Effects of nanoselenium supplementation on lactation performance, nutrient digestion and mammary gland development in dairy cows

The objective of this experiment was to evaluate the influence of nanoselenium (NANO-Se) addition on milk production, milk fatty acid synthesis, the development and metabolism regulation of mammary gland in dairy cows. Forty-eight Holstein dairy cows averaging 720 ± 16.8 kg of body weight, 66.9 ± 3.84 d in milk (dry matter intake [DIM]) and 35.2 ± 1.66 kg/d of milk production were divided into four treatments blocked by DIM and milk yields. Treatments were control group, low-Se (LSe), medium-Se (MSe) and high-Se (HSe) with 0, 0.1, 0.2 and 0.3 mg Se, respectively, from NANO-Se per kg dietary dry matter (DM). Production of energy- and fat-corrected milk (FCM) and milk fat quadratically increased (p < 0.05), while milk lactose yields linearly increased (p < 0.05) with increasing NANO-Se addition. The proportion of saturated fatty acids (SFAs) linearly decreased (p < 0.05), while proportions of monounsaturated fatty acids (MUFAs) linearly increased and polyunsaturated fatty acids (PUFAs) quadratically increased. The digestibility of dietary DM, organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) quadratically increased (p < 0.05). Ruminal pH quadratically decreased (p < 0.01), while total VFA linearly increased (p < 0.05) with increasing NANO-Se addition. The acetic to propionic ratio decreased (p < 0.05) linearly due to the unaltered acetic molar percentage and a quadratical increase in propionic molar percentage. The activity of CMCase, xylanase, cellobiase and pectinase increased linearly (p < 0.05) following NANO-Se addition. The activity of α-amylase increased linearly (p < 0.01) with an increase in NANO-Se dosage. Blood glucose, total protein, estradiol, prolactin, IGF-1 and Se linearly increased (p < 0.05), while urea nitrogen concentration quadratically decreased (p = 0.04). Moreover, the addition of Se at 0.3 mg/kg from NANO-Se promoted (p < 0.05) mRNA and protein expression of PPARγ, SREBP1, ACACA, FASN, SCD, CCNA2, CCND1, PCNA, Bcl-2 and the ratios of p-ACACA/ACACA and BCL2/BAX4, but decreased (p < 0.05) mRNA and protein expressions of Bax, Caspase-3 and Caspase-9. The results suggest that milk production and milk fat synthesis increased by NANO-Se addition by stimulating rumen fermentation, nutrients digestion, gene and protein expressions concerned with milk fat synthesis and mammary gland development.

Effect of Parenteral Supplementation of Minerals and Vitamins on Oxidative Stress Biomarkers and Hepatic Fatty Acid Metabolism in Dairy Cows During the Transition Period

In the present work we aimed to study the effects of parenteral vitamin and mineral supplementation on hepatic fatty acid metabolism as well as on the oxidative stress biomarkers in biological samples of transition cows. The supplemented group (SG, n = 11) received a subcutaneous injection of 5 mL of vitamin A palmitate 35 mg/mL, vitamin E acetate 50 mg/mL plus other injection of 5 mL of copper edetate 10 mg/mL, zinc edetate 40 mg/mL, manganese edetate 10 mg/mL, and sodium selenite 5 mg/mL on days - 60, - 30, and 7 (± 3) relative to calving. The control group (CG, n = 11) received two subcutaneous injections of 5 mL of 9 mg/mL sodium chloride at the same times of the SG. Blood, urine, and liver biopsies were sampled 21 (± 3) days before the expected calving date and 7 and 21 (± 3) days after calving. Results revealed that supplemented animals had higher glutation peroxidase (GSH-Px) activity, lower and higher concentration of 3-nitrotyrosine (3-NT) in the liver and plasma, respectively, higher expression of the mitochondrial beta-oxidation enzyme carnitine palmitoyltransferase 1 in the liver, and lower content of hepatic triacylglycerol, mirroring plasma liver function parameters. No differences between groups were found in the superoxide dismutase activity, MDA concentrations, the protein abundance of peroxisomal acyl-CoA oxidase 1, diacylglycerol O-acyltransferase 1, and peroxisome proliferator-activated receptor alpha. These results suggest that the vitamin and mineral supplementation provided to dairy cows had a beneficial effect on GSH-Px activity, hepatic 3-NT concentration, and on the metabolic adaptation during the peripartum period.

Effects of milk, milk replacer, and milk replacer plus ethoxyquin on the growth performance, weaning stress, and the fecal microbiota of Holstein dairy calves

The growth and health statuses of calves during the early stages of development have a significant effect on milk production during their first lactation period. Using appropriate milk replacers helps meet the long-term targets of dairy farmers. This study aimed to examine the effects of milk, milk replacer, and milk replacer plus ethoxyquin on growth performance, antioxidant status, immune function, and the gut microbiota of Holstein dairy calves. A total of 36 neonatal dairy calves were randomly divided into three groups and fed different diets: one group was fed milk, another group was fed milk replacer, and the third group was given milk replacer plus ethoxyquin. The supplementation with ethoxyquin was started on day 35 of the feeding period. The calves were weaned on day 45, and the experiment was conducted until day 49. The blood and fecal samples were collected at the end of the animal experiment. The results showed that milk replacers induced poor growth performance (body weight and average daily gain). However, milk replacer plus ethoxyquin aided in growth performance, enhanced the starter intake and blood antioxidative ability, and elevated the concentration of fecal valeric acid. Moreover, fecal fermentation and 16S rRNA analyses showed that milk replacer plus ethoxyquin altered the microbial composition (reducing Alistipes and Ruminococcaceae and increasing Bacteroides and Alloprevotella). Pearson's correlation assays showed that alterations in fecal microbiota strongly correlated with average daily gain and antioxidative ability. The results indicated the potential of milk replacer plus ethoxyquin in modulating the growth of dairy calves and in enhancing their ability to combat stress.

Effects of dietary antioxidant supplementation on metabolism and inflammatory biomarkers in heat-stressed dairy cows

Heat-stress-induced inflammation may be ameliorated by antioxidant supplementation due to the purported effects of increased production of reactive oxygen species or oxidative stress on the gastrointestinal tract barrier. Thus, study objectives were to evaluate whether antioxidant supplementation [AGRADO Plus 2.0 (AP); EW Nutrition] affects metabolism and inflammatory biomarkers in heat-stressed lactating dairy cows. Thirty-two mid-lactation multiparous Holstein cows were assigned to 1 of 4 dietary-environmental treatments: (1) thermoneutral (TN) conditions and fed a control diet (TN-CON; n = 8), (2) TN and fed a diet with AP (10 g antioxidant; n = 8), (3) heat stress (HS) and fed a control diet (HS-CON; n = 8), or (4) HS and fed a diet with AP (HS-AP; n = 8). The trial consisted of a 23-d prefeeding phase and 2 experimental periods (P). Respective dietary treatments were top-dressed starting on d 1 of the prefeeding period and continued daily throughout the duration of the experiment. During P1 (4 d), baseline data were collected. During P2 (7 d), HS was artificially induced using an electric heat blanket (Thermotex Therapy Systems Ltd.). During P2, the effects of treatment, day, and treatment-by-day interaction were assessed using PROC MIXED of SAS (SAS Institute Inc.). Heat stress (treatments 3 and 4) increased rectal, vaginal, and skin temperatures (1.2°C, 1.1°C, and 2.0°C, respectively) and respiration rate (33 breaths per minute) relative to TN cows. As expected, HS decreased dry matter intake, milk yield, and energy-corrected milk yield (32%, 28%, and 28% from d 4 to 7, respectively) relative to TN. There were no effects of AP on body temperature indices or production. Milk fat, protein, and lactose concentrations remained unaltered by HS or AP; however, milk urea nitrogen was increased during HS regardless of AP supplementation (26% relative to TN). Circulating glucose remained unchanged by HS, AP, or time. Additionally, HS decreased circulating glucagon (29% from d 3 to 7 relative to TN), but there was no additional effect of AP. There was a tendency for nonesterified fatty acid concentrations to be increased in HS-AP cows throughout P2 (60% relative to TN-CON), whereas it remained similar in all other treatments. Blood urea nitrogen increased for both HS treatments from d 1 to 3 before steadily decreasing from d 5 to 7, with the overall increase being most pronounced in HS-CON cows (27% relative to TN-CON). Further, supplementing AP decreased blood urea nitrogen in HS-AP on d 3 relative to HS-CON (15%). Circulating serum amyloid A tended to be and lipopolysaccharide binding protein was increased by HS, but neither acute-phase protein was affected by AP. Overall, AP supplementation appeared to marginally alter metabolism but did not meaningfully alter inflammation during HS.

Effect of dietary hempseed cake on milk performance and haemato-chemicals in lactating Alpine dairy goats

Owing to the high concentrations of crude protein and beneficial fatty acids, hempseed cake could be a high-quality feedstuff for ruminants. The aim of the present study was to evaluate the effects of hempseed cake on milk production and quality, as well as haemato-chemical parameters in Alpine goats. In total, 28 French Alpine dairy goats were evaluated over 45 days. All goats were fed meadow hay supplemented with 1.2 kg/day feed mixture. The feed mixture in control group contained soybean meal and extruded soybean. In the first experimental group, soybean meal and extruded soybean were partially replaced with 60 g/kg of hempseed cake (HC6). In the second experimental group, soybean meal and extruded soybean were partially replaced with 120 g/kg of hempseed cake (HC12). Feeding goats with HC6 and HC12 did not influence milk yield, although the concentration of milk urea was higher in the HC12 compared to control group. The HC12 decreased the linoleic acid (LA)/linolenic acid (ALA) ratio and glutathione peroxidase activity in the serum. Under the conditions evaluated in this study, the inclusion of HC6 in the diet was optimal with respect to chemical composition of milk and haemato-chemical parameters. Even though HC12 resulted in lowered LA/ALA ratio, which confers functional properties to goat milk, HC12 increased milk urea concentrations, and worsened serum antioxidant status.

Dihydropyridine Enhances the Antioxidant Capacities of Lactating Dairy Cows under Heat Stress Condition

Simple Summary

Additives contribute to improving the health of dairy cows, enhancing antioxidative capacities, and/or increasing milk production, etc. To alleviate the harmful effects of heat stress on dairy cows, a few feed additives studies have been conducted. Dihydropyridine has been used as a feed additive in dairy cow diets. However, the underlying mechanisms of its beneficial effects still remain unclear. In the present study, dairy cows were randomly divided into a control group and a dihydropyridine treatment group under heat stress in summer. The rumen and blood samples of dairy cows were collected to determine the changes in their antioxidative capacities. Meanwhile, the effects of dihydropyridine on ruminal microbial communities were also analyzed. Our data demonstrated that dihydropyridine enhanced the antioxidative capacities of dairy cows under heat stress conditions.

Abstract

Heat stress (HS), a nonspecific response to environmental heat, can seriously affect dairy cow health. Feed additives may alleviate HS in dairy cows by improving rumen fermentation efficacy, stimulating feed consumption, enhancing vasodilation, and/or improving antioxidant capacity. The temperature–humidity index (THI) indicates that spring is a non-HS season, and summer is an HS season. HS results in the decrease in dairy cow antioxidant capacities. Our results indicated the decrease in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidation (T-AOC) levels and the increase in malondialdehyde (MDA) level during HS season. Meanwhile, antioxidant indexes (SOD, GSH-Px, and T-AOC) were positively correlated with milk yield (p < 0.01), whereas MDA exhibited a significant negative correlation with milk yield (p < 0.05). In addition, the effects of dihydropyridine (DHP) on antioxidant capacity and ruminal microbial communities in dairy cows under HS were investigated. During summer, dairy cows were randomly assigned into two groups under HS, including a standard diet (S-ND) group and standard diet with 3 g/day/cow DHP (S-D) group. DHP treatment significantly restored SOD and GSH-Px levels under HS. Denaturing gradient gel electrophoresis results indicated that the DHP altered ruminal bacterial community mainly composed Proteobacteria and Firmicutes in dairy cows under HS. Our results suggest that DHP can enhance the antioxidant abilities of dairy cows with favorable effects on ruminal microbial communities under HS, further alleviating HS on dairy cows.

Effect of dietary inclusion of antioxidants and organic trace minerals on growth performance, carcass characteristics, and meat quality of finishing pigs with pre-slaughter transportation

A total of 320 pigs (body weight = 98 ± 4 kg) were assigned to four treatments, with eight replicates (pens) per treatment. Pigs were fed the following diets: a control diet (CON), the CON diet plus antioxidant blends (AOX), organic trace minerals (OTM), or both (AOX + OTM). After the feeding trial, two pigs from each pen were selected for slaughtering right away or after transportation. The inclusion of AOX, OTM, or AOX + OTM had no significant effect on feed intake, average daily gain, and feed efficiency compared with CON (P > 0.05). The pre-transportation significantly reduced the pH value of loin meat at 24 h post mortem and leg meat at 45 min post mortem (P < 0.05). The pigs in the AOX, OTM, and AOX + OTM group had significantly lower plasma malondialdehyde (MDA) content than the CON group (P < 0.05). Pre-transportation resulted in significantly higher meat MDA contents (P < 0.05), clearly influencing the oxidative stress of pigs. The inclusion of antioxidant blends or organic trace minerals had no significant effect on the growth performance and antioxidant capacity of finishing pigs.

Effect of wheat- or oat-straw inclusion with wheat bran or corn grain in prepartum diets on postpartum performance of transition dairy cows

Current study evaluated the effects of feeding straw source and energy supplementation during prepartum period on postpartum production performance and changes in blood metabolites of crossbred dairy cows. Twenty-eight crossbred (Holstein × Sahiwal) cows were randomly assigned to one of the following four dietary treatments: (1) wheat straw and corn grain (WSCG), (2) wheat straw and wheat bran (WSWB), (3) oat straw and corn grain (OSCG) and (4) oat straw and wheat bran (OSWB) in a 2 × 2 factorial experiment. Iso-nitrogenous diets fed as ad libitum total mixed ration contained 25% wheat straw (WS) or oat straw (OS) and 10% corn grain (CG) or wheat bran (WB). Experimental duration was 42 days before and 56 days after calving. After calving, all animals were fed a similar lactation diet. Pre- and postpartum dry-matter intake % of BW was not affected by treatments. Prepartum energy balance (EBAL) was higher for OS than WS and higher for CG than WB animals. Postpartum EBAL was higher in the WSCG than OSCG treatment. Milk production and composition were not affected by straw source or energy concentrate. Milk yield at Weeks 1, 2 and 3 was higher in the WSWB than WSCG and OSWB treatments. Total solids and feed efficiency were higher in the WSWB than WSCG treatment. Postpartum plasma concentration of non-esterified fatty acids was higher in the WS than the OS diet; however, the measured values were within normal limits. Postpartum plasma β-hydroxybutyrate concentration was not affected by straw source or energy concentrate. Cows fed WSWB prepartum were in positive EBAL, before and after calving, closer to the recommended requirements. Moreover, cows fed WSWB had a lower incidence of health disorders and subclinical ketosis, higher milk production and better feed conversion efficiency during first 3 weeks after calving.

Effect of feeding grape seed Proanthocyanidin extract on production performance, metabolic and anti-oxidative status of dairy cattle

ABSTRACT Aims to investigate the effects of grape seed proanthocyanidin extract (GSPE) on production performance, metabolism, and anti-oxidative status of Holstein dairy cattle in early lactation. Forty-eight multiparous Holstein dairy cattle were assigned to four groups (CON, G20, G40 and G80) and supplied with 0, 20, 40, and 80mg GSPE/kg of body weight/day. G20 significantly increased milk yield compared with other groups. Milk protein and non-fat-solids were increased in G20, G40 and G80 groups compared with the control group only at the 7th day during the experiment. No significant difference was observed in milk fat and somatic cell count, nor on parameters of energy metabolism in blood, liver function and kidney function between the four groups. There was no significant difference in glutathione peroxidase, superoxide dismutase, total antioxidant capacity, and hydrogen peroxide between the groups; but the malondialdehyde content of G20 significantly increased at day 14 in comparison with CON, and tended to increase at the 28th day. In conclusion, feeding 20mg GSPE/kg of body weight/day was associated with a significant increase in milk yield without detrimental effects on liver or kidney function and with substantial energy metabolism and antioxidant parameters improvement in early lactation dairy cattle.

Effect of milking frequency and α-tocopherol plus selenium supplementation on sheep milk lipid composition and oxidative stability

The aim of this research was to study the effect of milking frequency [once-daily milking (ODM) vs. twice-daily milking (TDM)] and antioxidant (AOX) supplementation on fatty acid (FA) profile and oxidative stability in sheep milk. Sixteen Assaf ewes were used; 8 did not receive any vitamin-mineral supplement (control), and the other 8 received an oral dose of 1,000 IU of α-tocopherol and 0.4 mg of Se daily. The experiment consisted of 2 consecutive periods; the first was 3 wk with TDM of both mammary glands. The second period was 8 wk and consisted of ODM of one mammary gland and TDM of the other gland. All ewes were fed ad libitum the same total mixed ration from lambing and throughout the experiment. There were no differences in plasma or milk Se concentrations between control and AOX ewes. However, plasma and milk α-tocopherol concentrations and AOX capacity were increased in ewes receiving the AOX supplement. Milk FA profile was practically unaffected after 21 d of AOX supplementation. However, after 77 d, AOX supplementation increased the relative percentage of C16:0 and cis-9 C18:1 and reduced the proportions of some saturated FA with less than 16 carbons and cis-9 C12:1. Antioxidant supplementation had no effect on the proportions of conjugated linoleic acid or total polyunsaturated FA (PUFA) but decreased the proportion of trans-7,cis-9 C18:2 and increased that of n-6 C20:3. Once-daily milking did not affect α-tocopherol, Se, or fat resistance to oxidation in milk. Total monounsaturated FA, cis-9 C16:1, and several cis and trans isomers of C18:1 were increased and total saturated FA were decreased in milk from ODM glands. Compared with TDM, ODM increased the proportions of cis-9,cis-12 C18:2 and several isomers of C18:2 and reduced those of cis-9,cis-12,cis-15 C18:3 and some PUFA of 20 and 22 carbons, but total proportion of PUFA was unaffected. Once-daily milking and AOX supplementation modified milk FA profile, but the effects of ODM could be considered of little biological relevance for consumer health. Supplementing ewes with α-tocopherol plus Se could be considered an effective strategy to improve plasma AOX status and reduce milk fat oxidation without substantial changes in the milk FA profile.

Dietary Supplementation of Yerba Mate (Ilex paraguariensis) during the Dry Period Improves Redox Balance in Lactating Dairy Cows

Thirty-six pregnant Holstein–Friesian cows were used to study the effect of Yerba Mate (YM) supplementation during the dry period on redox balance. The treatments groups were Control (no YM), YM 250 (250 g/cow/day), and YM 500 (500 g/cow/day). Blood samples were obtained 30 days prepartum, at calving, and monthly postpartum until four months post calving. Liveweight (LW) and body condition score (BCS) were assessed prepartum, at calving, and then postpartum monthly until the end of the trial. Plasma was analyzed for hydroperoxides (d-ROMs), advanced oxidation protein products (AOPP), and biological antioxidant potential (BAP). The oxidative stress index (OSI) was calculated as OSI = ROMs/BAP × 100. Cows were milked twice daily, and milk yield data were recorded daily. Redox balance was improved by YM supplementation, as reflected in the lower OSI values observed in the YM groups. Yerba Mate supplementation significantly affected LW, but did not affect BCS. Milk yield averaged 28.1 ± 0.40, 29.0 ± 0.48, and 29.9 ± 0.46 L/cow/day in the Control, YM 250, and YM 500 groups, respectively, but was not significant. Nutritional manipulation during the dry period with Yerba Mate has demonstrated the potential to improve redox balance and milk yield.

Spirulina supplementation during the transition period by grazing dairy cattle at tropical highland conditions

The objective of this experiment was to evaluate the effects of spirulina supplementation on oxidative stress, immunity, and productive performance during the transition period by grazing dairy cattle. Thirty multiparous gestating cows with an initial body weight (BW = 544 ± 57 kg) were enrolled in this experiment and were stratified by expected calving date. Cows were randomly assigned to one of the three experimental groups: (1) control, no supplementation of spirulina; (2) spirulina-15 (15 g/day of spirulina); and (3) spirulina-30 (30 g/day of spirulina). Body weight and body condition score (BCS) were recorded and blood samples were collected at - 21, 1, and 14 days, relative to calving. The day of parturition, colostrum and blood samples from calves were collected to measure IgG concentrations. After parturition milk yield, milk components and somatic cell count were monitored. Body weight, BW loss, BCS, and total antioxidant capacity were not affected by spirulina supplementation (P > 0.23) at any time point measured. Milk yield, milk components, and somatic cell count were not altered by treatment (P > 0.13). Results from this experiment suggest neither positive nor negative effects of spirulina supplementation on oxidative stress and productive performance during the transition period.

Feeding heat-oxidized oil to dairy cows affects milk fat nutritional quality

Heating oil and oilseeds results in oxidation products that affect ruminal biohydrogenation of polyunsaturated fatty acids, altering milk fatty acids profile, and could be transferred to milk. An experiment was conducted to investigate the effects of oil heating on rumen and milk fatty acids profile and the transfer of oxidation products to milk. Sunflower oil was heated at 150°C for 15 h and given to lactating dairy cows in a 2×2 arrangement: two groups of two cows, equipped with a ruminal cannula and receiving two diets (containing either heated or unheated oil) during two experimental periods. Oil heating generated hydroperoxides and/or hydroxyacids and aldehydes, in particular trans-2,trans-4-decadienal. In milk, heated oil only significantly decreased trans-11-C18:1 and cis-9,trans-11-CLA percentage compared to non-heated oil, and slightly increased cis-9,cis-12-C18:2 percentage, which was probably linked to an inhibition of the ruminal Δ12 isomerase by oxidative products in the rumen. However, feeding highly oxidized oil did not result in the appearance of hydroperoxides or hydroxyacids in milk and did not increase milk aldehydes content.

Effects of oil quality and antioxidant supplementation on sow performance, milk composition and oxidative status in serum and placenta

BACKGROUND

The aim of this study was to determine the effects of oil quality and antioxidant (AOX) supplementation on sow performance, milk composition and oxidative status.

METHODS

A total of 80 PIC (PIC breeding, 3 ~ 5 parities) sows with similar body condition were allocated to four groups (n = 20), receiving diets including fresh corn oil, oxidized corn oil, fresh corn oil plus AOX and oxidized corn oil plus AOX, respectively, from d 85 of gestation to d 21 of lactation. AOX was provided at 200 mg/kg diet and mixed with corn oil prior to dietary formulation.

RESULTS

The results showed that sows fed oxidized corn oil had significantly lower feed intake (P < 0.05) during lactation period. Feeding oxidized corn oil markedly decreased (P < 0.05) the contents of protein and fat in colostrums and milk, but the addition of AOX in oxidized corn oil prevented the decrease on protein content of colostrums. Moreover, sows fed oxidized corn oil had significantly lower serum activities of total SOD and Mn-SOD across lactation (P < 0.05). In contrast, addition of AOX to oxidized corn oil tended to inhibit the production of MDA (P = 0.08) in sows across lactation relative to fresh oil. Intriguingly, the placental oxidative status was affected by oil quality and AOX supplementation, as indicated by the markedly increased placental gene expression of GPX and SOD (P < 0.05) in sows fed oxidized corn oil but normalized by supplementation of AOX.

CONCLUSION

In conclusion, feeding oxidized corn oil did not markedly affect reproductive performance in addition to decreasing feed intake during lactation. Milk composition and systemic oxidative status were deteriorated in sows fed oxidized corn oil and partially improved by AOX supplementation. Moreover, placental antioxidant system of sows may have an adaptive response to oxidative stress, but normalized by AOX.

Serum fatty acids, biochemical indices and antioxidant status in goats fed canola oil and palm oil blend

Background

Dietary supplementation of unsaturated fats in ruminants, if not stabilized, can instigate oxidative stress which can have negative impact on production performance and enhance the susceptibility to various diseases. The current study examined the effect of dietary 80 % canola oil and 20 % palm oil blend (CPOB) on serum fatty acids, antioxidant profile and biochemical indices in goats. Thirty Boer bucks (4–5 months old; initial BW, 20.34 ± 0.77 kg) were randomly assigned to diets containing 0, 4 or 8 % CPOB and fed daily for a period of 90 days. Blood was sampled from the goats on 0, 30, 60 and 90 days of the trial and the serum was analyzed for fatty acids, cholesterol, glucose, total protein, antioxidants and lipid oxidation.

Results

Neither diet nor sampling time influenced serum TBARS value, catalase, glutathione peroxidase and superoxide dismutase activities, LDL cholesterol, VLDL cholesterol, triglycerides, glucose and total protein. Goats fed 4 and 8 % CPOB had higher (P < 0.05) total cholesterol and HDL cholesterol than the control goats on day 30, 60 and 90. The proportion of C15:0 decreased with increasing level of CPOB on day 30 and 60. Serum C18:1n-9 increased with increasing level of CPOB in diet on day 60. The proportion of C18:3n-3 and C22:5n-3 increased (P < 0.05), while the proportion of C18:2n-6 decreased (P < 0.05) with increase in the level of CPOB on day 60 and 90. Dietary CPOB did not affect serum total carotenoid and δ-tocopherol but did increase (P < 0.05) α and γ-tocopherol.

Conclusion

Dietary canola oil and palm oil blend could be supplemented in diets without instigating oxidative stress in goats.

mRNA Expression of lipogenic enzymes in mammary tissue and fatty acid profile in milk of dairy cows fed flax hulls and infused with flax oil in the abomasum

In the present study, the effect of flax hulls with or without flax oil bypassing the rumen on the expression of lipogenic genes in the mammary tissue of dairy cows was investigated. A total of eight dairy cows were used in a replicated 4 × 4 Latin square design. There were four periods of 21 d each and four treatments: control diet with no flax hulls (CONT); diet with 9·88 % flax hulls in the DM (HULL); control diet with 500 g flax oil/d infused in the abomasum (COFO); diet with 9·88 % flax hulls in the DM and 500 g flax oil/d infused in the abomasum (HUFO). A higher mRNA abundance of sterol regulatory element binding transcription factor, fatty acid (FA) synthase, lipoprotein lipase (LPL), PPARγ1, stearoyl-CoA desaturase (SCD) and acetyl-coenzyme A carboxylase-α was observed in cows fed HULL than in those fed CONT, and HUFO had the opposite effect. Compared with CONT, COFO and HUFO lowered the mRNA abundance of SCD, which may explain the lower proportions of MUFA in milk fat with flax oil infusion. The mRNA abundance of LPL in mammary tissue and proportions of long-chain FA in milk fat were higher in cows fed COFO than in those fed CONT. The highest proportions of trans FA were observed when cows were fed HULL. The present study demonstrates that flax hulls with or without flax oil infusion in the abomasum can affect the expression of lipogenic genes in the mammary tissue of dairy cows, which may contribute to the improvement of milk FA profile.

Effects of chestnut tannins on performance and antioxidative status of transition dairy cows

This study was conducted to evaluate the effects of chestnut tannins (CT) on performance and antioxidative status of transition dairy cows. Twenty multiparous Chinese Holstein cows in late gestation were paired according to expected calving date and randomly assigned either to a diet supplemented with CT (CNT, 10 g of CT/kg of diet, dry matter basis) or to an unsupplemented control (CON) diet from 3 wk prepartum to 3 wk postpartum. Blood samples were taken on d -21, 1, 7, and 21 relative to calving for analysis of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and malondialdehyde (MDA). Liver samples were taken by puncture biopsy on d 1 and 21 relative to calving for analysis of SOD, GSH-Px, and MDA. Data were analyzed for a completely randomized block design with repeated measures. The addition of CT had no significant effects on dry matter intake, body weight, body condition score, milk yield, 3.5% fat-corrected milk yield, and milk composition but did decrease milk MDA and somatic cell score in transition dairy cows. Dry matter intake decreased from d -21 to 0 and increased from d 1 to 21 relative to calving across treatments. During the experimental period, body weight and body condition score decreased, whereas milk MDA and somatic cell score increased across treatments. A time effect was also observed for plasma MDA, which peaked on d 1 relative to calving and remained higher than that on d -21 relative to calving across treatments. Addition of CT decreased MDA concentrations in plasma and liver. Neither time nor CT × time effects were observed for SOD and T-AOC in plasma and SOD and GSH-Px in liver; a time effect was observed for plasma GSH-Px, which peaked on d 1 relative to calving and remained higher than those on d -21 relative to calving across treatments. Addition of CT increased SOD, GSH-Px, and T-AOC activities in plasma and SOD and GSH-Px activities in liver. In conclusion, addition of CT might inhibit lipid peroxidation and increase antioxidant enzymes activities in plasma and liver of transition dairy cows. Supplementation of CT may be a feasible means to improve the antioxidative status of transition dairy cows.

Mammary gene expression and activity of antioxidant enzymes and oxidative indicators in the blood, milk, mammary tissue and ruminal fluid of dairy cows fed flax meal

The effects of flax meal (FM) on the activity of antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) in the blood, mammary tissue and ruminal fluid, and oxidative stress indicators (thiobarbituric acid-reactive substances(TBARS) and 1,1-diphenyl-2-picrylhydrazyl-scavenging activity) in the milk, plasma and ruminal fluid of dairy cows were determined.The mRNA abundance of the antioxidant enzymes and oxidative stress-related genes was assessed in mammary tissue. A total of eight Holstein cows were used in a double 4 x 4 Latin square design. There were four treatments in the diet: control with no FM(CON) or 5% FM (5FM), 10% FM (10FM) and 15% FM (15FM). There was an interaction between treatment and time for plasma GPx and CAT activities. Cows supplemented with FM had a linear reduction in TBARS at 2 h after feeding, and there was no treatment effect at 0, 4 and 6 h after feeding. TBARS production decreased in the milk of cows fed the 5FM and 10FM diets. There was a linear increase in nuclear factor (erythroid-derived 2)-like 2 (NFE2L2) mRNA abundance in mammary tissue with FM supplementation.A linear trend for increased mRNA abundance of the CAT gene was observed with higher concentrations of FM. The mRNA abundance of CAT, GPx1, GPx3, SOD1, SOD2, SOD3 and nuclear factor of k light polypeptide gene enhancer in B-cells (NFKB) genes was not affected by the treatment. These findings suggest that FM supplementation can improve the oxidative status of Holstein cows as suggested by decreased TBARS production in ruminal fluid 2 h post-feeding and increased NFE2L2/nuclear factor-E2-related factor 2 (Nrf2) mRNA abundance in mammary tissue.

Effects of feeding algal meal high in docosahexaenoic acid on feed intake, milk production, and methane emissions in dairy cows

This study examined effects on milk yield and composition, milk fatty acid concentrations and methane (CH4) emissions when dairy cows were offered diets containing different amounts of algal meal. The algal meal contained 20% docosahexaenoic acid (DHA) and cows were offered either 0, 125, 250, or 375 g/cow per d of algal meal corresponding to 0, 25, 50, or 75 g of DHA/cow per d. Thirty-two Holstein cows in mid lactation were allocated to 4 treatment groups, and cows in all groups were individually offered 5.9k g of dry matter (DM) per day of concentrates [683 g/kg of cracked wheat (Triticum aestivum), 250 g/kg of cold-pressed canola, 46 g/kg of granulated dried molasses, and 21 g/kg of mineral mix] and ad libitum alfalfa (Medicago sativa) hay. The algal meal supplement was added to the concentrate allowance and was fed during the morning and afternoon milking, whereas the alfalfa hay was fed individually in pens. Cows were gradually introduced to their diets over 7d and then fed their treatment diets for a further 16d. Dry matter intake and milk yield were measured daily, and milk composition was measured on a sample representative of the daily milk yield on Thursday of each week. For the last 2d of the experiment, cows were individually housed in respiration chambers to allow measurement of CH4 emissions. Dry matter intake, milk yield and milk composition were also measured while cows were in the respiration chambers. Cows ate all their offered concentrates, but measured intake of alfalfa decreased with increasing dose of DHA by 16.2, 16.4, 15.1, and 14.3 kg of DM/d, respectively. Milk yield (22.6, 23.5, 22.6, and 22.6 kg/cow per d) was not affected by DHA dose, but milk fat concentrations (49.7, 37.8, 37.0, and 38.3g/kg) and, consequently, milk fat yields (1.08, 0.90, 0.83, and 0.85 kg/d) decreased with addition of DHA. The feeding of algal meal high in DHA was associated with substantial increases in the concentrations of DHA (0.04, 0.36, 0.60, and 0.91 g/100g of milk fatty acids) and conjugated linoleic acid C18:2 cis-9,trans-11 (0.36, 1.09, 1.79, and 1.87 g/100g of milk fatty acids). Addition of DHA did not affect total emissions of CH4 (543, 563, 553, and 520 g/cow per d), nor emissions in terms of milk production (24.9, 22.1, 24.3, and 23.4 g of CH4/kg of milk), but emissions were increased with respect to total intake (22.6, 23.5, 24.5, and 24.4 g of CH4/kg of DM). These findings indicate that CH4 emissions were not reduced when dairy cows were fed a forage-based diet supplemented with DHA from algal meal.

The effect of zeolite on oxidant/antioxidant status in healthy dairy cows

This study was conducted to evaluate the effect of dietary zeolite (clinoptilolite) supplementation on the oxidative/antioxidative status on plasma in healthy dairy cows. Twenty dairy cows were divided into two groups of 10. Control group was fed the basal ration for 60 days. Zeolite group was fed the basal ration supplemented with 2.5% zeolite daily. To evaluate the oxidative and antioxidative status comprehensively, indicators such as total oxidant status, oxidative stress index, total antioxidant status, lipid hydroperoxide, total free sulphhydryl groups, ceruloplasmin concentrations, arylesterase, paraoxonase-1 and catalase activities were measured in plasma. Lipid hydroperoxide concentration was significantly (P< 0.05) decreased from 6.21 ± 0.94 to 4.90 ± 1.05 mmol H2O2Eq/l by zeolite supplementation. However, no significant effect was observed on the antioxidant and other oxidant indicators. In conclusion, although zeolite decreased the lipid hydroperoxide concentration, it cannot further strengthen antioxidant defense system in healthy dairy cows.

Mammary gene expression and activity of antioxidant enzymes and concentration of the mammalian lignan enterolactone in milk and plasma of dairy cows fed flax lignans and infused with flax oil in the abomasum

The objectives of the study were to investigate the effects of dietary supplementation of flax hulls and/or flax oil on the activity of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX)) in plasma and the mammary gland and the relative mRNA abundance of antioxidant genes in the mammary gland of dairy cows. A total of eight dairy cows were used in a replicated 4 × 4 Latin square design. There were four treatments: control with no flax hulls (CONT), 9·88 % flax hulls in the DM (HULL), control with 500 g flax oil/d infused in the abomasum (COFO), 9·88 % flax hulls in the DM and 500 g flax oil/d infused in the abomasum (HUFO). Plasma GPX activity tended to decrease with flax oil supplementation. Cows fed HULL had higher levels of CAT, GPX1 and SOD1 mRNA in the mammary gland and lower mRNA abundance of GPX3, SOD2 and SOD3 compared with those fed CONT. Abundance of CAT, GPX1, GPX3, SOD2 and SOD3 mRNA was down-regulated in the mammary gland of cows fed HUFO compared to those fed CONT. The mRNA abundance of CAT, GPX1, GPX3 and SOD3 was lower in the mammary gland of cows fed COFO than in the mammary gland of cows fed CONT. The present study demonstrates that flax hulls contribute to increasing the abundance of some antioxidant genes, which can contribute to protecting against oxidative stress damage occurring in the mammary gland and other tissues of dairy cows.

Effect of different rumen-inert fatty acids supplemented with a dietary antioxidant on performance and antioxidative status of early-lactation cows

The objective of the study was to evaluate the effect of diets supplemented with fatty acids of different degrees of saturation, in the absence or presence of an antioxidant (AOX; Agrado Plus, Novus International Inc., St. Charles, MO), on dairy cow lactation performance. Calcium salts of long-chain fatty acids were supplemented as a source of lower saturation fatty acid, and a palm acid product was supplemented as the higher saturation fatty acid source. Sixty early-lactation Chinese Holstein cows (100+/-23 d in milk) were randomly allocated to 4 dietary treatments in a 2 x 2 factorial design: (1) lower saturation fatty acid (LS), (2) LS and AOX, (3) higher saturation fatty acid (HS), and (4) HS and AOX. The Ca salts of long-chain fatty acids and palm acid product were supplied at 1.8 and 1.5% on a dry matter basis, respectively, to form isoenergetic diets. The AOX was added at 0.025% in the ration. The experiment lasted 9 wk, including 1 wk for adaptation. Lactation performance was recorded and milk was sampled and analyzed weekly. Blood samples were taken from the coccygeal vein to determine metabolism parameters on d 16, 36, and 56 during the experiment. Neither fatty acid type nor AOX supplementation showed a significant effect on dry matter intake during the study. Milk yield was lower in the LS-fed cows compared with the cows fed HS. Milk fat and milk protein concentrations were not affected by fatty acid type or AOX supplementation. Adding AOX increased the yield of milk in the LS-fed cows, but did not affect those fed HS. Activity of plasma superoxide dismutase was significantly lower, plasma glucose tended to be lower, and plasma malondialdehyde was higher in the LS-fed animals compared with those fed HS. Addition of AOX decreased both plasma nonesterified fatty acids and hydrogen peroxide contents and increased total antioxidant capacity across the fatty acid types. Plasma beta-hydroxybutyrate was not affected by fatty acid type or AOX treatment. Cows fed LS had higher cis-9C(18:1) and trans-10, cis-12C(18:2) in milk at the expense of C(18:0), whereas AOX addition increased milk cis-9C(18:1) at the expense of milk C(12:0), C(16:0), and trans-10, cis-12C(18:2). It is inferred that feeding LS resulted in inferior lactation performance, whereas addition of antioxidant partially alleviated these negative effects.