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1.
Herbage feeding with only little input of concentrates plays an important role in milk production in grassland dominated countries like Switzerland. The objective was to investigate the effects of a solely herbage‐based diet and level of milk production on performance, and variables related to the metabolic, endocrine and inflammatory status to estimate the stress imposed on dairy cows. Twenty‐five multiparous Holstein cows were divided into a control (C+, n = 13) and a treatment group (C?, n = 12), according to their previous lactation yield (4679–10 808 kg) from week 3 ante partum until week 8 post‐partum (p.p.). While C+ received fresh herbage plus additional concentrate, no concentrate was fed to C? throughout the experiment. Within C+ and C?, the median of the preceding lactation yields (7752 kg) was used to split cows into a high (HYC+, HYC?)‐ and low‐yielding (LYC+, LYC?) groups. Throughout the study, HYC+ had a higher milk yield (35.9 kg/d) compared to the other subgroups (27.2–31.7 kg/d, p < 0.05). Plasma glucose (3.51 vs. 3.72 mmol/l) and IGF‐1 (66.0 vs. 78.9ng/mL) concentrations were lower in HYC?/LYC? compared to HYC+/LYC+ cows (p < 0.05). Plasma FFA and BHBA concentrations were dramatically elevated in HYC? (1.1 and 1.6 mmol/l) compared to all other subgroups (mean values: 0.5 and 0.6 mmol/l, p < 0.05). Saliva cortisol, plasma concentrations of serum amyloid A (SAA), haptoglobin (Hp), beta‐endorphin (BE) and activity of alkaline phosphatase (AP) were not different between C+ and C?. In conclusion, herbage‐fed high‐yielding cows without supplementary concentrate experienced a high metabolic load resulting in a reduced performance compared to cows of similar potential fed accordingly. Low‐yielding cows performed well without concentrate supplementation. Interestingly, the selected markers for inflammation and stress such as cortisol, Hp, SAA, BE and AP gave no indication for the metabolic load being translated into compromised well‐being.  相似文献   

2.
Feeding dairy cows indoors or on pasture affects not only labour, machinery and housing costs, but also animals’ performance and metabolism. This study investigates the effects of indoor feeding (IF) with a partial‐mixed ration (PMR) versus pasture‐based feeding (PF) on milk production, fertility, backfat thickness (BFT), body weight (BW) loss and energy metabolism of Brown Swiss (BS) dairy cows with similar genetic production potential. The IF herd consisted of 13 cows fed a PMR composed of maize and grass silage plus protein concentrate according to each cow's requirements. The PF herd consisted of 14 cows offered barn‐ventilated hay ad libitum after calving from January until March and grazed on semi‐continuous pastures during the vegetation period. The IF cows produced more energy‐corrected milk (ECM) per standard lactation (9,407 vs. 5,960 kg; p < .01), more milk fat (378 vs. 227 kg; p < .01) and milk protein (326 vs. 215 kg; p < .01). The calving interval (377 vs. 405 days; p < .01) and time empty (86 vs. 118 days; p < .01) were shorter in the PF compared to IF, possibly also due to different selection criteria for maintaining the respective seasonal calving rhythm. The empty body fat loss calculated according to BCS until its nadir was higher in IF cows (IF: 10.4 vs. PF: 4.8 MJ/day; p < .01), but no differences were noted in total body fat loss estimated via BFT (p = .24). However, PF had lower blood glucose concentration at all investigated time points, but no differences occurred in serum non‐esterified fatty acid and β‐hydroxybutyrate concentrations post‐partum. In conclusion, BS cows were equally well suited for the IF with PMR and the PF system investigated here without developing a prominent metabolic load despite differences in nutrient supply. As such, investigated BS dairy cows in our trial seem to have a high capacity for metabolic adaptation to different production systems.  相似文献   

3.
In the present study, 42 multiparous Holstein cows were used to investigate the relationship between fat accumulation in the liver and dry matter intake, milk yield and blood metabolites. Based on the percentage of fat in the liver cell at 2 weeks post‐parturition, the cows were classified into three groups. These groups were: (i) less than 10% of fat (normal group, n = 29); (ii) 10–20% of fat (mild group, n = 6); and (iii) more than 20% of fat (moderate group, n = 7). The bodyweight of the moderate group was high (771 kg) before calving. The sufficiency rates of total digestible nutrients (TDN) were remarkably decreased (approximately 65%) in early lactation. The milk fat yield and milk fat composition of the moderate group were higher (P < 0.05) than the other groups at 1 and 2 weeks post‐parturition. It was suggested that non‐esterified fatty acids (NEFA) mobilized from adipose tissues was directly used by the mammary gland for synthesis of milk fat. The percentage of bromsulfalein (BSP) retention of the moderate group was high (21.1%) at 30 min, and it showed that the BSP clearance function was significantly decreased. The concentrations of NEFA, β‐hydroxybutyric acid and glucose were appropriate indicators of energy status; however, aspartate aminotransferase, γ‐glutamyl transpeptidase and total bilirubin were not sensitive indicators of a moderate fatty liver. Thus, high‐yielding cows that calve in an overweight condition are more likely to develop excessive fat accumulation in the liver because of great mobilization from adipose tissues post‐parturition. In cows with a moderately fatty liver, a decrease in TDN sufficiency rates, an increase of milk fat yield and a reduction of liver function were observed in early lactation. The increase of serum NEFA and milk fat composition resulting from mobilization of adipose tissues helped to diagnose moderate fatty liver.  相似文献   

4.
The aim of this study was to evaluate the oxidative status in ketotic cows. We observed changes in the oxidative status and correlations between the oxidative and metabolic status in non‐ketotic (n = 10), subclinical ketotic (n = 10) and ketotic cows (n = 10). Plasma samples were analysed by standard biochemical techniques and ELISA to determine traditional metabolic parameters: triglyceride (TG), phosphonium (P), calcium (Ca), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), immune globulin (Ig), total cholesterol (TC), high‐density lipoprotein (HDL), very low‐density lipoprotein (VLDL) and lactate dehydrogenase (LDH); energy metabolism indices: glucose, β‐hydroxybutyrate (BHBA) and non‐esterified fatty acids (NEFA); and indices of oxidative status: malondialdehyde (MDA), hydrogen peroxide (H2O2), vitamin C, vitamin E, superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), catalase (CAT), xanthine oxidase (XOD) and total antioxidant capacity (TAOC). The results of this study showed that plasma glucose levels were lower in ketotic and subclinical ketotic cows than in non‐ketotic cows; however, the plasma NEFA and BHBA concentrations were higher. In addition, significant decreases in TC, HDL and VLDL and significant increases in AST, ALT and LDH were observed in the plasma of the ketotic cows. The ketotic cows showed decreased plasma SOD, CAT, vitamin C and vitamin E, inhibited hydroxyl radical capacity and increased plasma H2O2 and MDA. There were positive correlations between the plasma NEFA and ALT, AST, LDH and MDA and negative correlations between the plasma NEFA and TC, HDL, VLDL, SOD, vitamin C, vitamin E, 1542280 uric acid and inhibited hydroxyl radical capacity. In addition, there were positive correlations between BHBA concentrations and ALT, AST and LDH and negative correlations between plasma BHBA concentrations and TC, HDL, VLDL, vitamin E and inhibited hydroxyl radical capacity. Overall, ketotic dairy cows experience oxidative stress, which is presumably associated with hyperketonemia and higher NEFA.  相似文献   

5.
The objective of this trial was to investigate the influences of conjugated linoleic acid (CLA ) and vitamin E (Vit. E) and their interactions on fatty acid composition and vitamins in milk (α‐tocopherol, retinol and β‐carotene) as well as on α‐tocopherol in blood of pluriparous cows from week 6 ante partum until week 10 post‐partum (p.p.). We assigned 59 pluriparous German Holstein cows to four treatment groups with the treatment factors CLA and Vit. E at two levels in a 2 × 2 factorial design. Milk fatty acid composition and milk vitamins were analysed on lactation days 7 and 28. α‐tocopherol in blood serum was analysed on days ?42, ?7, 1, 7, 14, 28 and 70 relative to parturition. Milk concentration of α‐tocopherol was influenced by Vit. E (p  < .001) and CLA (p  = .034). Percentage of cis ‐9, trans ‐11 CLA in total milk fat was influenced by treatment with CLA (p  < .001), while for percentage of trans‐ 10, cis ‐12 CLA an interaction between treatment and day (p  = .019), driven by an increase in both CLA groups from day 7 to day 28, was found. Serum ratios of α‐tocopherol to cholesterol were influenced by Vit. E (p  < .001). Results suggest that treatment with CLA during late pregnancy and early lactation is suitable to enhance the proportion of trans‐ 10, cis ‐12 CLA in milk and thereby influencing nutritional properties. As treatment with Vit. E did not have an impact on milk fatty acid composition, it might be possible to increase the antioxidative capacity of the dairy cow without affecting milk properties. Consequently, combined treatment with CLA and Vit. E might elicit synergistic effects on the cow and milk quality by increasing the proportion of CLA in milk fat as well as the excretion of Vit. E and the Vit. E levels in serum.  相似文献   

6.
Supplementing conjugated linoleic acid ( CLA ) is supposed to spare glucose due to the milk fat‐depressing effect of the trans ‐10, cis ‐12 CLA isomer, and allows repartitioning nutrients despite an energy deficiency in early lactation. However, there is still a lack of knowledge in terms of the dynamic pattern of the glucose turnover in transition dairy cows. We hypothesized that dairy cows supplemented with CLA have an altered rate of glucose turnover and insulin sensitivity during early lactation. We conducted three consecutive hyperglycaemic clamps (HGC ) in weeks ?2, +2 and +4 relative to parturition in Holstein cows supplemented daily either with 70 g of lipid‐encapsulated CLA (6.8 g trans ‐10, cis ‐12 and 6.6 g of the cis ‐9, trans ‐11 CLA isomer; CLA ; n  = 11) or with 56 g of control fat ( CON ; n  = 11). From week ?3 up to week +4 relative to parturition, milk yield and dry matter intake (DMI ) were recorded daily, while body weight (BW ) and milk composition were obtained once weekly. Blood samples were taken once weekly and every 30 min during the HGC . Plasma was analysed for concentrations of glucose, fatty acids (FFA ), beta‐hydroxybutyrate (BHB ), insulin, triglycerides and cholesterol. The CLA supplementation did not affect performance and metabolic parameters except for BHB and cholesterol. Furthermore, insulin concentrations and insulin sensitivity were affected by treatment. During the HGC in early lactation, insulin response was lower and decrease in FFA and BHB greater compared with the HGC in week ?2 although glucose target concentration achieved during the steady‐state period was similar for all three HGC . Our findings in terms of insulin and cholesterol suggest that body reserves are preserved through CLA feeding without restraining animal's performance. Furthermore, CLA effects on cholesterol and triglyceride concentrations indicated beneficial effects on hepatic lipid export contributing to an improved efficiency of prevailing metabolites in circulation.  相似文献   

7.
为了阐明不同能量平衡状况的围产期奶牛泌乳量、干物质摄入的变化及其机体代谢调节作用。在某一集约化牛场选取胎次、年龄相近的奶牛,分为高血糖组(H)和低血糖组(L),每组各15头。在产前21、14、7d和分娩当天,产后7、14、21d,分别记录奶牛围产期干物质摄入量(DMI)、泌乳量(MY),并测定血浆血糖(Glu)、游离脂肪酸(NEFA)、β-羟丁酸(BHBA)、胰岛素(Ins)、胰高血糖素(Gn)、瘦蛋白(Lp)、皮质醇(Cor)的浓度。结果显示,试验奶牛产后泌乳量和干物质摄入量均增加,但是产后能量负平衡发生率高于产前,产后21d达最高;两组产后血浆Glu水平均降低,血浆NEFA和BHBA升高,L组血浆NEFA和BH-BA水平高于H组(P0.05);H组血浆Ins与Lp水平高于L组(P0.05),血浆Gn与Cor水平低于L组(P0.05)。围产期不同能量平衡状态的奶牛机体能量代谢发生了各自适应性的变化。血浆低水平Ins、Lp和高水平Cor在缓解能量负平衡方面发挥了重要作用。  相似文献   

8.

Background

The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli (E. coli) for dairy cows during early lactation. Thirty, healthy primiparous Holstein cows were infused (h = 0) with ~20-40 cfu of live E. coli into one front mammary quarter at ~4-6 wk in lactation. Daily feed intake and milk yield were recorded. At –12, 0, 3, 6, 12, 18, 24, 36, 48, 60, 72, 96, 108, 120, 132, 144, 156, 168, 180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E. coli. Composite milk samples were collected at -180, -132, -84, -36, -12, 12, 24, 36, 48, 60, 72, 84, 96, 132 and 180 h relative to challenge (h = 0) and analyzed for lactate dehydrogenase (LDH), somatic cell count, fat, protein, lactose, citrate, beta-hydroxybutyrate (BHBA), free glucose (fglu), and glucose-6-phosphate (G6P). Blood was collected at -12, 0, 3, 6, 12, 18, 24, 36, 60, 72, 84, 132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids (NEFA), BHBA and glucose concentration. A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.

Results

By 12 h, E. coli was recovered from challenged quarters and shedding continued through 72 h. Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge. Daily feed intake and milk yield decreased (P <0.05) by 1 and 2 d, respectively, after mastitis challenge. Plasma BHBA decreased (12 h; P <0.05) from 0.96 ± 1.1 at 0 h to 0.57 ± 0.64 mmol/L by 18 h whereas concentration of plasma NEFA (18 h) and glucose (24 h) were significantly greater, 11 and 27%, respectively, after challenge. In milk, fglu, lactose, citrate, fat and protein yield were lower whereas yield of BHBA and G6P were higher after challenge when compared to pre-challenge values.

Conclusions

Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield. However, the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis. Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI. Decreases in both milk lactose yield and % after challenge may be partly attributed to reduced conversion of fglu to lactose. Rises in G6P yield and concentration in milk after challenge (24 h) may signify increased conversion of fglu to G6P. Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E. coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation.  相似文献   

9.
A study was conducted to evaluate the effects of three energy supply (E) levels [low (L), medium (M), high (H)], both pre‐partum (PRE) and post‐partum (POST), and their interactions on metabolic parameters and energy balance (EB) in dairy cows of three breeds. In both phases, E levels applied to a total of 81 multiparous cows of breeds Simmental (SI), Brown Swiss (BS) and Holstein–Friesian (HF; n = 27 for each breed) were 75%, 100% and 125% of recommendations of the German Society of Nutrition Physiology, using a 3 × 3 factorial arrangement of treatments. During the pre‐calving period, serum concentrations of non‐esterified fatty acids (NEFA) were higher for LPRE cows, and glucose concentrations were elevated for HPRE cows. During the lactation period, NEFA concentrations were greatest for treatment LPOST. Mean concentrations of β‐hydroxybutyrate (BHB) were highest for cows of the LPOST treatment, intermediate for MPOST and lowest for HPOST. Glucose concentrations were lower for LPOST cows. SI cows had lower BHB concentrations both pre‐ and post‐calving and higher glucose concentrations during early lactation than the other breeds. BHB concentration POST was highest for BS cows. Restricted feeding PRE resulted in a better energy status of cows fed above energy requirements POST (EPRE × EPOST interaction). HF cows had a higher EB pre‐calving, whereas SI cows had a less negative EB during early lactation, compared with the other breeds respectively. Correlations of serum NEFA, BHB and glucose concentrations with EB were strongest during the transition period. Results suggest that controlling energy intake during the dry period might be advantageous for the energy status of dairy cows after calving, whereas energy restriction in early lactation leads to metabolic stress. Evidence is provided of a clear relationship between EB and the blood metabolites NEFA and BHB, especially in the transition period.  相似文献   

10.
Due to seasonal changes in the quality and quantity of herbage, the nutrient supply to grazing dairy cows is not always sufficient, which may increase their metabolic load. To investigate the temporal pattern of behavioural changes in relation to concomitant metabolic alterations, we subjected 15 multiparous early lactating Holstein dairy cows (24 (SD 7.4) days in milk) to a short‐term metabolic challenge, which we provoked by abruptly withdrawing concentrate for 1 week. Cows grazed full‐time and were supplemented with concentrate in experimental week (EW) 1 and EW 3, whereas concentrate was withdrawn in EW 2. We analysed milk and blood samples to characterise the metabolic changes and found that the total yield of milk and protein decreased (p < 0.05) and fat yield, fat‐to‐protein ratio and acetone content increased (p < 0.05) from EW 1 to EW 2. Plasma glucose and insulin concentrations were lower (p < 0.05), and concentrations of nonesterified fatty acids and beta‐hydroxybutyrate were higher (p < 0.05) in EW 2 compared with EW 1. Apart from ingestive and rumination behaviour and activity, we also monitored the use of an automated brush on pasture. While time spent eating and ruminating increased (p < 0.05) in EW 2 compared with EW 1, time spent idling decreased (p < 0.05). Concomitantly, while time standing and moving increased (p < 0.05) from EW 1 to EW 2, walking time decreased (p < 0.05). The daily proportion of cows using the automated brush decreased (p < 0.05) in EW 2 compared with EW 1, as did the duration of brushing per day. In conclusion, grazing cows experiencing a metabolic challenge try to compensate for the nutrient deficiency by increasing eating time, a behavioural element important for short‐term survival. Due to the strong impact of weather conditions, we cannot currently recommend observation of outdoor brushing activity to address short‐term alterations in the metabolic state of grazing cows.  相似文献   

11.
Changes in ACTH challenge test characteristics in dairy cows changing their physiological status at different lactational stages and different feeding levels were not investigated in terms of repeatability yet. In 23 multiparous Holstein cows (10 cows fed a sole fresh herbage diet without concentrate, 13 cows fed with concentrate), three ACTH challenge tests were performed: once during pregnancy shortly prior to drying off ( T1 ), and in week 3 ( T2 ) and 8 ( T3 ) after parturition. Test characteristics were correlated to performance and metabolic parameters: DMI, BW, energy balance (EB), plasma concentrations of free fatty acids (NEFA) and beta‐hydroxybutyrate (BHB). Basal plasma cortisol concentrations were higher at T1 compared with T2 and T3 (p < .05). The adrenal cortex sensitivity (expressed as total AUC (AUCt) of cortisol response after ACTH application) was lowest at T2 compared with T1 and T3 (p < .05). Ranking of the individual animals’ responses was not repeatable between time points of the ACTH tests. Enhancing the energy deficiency during early lactation by omission of concentrate did not affect baseline cortisol concentrations in plasma, but decreased peak height at T2 (p < .05). Baseline plasma cortisol concentrations were positively correlated with cortisol peak values after ACTH application, previous lactation performance, milk yield and BW (p < .05). The AUCt was positively correlated with baseline cortisol concentrations, EB and DMI. Cortisol release after ACTH injection was lower in animals with high plasma concentrations of NEFA, BHB and with higher contents of fat and free fatty acids in milk (p < .05). Cortisol peak height after ACTH administration was higher in cows with a more positive EB, higher DMI and lower plasma concentrations of NEFA and BHB. In summary, cortisol responses to ACTH challenges in this study were not repeatable in dairy cows changing their physiological status.  相似文献   

12.
Thirty‐six cross‐bred cows were used to study the effect of long‐chain (flaxseed) or short‐chain (butyric acid) fatty acid supplementation on metabolic status, ovarian function and reproduction performance during transition period. Control cows received a routine feed of transition diet, while the cows in two treatment groups were supplemented with either 750‐g crushed flaxseed or 250 g butyric acid per cow per day. Ovarian activity was monitored by transrectal ultrasonography on 10th, 20th and 30th days post‐partum. Blood samples were collected by jugular venipuncture into heparinized polystyrene tubes; plasma was prepared and stored under ?20 °C until analysis. Results indicated that cows in flaxseed group were in positive energy balance as indicated by lower NEFA and Beta hydroxy Butyrate and higher glucose concentrations. Uterine involution was completed well within 30 days post‐partum in all the cows in flaxseed fed group compared to 76.9% in butyric acid supplemented and 61.5% in control groups. The size of dominant follicle and corpus luteum was significantly higher (p < 0.05) for flaxseed group compared to control group, which in turn resulted in higher concentrations of plasma progesterone. Cows fed on diets supplemented with flaxseed exhibited post‐partum heat earlier and bred sooner (p < 0.05) than control cows. It has been noticed that supplementation of flaxseed and butyric acid enhanced involution of uterus, early resumption of cyclicity and thereby early breeding. However, in view of the encouraging results obtained for flaxseed supplemented group, its organic nature and easier availability at farmer's gate, we concluded that flaxseed can be safely included in transition diet to modulate reproductive performance of dairy cattle.  相似文献   

13.
The objective of this study was to evaluate the effects of malic acid (MA) on feed intake, milk yield and composition, blood metabolites and energy balance in early lactation Holstein dairy cows from 1 to 63 day in milk (DIM). Twenty-eight multiparous Holstein dairy cows, blocked by lactation number, previous 305-d mature equivalent milk production, and expected calving date, were arranged into four groups in a randomized block design. Treatments were: control (without MA), LMA, MMA and HMA with 70, 140 and 210 g malic acid per cow per day, respectively. The supplement of food grade MA (99.8% of MA) was hand-mixed into the top one-third of the daily ration. Cows were fed ad libitum a total mixed ration consisting of equal proportion of forage and concentrate. Milk yield increased (P = 0.04), but feed intake and milk components were not affected (P > 0.05) by MA supplementation. The energy balance, expressed as the difference between energy input and output, tended to be higher (P = 0.08) for MA supplemented cows during the 63-DIM period MA and supplemented cows showed a trend (P = 0.07) toward less loss of BW during the 63-day period, especially during the first 21-day of lactation. Concentrations of plasma glucose and serum insulin were higher for cows fed LMA, MMA, and HMA relative to control and linearly (P < 0.01) increased with increasing MA supplementation. Concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA) and urine ketones were lower for MA-supplemented cows at 7, 14 and 21 DIM of lactation and linearly (P < 0.01) decreased with increasing MA supplementation. Although feed intake was not affected, milk yield increased, MA-supplemented cows experienced higher concentrations of plasma glucose and serum insulin, lower concentrations of plasma BHBA and NEFA, and lower concentrations of urine ketones, suggesting that nutrient digestibilities and energy availability may have been improved.  相似文献   

14.
This experiment aimed at evaluating the effect of calf management and breed on the metabolic and luteal function of post‐partum beef cows fed at maintenance. Fifty multiparous cows, 22 Parda de Montaña (PA) and 28 Pirenaica (PI), were assigned to either suckling once‐daily for 30 min (RESTR) or ad libitum (ADLIB) from the day after calving. Blood samples were collected to analyse metabolites [non‐esterified fatty acids (NEFA), β‐hydroxybutyrate, total protein and urea)], insulin‐like growth factor‐I (IGF‐I) and progesterone (P4) at different intervals. Cows from RESTR maintained their live‐weight (LW) over the first 3 months post‐partum, whereas ADLIB cows lost nearly 4% LW. Both genotypes showed similar LW gains during this period (p > 0.10). Calf daily gains were lower in RESTR than in ADLIB treatment (p < 0.05), but similar across breeds (p > 0.10). Milk and lactose production were lower in RESTR cows than in ADLIB (p < 0.05). Milk and protein yield were greater in PA than in PI breed (p < 0.05). Serum NEFA, total protein and urea were higher in PI cows suckling ADLIB than in the rest (p < 0.05). Cows from PI breed had greater NEFA values than PA ones on the first week post‐partum (p < 0.001). Circulating IGF‐I was not affected by suckling frequency, breed nor their interaction (p > 0.10). Suckling frequency, but not breed, affected the interval from calving to first ovulation (p < 0.001), being shorter in RESTR than in ADLIB cows. In conclusion, the ad libitum suckling practice improved cow milk yield and offspring gain compared to once‐daily suckling for 30 min from the day after calving, at the expense of impairing the onset of cyclicity. The effect of calf management was confounded with breed on the studied blood biochemical constituents, but any of these metabolites influenced the role of endocrine IGF‐I in these genotypes.  相似文献   

15.
Fifty‐one dairy cows with subclinical ketosis were used to investigate the effects of butafosfan alone or in combination with cyanocobalamin on metabolism. Treatments included i.v. injection of 10 ml/100 kg of body weight with butafosfan (BUT) or combined cyanocobalamin with butafosfan (BUTCO) at a similar concentration as in Catosal®. Control cows (CON) received a 0.9% saline solution. Cows were injected on days 1–3 at 22.3 ± 0.7 days post‐partum. Milk production and composition were not affected by the treatments. In plasma, CON cows had a significantly higher plasma NEFA concentration (0.59 ± 0.03 mm ) across the study period than BUTCO cows (p < 0.05; 0.42 ± 0.03 mm ), whereas the plasma NEFA concentration of BUT was intermediate (0.52 ± 0.03 mm ) but not significantly different from CON. Both BUTCO and BUT cows had lower (p < 0.05) plasma BHBA concentrations (1.02 ± 0.06 mm and 1.21 ± 0.06 mm , respectively) across the study period than CON (1.34 ± 0.06 mm ). Plasma glucose was not different between treatments, but plasma glucagon concentrations were consistently high in BUT compared to BUTCO and CON. Lowest post‐treatment glucagon levels were observed in BUTCO. Hepatic mRNA abundance of liver X receptor α, a nuclear receptor protein involved in lipid metabolism, was higher in BUTCO compared to BUT and CON (p < 0.05) on day 7. Furthermore, on day 7, the mRNA abundance of beta‐hydroxybutyrate dehydrogenase 2 was higher in BUTCO compared to BUT and CON (p < 0.01). In conclusion, injections of combined cyanocobalamin with butafosfan post‐partum in early lactation ketotic dairy cows act on lipid metabolism with effects on plasma metabolites, most likely mediated via modified activity of key factors in the liver. Results indicate that the application of butafosfan only in combination with cyanocobalamin exhibits the expected positive effects on metabolism.  相似文献   

16.
The objective of this experiment was to investigate the effect of fat supplementation during the transition period on pre and postpartum body weight (BW), body condition score (BCS), non‐esterified fatty acids (NEFA), glucose and leptin concentrations in Holstein cows. Holstein cows (n = 15) received a low fat diet (LF; 1.61 Mcal net energy for lactation (NEL)/kg of dry matter [DM]), moderate fat diet (MF; 1.68 Mcal NEL/kg DM) or a high fat diet (HF; 1.74 Mcal NEL/kg DM) for 4 weeks prior to calving. All cows were fed similar lactation diets ad libitum (1.74 Mcal NEL/kg DM) for 30 days after calving. Increasing diet energy density during transition period had no effect on prepartum DMI, BCS, BW, glucose and NEFA concentrations (P > 0.05); but leptin concentrations and energy balance (EB) were affected by treatments (P < 0.05). Animals fed HF had less plasma leptin prepartum. After parturition, BW, milk production, milk fat, protein, urea nitrogen and plasma glucose concentrations were affected by prepartum diets (P < 0.05). Fat supplementation prepartum did not affect postpartum NEFA. In conclusion, prepartum fat supplementation decreased leptin concentration prepartum.  相似文献   

17.
To evaluate the effects of calcium propionate (CaP) supplementation on feed intake, milk yield and milk composition, energy balance, blood metabolites and urine ketones in early lactation Holstein dairy cows from 1 to 63 days in milk (DIM), 32 multiparous Holstein dairy cows, blocked by lactation number, previous 305‐day milk production, and expected calving date, were arranged into four groups in a randomized block design. Treatments were control, LCaP, MCaP and HCaP with 0, 100, 200 and 300 g calcium propionate per cow per day respectively. The supplement of food grade CaP (99.8% of CaP) was hand‐mixed into the top one‐third of the daily ration. Cows were fed ad libitum a total mixed ration consisting of equal proportion of forage and concentrate. Feed intake, milk yield and components were not affected by CaP supplementation. The energy balance, expressed as the difference between energy input and output, tended to be higher (p = 0.08) for CaP‐supplemented cows during the 63‐DIM period, especially during the first 21‐DIM lactation. Calcium propionate‐supplemented cows showed a trend (p = 0.09) towards less loss of body weight (BW) during the 63‐DIM period. Concentrations of glucose in plasma and insulin in serum were higher for cows fed CaP relative to control and linearly (p < 0.01) increased with increasing CaP supplementation. Concentrations of non‐esterified fatty acids (NEFA), beta‐hydroxybutyrate (BHBA) and urine ketones were lower for CaP‐supplemented cows at 7, 14 and 21 DIM of lactation and linearly (p < 0.01) decreased with increasing CaP supplementation. These results indicated that nutrient digestibilities and energy status may have been improved.  相似文献   

18.
The objectives of this study were to determine the effects of a pre-partum diet with lower than recommended (DCAD = −82 mEq/kg of dietary DM) amounts of anionic salts on metabolism, health, reproductive performance and milk production in dairy cows. Sixty Holstein multiparous cows were enrolled 21 days prior to expected calving date. The animals were randomly assigned to receive one of two rations: 30 cows received anionic ration [−82 mEq (NA + K − Cl − S)/kg of DM] for 21 d to parturition and the other group (n = 30) were fed a usual dry period ration (+192 mEq/kg of DM). Serum samples obtained at days −21, +3 and +21 relative to calving were analyzed for β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), glucose, calcium (Ca), inorganic phosphorus, magnesium, chloride, sodium, potassium, cholesterol, urea, creatinine, total protein, albumin, and aspartate aminotransferase (AST). Urine pH declined from 8.4 at 21 d before calving (pre-treatment) to 6.2 at day 7 pre-partum in the treatment group. Repeated-measure mixed model analysis indicated that the concentrations of Ca were significantly increased and creatinine, and AST were significantly decreased by lowering DCAD. The concentrations of BHBA, NEFA and glucose were not affected by treatment. The incidence of milk fever and culling were 5 and 11 times higher in the control group in comparison with the treatment group, respectively. The intervals from calving to first breeding and to pregnancy were not influenced by treatment. There was no group effect on average daily milk yield or fat percentage.  相似文献   

19.
This study was performed to investigate the hypothesis that supplementation of conjugated linoleic acid (CLA) changes the concentrations of retinol and tocopherols in the milk of cows. To investigate this hypothesis, Holstein cows received daily from 3 weeks ante‐partum to 14 weeks post‐partum either 172 g of a CLA‐free rumen‐protected control fat (control group, n = 20) or the same amount of a rumen‐protected CLA fat, supplying 4.3 g of cis‐9, trans‐11 CLA and 3.8 g of trans‐10, cis‐12 CLA per d (CLA group, n = 20). Milk samples (collected at weeks 1, 3, 5, 8 and 11 of lactation) were analysed for retinol, α‐ and γ‐tocopherol concentrations. Milk of cows supplemented with CLA had higher concentrations of retinol (+34%), α‐tocopherol (+44%) and γ‐tocopherol (+21%) than milk of control cows (p < 0.05). The daily output of these vitamins via milk was also greater in cows of the CLA group than in cows of the control group (+36, 50 and 24% for retinol, α‐tocopherol and γ‐tocopherol, respectively, p < 0.05). In agreement with higher concentrations of tocopherols, concentrations of thiobarbituric acid‐reactive substances, determined in milk of week 5, were lower in cows of the CLA group than in control cows, indicative of a lower susceptibility of milk lipids to peroxidation. Plasma concentrations of retinol and α‐tocopherol, determined at 1 and 5 weeks post‐partum, were not different between the two groups of cows. In conclusion, this study shows that supplementing dairy cows with a moderate amount of CLA causes an increase of the concentrations of vitamins A and E in the milk and results in an increased output of those vitamins via milk. These effects might be beneficial with respect to the nutritional value of dairy products and the susceptibility of milk fat to oxidative deterioration.  相似文献   

20.
The aim of this work was to compare energy and lipid metabolism during the peripartum period between Modenese (MO) and Italian Friesian (IF) cows. The study was carried out on 33 pluriparous pregnant cows, 19 IF and 14 MO, reared together in the same herd and kept under equal conditions of management and nutrition. Blood was sampled from jugular vein starting 4 week before expected calving date until 4 week post‐calving, once weekly. Plasma was analysed for glucose, NEFA, BHBA, triglycerides and cholesterol concentrations. Body condition score (BCS) was assessed weekly after blood sampling. Data from antepartum (a.p.) and post‐partum (p.p.) periods were separately analysed as repeated measures by a linear mixed models with the effect of breed, time and their interaction as main factors and random cow within breed. The energy status differed between the two breeds during the peripartum period. We observed higher BCS a.p. and p.p. and lower BCS variations p.p. in MO compared to IF group. Modenese cows showed lower glucose and cholesterol concentrations (p < 0.001), but higher NEFA values, NEFA to cholesterol and NEFA to albumin ratios (p < 0.001) during a.p.; on the contrary, IF cows had higher (p < 0.05) cholesterol, NEFA, BHBA levels and NEFA to albumin ratio than MO ones during p.p. The differences observed between the two breeds suggest how MO cows are subjected to lipid mobilization during late gestation; on the contrary, IF cows are predisposed to mobilize their lipid reserves at the beginning of lactation to support high production. The results indicate a diverse ability to cope with metabolic stress and suggest the hypothesis that the differences in concentrations of plasma parameters and their variation amplitude around the calving period might depend on the different genetic merit for milk production between the two breeds.  相似文献   

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