Modulation of colostrum composition and fatty acid status in neonatal calves by maternal supplementation with essential fatty acids and conjugated linoleic acid starting in late lactation

Sufficient maternal supply of essential fatty acids (EFA) to neonatal calves is critical for calf development. In the modern dairy cow, EFA supply has shifted from α-linolenic acid (ALA) to linoleic acid (LA) due to the replacement of pasture feeding by corn silage–based diets. As a consequence of reduced pasture feeding, conjugated linoleic acid (CLA) provision by rumen biohydrogenation was also reduced. The present study investigated the fatty acid (FA) status and performance of neonatal calves descended from dams receiving corn silage–based diets and random supplementation of either 76 g/d coconut oil (CTRL; n = 9), 78 g/d linseed oil and 4 g/d safflower oil (EFA; n-6/n-3 FA ratio = 1:3; n = 9), 38 g/d Lutalin (BASF SE, Ludwigshafen, Germany) providing 27% cis-9,trans-11 and trans-10,cis-12 CLA, respectively (CLA; n = 9), or a combination of EFA and CLA (EFA+CLA; n = 11) in the last 9 wk before parturition and following lactation. The experimental period comprised the first 5 d of life, during which calves received colostrum and transition milk from their own dam. The nutrient compositions of colostrum and transition milk were analyzed. Plasma samples were taken after birth and before first colostrum intake and on d 5 of life for FA analyses of the total plasma fat and lipid fractions. Maternal EFA and CLA supplementation partly affected colostrum and transition milk composition but did not change the body weights of calves. Most EFA in calves were found in the phospholipid (PL) and cholesterol ester (CE) fractions of the plasma fat. Maternal EFA supplementation increased the percentage of ALA in all lipid fractions of EFA and EFA+CLA compared with CTRL and CLA calves on d 1 and 5, and the increase was much greater on d 5 than on d 1. The LA concentration increased from d 1 to 5 in the plasma fat and lipid fractions of all groups. The concentrations of docosapentaenoic acid, docosahexaenoic acid, and arachidonic acid in plasma fat were higher on d 1 than on d 5, and the percentage of n-3 metabolites was mainly increased in PL if dams received EFA. The percentage of cis-9,trans-11 CLA was higher in the plasma fat of EFA+CLA than CTRL calves after birth. By d 5, the percentages of both CLA isomers increased, leading to higher proportions in plasma fat of CLA and EFA+CLA than in CTRL and EFA calves. Elevated cis-9,trans-11 CLA enrichment was observed on d 5 in PL, CE, and triglycerides of CLA-treated calves, whereas trans-10,cis-12 CLA could not be detected in individual plasma fractions. These results suggest that an altered maternal EFA and CLA supply can reach the calf via the placenta and particularly via the intake of colostrum and transition milk, whereas the n-3 and n-6 FA metabolites partly indicated a greater transfer via the placenta. Furthermore, the nutrient supply via colostrum and transition milk might be partly modulated by an altered maternal EFA and CLA supply but without consequences on calf performance during the first 5 d of life.     

The effects of feeding fish oil on uterine secretion of PGF2alpha, milk composition, and metabolic status of periparturient Holstein cows

The objectives were to determine the effect of dietary fish oil (FO) on uterine secretion of PGF2alpha, milk production, milk composition, and metabolic status during the periparturient period. Holstein cows were assigned randomly to diets containing FO (n = 13) or olive oil (OO, n = 13). Cows were fed prepartum and postpartum diets that provided approximately 200 g/d from 21 d before the expected parturition until 21 d after parturition. The FO used contained 36% eicosapentaenoic acid (EPA, C20:5, n-3) and 28% docosahexaenoic acid (DHA, C22:6, n-3). Blood samples were obtained from 14 d before the due date until d 21 postpartum. A total of 6 FO and 8 OO cows without periparturient disorders were used in the statistical analyses of PGF2alpha-metabolite (PGFM) and metabolite concentrations. Length of prepartum feeding with OO or FO did not differ. Proportions of individual and total n-3 fatty acids were increased in caruncular tissue and milk of cows fed FO. The combined concentrations of EPA and DHA in caruncular tissue were correlated positively with the number of days supplemented with FO. Cows fed FO had reduced concentrations of plasma PGFM during the 60 h immediately after parturition compared with cows fed OO. Concentrations of prostaglandin H synthase-2 mRNA and protein in caruncular tissue were unaffected by diet. Production of milk and FCM were similar between cows fed the two oil diets. However, cows fed FO produced less milk fat. Feeding FO reduced plasma concentrations of glucose. Dietary fatty acids given during the periparturient period can reduce the uterine secretion of PGF2alpha in lactating dairy cows and alter the fatty acid profile of milk fat.     

Effect of supplementing fat to pregnant nonlactating cows on colostral fatty acid profile and passive immunity of the newborn calf

The objectives were to evaluate the effect of supplementing saturated or unsaturated long-chain fatty acids (FA) to nulliparous and parous Holstein animals (n = 78) during late gestation on FA profile of colostrum and plasma of newborn calves and on production and absorption of IgG. The saturated FA supplement (SAT) was enriched in C18:0 and the unsaturated FA supplement (ESS) was enriched in the essential FA C18:2n-6. Fatty acids were supplemented at 1.7% of dietary dry matter to low-FA diets (1.9% of dietary dry matter) during the last 8 wk of gestation. Calves were fed 4 L of colostrum within 2 h of birth from their own dam or from a dam fed the same treatment. Feeding fat did not affect prepartum dry matter intake, body weight change, or gestation length. Parous but not nulliparous dams tended to give birth to heavier calves if fed fat prepartum. Parous dams were less able to synthesize essential FA derivatives, as evidenced by lower desaturase indices, compared with nulliparous dams, suggesting a greater need for essential FA supplementation. The FA profile of colostrum was modified to a greater degree by prepartum fat feeding than was that of neonatal calf plasma. The placental transfer and synthesis of elongated n-3 FA (C20:5, C22:5, and C22:6) were reduced, whereas the n-6 FA (C18:2, C18:3, and C20:3) were increased in plasma of calves born from dams fed ESS rather than SAT. Supplementing unsaturated FA prepartum resulted in elevated concentrations of trans isomers of unsaturated monoene and diene FA, as well as C18:2n-6 in colostrum. Serum concentrations of IgG tended to be increased in calves born from dams fed fat compared with those not fed fat, and prepartum feeding of SAT tended to improve circulating concentrations of IgG in newborn calves above the feeding of ESS. Apparent efficiency of absorption of IgG was improved in calves born from dams fed fat, and SAT supplementation appeared more effective than supplementation with ESS. Feeding SAT prepartum may be of greater benefit based upon greater circulating IgG concentrations of calves after colostrum feeding. Feeding moderate amounts of saturated or unsaturated long-chain FA during the last 8 wk of gestation changed the FA profile of colostrum and plasma of neonates to reflect that of the supplements.     

Fatty acid profile characterization in colostrum,transition milk,and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 38% and 19% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 72% higher in PP cows throughout the milking period, as well as 13% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 25% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 29% higher in colostrum than mature milk and 33% higher in MP cows. Linoleic acid was also 15% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 2.7-fold higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 40% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.     

Fatty acid profile characterization in colostrum,transition milk,and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 16% and 27% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 42% higher in PP cows throughout the milking period, as well as 15% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 13% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 23% higher in colostrum than mature milk and 25% higher in MP cows. Linoleic acid was also 13% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 63% higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 25% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.     

Influence of rate of inclusion of microalgae on the sensory characteristics and fatty acid composition of cheese and performance of dairy cows

Modification of milk and cheese fat to contain long-chain n-3 fatty acids (FA) by feeding microalgae (ALG) to dairy cows has the potential to improve human health, but the subsequent effect on the sensory attributes of dairy products is unclear. The objective was to determine the effect of feeding dairy cows different amounts of ALG that was rich in docosahexaenoic acid (DHA) on milk and cheese FA profile, cheese sensory attributes, and cow performance. Twenty Holstein dairy cows were randomly allocated to 1 of 4 dietary treatments in a 4 × 4 row and column design, with 4 periods of 28 d, with cheddar cheese production and animal performance measurements undertaken during the final 7 d of each period. Cows were fed a basal diet that was supplemented with ALG (Schizochytrium limancinum) at 4 rates: 0 (control, C), 50 (LA), 100 (MA), or 150 g (HA) of ALG per cow per day. We found that both milk and cheese fat content of DHA increased linearly with ALG feed rate and was 0.29 g/100 g FA higher in milk and cheese from cows fed HA compared with C. Supplementation with ALG linearly reduced the content of saturated FA and the ratio of n-6:n-3 FA in milk and cheese. Supplementation with ALG altered 20 out of the 32 sensory attributes, with a linear increase in cheese air holes, nutty flavor, and dry mouth aftertaste with ALG inclusion. Creaminess of cheese decreased with ALG inclusion rate and was positively correlated with saturated FA content. We also observed a quadratic effect on fruity odor, which was highest in cheese from cows fed HA and lowest in LA, and firmness and crumbliness texture, being highest in MA and lowest in HA. Supplementation with ALG had no effect on the dry matter intake, milk yield, or live weight change of the cows, with mean values of 23.1, 38.5, and 0.34 kg/d respectively, but milk fat content decreased linearly, and energy-corrected milk yield tended to decrease linearly with rate of ALG inclusion (mean values of 39.6, 38.4, 37.1, and 35.9 g/kg, and 41.3, 41.3, 40.5, and 39.4 kg/d for C, LA, MA, and HA, respectively). We conclude that feeding ALG to high-yielding dairy cows improved milk and cheese content of DHA and altered cheese taste but not cow performance, although milk fat content reduced as inclusion rate increased.     

Effects of increased supplementation of n-3 fatty acids to transition dairy cows on performance and fatty acid profile in plasma, adipose tissue, and milk fat

The objective of this study was to determine the effects of feeding an increased amount of extruded flaxseed with high proportions of n-3 fatty acids (FA) to transition dairy cows on performance, energy balance, and FA composition in plasma, adipose tissue, and milk fat. Multiparous Israeli-Holstein dry cows (n = 44) at 256 d of pregnancy were assigned to 2 treatments: (1) control cows were fed prepartum a dry-cow diet and postpartum a lactating-cow diet that consisted of 5.8% ether extracts; and (2) extruded flaxseed (EF) cows were supplemented prepartum with 1 kg of extruded flaxseed (7.9% dry matter)/cow per d, and postpartum were fed a diet containing 9.2% of the same supplement. The EF supplement was fed until 100 d in milk. On average, each pre- and postpartum EF cow consumed 160.9 and 376.2 g of C18:3n-3/d, respectively. Postpartum dry matter intake was 3.8% higher in the EF cows. Milk production was 6.4% higher and fat content was 0.4% U lower in the EF group than in the controls, with no differences in fat and protein yields. Energy balance in the EF cows was more positive than in the controls; however, no differences were observed in concentrations of nonesterified fatty acids and glucose in plasma. Compared with controls, EF cows had greater proportions of C18:3n-3 in plasma and adipose tissue. The proportion of n-3 FA in milk fat was 3.7-fold higher in the EF cows, and the n-6:n-3 ratio was decreased from 8.3 in controls to 2.3 in the EF cows. Within-group tests revealed that the C18:3n-3 content in milk fat in the EF cows was negatively correlated with milk fat percentage (r = –0.91) and yield (r = –0.89). However, no decrease in de novo synthesis of less than 16-carbon FA was found in the EF group, whereas C16:0 yields were markedly decreased. It appears that the enrichment of C18:3n-3 in milk fat was limited to approximately 2%, and the potential for increasing this n-3 FA in milk is higher for cows with lower milk fat contents. In conclusion, feeding increased amounts of C18:3n-3 during the transition period enhanced dry matter intake postpartum, increased milk production, decreased milk fat content, and improved energy balance. Increased amounts of EF considerably influenced the FA profile of plasma, adipose tissue, and milk fat. However, the extent of C18:3n-3 enrichment in milk fat was limited and was negatively correlated with milk fat content and yield.     

Atlantic salmon (Salmo salar) muscle structure integrity and lysosomal cathepsins B and L influenced by dietary n-6 and n-3 fatty acids

This study had two main objectives: first, to evaluate the impact of different types and levels of dietary n-6 and n-3 fatty acids (FAs) on Atlantic salmon muscle structure integrity; second, to highlight a possible role of lysosomes and lysosomal degrading enzymes, cathepsins, in fish muscle structure integrity, in relation to dietary fatty acids. Four groups of Atlantic salmon (90 g starting weight) in fresh water tanks were fed one of four diets containing 23% crude lipids, with 100% of the added oils as either fish oil (FO), rapeseed oil (RO), eicosapentaenoic acid (EPA) enriched-oil or docosahexaenoic acid (DHA) enriched-oil. The RO diet was characterised by low levels of EPA + DHA (10% of total FAs), whereas the EPA and DHA diets were characterised by very high levels of EPA + DHA (>50% of total FAs). Fatty acid composition of the muscle crude lysosomal fraction (CLF) generally reflected the diets. Salmon fed the RO diet presented a muscle CLF FA composition close to the one of the FO group, showing moderate PUFA levels, and comparable cathepsin B and cathepsin L activities, relative gene expression of cathepsin B and cathepsin L in the muscle and rate of myofibre–myofibre detachments post-mortem. Salmon fed the EPA and DHA-enriched-oil diets presented a fairly similar muscle CLF FA composition, but different from the FO and RO groups. In the EPA and DHA groups, the percentage of PUFAs in the muscle CLF, the rate of myofibre–myofibre detachments and the relative gene expression of cathepsin B were higher than in the FO and RO groups. Cathepsin B and cathepsin L total activities in the muscle were however lower in the EPA and DHA groups 0 h post-mortem. Dietary lipids influenced the level of lysosomal degrading enzyme activity cathepsin B and cathepsin L as well as the relative gene expression of cathepsin B. Feeding Atlantic salmon with rapeseed oil and extreme levels of EPA + DHA highlighted the impact of fatty acid composition of the diet on salmon muscle integrity and the complexity of the process involving muscle lysosomes and cathepsins in relation to these dietary fatty acids.     

Uterine,ovarian, and production responses of lactating dairy cows to increasing dietary concentrations of menhaden fish meal

The primary objective was to determine whether the dietary polyunsaturated fatty acids, eicosapentaenoic (EPA, C20:5, n-3) and docosahexaenoic (DHA, C22:6, n-3), present in fish meal (FM) can attenuate uterine secretion of PGF2alpha in response to a challenge with estradiol and oxytocin in lactating dairy cows. Cycling multiparous cows (n = 32) were fed diets containing 0 (OFM), 2.6 (2.6FM), 5.2 (5.2FM), or 7.8% menhaden FM (7.8FM). The diet consisting of 7.8FM also contained fish oil (0.28% of dietary dry matter) to increase intake of EPA and DHA. Average dry matter intake was 24.9 kg/d and unaffected by diet. Combined intakes of EPA and DHA averaged 0, 12.8, 24.1, and 54.0 g/d from the OFM, 2.6FM, 5.2FM, and 7.8FM diets, respectively. At 30 to 34 d after initiation of dietary treatments, cows received an i.m. injection of 100 microg of GnRH followed by i.m. administration of 25 and 15 mg of PGF2alpha after 7 and 8 d, respectively. Synchronous ovulation was induced by an injection of 3000 IU of human chorionic gonadotropin (hCG) given 24 h later on d 9. Subsequent luteal phase increases in plasma progesterone concentrations did not differ (0.88 ng/ml per day). At 15 d after hCG injection, cows were injected with estradiol-17beta (3 mg, i.v.) at 0900 h and oxytocin (100 IU, i.v.) at 1300 h. Plasma PGF2alpha metabolite concentrations after oxytocin injection were reduced in cows fed diets containing FM compared with those fed OFM. Milk production (39.1 kg/d) and concentrations of fat, protein, or urea nitrogen in milk were not affected by diet. Feeding fish meal and fish oil containing eicosapentaenoic acid and docosahexaenoic acid reduced the proportion of n-6 fatty acids and increased that of n-3 fatty acids in milk in a dose-responsive manner.     

Effect of supplementation with calcium salts of fish oil on n-3 fatty acids in milk fat

Enrichment of milk fat with n-3 fatty acids, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may be advantageous because of their beneficial effects on human health. In addition, these fatty acids play an important role in reproductive processes in dairy cows. Our objective was to evaluate the protection of EPA and DHA against rumen biohydrogenation provided by Ca salts of fish oil. Four Holstein cows were assigned in a Latin square design to the following treatments: 1) ruminal infusion of Ca salts of fish oil and palm fatty acid distillate low dose (CaFO-1), 2) ruminal infusion of Ca salts of fish oil and palm fatty acid distillate high dose (CaFO-2), 3) ruminal infusion of fish oil high dose (RFO), and 4) abomasal infusion of fish oil high dose (AFO). The high dose of fish oil provided ∼16 and ∼21 g/d of EPA and DHA, respectively, whereas the low dose (CaFO-1) provided 50% of these amounts. A 10-d pretreatment period was used as a baseline, followed by 9-d treatment periods with interceding intervals of 10 d. Supplements were infused every 6 h, milk samples were taken the last 3 d, and plasma samples were collected the last day of baseline and treatment periods. Milk fat content of EPA and DHA were 5 to 6 times greater with AFO, but did not differ among other treatments. Milk and milk protein yield were unaffected by treatment, but milk fat yield and DM intake were reduced by 20 and 15%, respectively, by RFO. Overall, results indicate rumen biohydrogenation of long chain n-3 fatty acids was extensive, averaging >85% for EPA and >75% for DHA for the Ca salts and unprotected fish oil supplements. Thus, Ca salts of fish oil offered no protection against the biohydrogenation of EPA and DHA beyond that observed with unprotected fish oil; however, the Ca salts did provide rumen inertness by preventing the negative effects on DM intake and milk fat yield observed with unprotected fish oil.     

Colostrum source and passive immunity transfer in dairy bull calves

Colostrum is essential for good neonate health; however, it is not known whether different calves absorb the nutrients from colostrum equally well. In this study, the absorption of protein, IgG, and γ-glutamyl transferase was compared in newborn dairy bull calves for 1 wk after feeding colostrum from different sources. Thirty-five Holstein-Friesian bull calves were randomly allocated into 3 groups and fed colostrum within 4 h after birth. Group A calves (n = 12) were bottle fed colostrum from their own dam for 3 d. Colostrum from these group A cows was also used as foster cow colostrum for the group B calves (n = 12), such that each group A and B calf pair received identical colostrum from each milking of the respective group A dam (10% of birth weight per day). The group C calves (n = 11) were fed 1 bottle (2 L) of pooled colostrum and transition milk (referred to as pooled colostrum), as was the standard practice on the dairy farm. The pooled colostrum was collected from the other dairy cows on the farm 0 to 4 d postpartum and stored at 4°C for less than 12 h. Blood was sampled from calves before the first feeding and at 1, 2, 3, and 7 d after birth. Levels of total solids, total protein, and IgG were higher in the dam colostrum than in the pooled colostrum. At birth, there were no differences between the calf groups for any measurements, and all calves had very low IgG levels. After receiving colostrum, the glucose, plasma γ-glutamyl transferase, serum total protein, and IgG concentrations increased significantly in all calves. There were no differences in any blood measurements at any time point between the pairs of group A and group B calves that received colostrum from the same cow except for the IgG concentration 2 d after birth. However, the group A calves had a higher total serum protein level and IgG concentration than the group C calves for all the time points after the first feeding. The group B calves had a higher IgG concentration than the group C calves on d 1, 2, and 7 after birth. Compared with groups A and B, there was no difference in the proportion of calves in group C that failed to have passive immunity transferred adequately based on the IgG threshold (<10 g/L). Thus, the calves receiving identical colostrum from the same cow had the same levels of IgG, and even the pooled colostrum provided sufficient transfer of IgG as the calves were fed within 4 h after birth.     

Effects of peripartum propylene glycol or fats differing in fatty acid profiles on feed intake, production, and plasma metabolites in dairy cows

Dry multiparous cows were used to investigate the effects on intake, production, and metabolism of either a supplement containing 55% dry propylene glycol (PGLY), a prilled fat supplement (PrFA) containing a low proportion of unsaturated fatty acids (FA), or calcium soaps of FA supplement (CaLFA) containing a high proportion of unsaturated FA. Fifty-three dry cows (256 d pregnant) were stratified into 4 groups and began one of the following dietary treatments: 1) control cows were fed a dry cow diet and at postpartum were fed a lactating cow diet; 2) diets of cows in the PGLY group were supplemented with 500 g/d per cow of dry PGLY until 21 d in milk (DIM); 3) diets of cows in the PrFA group were supplemented with 230 g/d per cow of PrFA until 100 DIM; 4) diets of cows in the CaLFA group were supplemented with 215 g/d per cow of CaLFA until 100 DIM. Prepartum DMI was lower in the PrFA and CaLFA groups than in the control and PGLY groups, whereas postpartum DMI in the PrFA group was higher than that in the control group. Milk production until 100 DIM in both fat-supplemented groups was 4.5% higher than that in the control group. Plasma glucose concentrations pre- and postpartum were higher in the PGLY group than in the PrFA and CaLFA groups, but were similar to those in the control group. Prepartum nonesterified FA (NEFA) concentrations in plasma were increased by 43 and 70% in the PrFA and CaLFA groups, respectively, as compared with the control and PGLY groups. Both fat supplements increased plasma β-hydroxybutyrate concentrations over those of the PGLY and control groups pre- and postpartum. Peripartum plasma insulin concentrations in the control group were 1.7-fold higher than in the PrFA group and 2.1-fold higher than in the CaFA group. Differences between the PrFA and CaLFA groups were observed: DMI was higher pre- and postpartum in the PrFA group than in the CaLFA group, and prepartum plasma NEFA concentrations were 19% higher and insulin concentrations were 21% lower in the CaLFA group than in the PrFA group. No significant differences were observed in DMI, plasma glucose, NEFA, and β-hydroxybutyrate concentrations between the control and PGLY groups. Feeding fat to cows during late pregnancy decreased the DMI and negatively affected the metabolic status of the cows, as reflected by plasma metabolites. Furthermore, protected fat with a high proportion of unsaturated FA (CaLFA) was more pronounced in increasing plasma NEFA concentrations and depressing plasma insulin concentrations than fat with a low proportion of unsaturated FA (PrFA).     

Effect of supplementing essential fatty acids to pregnant nonlactating Holstein cows and their preweaned calves on calf performance,immune response,and health

The objective was to evaluate the effect of supplementing saturated or unsaturated fatty acids (FA) during late gestation of cows and during the preweaning period of calves on growth, health, and immune responses of calves. During the last 8 wk of pregnancy, Holstein cattle (n = 96) were fed no fat supplement (control), a saturated FA (SFA) supplement enriched in C18:0, or an unsaturated FA supplement enriched in the essential FA linoleic acid. Newborn calves were fed a milk replacer (MR) with either low linoleic acid (LLA; coconut oil) or high linoleic acid (HLA; coconut oil and porcine lard) concentration as the sole feedstuff during the first 30 d. A grain mix with minimal linoleic acid was offered between 31 and 60 d of life. At 30 and 60 d of life, concentrations of linoleic acid in plasma were increased in calves born from dams supplemented with essential FA compared with SFA (44.0 vs. 42.5% of total FA) and in calves consuming HLA compared with LLA MR (46.3 vs. 40.8% of total FA). Total n-3 FA concentration was increased in plasma of calves fed HLA compared with LLA MR (1.44 vs. 1.32%) primarily due to increased α-linolenic acid. Prepartum supplementation with SFA tended to improve dry matter intake (48.8 vs. 46.7 kg) and improved average daily gain (0.50 vs. 0.46 kg/d) by calves without affecting efficiency of gain or circulating concentrations of anabolic metabolites or hormones. Increasing mean intake of linoleic acid from approximately 4.6 to 11.0 g/d during the first 60 d of life increased average daily gain (0.50 vs. 0.45 kg/d) without a change in dry matter intake, thus improving feed efficiency (0.63 vs. 0.59 kg of gain/kg of dry matter intake). Improved weight gain in calves fed HLA MR was accompanied by increased or tendency to increase plasma concentrations of glucose (92.7 vs. 89.9 g/dL) and insulin-like growth factor I (59.5 vs. 53.2 g/dL), increased hematocrit (36.0 vs. 34.4%) and concentration of blood lymphocytes (4.61 vs. 4.21 × 10³/μL), lowered plasma concentrations of acid-soluble protein (78.8 vs. 91.3 mg/L) and blood platelets (736 vs. 822 × 10³/μL), and increased production of IFN-γ by peripheral blood mononuclear cells at 30 d of age (48.1 vs. 25.6 pg/mL), possibly indicating an earlier development of the immune system. Partial replacement of coconut oil with porcine lard in MR improved calf performance and some aspects of immunity.     

Effect of fish oil and canola oil supplementation on immunological parameters,feed intake,and growth of Holstein calves

Supplemental n-3 fatty acids (FA) may support better immune responses than n-6 and n-9 FA in dairy calves. The objective was to evaluate the effect of n-3 FA, supplemented as a fish oil product (FO) in the milk replacer (MR), in comparison to n-6 and n-9 FA, supplemented as canola oil (CO), on body weight (BW), daily gain, and immunological parameters of preweaning Holstein calves. The study was conducted from September to December 2019. Calves were randomly allocated to a control group (n = 15; BW = 36.2 ± 1.5 kg; mean ± SEM) supplemented daily with 30 mL of CO and to an experimental group (n = 15; BW = 36.3 ± 1.5 kg) supplemented with 60 g of a product containing 30 g of FO. Both treatments were added to the MR during the morning feeding. All calves were fed 4 L of MR at 12.5% solids at 0700 and 1600 h for wk 1, 6 L from wk 2 to 7, and 3 L once daily (0700 h) during wk 8 until weaning (56 d). Blood samples were collected at 7, 14, 21, 28, 35, 42, 49, and 56 d of age for serum haptoglobin, TNF-α, IL-1β, and protectin. Dry matter intake was recorded in all experimental calves daily. Seroneutralization titers to vaccination against viral diseases (infectious bovine rhinotracheitis, parainfluenza 3, bovine viral diarrhea, and bovine respiratory syncytial virus) were determined. Mixed models for repeated measures were developed to analyze variables over time. Seroneutralization titers were analyzed by the Kruskal-Wallis test. The other variables were compared by a generalized linear model. Serum FA profile at 35 d of age showed that FO supported higher concentrations of n-3 FA than CO. Final BW [65.2 vs. 62.0 kg, standard error of the mean (SEM) = 2.1 kg] and average daily gain (0.52 vs. 0.46 kg/d, SEM = 0.1 kg/d) tended to be higher for the FO than the CO group. An interaction of treatment × day for dry matter intake was observed, especially during weaning (2.17 kg vs. 1.94 kg, SEM = 0.158 kg, for FO and CO group, respectively). Blood lactate (mmol/L) was higher in the CO than in the FO group at d 7. Haptoglobin and IL-1β were higher for the CO group on d 14 than the FO group. The TNF- α concentrations for the FO group were reduced over time, whereas the concentrations in the CO group remained constant. Protectin was higher in the FO group on d 14, but was lower on d 28, 35, and 49. Seroneutralization antibody titers postvaccination for the PI₃ virus were higher for the FO than the CO group. In conclusion, calves supplemented with FO had lower concentrations of blood lactate, haptoglobin, IL-1β and TNF-α than calves supplemented with CO during the study period. The FO supplementation had a higher DMI than CO supplementation. Results of this trial should be interpreted with caution due to the lack of a negative control group as well as the lower birth weight and growth rate observed under heat stress conditions.     

Digestion, milk production and milk fatty acid profile of dairy cows fed flax hulls and infused with flax oil in the abomasum

Flax hull, a co-product obtained from flax processing, is a rich source of n-3 fatty acids (FA) but there is little information on digestion of flax hull based diets and nutritive value of flax hull for dairy production. Flax oil is rich in α-linolenic acid (LNA) and rumen bypass of flax oil contributes to increase n-3 FA proportions in milk. Therefore, the main objective of the experiment was to determine the effects of abomasal infusion of increasing amounts of flax oil on apparent digestibility, dry matter (DM) intake, milk production, milk composition, and milk FA profile with emphasis on the proportion of LNA when cows were supplemented or not with another source of LNA such as flax hull. Six multiparous Holstein cows averaging 650±36 kg body weight and 95±20 d in milk were assigned to a 6×6 Latin square design (21-d experimental periods) with a 2×3 factorial arrangement of treatments. Treatments were: 1) control, neither flax hull nor flax oil (CON), 2) diet containing (DM basis) 15·9% flaxseed hull (FHU); 3) CON with abomasal infusion of 250 g/d flax oil; 4) CON with abomasal infusion of 500 g/d flax oil; 5) FHU with abomasal infusion of 250 g/d flax oil; 6) FHU with abomasal infusion of 500 g/d flax oil. Infusion of flax oil in the abomasum resulted in a more pronounce decrease in DM intake for cows fed the CON diets than for those fed the FHU diets. Abomasal infusion of flax oil had little effect on digestibility and FHU supplementation increased digestibility of DM and crude protein. Milk yield was not changed by abomasal infusion of flax oil where it was decreased with FHU supplementation. Cows fed FHU had higher proportions of 18:0, cis9-18:1, trans dienes, trans monoenes and total trans in milk fat than those fed CON. Proportion of LNA was similar in milk fat of cows infused with 250 and 500 g/d flax oil in the abomasum. Independently of the basal diet, abomasal infusion of flax oil resulted in the lowest n-6:n-3 FA ratio in milk fat, suggesting that the most important factor for modification of milk FA profile was the amount of n-3 FA bypassing the rumen and not the amount of flax hull fed to dairy cows. Moreover, these data suggest that there is no advantage to supply more than 250 g/d of flax oil in the abomasum to increase the proportion of LNA in milk fat.     

Effects of feeding different linseed sources on omasal fatty acid flows and fatty acid profiles of plasma and milk fat in lactating dairy cows

The aim of this experiment was to study the effects of feeding different linseed sources on omasal fatty acid (FA) flows, and plasma and milk FA profiles in dairy cows. Four ruminally cannulated lactating Holstein-Friesian cows were assigned to 4 dietary treatments in a 4×4 Latin square design. Dietary treatments consisted of supplementing crushed linseed (CL), extruded whole linseed (EL), formaldehyde-treated linseed oil (FL) and linseed oil in combination with marine algae rich in docosahexaenoic acid (DL). Each period in the Latin square design lasted 21 d, with the first 16 d for adaptation. Omasal flow was estimated by the omasal sampling technique using Cr-EDTA, Yb-acetate, and acid detergent lignin as digesta flow markers. The average DM intake was 20.6 ± 2.5 kg/d, C18:3n-3 intake was 341 ± 51 g/d, and milk yield was 32.0 ± 4.6 kg/d. Milk fat yield was lower for the DL treatment (0.96 kg/d) compared with the other linseed treatments (CL, 1.36 kg/d; EL, 1.49 kg/d; FL, 1.54 kg/d). Omasal flow of C18:3n-3 was higher and C18:3n-3 biohydrogenation was lower for the EL treatment (33.8 g/d; 90.9%) compared with the CL (21.8 g/d; 94.0%), FL (15.5 g/d; 95.4%), and DL (4.6 g/d; 98.5%) treatments, whereas whole-tract digestibility of crude fat was lower for the EL treatment (64.8%) compared with the CL (71.3%), FL (78.5%), and DL (80.4%) treatments. The proportion of C18:3n-3 (g/100 g of FA) was higher for the FL treatment compared with the other treatments in plasma triacylglycerols (FL, 3.60; CL, 1.22; EL, 1.35; DL, 1.12) and milk fat (FL, 3.19; CL, 0.87; EL, 0.83; DL, 0.46). Omasal flow and proportion of C18:0 in plasma and milk fat were lower, whereas omasal flow and proportions of biohydrogenation intermediates in plasma and milk fat were higher for the DL treatment compared with the other linseed treatments. The results demonstrate that feeding EL did not result in a higher C18:3n-3 proportion in plasma and milk fat despite the higher omasal C18:3n-3 flow. This was related to the decreased total-tract digestibility of crude fat. Feeding FL resulted in a higher C18:3n-3 proportion in plasma and milk fat, although the omasal C18:3n-3 flow was similar or lower than for the CL and EL treatment, respectively. Feeding DL inhibited biohydrogenation of trans-11,cis-15-C18:2 to C18:0, as indicated by the increased omasal flows and proportions of biohydrogenation intermediates in plasma and milk fat.     

Postpartum responses of dairy cows supplemented with n-3 fatty acids for different durations during the peripartal period

The objective of this study was to determine the effect of different durations of n-3 supplementation during the peripartal period on production and reproduction performance of Holstein dairy cows. Thirty-two Holstein dry cows (16 multiparous and 16 primiparous) were blocked within parity for similar expected calving dates 8 wk before calving. Cows within blocks were assigned randomly to 1 of 4 treatments: (1) control without n-3 fatty acid (FA) supplementation during the dry period; (2) n-3 FA supplementation during the whole dry period (8 wk); and (3) n-3 FA supplementation during the early dry period (first 5 wk; far-off), or (4) n-3 FA supplementation during the late dry period (last 3 wk; close-up). All cows received the same diet without n-3 FA after calving for the first 6 wk of lactation. Ovaries of each cow were examined 10, 17, 24, and 34 d from calving (calving = d 0) by transrectal ultrasonography to determine follicular development. Blood samples were collected at 14-d intervals starting on the first day of the dry period (8 wk before expected calving) to determine plasma concentrations of glucose, β-hydroxybutyrate, nonesterified fatty acids, urea N, aspartate aminotransferase, and insulin. Blood samples were also collected on d 1, 10, 17, 24, 31, and 38 postpartum for determination of progesterone concentration. Milk yield was recorded daily throughout the experiment and samples were taken twice weekly (Monday and Thursday mornings) for analysis of fat, protein, and lactose. Yields of milk and 4% fat-corrected milk and milk composition were similar among treatments except for fat proportion, which tended to be lower in cows that were fed n-3 FA throughout the dry period. We observed no differences among treatments for plasma concentrations of metabolites and hormones. The cows that were fed in the 3 n-3 FA treatments had larger ovulatory follicles compared with those fed the controlled diet. Treatments did not differ significantly in terms of the number of days open, day to first service, or number of services per pregnancy. In conclusion, n-3 FA supplementation throughout the dry period or in the early or late prepartal period had no carryover reproductive postpartum benefits and no effect on the production of Holstein dairy cows.     

In vitro response to EPA,DPA, and DHA: Comparison of effects on ruminal fermentation and biohydrogenation of 18-carbon fatty acids in cows and ewes

The modulation of milk fat nutritional quality through fish oil supplementation seems to be largely explained by the action of n-3 very long chain polyunsaturated fatty acids (PUFA) on ruminal biohydrogenation (BH) of C18 fatty acids (FA). However, relationships among this action, disappearance of those PUFA in the rumen, and potential detrimental consequences on ruminal fermentation remain uncertain. This study compared the effect of 20:5n-3 (eicosapentaenoic acid; EPA), 22:5n-3 (docosapentaenoic acid; DPA), and 22:6n-3 (docosahexaenoic acid; DHA) on rumen fermentation and BH of C18 FA and was conducted simultaneously in cows and sheep to provide novel insights into interspecies differences. The trial was performed in vitro using batch cultures of rumen microorganisms with inocula collected from cannulated cows and ewes. The PUFA were added at a dose of 2% incubated dry matter, and treatment effects on ruminal C18 FA concentrations, PUFA disappearances, and fermentation parameters (gas production, ammonia and volatile FA concentrations, and dry matter and neutral detergent fiber disappearances) were examined after 24 h of incubation. A principal component analysis suggested that responses to PUFA treatments explained most of the variability; those of ruminant species were of lower relevance. Overall, EPA and DHA were equally effective for inhibiting the saturation of trans-11 18:1 to 18:0 and had a similar influence on ruminal fermentation in cows and sheep (e.g., reductions in gas production and acetate:propionate ratio). Nevertheless, DHA further promoted alternative BH pathways that lead to trans-10 18:1 accumulation, and EPA seemed to have specific effects on 18:3n-3 metabolism. Only minor variations attributable to DPA were observed in the studied parameters, suggesting a low contribution of this FA to the action of marine lipids. Although most changes due to the added PUFA were comparable in bovine and ovine, there were also relevant specificities, such as a stronger inhibition of 18:0 formation in cows and a greater increase in 18:3n-3 metabolites in sheep. No direct relationship between in vitro disappearance of the incubated PUFA and effect on BH (in particular, inhibition of the last step) was found in either cows or ewes, calling into question a putative link between extent of disappearance and toxicity for microbiota. Conversely, an association between the influence of these PUFA on ruminal lipid metabolism and fermentation may exist in both species. In vivo verification of these findings would be advisable.     

Advances in dietary enrichment with n-3 fatty acids

Evidence for the effectiveness of the enrichment of food products with n-3 fatty acids by inclusion of either plant- or fish-derived materials in the diets of chickens, turkeys, ostriches, cows, pigs, and goats has been reviewed. Both linseed oil/meal and fish products can increase the levels of total n-3 fatty acids in animal products, including milk, eggs, meat, and deli products. The extent of this increase in n-3 fatty acid contents seems to be dependent on the nature of diet supplementation. Encapsulation of linseed oil may result in higher milk cow ALA contents, as compared to unprotected linseed oil. Available literature indicates that the levels of EPA and DHA in food products may be increased more, if the animals' diet was supplemented with fish products rather than linseed products. However, organoleptic properties of food products may be compromised. This pitfall may be reduced by the addition of antioxidants and/or application of micro-encapsulation. Generation of transgenic animals and plants has shown very promising results. Thus far, transgenic pigs and mice have been successfully generated. These animals have a low ratio of n-6:n-3 fatty acids in their tissues and milk. The advantages and disadvantages of the above-mentioned methods have been discussed. The evidence for health-promoting effects of such enriched food products has been included.     

Effects of feeding rumen-protected linseed fat to postpartum dairy cows on plasma n-3 polyunsaturated fatty acid concentrations and metabolic and reproductive parameters

High-yielding dairy cows experience a negative energy balance and inflammatory status during the transition period. Fat supplementation increases diet energy density, and plasma n-3 polyunsaturated fatty acids (PUFA) have been proposed to improve immune function. This study tested the hypothesis that dietary supplementation with a rumen-protected and n-3 PUFA-enriched fat could ameliorate both the energetic deficit and immune status of postpartum high-yielding dairy cows, improving overall health and reproductive efficiency. At 11 d in milk (DIM), cows were randomly allocated to groups (1) n-3 PUFA (n = 29), supplemented with encapsulated linseed oil supplying additional up to 64 g/d (mean 25 ± 4 g/d) of α-linolenic acid (ALA), or (2) control (n = 31), supplemented with hydrogenated palm oil without ALA content. Fat supplements of the n-3 PUFA and control groups were available through an automated, off-parlor feeding system, and intake depended on the cow's feeding behavior. Plasma ALA concentrations were higher in n-3 PUFA than control cows, following a linear relation with supplement ingestion, resulting in a lower n-6/n-3 ratio in plasma. Metabolic parameters (body condition score and glucose and β-hydroxybutyric acid blood concentrations) were unaffected, but milk yield improved with increased intake of fat supplements. Plasma total adiponectin concentrations were negatively correlated with ingestion of n-3 PUFA-enriched fat supplement, following a linear relation with intake. Conception rate to first AI increased with higher intake of both fats, but a decrease of calving-to-conception interval occurred only in n-3 PUFA cows. Postpartum ovarian activity and endometrial inflammatory status at 45 DIM were unaffected. In conclusion, this study evinced a positive linear relation between rumen-protected linseed fat intake and plasma n-3 PUFA concentrations, which modulated adiponectin expression and improved reproductive parameters.