Chromium improves production and alters metabolism of early lactation cows in summer

Chromium in the Diet of Dairy Calves: Benefits for Growth Performance, Feed Efficiency, Digestibility, and Health

Chromium (Cr) is a mineral that helps animals subjected to stressful conditions. The suckling period is characterized by several stressful episodes, particularly during the first hours after birth and at weaning. There is little consumption of concentrate by calves in the first weeks of life; consequently, consuming any supplement added to feed would be negligible. Thus, the hypothesis was that the calves would take it in earlier if Cr were consumed in a milk replacer instead. Therefore, our study aimed to determine whether including organic Cr in calf feed (via milk replacer or concentrate) during the suckling phase would improve calf health and growth performance. Twenty-four male Holstein calves with an average age of 8 ± 4 days and 39.8 ± 6.9 kg average body weight were used. Calves were randomly divided into three groups: (a) Chromium-Milk (CR-M), receiving 4 mg Cr/animal/day via milk replacer during the 60 experimental days of suckling (n = 8); (b) Chromium-Concentrate (CR-C), receiving 4 mg Cr/animal/day via concentrate (n = 8); (c) Control (C), animals that did not receive Chromium (n = 8). The experiment lasted 75 days, divided into two well-defined stages: suckling (1-60 days) and weaning (61-75 days). Body weight weekly, daily feed intake, and blood samples taken every two weeks during the experiment were evaluated. At the end of the experiment, the apparent digestibility evaluation was carried out, with the results of weight and consumption carried out, and a feed efficiency analysis was carried out. It was observed that the inclusion of organic Cr (regardless of whether it was milk or concentrate) increased body weight gain (kg) for the CR-C group: 41.8 kg, CR-M: 40.4 kg compared to the C: 34.2 kg (p = 0.01). The protein digestibility was higher in the CR-M group (52%, p = 0.05). Cr consumption increased Cr concentrations in the serum of the calves and was higher in the first week in the animals in the CR-M group. This did not happen for the C group; however, with higher concentrate consumption, Cr concentrations increased and remained high until the end of the experiment. Glucose concentrations were higher in the groups that consumed Cr. Total protein concentrations were higher in the CR-M and CR-C groups than in group C. Immunoglobulin A concentrations were higher in groups CR-C and CR-M than in group C (days 40 and 60). In conclusion, the adding Cr to calf feed improves their health, indirectly favors growth performance, and increases protein digestibility.

Effects of dietary chromium supplementation on blood biochemical parameters in dairy cows: A multilevel meta-analytical approach

Chromium (Cr) has been reported to modulate blood biochemistry in dairy cows. However, there is a discrepancy in the literature regarding the effects of dietary Cr supplementation on various blood parameters. This meta-analysis aimed to evaluate the effects of Cr supplementation in dairy cows on blood glucose, insulin, glucagon, nonesterified fatty acid (NEFA), cortisol, and serum total protein (STP) concentrations. Following relevant literature data extraction, a 3-level meta-analytical random effect model was fitted to the data expressed as standardized mean difference (SMD) of outcome measures of control versus Cr-supplemented cows (i.e., difference in mean between control and treatment group or pooled standard deviation). The SMD can be categorized as having a small effect (0.20), a moderate effect (0.50), and a large effect (0.80). The meta-regression identified the potential sources of heterogeneity, including the body weight of cows, experimental duration/duration of Cr supplementation, blood sampling time (3 wk before parturition until 4 wk after parturition categorized as the transition period, else as the nontransition period), and form of Cr complexes. Blood glucose did not differ significantly between control and Cr-supplemented cows with an estimated SMD of μ = 0.0071 (95% confidence interval [CI]: -0.212 to 0.226). The effect of Cr supplementation on blood insulin was also nonsignificant with an SMD of μ = 0.0007 (95% CI: -0.191 to 0.193). Cows receiving Cr supplements had significantly higher levels of glucagon than controls (95% CI: 0.116 to 0.489), with an estimated SMD = 0.303. Combined transition and nontransition data suggest Cr supplementation did not affect the concentration of NEFA. However, in transition cows, Cr supplementation significantly decreased blood NEFA levels as compared with controls (95% CI: -0.522 to -0.0039), with estimated SMD = -0.263. The estimated SMD was μ = -0.1983 (95% CI: -0.734 to 0.337) for cortisol and -0.0923 (95% CI: -0.316 to 0.131) for total protein. In summary, Cr supplementation in the transition cows decreased NEFA concentration. Blood glucose, insulin, cortisol, and STP concentrations were unaffected. However, Cr supplementation increased glucagon concentration.

Plasma metabolic profiling reveals that chromium yeast alleviates the negative effects of heat stress in mid-lactation dairy cows

Chromium yeast (CY) supplementation has the potential to alleviate the negative effects of heat stress in dairy cows, but the mechanism remains elusive. We aimed to identify the metabolic mechanisms whereby CY supplementation alleviates the negative effects of heat stress in mid-lactation dairy cows. Twelve Holstein dairy cows with similar milk yield (24.6 ± 1.5 kg/d), parity (2 or 3) and days in milk (125 ± 8 d) were fed the same basal diet containing 0.09 mg of Cr/kg DM. They were allocated randomly to 2 groups: a control group (CON, without CY supplementation) and a CY group (CY, administered 0.36 mg Cr/kg DM). The experiment was performed over 8 weeks during a hot summer, in which the mean temperature-humidity index was 79.0 ± 3.13 (>72), indicating that the dairy cows were exposed to heat stress. Chromium yeast supplementation reduced rectal temperature (P = 0.032), and increased the lactation performance by increasing the yield of milk (+2.6 kg/d), protein, lactose and total solid, and protein and lactose percentages in the milk of the heat-stressed dairy cows (P < 0.05). Supplementation with CY increased the serum glucose and thyroxine concentrations, but reduced the urea nitrogen, insulin, and triiodothyronine concentrations on d 56 (P < 0.05). Furthermore, plasma metabolomic analysis was performed using liquid chromatography tandem-mass spectrometry, which identified 385 metabolites in the two groups. Subsequently, 16 significantly different metabolites in the plasma, were significantly higher in the CY group (variable importance for the projection >1.0, P < 0.05), and found to be involved in 6 Kyoto Encyclopedia of Genes and Genomes pathways, including those involved in nicotinate and nicotinamide metabolism. Specifically, plasma concentration of nicotinamide was higher after CY supplementation, which might also contribute to the reduction of rectal temperature, the regulation of glucose homeostasis, and an improvement in the lactation performance of heat-stressed dairy cows. In conclusion, CY supplementation reduces rectal temperature, influences metabolism by reducing serum insulin concentration and increasing serum glucose and plasma nicotinamide concentrations, and finally increases lactation performance of heat-stressed dairy cows.

Effects of dietary chromium supplementation on dry matter intake and milk production and composition in lactating dairy cows: A meta-analysis

Introduction

Chromium (Cr) is an essential mineral that has been demonstrated to enhance milk production in dairy cows. This study aims to evaluate the effects of dietary Cr supplementation on dry matter intake (DMI), milk production and composition using a meta-analysis based on existing literature.

Methods

A random effects meta-analysis was performed to investigate the effects of dietary Cr supplementation on DMI, milk production and composition. The heterogeneity was assessed using the I 2 statistic and Q test, while Egger's test was used to evaluate publication bias.

Results

The meta-analysis discovered that Cr-supplemented cows had a significantly higher DMI compared to those not supplemented, with an increase of 0.72 kg/day [95% confidence interval (CI), 0.46-0.97]. The regression model indicated that DMI significantly increased by 0.9 g/kg of body weight (BW) and by 80.5 g for an increase of 1 mg of Cr supplement. The supplementation phase was associated with an increase in DMI, with an increase of 0.4582 kg/day for BFP (before parturition) and 0.853 kg/day for AFP (after parturition). The methionine and yeast forms of Cr increased DMI by 0.714 and 1.137 kg/day, respectively. The DMI was increased by 2.137 and 0.620 kg/day for multiparous (MP)+ primiparous (PP) cows and MP cows, respectively. Milk production was also increased by Cr supplementation, with an increase of 1.20 kg/day (95% CI, 0.65-1.76). The regression model indicated that milk production increased by 2.3 g/day for an increase of 1 kg of BW and by 122.4 g/day for an increase of 1 mg of Cr supplement. Milk production also increased with the duration of the experiment and days in milk. The amino acid and methionine forms of Cr complexes increased milk production by 1.645 and 1.448 kg/day, respectively. Milk production increased by 1.087 and 1.920 kg/day for MP and PP cows, respectively. Milk composition was not significantly affected by Cr supplementation. Egger's test for publication biases was not significant for all responses of interest.

Discussion

The meta-analysis showed that Cr supplementation improves DMI and milk production in dairy cows. The results suggest that the supplementation phase, form of Cr, and parity should be considered when supplementing dairy cows with Cr. The results have important implications for the dairy industry and can contribute to the development of more effective feeding strategies for dairy cows.

Reproductive and lactational responses of multiparous dairy cattle to short-term postpartum chromium supplementation during the summer months

The objective of this work was to evaluate the potential benefits of short-duration, high-dose chromium (Cr) supplementation in early postpartum dairy cows during the summer months. Multiparous, early-lactation cows (20.95 ± 0.21 d in milk) were assigned to 1 of 2 treatment groups: (1) control diet (Con; n = 10) or (2) control diet + Cr propionate (CrPro; 12 mg/head per day Cr; n = 12). Measurements of ovarian structures, respiration rates (RR), rectal temperatures (RT), and blood glucose concentrations were recorded every 3 d. Blood was also collected for analysis of plasma progesterone concentrations. Every 6 d, in conjunction with ultrasonography, endometrial cytology samples were collected via cytobrush from each cow to determine the incidences of subclinical endometritis, as determined by polymorphonuclear leukocyte (PMNL)%. No differences were detected in RR, RT, blood glucose, feed intake, milk yield, or change in body weight. The supplementation did, however, improve some reproductive parameters. At cytology sample 6, the PMNL% increased in Con cows, and was greater than the PMNL% in the CrPro group. Chromium consumption did not affect the number or size of most follicles, with the exception being the 6 to 9 mm category where the CrPro group had a greater average diameter and tended to have greater numbers of follicles in this category. While corpus luteum numbers and size did not differ between treatments, the ratio of progesterone to average corpus luteum volume was greater in the CrPro group compared with the Con group. The results from this study indicate that, whereas the short-term, high-dose supplementation strategy did not affect feed intake or milk yield, this Cr supplementation strategy could benefit reproductive performance during periods of stress.

Effects of sodium bicarbonate and chromium propionate supplementation on growth performance, blood indices of Beetal bucks under heat stress

The objective of the current experiment was to determine the effects of sodium bicarbonate (SBC) and chromium propionate (Cr) supplementation on dry matter intake (DMI), growth performance, blood indices, feed sorting behavior, and digestibility of nutrients during the hot and humid condition in Beetal bucks. Twenty-eight Beetal bucks were randomly assigned to four concentrates treatments (n = 7 bucks/treatment) under 2 × 2 factorial arrangements. The factors were (1) chromium supplementation, basal diet without any supplementation (C) and basal diet with Cr @ 1.5 mg Cr/head/day (Cr), and (2) sodium bircbonate supplementation, basal diet supplemented with SBC @15 g/kg of DM (SBC) and diet containing SBC @ 15 g/kg of DM) and Cr @ 1.5 mg/day/animal (SBC + Cr). Chromium was drenched to each animal during the morning feeding. The average daily noon temperature-humidity index (THI) was 86.37 ± 4.01. The daily DMI and ADG was higher (P < .0001) in the SBC, and trend for daily DMI was observed (P < 0.01) for the Cr. The feed to gain ratio was tended to improve (P = 0.056) by the supplementation of Cr. Plasma glucose, cholesterol, and catalase concentration were lower (P < 0.05) in the Cr supplemented, whereas plasma BUN and TPP were not influenced (P > 0.05) by the Cr or the SBC supplementation. The feed selection index indicated that supplementation of Cr and SBC had no effects on selection or rejection of feed particles. In Cr-supplemented bucks, there was a trend for higher ADF digestibility. Digestibility of dry matter, organic matter, NDF, and ADF were not affected by Cr or SBC supplementation. In conclusion, co supplementation of Cr @ 1.5 mg/d and SBC @ 15 g/kg resulted in highest DMI, ADG and improved the feed efficiency in heat-stressed fattening bucks by alleviating negative impacts of HS.

Nutritional management of dairy animals for sustained production under heat stress scenario

Dairy industry plays a significant role in the agriculture sector for sustainable growth. Heat stress, on the other hand, has been proven to have a detrimental impact on dairy output in terms of growth, reproductive performance and milk production in dairy animals, especially in tropical areas. Heat stress is one of the most significant issues facing the dairy industry, as rising temperatures and humidity limit animal productivity throughout the summer, resulting in devastating economic repercussions. The purpose of this review is to gather knowledge on the effects of heat stress on dairy output and how to ameliorate them. The diversion of energy resources from the production to the adaptation pathway may be responsible for the loss in productive capacity of dairy animals, when they are exposed to heat stress. There are different approaches pertaining to relieving the adverse effects of heat stress on dairy production system. These approaches may be classified into three major categories viz. genetic, management and nutritional interventions. These approaches might help dairy animals to perform better by reducing the harmful impacts of heat stress. Appropriate shelter design, giving shade, employing sprinklers, installing cooling devices, and using fans and ventilation systems are among the management strategies. The nutritional interventions comprise ration balancing and providing essential micronutrients to improve the productive and reproductive performance. Some of the most widely used dietary measures to ensure optimal production are inclusion of protein or fat (prill fat), micronutrients antioxidants (vitamins and minerals) and some feed additives (Astaxanthin, betaine, melatonin, Chlorophytum borivilianum) in the diet. These antioxidants and feed additives can be used to attenuate the negative effects of environmental stress. Furthermore, providing adequate energy and antioxidants help to ensure optimum growth, milk production and reproduction efficiency during heat stress. This review provides an overview of the consequences of heat stress on dairy animals, emphasizes essential nutritional strategies for heat stress reduction in dairy animals, and evaluates the influence of various feed supplements on growth, productivity and physiology.

Effect of chromium methionine supplementation on lactation performance, hepatic respiratory rate and anti-oxidative capacity in early-lactating dairy cows

Chromium may regulate dairy cow metabolism; a chelated formation of chromium methionine (Cr-Met) is available to the feed industry. The objective of this study was to investigate the effect of Cr-Met supplementation on lactation performance, hepatic respiratory rate and anti-oxidative capacity in early-lactating Holstein dairy cows. 64 multiparous cows were assigned to 16 blocks based on parity and milk yield and then the four cows in a block were randomly allocated to four treatment groups with 0, 4, 8 or 16 g/d of Cr-Met per cow supplemented to a basal diet. Cows were moved from an open dry lot to a naturally ventilated tie stall barn 2 weeks before treatment to adapt to this facility, fed and milked at 0630, 1400, and 1930 h every day. The experiment lasted for 12 weeks. Milk yield and composition were recorded weekly. Dry matter intake was measured every 2 weeks for a total of six times throughout the trial. The plasma variables were measured in weeks 4, 8 and 12 of the experiment. Supplementation of Cr-Met did not affect DM intake of cows. As the supplementation of Cr-Met increased, yields of milk, fat, energy corrected milk (P < 0.01) and lactose (P = 0.01) increased in a linear manner. In terms of plasma variables, insulin concentration decreased in a linear manner with Cr-Met supplementation. As for variables relating to hepatic respiration rate, concentrations of pyruvate and NAD in the plasma were increased in quadratic manners, and lactic dehydrogenase activity was linearly increased as Cr-Met feeding levels increased. Moreover, plasma glutathione peroxidase and superoxide dismutase activity were increased in a linear manner. In conclusion, our study suggested that Cr-Met supplementation improved lactation performance of early-lactating dairy cows through enhancing antioxidant capacity and hepatic cellular respiration.

Nutritional Physiology and Biochemistry of Dairy Cattle under the Influence of Heat Stress: Consequences and Opportunities

Simple Summary

Modern dairy cows have elevated internal heat loads caused by high milk production, and the effects of accumulating incremental heat are exacerbated when temperature and humidity increases in the surroundings. To shed this additional heat, cows initiate a variety of adaptive mechanisms including increased respiration rate, panting, sweating, reduced milk yield, vasodilatation, and decreased reproductive performance. Hormonal changes based on reciprocal alterations to the energetic metabolism are particularly accountable for reduced efficiency of the dairy production under the heat stress. As animals experience negative energy balance; glucose, which is also a precursor of milk lactose, becomes the preferential energy fuel. In the absence of proper mitigations, heat stress possesses potential risk of economic losses to dairy sector. Besides physical measures for the timely prediction of the actual heat stress coupled with its proper amelioration, nutritional mitigation strategies should target modulating energetic metabolism and rumen environment.

Abstract

Higher milk yield and prolificacy of the modern dairy cattle requires high metabolism activities to support them. It causes high heat production by the body, which coupled with increasing environmental temperatures results in heat stress (HS). Production, health, and welfare of modern cattle are severely jeopardized due to their low adaptability to hot conditions. Animal activates a variety of physiological, endocrine, and behavioral mechanisms to cope with HS. Traditionally, decreased feed intake is considered as the major factor towards negative energy balance (NEBAL) leading to a decline in milk production. However, reciprocal changes related to insulin; glucose metabolism; failure of adipose mobilization; and skeletal muscle metabolism have appeared to be the major culprits behind HS specific NEBAL. There exists high insulin activity and glucose become preferential energy fuel. Physiological biochemistry of the heat stressed cows is characterized by low-fat reserves derived NEFA (non-esterified fatty acids) response, despite high energy demands. Besides these, physiological and gut-associated changes and poor feeding practices can further compromise the welfare and production of the heat-stressed cows. Better understanding of HS specific nutritional physiology and metabolic biochemistry of the dairy cattle will primarily help to devise practical interventions in this context. Proper assessment of the HS in cattle and thereby applying relevant cooling measures at dairy seems to be the basic mitigation approach. Score of the nutritional strategies be applied in the eve of HS should target supporting physiological responses of abatement and fulfilling the deficiencies possessed, such as water and minerals. Second line of abatement constitutes proper feeding, which could augment metabolic activities and synergizes energy support. The third line of supplemental supports should be directed towards modulating the metabolic (propionates, thiazolidinediones, dietary buffers, probiotics, and fermentates) and antioxidant responses (vitamins). Comprehensive understanding of the energetic metabolism dynamics under the impact of incremental heat load and complete outlook of pros and cons of the dietary ameliorating substances together with the discovery of the newer relevant supplementations constitutes the future avenues in this context.

Potential use of chromium to combat thermal stress in animals: A review

Heat stress (HS) has adverse effects on the body: it decreases body weight, feed efficiency, feed intake, carcass quality, and nutrient digestibility. Chromium (Cr) can prevent lipid peroxidation induced by HS through its strong antioxidant activities, especially when it is added to the poultry diet. It improves the action of insulin and nutrient metabolism (of lipids, proteins, nucleic acid, and carbohydrates) through activation of enzymes associated with such pathways. The results of the studies on Cr added to diets with concentrations of 0.05 mg Cr/kg of Cr-methionine led to improved feed efficiency and DM intake by cows and Holstein dairy calves exposed to high environmental temperatures. Moreover, calves that received Cr at levels of 0.05 mg/kg of body weight tended to have higher serum concentrations of glucose and higher ratios of insulin to glucose. In heat-stressed pigs, Cr addition (200 ppb) increased blood neutrophils by about 37%. Several studies have asserted that Cr can inhibit inflammation in lactating cows by promoting the release of Hsp72, assisting production of IL-10 and inhibiting degradation of IκBα in HS conditions. In addition, Cr supplementation was observed to possibly have positive impacts on both cell-mediated and humeral immunity in heat-stressed buffalo calves. Studies over the last two decades have shown with certainty that chromium supplementation has an impact on many variables in chickens. Moreover, Cr is believed to increase insulin action in insulin-sensitive tissues (i.e., adipose and muscles), resulting in increased farm animal productivity through the improvement of feed intake, growth rate, carcass quality, reproductive parameters and immune functions.

Long-term chromium picolinate supplementation improves colostrum profile of Santa Ines ewe

Chromium (Cr) is a micromineral that is involved in the metabolism of carbohydrates, lipids, ammonia, and nucleic acids; thus, its supplementation can influence the nutritional status of ruminants, and consequently, colostrum profile, since this secretion depends on products secreted by the mammary gland and elements of the maternal bloodstream. The present study investigated the influence of supplementation with Cr bound to organic molecule on the nutritional, immune, and antioxidant quality of ewe colostrum. Thirty-two multiparous Santa Ines ewes (55.3 ± 8.00 kg body weight) were randomly assigned into four groups: T1 (0.0 mg of chromium picolinate (CrPic) supplementation per ewe, n = 8), T2 (0.15 mg of CrPic per ewe, n = 9), T3 (0.30 mg of CrPic per ewe, n = 7), and T4 (0.45 mg of CrPic per ewe, n = 8). Supplementation was supplied during the breeding season, pregnancy, and lactation. Shortly after calving, the first milking colostrum was collected to determine its chemical composition, activity of lysozyme, lactoperoxidase, ceruloplasmin, catalase, glutathione peroxidase, and oxygen radical absorbance capacity. The results show that lactoperoxidase activity decreased with CrPic supplementation (P < 0.01), revealing that this micromineral reduces an important component of defense mechanism in the body. Therefore, the results of this work show that supplementation with chromium picolinate influences colostrum quality.

Impacts of feeding zinc-methionine or chromium-methionine on performance, antioxidant status and physiological responses to transportation stress on lambs

Context Road transportation of farm animals is an unavoidable activity in animal husbandry, which may lead to the stress. Metabolic modifiers, such as minerals, may be an effective strategy to improve the performance and immune system of animals. Aims The present study examined the effects of chromium-methionine (Cr-Met) and zinc-methionine (Zn-Met) supplementation on animal performance and response to transportation stress. Methods Eighteen lambs (18–20 weeks of age) were randomly assigned to the following three dietary treatments for 10 weeks: (1) basal diet (control, 0.021 g/kg Zn and 0.0001 g/kg Cr); (2) basal diet with addition of 10 Cr-Met mg/kg DM (containing 1 mg/kg Cr); and (3) basal diet with addition of 500 Zn-Met mg/kg DM (containing 50 mg/kg Zn). After a 6-week supplementation period, the lambs were transported by road for 3 h. Key results Mineral supplements did not affect final bodyweight, average daily gain or feed conversion ratio. The blood cortisol and aspartate aminotransferase concentrations were increased (P &lt; 0.05) immediately after transportation (AT1) in all groups; however, they were lower in supplemented lambs than in the control (P &lt; 0.05). Animals fed Cr-Met or Zn-Met diets had a higher albumin concentration at AT1 than did the control group (P &lt; 0.05). Lambs on the Zn-Met diet showed a higher blood triiodothyronine and triiodothyronine to thyroxin ratio at AT1 and at 24 h after transportation (AT2) than did lambs receiving the control diet (P &lt; 0.05). Lambs fed the Cr-Met diet had a lower blood malondialdehyde at AT1 and AT2 than did the control lambs (P &lt; 0.05). Total antioxidant capacity (TAC) was higher in the Zn-Met-supplemented group than in other groups (P &lt; 0.05). Supplementation with dietary Zn-Met increased serum TAC concentration in the kidney tissue compared with the control (P &lt; 0.05), but had no effect on superoxide dismutase and glutathione peroxidase activities. The Cr-Met group showed also a lower malondialdehyde concentration (P &lt; 0.05) and higher TAC, superoxide dismutase and glutathione peroxidase activities in the liver tissue (P &lt; 0.05). Conclusions Dietary supplementation with 10 mg Cr-Met/kg (1 mg Cr) in comparison to 500 mg Zn-Met/kg (50 mg Zn) improved the stress response of lambs subjected to a short-time road transportation, whereas growth performance was not affected. Implications The administration of Cr-Met or Zn-Met to diet of lambs before transportation could reduce the adverse effects of road transportation stress.

Genetic Selection for Thermotolerance in Ruminants

Variations in climatic variables (temperature, humidity and solar radiation) negatively impact livestock growth, reproduction, and production. Heat stress, for instance, is a source of huge financial loss to livestock production globally. There have been significant advances in physical modifications of animal environment and nutritional interventions as tools of heat stress mitigation. Unfortunately, these are short-term solutions and may be unsustainable, costly, and not applicable to all production systems. Accordingly, there is a need for innovative, practical, and sustainable approaches to overcome the challenges posed by global warming and climate change-induced heat stress. This review highlights attempts to genetically select and breed ruminants for thermotolerance and thereby sustain production in the face of changing climates. One effective way is to incorporate sustainable heat abatement strategies in ruminant production. Improved knowledge of the physiology of ruminant acclimation to harsh environments, the opportunities and tools available for selecting and breeding thermotolerant ruminants, and the matching of animals to appropriate environments should help to minimise the effect of heat stress on sustainable animal genetic resource growth, production, and reproduction to ensure protein food security.

Effects of dietary chromium propionate on growth performance, metabolism, and immune biomarkers in heat-stressed finishing pigs1

Study objectives were to determine the effects of chromium (Cr) propionate (Cr propionate 0.04%; 0.5 g/kg of feed to deliver 200 parts per billion Cr/d; KemTRACE Cr, Kemin Industries, Inc., Des Moines, IA) on growth performance, metabolism, and health biomarkers in heat-stressed and nutrient-restricted pigs. Crossbred barrows (n = 96; 105 ± 1 kg BW) were enlisted in an experiment conducted in two replicates, blocked by initial BW, and randomly assigned to one of six dietary-environmental treatments: (i) thermoneutral (TN) and fed ad libitum a control diet (TNCtl), (ii) TN and fed ad libitum a Cr supplemented diet (TNCr), (iii) TN and pair-fed a control diet (PFCtl), (iv) TN and pair-fed a Cr supplemented diet (PFCr), (v) heat stress (HS) and ad libitum fed a control diet (HSCtl), or (vi) HS and ad libitum fed a Cr supplemented diet (HSCr). The study consisted of three experimental periods (P). During P0 (5 d), all pigs were housed in TN conditions (21.3 ± 0.1 °C, 56.8 ± 0.3% relative humidity [RH]) and fed the control diet ad libitum. During P1 (5 d), pigs were fed their respective dietary treatments ad libitum and kept in TN conditions. During P2 (35 d), HSCtl and HSCr-treated pigs were fed ad libitum and exposed to progressive cyclical HS conditions (27 to 31 °C, 50 ± 0.3% RH), while TNCtl, TNCr, PFCtl, and PFCr pigs remained in TN conditions and were fed ad libitum or pair-fed to their respective HSCtl and HSCr counterparts to eliminate the confounding effects of dissimilar feed intake. Overall, HS pigs had increased (P < 0.01) rectal temperature, skin temperature, and respiration rate (0.3 °C, 3.8 °C, and 32 breaths per minute, respectively) relative to TN pigs. Overall, HS decreased ADFI and ADG (20 and 21%, respectively; P < 0.01) compared with TN controls. Final BW tended to be increased in HSCr (2.7 kg, P = 0.06) compared with HSCtl pigs. Similarly, ADG tended to be increased during P2 in HSCr relative to HSCtl-treatment (0.77 vs. 0.72 kg/d; P = 0.10). There were no effects of Cr on most production parameters, but ADFI tended to be increased in Cr relative to Ctl-fed pigs (3.19 vs. 3.09 kg/d; P = 0.08). No effects of Cr supplementation were detected on circulating glucose, insulin, NEFA, cholesterol, triglycerides, or lipopolysaccharide binding protein. However, blood neutrophils were increased in HSCr (37%; P < 0.01) relative to HSCtl pigs. In summary, these results suggest Cr supplementation may benefit growth performance during HS.

A Review on the Role of Chromium Supplementation in Ruminant Nutrition-Effects on Productive Performance, Blood Metabolites, Antioxidant Status, and Immunocompetence

With the increase in the global herd, the use of metabolic modifiers has become an important area for many researchers looking for a supraphysiological diet to improve production parameters. For improving the performance of high yielding cows, the optimal balance of all nutrients including microminerals is important. Chromium (Cr) is one of the important micronutrients which plays an important role in metabolism of ruminants. Experimental studies have found that Cr could change performance, immune responses, glucose and fatty acid metabolism, and antioxidant status in dairy cows. In some studies, Cr supplementation improved dry matter intake, milk production, and milk composition of dairy cows in the early, mid, or late stage of lactation. Also, in some studies, performance of growing animal, immune response, and some blood parameters responded positively to Cr supplementation. In conclusion, the effects of Cr supplementation on performance of ruminants are inconsistent; however, its long-term effects on health, productivity, immune system, and antioxidant activity of ruminants still need to be investigated.

Hypoglycemic activity and acute oral toxicity of chromium methionine complexes in mice

The hypoglycemic activity of chromium methionine (CrMet) in alloxan-induced diabetic (AID) mice was investigated and compared with those of chromium trichloride hexahydrate (CrCl3·6H2O) and chromium nicotinate (CrNic) through a 15-day feeding experiment. The acute oral toxicity of CrMet was also investigated in ICR (Institute for Cancer Research) mice by a single oral gavage. The anti-diabetic activity of CrMet was explored in detail from the aspects of body weight (BW), blood glucose, triglyceride, total cholesterol, liver glycogen levels, aspartate transaminase (AST) and alanine transaminase (ALT) levels. The obtained results showed that CrMet had beneficial effects on glucose and lipid metabolism, and might possess hepatoprotective efficacy for diabetes. Daily treatment with 500 and 1000μg Cr/kg BW of CrMet in AID mice for 15 days indicated that this low-molecular-weight organic chromium complex had better bioavailability and more beneficial effects on diabetics than CrCl3·6H2O. CrMet also had advantage over CrNic in the control of AST and ALT activities. Acute toxicity studies revealed that CrMet had low toxicity potential and relatively high safety margins in mice with the LD50 value higher than 10.0g/kg BW. These findings suggest that CrMet might be of potential value in the therapy and protection of diabetes.

Body condition, energy balance and immune status of periparturient Murrah buffaloes (Bubalus bubalis) supplemented with inorganic chromium

Periparturient Murrah buffaloes were used to determine whether body condition, energy balance and immune status are affected by inorganic Cr supplementation. Twenty-four Murrah buffaloes were blocked into four groups having six animals in each group and fed for 60 days pre-partum to 150 days post-partum. Feeding regimen was same in all the groups except that these were supplemented with 0.0, 0.5, 1.0 and 1.5 of Cr per kilogram of dry matter (DM) in the four respective groups. Buffaloes were weighed at fortnightly intervals. Blood samples were collected from the jugular vein at days -60, -30, -15, -7, 0, 7, 15, 30, 60, 90, 120 and 150 of experimental feeding for the estimation of non-esterified fatty acid (NEFA), beta-hydroxybutyric acid (BHBA), Cr level, lymphocyte proliferation, neutrophil phagocytic activity, plasma total immunoglobulin (TIg), immunoglobulin G (IgG) and cortisol levels. Results revealed that with approaching parturition, dry matter intake (DMI), immune response and plasma Cr level decreased (P < 0.05) gradually and minimum values were observed on the day of parturition in all groups. In contrast, body condition score (BCS), plasma NEFA and BHBA concentrations showed increasing (P < 0.05) trends towards calving and level decreased after calving. Dietary Cr supplementation did not have any effect on DMI and BCS, but immune response and plasma Cr concentration showed a positive correlation with dietary Cr supplementation. Buffaloes supplemented with 1.5 mg/kg Cr had significantly (P < 0.05) low plasma NEFA and BHBA concentrations. The results of present findings indicated that dietary inorganic Cr supplementation reduced lipid mobilization and improved immune response in periparturient buffaloes.

Energy metabolites, lipid variables and lactation performance of periparturient Murrah buffaloes (Bubalus bubalis) fed on diet supplemented with inorganic chromium

The aim of this study was to elucidate the effects of chromium (Cr) supplementation as inorganic Cr (CrCl3·6H2O) on energy balance, lipid peroxidation, and lactation performance in periparturient Murrah buffaloes. Twenty-four multiparous Murrah buffaloes according to lactation, parity, body mass, and expected calving date were divided equally. Experimental buffaloes were randomly assigned to four treatment diets: a control diet and three diets with an inorganic Cr supplementation at 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM), respectively from 60 days before expected calving date until 60 days of lactation. Milk productions of buffaloes were recorded every day until 60 days in milk. Blood samples were collected at days -60, -45, -30,-21, -15, -7, -3, 0, 7, 15, 21, 30, 45, and 60 days relative to actual calving for determination of plasma glucose, nonesterified fatty acid (NEFA), thiobarbituric acid reactive substance (TBARS), total cholesterol, total protein, albumin, blood urea nitrogen (BUN), and minerals. Adding inorganic Cr to the diet of Murrah buffaloes increased milk yield. Percentage of fat and total solid yield increased significantly through the experiment in the Cr-supplemented group. At the day of calving, buffaloes showed a decrease in dry matter intake (DMI), plasma glucose, and zinc (Zn) and Cr concentrations. In contrast, plasma NEFA, TBARS, and copper (Cu) levels were found highest at the day of calving among all groups. Cr supplementation increased peripheral blood glucose concentration while decreased level of NEFA and TBARS was recorded in Cr-fed buffaloes. Supplemental Cr had no effect on plasma cholesterol, total protein, albumin, and BUN in periparturient period. Dietary Cr supplementation had positive effect on plasma Cr concentration, but the plasma concentration of Cu, Zn, and iron (Fe) was not affected by different dietary Cr level supplementation. The results suggest that dietary inorganic Cr supplementation improved milk yield by reducing negative energy balance and lipid peroxidation in buffaloes during periparturient period.

Effect of feeding inorganic chromium on growth performance, endocrine variables, and energy metabolites in winter-exposed buffalo calves (Bubalus bubalis)

We investigated the effect of chromium (Cr) supplementation on the growth performance, energy metabolites, and hormonal variation in winter-exposed buffalo calves. Twenty-four female buffalo calves were randomly allotted to four dietary treatments (n = 6) for a period of 120 days. Feeding regimen was the same in all the groups, except the animals in the four respective groups were additionally supplemented with 0.0, 0.5, 1.0, and 1.5 mg of Cr/kg DM in the form of CrCl3.6H2O. Calves were monitored daily for physiological variables and dry matter intake (DMI). Blood samples were collected at fortnightly intervals from each buffalo calves to measure concentrations of hormones (insulin, cortisol, and growth hormone), energy metabolites (glucose and non-esterified fatty acids), and plasma mineral levels. After 120 days of feeding trial, buffalo calves fed with Cr had lower (P < 0.05) circulating plasma concentrations of glucose, insulin, and cortisol hormones, whereas plasma thyroid hormone and non-esterified fatty acids concentrations were found similar (P > 0.05) among all the treatments. The results suggested that dietary Cr supplementation influenced plasma Cr levels without affecting the plasma concentrations of other trace minerals. However, physiological variables, nutrient intake, and growth performance of buffalo calves did not differ among all treatments (P > 005). In summary, the current study showed that supplementation of Cr at the level of 1.0 and 1.5 mg of Cr/kg DMI was more effective in improving glucose utilization by increasing potency of insulin hormone and reducing concentration of cortisol hormone. Results also suggested that supplemental Cr also improves blood plasma Cr levels.

Nutritional interventions to alleviate the negative consequences of heat stress

Energy metabolism is a highly coordinated process, and preferred fuel(s) differ among tissues. The hierarchy of substrate use can be affected by physiological status and environmental factors including high ambient temperature. Unabated heat eventually overwhelms homeothermic mechanisms resulting in heat stress, which compromises animal health, farm animal production, and human performance. Various aspects of heat stress physiology have been extensively studied, yet a clear understanding of the metabolic changes occurring at the cellular, tissue, and whole-body levels in response to an environmental heat load remains ill-defined. For reasons not yet clarified, circulating nonesterified fatty acid levels are reduced during heat stress, even in the presence of elevated stress hormones (epinephrine, glucagon, and cortisol), and heat-stressed animals often have a blunted lipolytic response to catabolic signals. Either directly because of or in coordination with this, animals experiencing environmental hyperthermia exhibit a shift toward carbohydrate use. These metabolic alterations occur coincident with increased circulating basal and stimulated plasma insulin concentrations. Limited data indicate that proper insulin action is necessary to effectively mount a response to heat stress and minimize heat-induced damage. Consistent with this idea, nutritional interventions targeting increased insulin action may improve tolerance and productivity during heat stress. Further research is warranted to uncover the effects of heat on parameters associated with energy metabolism so that more appropriate and effective treatment methodologies can be designed.