fat (37.9% lactose and 23.4% crude fat) MR. Calves were fed pooled colostrum within 2 h (18% of metabolic body weight (MBW)) and 12 h (9 %MBW) postnatal, followed by MR feeding (18 %MBW) twice daily. Calves were weighed pre-prandially at birth and on d 7. Calves were euthanized on d 7 to sample intestinal tissue and analyze body composition using dual-energy x-ray absorptiometry. Samples of intestinal segments were processed to evaluate histomorphology using bright-field microscopy. Data were analyzed using PROC MIXED in SAS software. Total gain (3.90 vs. 2.29 ± 0.38 kg, P = 0.01) and gain:ME intake (44.64 vs. 28.61 ± 4.32 kg, P = 0.02) were greater for high-fat compared to high-lactose calves, whereas body composition was unaffected (P = 0.13). Proportionally, the large intestine was 0.11 ± 0.02 %BW heavier (P = 0.03) in high-fat calves compared to high-lactose calves, while their small intestine tended to be 0.16 ± 0.06 %BW heavier (P = 0.09). Small and large intestine length did not differ (P = 0.96). High-fat calves had wider villi (125.41 vs. 96.58 µm, P = 0.05) in the jejunum but shorter villi (414.17 vs. 470.96 µm, P = 0.02) in the ileum compared to high-lactose calves. Macronutrient composition affected intestinal histomorphology and improved efficiency of ME use for BW gain. Understanding how fat (including its source) influences nutrient efficiency in dairy calves may improve nutritional strategies on farm.

Feeding calves an elevated plane of nutrition pre-weaning improves growth. However, some controversy remains about the optimal time of weaning required to minimize the decline in growth commonly associated to milk withdrawal. This experiment aimed to determine the influence of weaning age on performance of calves fed milk replacer on an elevated plane of nutrition (8L d, 150 g L, 1.2 kg calf d) and to further understand the impacts of weaning age on gastrointestinal development. To meet these objectives, 108 Holstein bull calves (18.7±2.69 d old) were blocked by BW and randomly assigned to one of three treatments: step-down weaning at 8, 10 or 12 weeks of age. Daily milk replacer supply and refusals, and weekly starter and hay intakes were recorded throughout the 10 week experiment. Average daily gain (kg d) and BW (kg) were measured weekly. Digestive tract development was assessed by sampling blood and fecal matter at 5, 7, 9, 11 and 13 weeks of age. Blood was analysed for βHBA as a marker of rumen development (ruminal ketogenesis) and fecal starch content was used to evaluate its total tract digestibility. Intakes of starter were higher in calves weaned at 8 weeks of age, from week 7 onwards, translating into differences in total starter consumption across the 10 week trial (P 0.05), yet, βHBA presented smaller spikes at weaning with increasing weaning age (P

Made available in DSpace on 2015-10-22T06:21:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-01-01. Added 1 bitstream(s) on 2015-10-22T09:46:18Z : No. of bitstreams: 1 S0101-20612015000100189.pdf: 1200210 bytes, checksum: 60e2ee5b36ff829d54b533be0da63709 (MD5) CICYT Instituto de Salud Carlos III, ISCIII (CIBEROBN) from the Spanish Ministry of Science and Innovation Ministerio de Ciência e Innovacion (MICINN) Quality Group from Generalitat de Catalunya Generalitat de Catalunya (GC) Foundation Alfonso Martin Escudero Culinary herbs and spices have long been considered essentially as flavor enhancers or preservatives, with little attention given to their potential health-promoting properties. Nevertheless, recent research has shown them to be significant dietary sources of bioactive phenolic compounds. Despite noteworthy efforts performed in recent years to improve our knowledge of their chemical composition, a detailed phenolic profile of these plant-based products is still lacking. In the present work, antioxidant activities and phenolic composition of five herbs and spices, namely caraway, turmeric, dill, marjoram and nutmeg, have been studied. The use of liquid chromatography coupled to LTQ-Orbitrap mass spectrometry enabled the identification of up to 42 phenolic compounds. To the best of our knowledge, two of them, apigenin-C-hexoside-C-pentoside and apigenin-C-hexoside-C-hexoside have not been previously reported in turmeric. Qualitative and quantitative differences were observed in polyphenol profiles, with the highest phenolic content found in caraway. Multivariate statistical treatment of the results allowed the detection of distinctive features among the studied herbs and spices. Nutrition and Food Science Department, Reference Network Food Technology – XaRTA, Research Institute of Nutrition and Food Safety – INSA, Pharmacy School, University of Barcelona, Spain Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición – CIBEROBN, Instituto de Salud Carlos III, Spain Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science and Technology, University of Vigo, Spain Nutreco Research and Development, Boxmeer, The Netherlands Department of Food and Nutrition, School of Pharmaceutical Science, São Paulo State University, São Paulo, SP, Brazil CICYT: AGL2010-22319-C03 CICYT: AGL2013-49083-C3-1-R GC: 2014 SGR 773

This study evaluated the effect of dietary vitamin E supplementation (1000mg of DL-α-tocopheryl acetate/kg of basal diet) on physicochemical and fatty acid stability of fresh and thawed lamb leg chops, frozen stored for 3, 6 and 9months. Legs were chopped, modified atmosphere packaged (70%O2/30%CO2) and maintained under retail conditions (4±0.5°C, with 14h fluorescent light) for 9days. Muscle α-tocopherol concentration was over 3.5-fold higher in supplemented samples than in control lambs. The effect of dietary vitamin E was independent of frozen storage, so these effects were analysed separately. Vitamin E supplementation reduced lipid oxidation (P≤0.001) and decreased metmyoglobin formation, leading to a more attractive colour of meat. Moreover, supplementation led to a higher percentage of polyunsaturated fatty acids. Therefore, vitamin E supplementation could be recommended for preserving either fresh or thawed lamb.

The increasing availability of automated milk dispensers on dairy farms facilitates ad libitum milk supply but weaning calves from high milk allowances is a challenging process. This study evaluated different gradual weaning methods for their impact on starter intake and growth. Thirty-six Holstein (n = 30) or crossbred (n = 6) bull calves were individually housed from d 2–14 of age and had ad libitum access to milk replacer from teat buckets. From d 15–84 of age, calves were grouped and had ad libitum access to milk replacer, starter, straw and water from automated feeders. At d 35, calves were blocked (age and breed), and randomly assigned to a weaning method: (1) Linear (LIN), milk supply was stepped down to 6 L/d on d 36, and linearly reduced between d 36 and 63 from 6 to 2 L/d. (2) Step-down (STEP), milk supply was stepped down to 6 L/d from d 36–48, 4 L/d from d 49–56 and 2 L/d from d 57–63. (3) Dynamic (DYN), at d 36, milk supply was reduced for each individual calf to 75% of the average voluntary consumption between d 29–35, then maintained for 9 d, and then reduced to 50% for 10 d, and to 25% for 9 d. DYN calves received more milk during weaning than LIN calves, whereas STEP calves had intermediate milk intake. Starter intake was not affected by weaning method. DYN calves grew faster and were heavier than STEP calves during post-weaning period, whereas LIN calves performed similarly to DYN calves (1.329 ± 0.082, 1.099 ± 0.082 and 1.228 ± 0.082 kg/d; 123.5 ± 2.41, 116.6 ± 2.41 and 120.4 ± 2.41 kg at d 84). These results highlight the post-weaning benefits of DYN and LIN weaning methods when compared with more abrupt step-down strategies.

It is unknown how dairy heifer skeletal muscle responds to increased pre-weaning ME intake. Therefore, the objective was to determine how elevated ME provision during the pre-weaning period affects the expression of the skeletal muscle transcriptome. Holstein heifers consumed either 5.9 (elevated, ELE, n = 4) or 2.8 ± 0.2 Mcal ME (control, n = 6) per day in milk replacer (28% CP, 15% fat). Heifers were harvested at d 54 and semimembranosus muscle was snap-frozen in liquid N(2) and stored at -80°C until analysis with Affymetrix Bovine Gene 1.1 ST arrays to profile transcriptome expression. A moderated t-test using a Bayesian model was used to generate the gene data set. Ingenuity Pathway Analysis software analyzed the fold change (FC; ELE/control) in expression of 18,811 genes, of which 577 met the threshold (P < 0.01) for analysis. These results reflect myocyte and intramuscular adipocyte contributions to the transcriptome expression. Decreased or increased activity was declared using a z-score ≤ -2 or ≥ 2, respectively, and trends were discussed when -2 < z < 0 or 0 < z < 2. PPARGC1A was identified as the top affected (P < 0.001, 22 molecules) upstream regulator within the transcriptome. Based on FC of gene expression, triacylglycerol concentration was predicted to increase (z = 2.043, P < 0.001, 26 molecules affected) while the quantity of lipid peroxide may decrease (z = -1.982, P = 0.003) for ELE calves. As a result, lipid metabolism was the most affected (P ≤ 0.017, 96 molecules) cellular function, while the adipogenic pathway was determined to be the third top affected (P = 0.010, 118 molecules) canonical pathway. Gene results suggest that consumption of increased ME during the pre-weaning period affected adipogenesis and increased triacylglycerol storage while simultaneously reducing lipid peroxidation within skeletal muscle.

Most milk replacers (MR) contain more lactose than whole milk, which could potentially reduce insulin sensitivity and thus energy utilization in calves. This study evaluated effects of replacing lactose by fat in MR on glucose homeostasis in neonatal dairy calves fed high quantities of MR. Thirty-two male Holstein-Friesian calves (mean ± SE; 43.2 ± 0.81 kg) were blocked by dam parity and BW, and randomly assigned (n = 16) to a high-lactose (17.3% crude fat, 44.3% lactose and 23.2% CP) or high-fat (23.3% crude fat, 37.3% lactose and 23.5% CP) MR. Calves were individually housed, and fed pooled colostrum within 2 h and at 12 h after birth at 18 and 9% of BW(0.75), respectively. From 24 h after birth, calves were transitioned to be fed MR at 18% of BW(0.75) (150 g/L) twice daily at 0700 and 1900 h. A glucose tolerance test was conducted on d 4 after an 8 h fast by an intravenous infusion of glucose (0.54 g/kg BW(0.75)), followed by an intravenous infusion of insulin (3.9 µg/kg BW(0.75)) after 20 min. Sequential blood samples were collected from a catheter, and analyzed for plasma glucose concentration. Maximum glucose concentration and corresponding time point were unaffected by treatment. Area under the curve (AUC) calculated over 20 min was 7% greater (179.7 ± 4.82 vs. 167.7 ± 4.28 mmol/L; P = 0.04) in high-lactose calves as compared with high-fat. Baseline glucose concentration and AUC over 420 min tended (P = 0.09) to be greater in high-lactose calves compared with high-fat. Balancing the lactose to fat ratio of MR toward that of whole milk, by increasing fat and reducing lactose may affect glucose homeostasis in neonatal calves fed a high plane of MR in two meals per day.

Early life nutrient supply can affect the performance of future dairy cows. Adipose tissue is likely to be a key part of that process as it is involved in the regulation of energetic, reproductive and immunological processes. However, it is not clear how early life nutrition alters the molecular regulation of adipose tissue in calves and potentially adult individuals. This study aimed at determining how differences in pre-weaning nutrient supply alter the adipose tissue transcriptome. A total of 12 female Holstein calves were fed two levels of milk replacer (28% CP, 15% fat): restricted (2.8 Mcal ME intake per day, n=5) or enhanced (5.9 Mcal ME intake per day, n=5). All calves had ad libitum access to a commercial calf starter (22% CP) and water. Calves were harvested at 54 ± 2 days and adipose tissue was collected for transcriptome analysis through microarray. Ingenuity Pathway Analysis analyzed the expression of 19,968 genes, of which 396 were differentially expressed (DE) between groups (P +2), including Lipid Metabolism (Fatty Acid Metabolism), Cell Cycle (Entry into Interphase, Interphase, Mitosis and Cell Cycle Progression), Cellular Assembly and Organization (Cytoskeleton Formation and Cytoplasm Development) and Molecular Transport (Transport of Carboxilic Acid). These findings indicate that adipose tissue of calves under an enhanced nutrient supply is physiologically distinct form restricted calves due to an increased development/expansion rate (adipocyte hypertrophy and hyperplasia) and also a higher metabolic activity through increased fatty acid metabolism. Future studies are necessary to explore whether early life changes in adipose tissue regulation can produce carryover effects and lead to improved adult life performance of dairy cows.

Performance of dairy cows can be influenced by early life nutrient supply. Adipose tissue is diet sensitive and an important component in that process as it is involved in the regulation of energetic, reproductive and immunological functions. However, it is not clear how early life nutrition alters the molecular regulation of adipose tissue in calves and potentially adult individuals. This study aimed at determining how differences in pre-weaning nutrient supply alter gene expression profiles and physiology in omental adipose tissue. A total of 12 female Holstein calves were fed two levels of milk replacer supply: a restricted amount of 11.72 MJ of metabolizable energy (ME) intake per day (n = 6) or an enhanced amount of 1.26 MJ ME intake per kg of metabolic body weight (BW0.75), resulting in supply from 17.58 to 35.17 MJ ME intake per day (n = 6). All calves had ad libitum access to a commercial calf starter and water. Analysis of the transcriptome profiles at 54 ± 2 days of age revealed that a total of 396 out of 19,968 genes were differentially expressed (DE) between groups (p < 0.001, FDR < 0.1). The directional expression of DE genes through Ingenuity Pathway Analysis showed that an enhanced nutrient supply alters adipose tissue physiology of pre-weaned calves. Several biological functions were increased (Z-score > +2), including Lipid Metabolism (Fatty Acid Metabolism), Cell Cycle (Entry into Interphase, Interphase, Mitosis and Cell Cycle Progression), Cellular Assembly and Organization (Cytoskeleton Formation and Cytoplasm Development) and Molecular Transport (Transport of Carboxylic Acid). These changes were potentially orchestrated by the activation/inhibition of 17 upstream regulators genes. Our findings indicate that adipose tissue of calves under an enhanced nutrient supply is physiologically distinct from restricted calves due to an increased development/expansion rate and also a higher metabolic activity through increased fatty acid metabolism.

Herbs and spices have long been used to improve the flavour of food without being considered as nutritionally significant ingredients. However, the bioactive phenolic content of these plant-based products is currently attracting interest. In the present work, liquid chromatography coupled to high-resolution/accurate mass measurement LTQ-Orbitrap mass spectrometry was applied for the comprehensive identification of phenolic constituents of six of the most widely used culinary herbs (rosemary, thyme, oregano and bay) and spices (cinnamon and cumin). In this way, up to 52 compounds were identified in these culinary ingredients, some of them, as far as we know, for the first time. In order to establish the phenolic profiles of the different herbs and spices, accurate quantification of the major phenolics was performed by multiple reaction monitoring in a triple quadrupole mass spectrometer. Multivariate statistical treatment of the results allowed the assessment of distinctive features among the studied herbs and spices.