Effects Of Negative Energy Balance Research Articles

Performance of grazing cows fed supplements from coproducts of biodiesel industry replacing soybean meal.

The objective of the present study was to evaluate the substitution of soybean meals by biodiesel co-products on the performance and nutrient balance of lactating cows on pasture. Twelve dairy cows (7/8 Holstein-Gir) in early lactation were included in this feeding trial. These animals had an average daily milk yield of 21.1kg and were distributed in a 4 × 4 triple Latin square experimental design. Protein supplements fed to these lactating cows contained peanut meal, cotton and sunflower as a complete replacement for soybean meal. Nutrient intake and digestibility, milk production, microbial protein synthesis, energy and protein balance were the parameters assessed in this study. Supplements containing different biodiesel co-products did not influence (P > 0.05) the level of forage intake, supplementation and nutrient by lactating cows, except for the total digestible nutrients (TDN) intake which was higher (P ≤ 0.05) in cows supplemented with cottonseed meal. The cotton meal also promoted higher digestibility of TDN (P = 0.001) and total carbohydrates (TCHO; P = 0.001) of the diet and, as a result, higher energy consumption (P = 0.01) and lower negative energy balance (P = 0.01). Cottonseed meal is a co-product of the biodiesel industry that has the ability to replace soybean meal as a source of protein in the supplement without affecting performance and promoting greater energy availability, demonstrating its ability to reduce the effects of negative energy balance in cows at the beginning of lactation kept on tropical pastures.

Negative energy balance affects perinatal ewe performance, rumen morphology, rumen flora structure, and placental function.

This study investigated the effects of negative energy balance (NEB) on perinatal ewes, with a focus on changes in growth performance, serum biochemical parameters, rumen fermentation, ruminal bacteria composition, placental phenotype-related indicators, and expression levels of genes related to placental function. Twenty ewes at 130 days of gestation were randomly allocated to either the positive energy balance (PEB) or NEB groups. In the experiment, ewes in the PEB group were fed the same amount as their intake during the pre-feeding baseline period, while ewes in the NEB group were restricted to 70% of their individual baseline feed intake. The experiment was conducted until 42 days postpartum, and five double-lamb ewes per group were selected for slaughter. The results demonstrated that NEB led to a significant decrease in body weight, carcass weight, and the birth and weaning weights of lambs (P < 0.05). Additionally, NEB caused alterations in serum biochemical parameters, such as increased non-esterified fatty acids and β-hydroxybutyrate levels and decreased cholesterol and albumin levels (P < 0.05). Rumen fermentation and epithelial parameters were also affected, with a reduction in the concentrations of acetic acid, butyric acid, total acid and a decrease in the length of the rumen papilla (P < 0.05). Moreover, NEB induced changes in the structure and composition of ruminal bacteria, with significant differences in α-diversity indices and rumen microbial community composition (P < 0.05). Gene expression in rumen papilla and ewe placenta was also affected, impacting genes associated with glucose and amino acid transport, proliferation, apoptosis, and angiogenesis (P < 0.05). These findings screened the key microbiota in the rumen of ewes following NEB and highlighted the critical genes associated with rumen function. Furthermore, this study revealed the impact of NEB on placental function in ewes, providing a foundation for investigating how nutrition in ewes influences reproductive performance. This research demonstrates how nutrition regulates reproductive performance by considering the combined perspectives of rumen microbiota and placental function.

Impact of absolute food deprivation on the reproductive system in male goldfish exposed to sex steroids.

There is a link between metabolism and reproduction as metabolic hormones affect hypothalamus-pituitary-testis (HPT) hormonal functions and vice versa. The aim of the present study was to investigate the effects of negative energy balance on the reproductive system in male goldfish exposed to testosterone (T) and 17β-estradiol (E2). Following 7 days of food deprivation (FD), ANOVA models showed significant FD × sex steroid interactions on sperm quality and circulating sex steroid levels. When FD effects were investigated, 11-ketotestosterone (11-KT) level and sperm motility and velocity decreased in food-deprived goldfish in the control group. In E2-exposed goldfish, FD decreased sperm production in addition to sperm motility and velocity that coincided with an elevation of circulating E2 level. However, FD did not significantly impact sex steroids and sperm quality in T-exposed goldfish. ANOVA models showed non-significant FD × sex steroid interactions for HSI, GSI, circulating luteinizing hormone (Lh) level, and metabolic (preproghrelin, goat and nucb2) and reproductive (kiss1, gpr54 and gnrh3) mRNAs. Furthermore, results showed that FD decreased HSI, and increased Lh levels and testicular preproghrelin and goat mRNAs, while sex steroids increased mid-brain nucb2, kiss1 and gpr54 mRNAs. Together, our results suggest that FD-induced inhibition of androgenesis resulted in diminished sperm quality associated with activation of the testicular ghrelinergic system, and negative feedback of 11-KT increased Lh level. The FD-induced testicular metabolic and hormonal system was impacted in goldfish exposed to sex steroids. However, the negative effects of FD on sperm quality were accelerated in E2-exposed goldfish due to estrogenic activity. This study provides novel information to better understand metabolic-associated reproductive disorders in fish.

Efeitos da nutrição parenteral total associada à glutamina, à fluidoterapia enteral, associada ou não à glutamina, e fluidoterapia sobre o lipidograma de equinos submetidos à inanição após laparotomia

ABSTRACT In order to evaluate the effect of total parenteral nutrition associated with glutamine and enteral fluid therapy, associated or not with glutamine, on the lipidogram of horses subjected to starvation (phase 1) and refeeding (phase 2), 16 adult healthy horses were used, mixed breed, aged between four and fourteen years and average weight of 248.40 ± 2.28kg, divided into four experimental groups, with four animals per group: Group ENTGL: enteral fluid therapy with electrolytes associated with glutamine; Group PARGL: total parenteral nutrition associated with glutamine; Group ENTFL: enteral fluid therapy with electrolytes; and Group PARFL: parenteral fluid therapy. This study was divided into two phases: phase 1 and phase 2. Phase 1 consisted of performing exploratory laparotomy and beginning of starvation, in addition to the administration of treatments, according to the group, while phase 2 consisted of re-feeding the animals. Total cholesterol values remained within the normal range for the species throughout the experimental period, but there was a slight increase during phase 1, followed by a decrease in values in phase 2. Hypertriglyceridemia in the ENFL, ENTGL and PARFL groups during phase 1 occurred because of the negative energy balance. The provision of enteral fluid therapy with electrolytes and an energy source, with or without glutamine, or parenteral fluid therapy were not effective in reversing the effects of negative energy balance. Thus, therapeutic protocols that combine enteral or parenteral fluid therapy for prolonged periods and food deprivation need additional nutritional support to avoid the deleterious effects of negative energy balance.

Dynamics of productivity and indicators of functional homeostasis of lactating cows when supplements based on natural zeolites enriched with a biocomplex of free L-amino acids are introduced into the diet

Purpose: to study the effect of feeding lactating cows with a feed additive enriched with a biocomplex of free L-amino acids of plant origin on the indicators of functional homeostasis, productivity and quality characteristics of milk.Materials and methods. Research and production tests were carried out on the basis of the OS "Streletskaya" branch of the Federal State Budgetary Scientific Institution "Federal Research Center of Legumes and Groats". To conduct scientific and production tests, 2 groups of cows of 3-4 lactation were formed, 70 heads each. The groups were formed on the principle of analogous pairs.The cows of the experimental group, starting from the second day after calving, in the morning, once a day, received a granulated feed additive "ZEO-AMINO" (Russia) fraction 0.2-0.7 mm at the rate of 2% of the dry matter of the ration daily for the first 100 days lactation. Experimental animals were monitored daily. Clinical examination of animals was carried out with obligatory control of the general condition, thermometry, counting of respiratory movements and rumen contractions, assessment of the udder condition. The productivity of cows was determined according to the results of control milking. Morphological and biochemical blood tests were performed.Results. It was revealed that the daily use of a granular feed additive of fraction 0.2-0.7 mm, starting from the second day after calving, once a day at the rate of 2% of the dry matter of the diet during the first 100 days of lactation, contributes to an increase in the average daily milk yield of cows on average by 15.9%; by 7 months lactation, an increase in the average daily milk yield was established by an average of 18.3%. It was found that feeding the supplement to cows after calving due to better absorption of nitrogen in the diet and accumulation of proteins in the animal's body allows partially neutralizing the negative consequences of negative energy balance after calving, and contributes to a more intensive recovery of live weight loss, which is reliably confirmed by indicators of animal productivity. The results of a biochemical blood test suggest that the use of a feed supplement in obtaining milk has a positive effect on the assimilation of the diet, metabolism and assimilation processes in the body, activates a number of vital functions during the normal course of physiological processes and ensuring functional homeostasis, which ultimately determines increasing the milk production of animals. Analysis of the quality indicators of milk allows us to conclude that the mass fraction of fat when feeding the additive increased by an average of 0.12 abs. %; the mass fraction of protein increased by an average of 0.22 abs.%.Conclusion. To increase milk productivity, reduce the negative effects of negative energy balance after calving, and more intensively restore body weight loss, as well as increase the efficiency of using feed proteins and normalize metabolic processes, it is recommended that daily use of the feed granulated dietary supplement "ZEO-AMINO" fraction in the diets of dairy cows 0.2-0.7 mm at the rate of 2% of the dry matter of the diet, starting from the second day after calving, once a day during the first 100 days of lactation.

The relationship between body condition score, thyroxin, and health condition and serum energy indices, insulin like growth factor-1, and lipids profile over the transition period in Holstein dairy cows.

Lipid mobilization increases significantly in cows around the time of calving; a correlation between excessive blood NEFA concentrations, oxidative stress, and impaired health status in transition dairy cattle was observed. The relationship between serum thyroxin (T4) values and energy indices and lipid profile in all cows, non-fat cows (NFCs), fat cows (FCs), healthy, and diseased animals were estimated in the present study. Blood samples were obtained from fifty multiparous cows on -14, +10, +20, and +30 days relative to parturition. They had similar diets and were kept under the same management conditions. NEFA and BHBA values increased significantly on the 10th day of calving. Inversely, glucose, T4, triglyceride, LDL-C, and VLDL-C decreased significantly ten days after calving. There was a significant negative correlation between serum T4 and NEFA for all cows and FCs. Serum T4 and BHBA values had a significant negative correlation in NFCs, FCs, healthy, and diseased cows. In addition, serum T4 and fructosamine had a significant negative relationship in FCs and a significant positive correlation in diseased cows. Serum T4 values had a significant negative correlation with cholesterol, HDL-C, and a positive correlation with triglyceride and VLDL-C for all cows, NFCs, FCs, and healthy cows. The data emphasized the effects of negative energy balance during the transition period on serum lipids profile and thyroid function. In addition, the correlation between T4 and energy and lipids indices may indicate a possible effect of health and body condition status on thyroid responses.

Effect of feed restriction on dairy cow milk production: a review.

In the dairy cow, negative energy balance affects milk yield and composition as well as animal health. Studying the effects of negative energy balance on dairy cow milk production is thus essential. Feed restriction (FR) experiments attempting to reproduce negative energy balance by reducing the quantity or quality of the diet were conducted in order to better describe the animal physiology changes. The study of FR is also of interest since with climate change issues, cows may be increasingly faced with periods of drought leading to a shortage of forages. The aim of this article is to review the effects of FR during lactation in dairy cows to obtain a better understanding of metabolism changes and how it affects mammary gland activity and milk production and composition. A total of 41 papers studying FR in lactating cows were used to investigate physiological changes induced by these protocols. FR protocols affect the entire animal metabolism as indicated by changes in blood metabolites such as a decrease in glucose concentration and an increase in non-esterified fatty acid or β-hydroxybutyrate concentrations; hormonal regulations such as a decrease in insulin and insulin-like growth factor I or an increase in growth hormone concentrations. These variations indicated a mobilization of body reserve in most studies. FR also affects mammary gland activity through changes in gene expression and could affect mammary cell turnover through cell apoptosis, cell proliferation, and exfoliation of mammary epithelial cells into milk. Because of modifications of the mammary gland and general metabolism, FR decreases milk production and can affect milk composition with decreased lactose and protein concentrations and increased fat concentration. These effects, however, can vary widely depending on the type of restriction, its duration and intensity, or the stage of lactation in which it takes place. Finally, to avoid yield loss and metabolic disorders, it is important to identify reliable biomarkers to monitor energy balance.

The Capacity of Holstein-Friesian and Simmental Cows to Correct a Negative Energy Balance in Relation to Their Performance Parameters, Course of Lactation, and Selected Milk Components.

Simple SummaryThe aim of the study was to analyse the ability of Simmental (SIM) and Holstein-Friesian (HF) cows to correct a negative energy balance (NEB). NEB dynamics were assessed based on the content of NEFA in the blood; a reduction in body condition score; and levels of C16:0, C18:0 and C18:1 in the milk. The efficiency of liver metabolism was evaluated based on the content of BHBA in the blood and urea in the milk. The rate of changes was analysed during lactation, with assessments of daily yield, production at peak lactation and its duration, and changes in selected milk components. The results indicated that the most significant changes took place up to the peak of lactation. During this time, the values for parameters characterizing NEB were similar in both breeds. After the peak of lactation, the body condition score of SIM cows was restored more quickly. HF cows, on the other hand, achieved greater milk production and reached peak lactation earlier, but they were less capable of correcting the NEB, as indicated by the higher content of non-esterified fatty acid and β-hydroxybutyrate as well as C16:0, C18:0, and C18:1 in most cases. Their milk also contained more urea. The dynamics of NEB were found to be linked to the level of leptin, which has an anorectic effect. The results of the study indicate the great potential of Simmental cows and may facilitate the search for solutions for the more efficient exploitation of their potential.A significant factor in improving the performance of dairy cows is their physiological ability to correct a negative energy balance (NEB). This study, using Simmental (SIM) and Holstein-Friesian (HF) cows, aimed to assess changes in NEB (non-esterified fatty acid; body condition score; and C16:0, C18:0, and C18:1) and its effect on the metabolic efficiency of the liver (β-hydroxybutyrate and urea). The effects of NEB on daily yield, production at peak lactation and its duration, and changes in selected milk components were assessed during complete lactation. Up to peak lactation, the loss of the body condition score was similar in both breeds. Subsequently, SIM cows more efficiently restored their BCS. HF cows reached peak lactation faster and with a higher milk yield, but they were less able to correct NEB. During lactation, their non-esterified fatty acid, β-hydroxybutyrate, C16:0, C18:0, C18:1, and urea levels were persistently higher, which may indicate less efficient liver function during NEB. The dynamics of NEB were linked to levels of leptin, which has anorectic effects. Its content was usually higher in HF cows and during intensive lactogenesis. An effective response to NEB may be exploited to improve the production and nutritional properties of milk. In the long term, it may extend dairy cows’ productive life and increase lifetime yield.

Effect of feeding bypass fat to dairy animals- A Review

The last 3 weeks each of pregnancy and early lactation are very critical for the dairy animals because of the challenges posed by metabolic and hormonal changes in the body. The dry matter intake of these animals starts declining during advanced pregnancy and gets reduced up to 30% just 3 weeks before parturition. Most of the energy is utilized for the production of colostrum and milk after parturition due to which the animal faces negative energy balance. The animal also loses its body condition score due to the utilization of its body fat to meet energy requirements that lead to an increase in non-esterified fatty acids in the blood. The animals are prone to metabolic disorders and decreased production of milk when its body fats are depleted. The energy requirements of such animals could be met by increasing the energy density of their diet. There is an increase in rumen acidosis if more quantity of concentrate is offered to such animals. Acidosis leads to the poor digestion of fibers in the rumen. There is increased production of propionate in comparison to acetate which is responsible for less percentage of fat in the milk of these animals. The ill effects of negative energy balance may be eliminated if these animals are offered bypass fat in their diet. The cellulose digesting bacteria stay unharmed due to bypass fat where as ordinary fat may harm these bacteria if more than 1% of its dry matter intake is fed. Therefore, it is advisable to offer bypass or prilled fat to the animals during transition period.

Embryonic response to high beta-hydroxybutyrate (BHB) levels in postpartum dairy cows

Cows at the beginning of lactation often do not meet their energy needs by feeding and therefore mobilize body fat, which produces ketone bodies, including β-hydroxybutyrate (BHB). They are nevertheless usually inseminated around 60 d postpartum, when they are still in this characteristic period of energy deficit. The aim of this study was to observe the effects of negative energy balance on embryo quality and to identify ways to improve the fertility of dairy cows. Holstein cows (n = 18) grouped as high or low BHB based on blood measurement at day 45 postpartum were estrus-synchronized and treated with follicle-stimulating hormone to obtain multiple follicle development, induced to ovulate and inseminated with sexed semen around day 60 postpartum. Of the 290 embryos collected over 16 mo, 159 were of quality I to IV. Based on microarray analysis of gene expression, exposure to an energy deficit metabolic environment (high BHB) during early development appeared to modify signaling by the mTOR and sirtuins pathways in the embryo, implying mitochondrial dysfunction and inhibition of transcription, leading to slower cell division, thus programming the embryo to be more energy efficient. Altered methylation markers suggested that such coping mechanisms might persist into adulthood.

Effects of food restriction and/or aerobic exercise on the GLUT4 in type 2 diabetic male rats.

Background:The aim of present study was to compare the effects of negative energy balance with food restriction and/or aerobic exercise on the glucose, insulin, and GLUT4 levels in diabetic male rats.Methods:Fifty-six 10-week old male Wistar rats were randomly assigned to seven groups: a non-diabetic (ND) group and six diabetic groups. After an infusion of type 2 diabetes, the diabetic groups were given labels as well, namely diabetic control (DC) group, exercise (Ex) group, food restriction with standard diet (FRSD) group, food restriction with low-carbohydrate diet (FRLCD) group, food restriction with standard diet combination in exercise (FRSDE) group, and food restriction with low-carbohydrate diet combination in exercise (FRLCDE) group. Further, to induce caloric restriction (CR), food intake was reduced by 20% and given to food restriction consists of both of (FRSD and FRLCD). Hundred percent food consumption for the Ex group was fixed, but instead, 20% of their energy intake in exercise was calculated, and time of daily exercise was determined. Finally, a combination of reduced food intake (10%) and exercise (10%) was applied in each group FRSDE and FRLCDE for 8 weeks.Results:The results showed that type 2 diabetes inductions had reduced glucose, insulin, and GLUT4 gene expression compared to the ND group (P = 0.001). However, there were significant differences in GLUT4 gene expression between groups after 8 weeks of intervention (P = 0.001). A post hoc least significant difference test show that compared to DC group, GLUT4 gene expression level of Ex, FRSDE, and FRLCDE groups was significantly increased 47% (P = 0.004), 60% (P = 0.001), and 65% (P = 0.001), respectively after 8 week of intervention, but it was not significant or with any other diabetic groups (P > 0.05). Moreover, glucose levels were significantly higher in the FRLCDE, FRLCD, FRSD, FRSDE, Ex groups compared with the DC group in the same period (P = 0.0.01).Conclusions:It was concluded that FRSD and FRLCD combination in regular exercise was elevated of GLUT4 gene expression in type 2 diabetes. These results may help to develop new methods for the treatment of obesity and type 2 diabetes mellitus.

Metabolic and Ruminal Fluid Markers of Dairy Cows Supplemented with a Combination of Yeast Culture and Hydrolyzed Yeast

Background: In order to reduce the effects of a negative energy balance, some measures have been taken into account in nutritional management during the transition period. The use of yeast, has been a good alternative used to improve the rumen metabolism and helping the adjustment of the microbiotato the new diet. The aim of the study was to evaluate the effects of supplementing a combination of yeast culture and hydrolyzed yeast on the metabolism of dairy cows during the transition period.Materials, Methods &amp; Results: The experiment was conducted in a semi-extensive system, using 20 Holstein cows, divided equally into a control group (CG) and a supplemented group (SG). The SG received 28 g/animal/day of a combination of yeast culture and hydrolyzed yeast from 20 ± 2 days pre-calving until early lactation (18 ± 3 days). Serum concentrations of non-esterified fatty acids (NEFA), albumin and urea were determined at calving, and for three time points during the early postpartum period and three time points during the early lactation period. Regarding energy metabolism, prepartum concentrations of NEFA were higher than the physiological standard in both groups. However, NEFA, albumin and urea decreased during the early postpartum period in the supplemented animals and could be attributed to the yeast in enhancing ruminal microorganisms’ cellulolytic capacity, increasing fibre digestibility and starch utilization.Discussion: The increased concentration of non-esterified fatty acids (NEFA) due to the mobilization of fat deposits that happens in the transition period, especially in the postpartum period reflects the cow’s adaptation to the negative energy balance (NEB). The lower concentrations of NEFA observed in the present study could be attributed to the effect of the yeast in enhancing the ruminal microorganisms’ cellulolytic capacity. The control cows had a BCS within the recommended range while the supplemented group had it close to the minimal limit proposed for this period. Thus, supplemented cows lost less BCS during the early postpartum period, had a lower BCS loss during the experimental period and had lower NEFA concentration that the CG. It was possible to observe a difference in serum albumin and urea between treatments only in the postpartum period. Besides showing no significant effect in BCS on prepartum period, control cows had a BCS within the recommended range while the supplemented group had it close to the minimal limit proposed for this period. Cows with high BCS prepartum had higher plasma NEFA before and after calving. It can be observed in the present study in both groups. However, a positive effect in prevent subclinical disorders might be attributed to YC, since the SG showed low NEFA plasma levels compared to the CG. Thus, supplemented cows lost less BCS during the early postpartum period, had a lower BCS loss during the experimental period and had lower NEFA concentration that the CG. There is a negative correlation between BCS and NEFA in the early postpartum period and this information explains the results observed in the present study where BCS declines in the SG are followed by a NEFA increase. This is not so marked in the CG, indicating that SG supplementation can act by improving digestibility. Yeast supplementation promotes higher output energy, enhancing postpartum performance in dairy cows. Yeast supplementation showed benefits in early lactation compared to the prepartum and early postpartum periods, suggesting that supplementation has to have an adaptation period to be effective in protein synthesis. In conclusion, supplementation with a combination of yeast culture and hydrolyzed yeast to cows during the transition period can positively influence the energy and protein metabolism, reducing the collateral effects of negative energy balance.

Prolonged high altitude exposure exacerbates fat‐free mass and fat mass loss during negative energy balance regardless of dietary protein intake

Protein intake above the recommended dietary allowance attenuates fat‐free mass (FFM) loss during moderate negative energy balance (~40% energy deficit) at sea level (SL). Sustained periods of strenuous physical activity at high altitude (HA) may exacerbate FFM loss, especially during energy deficit. However, increased dietary protein intake has not been evaluated as a countermeasure to FFM loss at HA. This study aimed to determine whether consuming dietary protein at amounts consistent with current recommendations for elevated physical activity (2.0 g protein/kg) attenuates FFM loss during prolonged energy deficit at HA. Seventeen healthy males (mean ± SD, 23.4 ± 5.6y, 81.9± 13.9 kg) participated in a 2‐phase, 43‐d study. During phase 1 (SL), participants were instructed to consume a weight maintenance diet with standard protein intake(1.0 g protein/kg, STD) for 21 d. During phase 2, participants resided at HA (4300 m, Pikes Peak, CO) for 22 d and were randomly assigned to either a STD or high (2.0 g protein/kg, HIGH) protein diet designed to elicit a 40% energy deficit (30% dietary restriction and 10% increase in physical activity, estimated energy deficit was 1074 ± 122 kcal/d based on the total energy requirements necessary to maintain body mass during phase 1) and~3 kg total body mass loss. Diet and physical activity were highly controlled. Total body mass, FFM, and fat mass (FM) were assessed by dual energy x‐ray absorptiometry and resting metabolic rate (RMR) by indirect calorimetry. Volunteers were weight stable during SL and lost −7.9 ± 1.9 kg(P&lt;0.01)during HA, regardless of protein group (P&gt;0.05). Decrements in FFM (−4.0 ± 3.3 vs. −3.2 ± 1.5 kg) and FM (−3.3 ± 1.8 vs. −3.9 ± 0.8 kg) were not statistically different between STD and HIGH (P&gt;0.05). The overall energy deficit was 2306 ± 444kcal/d when calculated based on changes in FFM and FM. The additional energy deficit was attributable, in part, to an increase in RMR, which peaked at 58%above SL on HA day 1 and remained ≥ 25% higher than SL throughout HA(P&lt;0.05), accounting for 27% (634 ± 273 kcal/d) of the total energy deficit at HA. The remaining 598 kcal/d (26% of total deficit) could not be accounted for by estimated energy expenditure of prescribed daily physical activity and measured energy intake, suggesting the energy cost of physical activity may be greater at HA than SL. Prolonged HA exposure exacerbated the catabolic effects of negative energy balance. In this context, consuming a higher versus standard protein diet was equally ineffective at sparing FFM with weight loss. The opinions or assertions contained herein are the private views of the author(s)and are not to be construed as official or reflecting the views of the Army or the Department of Defense.Support or Funding InformationSupported by USAMRMC.

Administration of early post-partum oral drench in dairy cows: effect on metabolic profile

&lt;p&gt;Some prophylactic treatments have been proposed in high-yielding dairy cattle in order to minimize the effects of negative energy balance and some disturbances such as hypocalcaemia and ketosis. The objective of this study was to evaluate the effects of two doses of Drench within 24 h after calving on the metabolic profile and prevention of ketosis. A total of 48 cows from a herd in Rio Grande do Sul state (southern Brazil) was used in the study. The animals were randomly selected and treated orally with Drench (N= 32, propylene glycol, electrolytes and choline in 40 L of water) and water (N= 16) used as control. Blood samples were collected by blood coccygeal venipuncture through a vacutainer plain system tubes. Biochemical determinations were performed in serum (albumin, urea, cholesterol, triglycerides, non-esterified fatty acids -NEFA-, calcium, phosphorus, magnesium, aspartate transaminase -AST- and gammaglutamyl-transferase -GGT-) and a cow-side determination of beta-hydroxybutyrate (BHB) was performed using the Abbot blood Precision Xtra system. All cows in the experiment had their milk production controlled. The Drench treatment produces a tendency to a better milk yield (32.5 vs 29.6 L/cow/day) and helps to prevent subclinical ketosis, as indicated by a lesser prevalence of subclinical ketosis (29.7 vs 37.2%) and mean values of BHB (1.19 vs 1.27 mmol/L) as well as a lesser lipolysis as indicated by NEFA values (509 vs 1.560 µmol/L). The other components of the metabolic profile did not have substantial effects between treatments. In short, on the conditions of the present work, the Drench treatment is an effective management tool for prevention of subclinical ketosis and severe lipolysis.&lt;/p&gt;

Upgrading local cattle in tropical west Africa: Metabolic hormone concentrations during the post-partum period in Sanga and Friesian–Sanga crossbred cows

Cattle farmers in Ghana want larger animals with better milk yield and have therefore focused on improving the indigenous tropical Sanga breed by crossing with the temperate Friesian breed. However, in the Friesian–Sanga crossbred, a major limitation to reproductive performance is extended postpartum anoestrus, perhaps exacerbated by under-nutrition under field conditions. We therefore tested whether the breeds vary in the circulating concentrations of metabolic hormones that mediate the effects of nutrition on the reproductive axis during the postpartum period. Two herds comprising 16 Sanga, and 16 Friesian–Sanga cows, were grazed separately on natural pastures of similar nutritive value with no feed supplements. Every week during weeks 1 to 10 postpartum, the cows were weighed, body condition score (BCS) was assessed, and blood was sampled. Resumption of ovarian activity, detected from progesterone profiles, was used to classify cows as ‘early-cycling’ (≤45 days), ‘late-cycling’ (46–70 days) or ‘non-cycling’ (after 70 days). Resumption of ovarian cyclicity, body weight and body condition score did not differ between breeds, but daily milk yield was lower for Sanga (1.01±0.02kg/day) than for Friesian–Sanga crossbreds (1.57±0.02kg/day; P<0.001). Compared with Friesian–Sanga crossbreds, Sanga cows had greater plasma concentrations of IGF-I (18.7±0.7 versus 14.8±0.7ng/mL; P<0.001) and leptin (1.12±0.01 versus 0.96±0.01ng/mL; P<0.001), but the two breeds had similar concentrations of GH and insulin. After calving, the IGF-I/GH ratio recovered more rapidly in the Sanga than in the crossbred (P=0.01). In both breeds, early-cycling cows had greater concentrations of IGF-I and leptin than late- or non-cycling cows. It was concluded that, during the postpartum period, the Sanga breed is better able to avoid the effects of negative energy balance, maintain metabolic homeostasis and prevent uncoupling of the GH–IGF axis, compared with the Friesian–Sanga crossbreed.

0531. Cumulative effects of negative energy balance on myocardial deformity and diastolic function during the first week of ICU: a pilot study

Methods We made an observational, analytical, prospective, longitudinal pilot study. Dependents variables: LS, echocardiographic parameter used to assess myocardial deformity (contraction). We considered as an improvement an increase ≥10%. E/e ratio, parameter used to assess DF. A reduction of E/e ratio ≥10% was considered DF improvement. I. V,: NEB during the first week of admision. Improvement in the NS: assessed by an increase in at least one level of prealbumin nutritional scale (PNS) after 10 days of receiving 100% of estimated energy (EE) requirements (H. Benedict). (PNS: Normal>18 md/dl, mild undernutrition: 17.9-15, moderate: 14.9-10 severe 100 Hz, for further analysis “of line” of LS. (Blind analysis). Exclusion crit.: nephrotic syndrome, cirrhosis, chronic renal and HF. PCR, MV (PEEP), PVC were recorded.

Major Metabolic Diseases Affecting Cows in Transition Period

The aim of this study was to perform a literary review on the main metabolic diseases affecting cows during the transition period. The heat increment promoted by higher energy demand that occurs during the transition period between the end of lactation and early management, combined with low dry matter intake due to fetal growth major and consequent reduced ability of the rumen, make the dairy cow highly susceptible to the metabolic diseases ketosis, milk fever and hepatic lipidosis. The increase in blood concentrations of non-esterifies fatty acids during this transition period appear to be linked to the onset of these disorders and this can be explained by the high energy mobilization because of the negative energy balance. Diets with high energy density during this period are extremely necessary to minimize the effects of negative energy balance. In addition it is recommended to feed the animals with foods smaller particles because the capacity of the rumen is reduced. It also recommends the provision of lipid sources such as protected fat and vegetable oils that do not degrade the ruminal microorganisms and even precursors of glucose, such as propylene glycol or starchy concentrates, and not by lipid.

A mathematical model of the bovine oestrous cycle: Simulating outcomes of dietary and pharmacological interventions

A mathematical model was constructed to simulate the bovine oestrous cycle by using nonlinear differential equations to describe the biological mechanisms which regulate the cycle. The model predicts circulating concentrations of gonadotrophin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, oestradiol, inhibin and progesterone. These hormones collectively provide control and feedback mechanisms between the hypothalamus, pituitary gland and ovaries, which regulate ovarian follicular dynamics, corpus luteum function and ovulation. When follicular growth parameters are altered, the model predicts that cows will exhibit either two or three follicular waves per cycle, as seen in practice. Changes in other parameters allow the model to simulate: effects of nutrition on follicle recruitment and size of the ovulatory follicle; effects of negative energy balance on postpartum anoestrus; and effects of pharmacological intervention on hormone profiles and timing of ovulation. It is concluded that this model provides a sound basis for exploring factors that influence the bovine oestrous cycle in order to test hypotheses about nutritional and hormonal influences which, with further validation, should help to design dietary or pharmacological strategies for improving reproductive performance in cattle.

NUTRITIONAL STRATEGIES TO MITIGATE THE EFFECTS OF NEGATIVE ENERGY BALANCE ON REPRODUCTIVE PERFORMANCE OF EARLY POSTPARTUM DOES

The objective of this study was to research nutritional strategies to mitigate the effects of Negative Energy Balance (NEB) on reproductive performance of early postpartum does. Twenty seven does in their second week of lactation and their kids were randomly assigned to three levels of supplement diet, replicated three times. The diets were: (1) Low Energy/Protein supplement level (LEP; Control), (2) Medium Energy/Protein supplement level (MEP), or (3) High Energy/Protein supplement level (HEP). The LEP (control) diet was fed at 0.95%, MEP at 1.50% and HEP at 1.90% of BW on a DM basis. The study lasted 28 days. Supplement level did not (p>0.10) reverse the expected loss in doe body condition during the early stages of lactation. The does lost on average 0.056 kg day-1 through the duration of the study. The average body condition score of the does at the start of the experiment was 1.80 (on a scale of 1-5) and 1.75 at the end. The HEP kids tended (p<0.10) to gain faster than LEP kids; no difference (p>0.10) between HEP and MEP or MEP and LEP kids. The HEP kids gained 0.087 kg day-1; MEP kids gained 0.061 kg day-1 whereas LEP kids gained 0.022 kg day-1. In conclusion, something in addition to high energy/protein supplement level may be needed to mitigate the effects of NEB which is in part responsible for delayed return of ovulatory events in early postpartum does.

Skeletal muscle responses to negative energy balance: effects of dietary protein.

Sustained periods of negative energy balance decrease body mass due to losses of both fat and skeletal muscle mass. Decreases in skeletal muscle mass are associated with a myriad of negative consequences, including suppressed basal metabolic rate, decreased protein turnover, decreased physical performance, and increased risk of injury. Decreases in skeletal muscle mass in response to negative energy balance are due to imbalanced rates of muscle protein synthesis and degradation. However, the underlying physiological mechanisms contributing to the loss of skeletal muscle during energy deprivation are not well described. Recent studies have demonstrated that consuming dietary protein at levels above the current recommended dietary allowance (0.8 g · kg(-1) · d(-1)) may attenuate the loss of skeletal muscle mass by affecting the intracellular regulation of muscle anabolism and proteolysis. However, the specific mechanism by which increased dietary protein spares skeletal muscle through enhanced molecular control of muscle protein metabolism has not been elucidated. This article reviews the available literature related to the effects of negative energy balance on skeletal muscle mass, highlighting investigations that assessed the influence of varying levels of dietary protein on skeletal muscle protein metabolism. Further, the molecular mechanisms that may contribute to the regulation of skeletal muscle mass in response to negative energy balance and alterations in dietary protein level are described.