Tuomo Kokkonen

Effect of plant oils and camelina expeller on milk fatty acid composition in lactating cows fed diets based on red clover silage

Five multiparous Finnish Ayrshire cows fed red clover silage-based diets were used in a 5 × 5 Latin square with 21-d experimental periods to evaluate the effects of various plant oils or camelina expeller on animal performance and milk fatty acid composition. Treatments consisted of 5 concentrate supplements containing no additional lipid (control), or 29 g/kg of lipid from rapeseed oil (RO), sunflower-seed oil (SFO), camelina-seed oil (CO), or camelina expeller (CE). Cows were offered red clover silage ad libitum and 12kg/d of experimental concentrates. Treatments had no effect on silage or total dry matter intake, whole-tract digestibility coefficients, milk yield, or milk composition. Plant oils in the diet decreased short- and medium-chain saturated fatty acid (6:0-16:0) concentrations, including odd- and branched-chain fatty acids and enhanced milk fat 18:0 and 18-carbon unsaturated fatty acid content. Increases in the relative proportions of cis 18:1, trans 18:1, nonconjugated 18:2, conjugated linoleic acid (CLA), and polyunsaturated fatty acids in milk fat were dependent on the fatty acid composition of oils in the diet. Rapeseed oil in the diet was associated with the enrichment of trans 18:1 (Δ4, 6, 7, 8, and 9), cis-9 18:1, and trans-7,cis-9 CLA, SFO resulted in the highest concentrations of trans-5, trans-10, and trans-11 18:1, Δ9,11 CLA, Δ10,12 CLA, and 18:2n-6, whereas CO enhanced trans-13-16 18:1, Δ11,15 18:2, Δ12,15 18:2, cis-9,trans-13 18:2, Δ11,13 CLA, Δ12,14 CLA, Δ13,15 CLA, Δ9,11,15 18:3, and 18:3n-3. Relative to CO, CE resulted in lower 18:0 and cis-9 18:1 concentrations and higher proportions of trans-10 18:1, trans-11 18:1, cis-9,trans-11 CLA, cis-9,trans-13 18:2, and trans-11,cis-15 18:2. Comparison of milk fat composition responses to CO and CE suggest that the biohydrogenation of unsaturated 18-carbon fatty acids to 18:0 in the rumen was less complete for camelina lipid supplied as an expeller than as free oil. In conclusion, moderate amounts of plant oils in diets based on red clover silage had no adverse effects on silage dry matter intake, nutrient digestion, or milk production, but altered milk fat composition, with changes characterized as a decrease in saturated fatty acids, an increase in trans fatty acids, and enrichment of specific unsaturated fatty acids depending on the fatty acid composition of lipid supplements.

Effects of abomasal infusion of tallow or camelina oil on responses to glucose and insulin in dairy cows during late pregnancy.

Late pregnancy is associated with moderate insulin resistance in ruminants. Reduced suppression of lipolysis by insulin facilitates mobilization of nonesterified fatty acids (NEFA) from adipose tissue, resulting in elevated plasma NEFA concentrations. Decrease in dry matter intake (DMI) before parturition leads to accelerated lipomobilization and increases plasma NEFA, which may further impair insulin sensitivity. The aim of the study was to evaluate the effects of elevation of plasma NEFA concentration by abomasal infusions tallow (TAL) or camelina oil (CAM) on whole-body responses to exogenous glucose and insulin. We further assessed whether CAM, rich in C18:3n-3, enhances whole-body insulin sensitivity compared with TAL. Six late-pregnant, second-parity, rumen-cannulated dry Ayrshire dairy cows fed grass silage to meet 95% of metabolizable energy requirements were used in a replicated 3 × 3 Latin square with 5-d periods and 5 recovery days between each period. Treatments consisted of abomasal infusion of 500 mL/d (430 g of lipids/d) of water (control), TAL, or CAM administered in 10 equal doses daily. Intravenous glucose tolerance test (IVGTT) and i.v. insulin challenge (IC) were performed on d 5 after 98 and 108 h of treatment infusions, respectively. Infusion of lipids increased basal plasma NEFA concentrations on d 5 (CAM: 0.25; TAL: 0.28; control: 0.17 mmol/L). Following glucose injection, the rate of glucose clearance (CR) was lower in lipid-treated cows (CAM: 1.34; TAL: 1.48; control: 1.74%/min) and time to reach half-maximal glucose concentration (T(1/2)) was longer (CAM: 54; TAL: 47; control: 42 min). Similar responses were observed after insulin injection. Increased plasma NEFA concentration tended to decrease insulin secretion in IVGTT. Infusion of CAM increased plasma C18:3n-3 content (CAM: 26.4; TAL: 16.1; control: 20.9 g/100g of fatty acids). Data suggest that CAM had an insulin-sensitizing effect, because the disposition index and insulin sensitivity index, derived from minimal model analysis, were higher in CAM than in TAL during IVGTT, and lower insulin concentrations during IC led to similar glucose clearance in CAM as in TAL. These results indicate that elevated plasma NEFA concentration per se induces whole-body insulin resistance in late-pregnant dry cows.

Prepartal dietary energy alters transcriptional adaptations of the liver and subcutaneous adipose tissue of dairy cows during the transition period

Overfeeding during the dry period may predispose cows to increased insulin resistance (IR) with enhanced postpartum lipolysis. We studied gene expression in the liver and subcutaneous adipose tissue (SAT) of 16 Finnish Ayrshire dairy cows fed either a controlled energy diet [Con, 99 MJ/day metabolizable energy (ME)] during the last 6 wk of the dry period or high-energy diet (High, 141 MJ/day ME) for the first 3 wk and then gradually decreasing energy allowance during 3 wk to 99 MJ/day ME before the expected parturition. Tissue biopsies were collected at -10, 1, and 9 days, and blood samples at -10, 1, and 7 days relative to parturition. Overfed cows had greater dry matter, crude protein, and ME intakes and ME balance before parturition. Daily milk yield, live weight, and body condition score were not different between treatments. The High cows tended to have greater plasma insulin and lower glucagon/insulin ratio compared with Con cows. No differences in circulating glucose, glucagon, nonesterified fatty acids and β-hydroxybutyrate concentrations, and hepatic triglyceride contents were observed between treatments. Overfeeding compared with Con resulted in lower CPT1A and PCK1 and a tendency for lower G6PC and PC expression in the liver. The High group tended to have lower RETN expression in SAT than Con. No other effects of overfeeding on the expression of genes related to IR in SAT were observed. In conclusion, overfeeding energy prepartum may have compromised hepatic gluconeogenic capacity and slightly affected IR in SAT based on gene expression.

Relationships among Body Condition, Insulin Resistance and Subcutaneous Adipose Tissue Gene Expression during the Grazing Season in Mares.

Obesity and insulin resistance have been shown to be risk factors for laminitis in horses. The objective of the study was to determine the effect of changes in body condition during the grazing season on insulin resistance and the expression of genes associated with obesity and insulin resistance in subcutaneous adipose tissue (SAT). Sixteen Finnhorse mares were grazing either on cultivated high-yielding pasture (CG) or semi-natural grassland (NG) from the end of May to the beginning of September. Body measurements, intravenous glucose tolerance test (IVGTT), and neck and tailhead SAT gene expressions were measured in May and September. At the end of grazing, CG had higher median body condition score (7 vs. 5.4, interquartile range 0.25 vs. 0.43; P=0.05) and body weight (618 kg vs. 572 kg ± 10.21 (mean ± SEM); P=0.02), and larger waist circumference (P=0.03) than NG. Neck fat thickness was not different between treatments. However, tailhead fat thickness was smaller in CG compared to NG in May (P=0.04), but this difference disappeared in September. Greater basal and peak insulin concentrations, and faster glucose clearance rate (P=0.03) during IVGTT were observed in CG compared to NG in September. A greater decrease in plasma non-esterified fatty acids during IVGTT (P<0.05) was noticed in CG compared to NG after grazing. There was down-regulation of insulin receptor, retinol binding protein 4, leptin, and monocyte chemoattractant protein-1, and up-regulation of adiponectin (ADIPOQ), adiponectin receptor 1 and stearoyl-CoA desaturase (SCD) gene expressions in SAT of both groups during the grazing season (P<0.05). Positive correlations were observed between ADIPOQ and its receptors and between SCD and ADIPOQ in SAT (P<0.01). In conclusion, grazing on CG had a moderate effect on responses during IVGTT, but did not trigger insulin resistance. Significant temporal differences in gene expression profiles were observed during the grazing season.

Effect of silage dry matter content and rapeseed meal supplementation on dairy cows: 2. Rumen fermentation and digesta passage rate

The effects of direct-cut and wilted silage with or without rapeseed meal (RSM) supplementation on rumen fermentation and digesta passage rates were studied in a 44 balanced Latin square experiment with four multiparous cows. The dry matter (DM) and crude protein (CP) degradabilities of silages were determined in sacco. RSM supplementation replaced 16% of the oat‐barley concentrate mixture. The daily concentrate amount was 10 kg. Silages were given ad libitum. The effective degradabilities of dry matter and protein (EPD) were higher (p<0.001) in direct-cut silage but wilted silage had higher (p<0.001) content of rapidly degradable protein. Rumen ammonia concentration was higher with direct-cut silage (10.16 versus 8.47 mmol/l, p<0.01), reflecting higher CP content and EPD. Rumen pH and total volatile fatty acid (VFA) concentration in rumen were not affected by silage type, and the differences in molar proportions of rumen VFA’s were small. The proportion of propionate tended to be higher (p<0.10) with wilted silage, whereas the proportion of butyrate was higher (133 versus 128 mmol/mol, p<0.01) with direct-cut silage. The retention time of the digesta particle phase in alimentary tract was shorter (p<0.05 or better) with wilted silage. Pool mean retention time (PMRT), which illustrates the retention time of particles in rumen, was shorter (34.0 versus 28.3 h, p<0.05) with wilted silage. Similarly, retention time of particles in the rumen pool of particles small enough to leave the rumen tended to be shorter (p<0.10) with wilted silage. RSM supplementation tended to increase (p<0.10) rumen ammonia concentration and decreased the molar proportion of rumen butyrate (132 versus 127 mmol/l, p<0.05). The retention time of particles in pool, which illustrates the rate of particle break down in the rumen, was shorter (p<0.10) with RSM. In conclusion, the ruminal retention time

Effect of Concentrate Crude Protein Level on Grass Silage Intake, Milk Yield and Nutrient Utilisation by Dairy Cows in Early Lactation

Twenty-one multiparous dairy cows were fed concentrates containing three levels (119, 154 and 191g/kg DM) of crude protein (CP) during the first ten weeks of lactation. Part of the grain and molassed sugar beat pulp was substituted with 0% (RSM0), 15% (RSM15) or 30% (RSM30) rapeseed meal. Wilted grass silage was fed ad libitum after calving. The average response between RSM0 and RSM15 was +1.66kg milk/d per percentage unit change in concentrate CP content. No further response occurred between RSM15 and RSM30. The positive effect of RSM inclusion was seen throughout the experimental period and was associated with increased plasma non esterified fatty acids (NEFA) and decreased plasma insulin concentration one week after calving, and higher efficiency of metabolisable energy utilisation for milk production. Digestibility of the diet remained unaffected. Milk and plasma urea tended to increase with RSM30 indicating excessive supply of rumen degradable protein. Because of the limited potential of cows to compensate for a deficit in feed protein supply by mobilising tissue protein, a substantial milk yield response can be achieved with a moderate level of protein supplementation during early lactation.

Effect of prepartal ad libitum feeding of grass silage on transcriptional adaptations of the liver and subcutaneous adipose tissue in dairy cows during the periparturient period.

Prepartal energy overfeeding may predispose cows to a state of increased insulin resistance with greater lipolysis after parturition. The aim of the study was to evaluate the effects of prepartal overfeeding in terms of abundant grass silage ration on the liver and subcutaneous adipose tissue (SAT) gene expression around parturition. Sixteen multiparous Finnish Ayrshire dairy cows were fed ad libitum either grass silage [high energy, HE; 144 MJ/d of metabolizable energy (ME) intake, n=8] or a mixture of grass silage, wheat straw, and rapeseed meal [55:40:5 (CON), 109 MJ/d of ME, n=8] during the dry period (58.2±4.89 d, mean ± standard deviation). Tissue biopsies and blood samples were collected at -14 (±4.98), 1, and 7 d relative to the actual parturition date. The HE cows had greater total dry matter intake, ME intake, and ME balance during the dry period than the CON cows. Compared with CON, the increases in body weight and body condition score were greater in HE during the dry period. Milk yield during the first 2 wk of lactation was not different between the groups. Plasma glucose, nonesterified fatty acids, insulin, glucagon, and β-hydroxybutyrate did not differ between the groups during the transition period. Dietary treatment did not affect hepatic triglyceride content; however, a delayed increase in hepatic total lipid content was observed in the HE cows at d 1 postpartum. Hepatic cytosolic phosphoenolpyruvate carboxykinase 1 mRNA expression was lower in HE than in CON at d 1 and 7 postpartum. Adiponectin receptor 1 and 2 mRNA abundance tended to be lower in SAT of HE than CON. Lower lipoprotein lipase, leptin, and stearoyl-coenzyme A desaturase mRNA abundances were observed at d 7 postpartum in SAT of the HE cows compared with the CON cows. We concluded that prepartal ad libitum feeding of grass silage may decrease insulin sensitivity and lipogenesis in SAT during peripartal period and may attenuate the increase of hepatic gluconeogenic capacity from propionate compared with a controlled-energy diet.

Effect of incremental amounts of camelina oil on milk fatty acid composition in lactating cows fed diets based on a mixture of grass and red clover silage and concentrates containing camelina expeller

Camelina is an ancient oilseed crop that produces an oil rich in cis-9,cis-12 18:2 (linoleic acid, LA) and cis-9,cis-12,cis-15 18:3 (α-linolenic acid, ALA); however, reports on the use of camelina oil (CO) for ruminants are limited. The present study investigated the effects of incremental CO supplementation on animal performance, milk fatty acid (FA) composition, and milk sensory quality. Eight Finnish Ayrshire cows (91d in milk) were used in replicated 4×4 Latin squares with 21-d periods. Treatments comprised 4 concentrates (12kg/d on an air-dry basis) based on cereals and camelina expeller containing 0 (control), 2, 4, or 6% CO on an air-dry basis. Cows were offered a mixture of grass and red clover silage (RCS; 1:1 on a dry matter basis) ad libitum. Incremental CO supplementation linearly decreased silage and total dry matter intake, and linearly increased LA, ALA, and total FA intake. Treatments had no effect on whole-tract apparent organic matter or fiber digestibility and did not have a major influence on rumen fermentation. Supplements of CO quadratically decreased daily milk and lactose yields and linearly decreased milk protein yield and milk taste panel score from 4.2 to 3.6 [on a scale of 1 (poor) to 5 (excellent)], without altering milk fat yield. Inclusion of CO linearly decreased the proportions of saturated FA synthesized de novo (4:0 to 16:0), without altering milk fat 18:0, cis-9 18:1, LA, and ALA concentrations. Milk fat 18:0 was low (<5g/100g of FA) across all treatments. Increases in CO linearly decreased the proportions of total saturates from 58 to 45g/100g of FA and linearly enriched trans-11 18:1, cis-9,trans-11 18:2, and trans-11,cis-15 18:2 from 5.2, 2.6, and 1.7 to 11, 4.3, and 5.8g/100g of FA, respectively. Furthermore, CO quadratically decreased milk fat trans-10 18:1 and linearly decreased trans-10,cis-12 18:2 concentration. Overall, milk FA composition on all treatments suggested that one or more components in camelina seeds may inhibit the complete reduction of 18-carbon unsaturates in the rumen. In conclusion, CO decreased the secretion of saturated FA in milk and increased those of the trans-11 biohydrogenation pathway or their desaturation products. Despite increasing the intake of 18-carbon unsaturated FA, CO had no effect on the secretions of 18:0, cis-9 18:1, LA, or ALA in milk. Concentrates containing camelina expeller and 2% CO could be used for the commercial production of low-saturated milk from grass- and RCS-based diets without major adverse effects on animal performance.

Effects of replacing rapeseed meal with fava bean at 2 concentrate crude protein levels on feed intake, nutrient digestion, and milk production in cows fed grass silage–based diets

The objective of this study was to evaluate the production and physiological responses of dairy cows to the substitution of fava bean for rapeseed meal at 2 protein supplementation levels in grass silage-based diets. We used 6 primiparous and 6 multiparous Finnish Ayrshire cows in a cyclic changeover trial with a 2×3 factorial arrangement of treatments. The experimental diets consisted of formic acid-treated timothy-meadow fescue silage and 3 isonitrogenous concentrates containing either rapeseed meal, fava bean, or a 1:1 mixture of rapeseed meal and fava bean at low and high inclusion rates, resulting in concentrate crude protein (CP) levels of 15.4 and 19.0% in dry matter. Silage dry matter intake decreased linearly when rapeseed meal was replaced with fava bean, the negative effect being more distinct at the high CP level than the low (-2.3 vs. -0.9kg/d, respectively). Similarly, milk and milk protein yields decreased linearly with fava bean, the change tending to be greater at the high CP level than the low. Yield of milk fat was lower for fava bean compared with rapeseed meal, the difference showing no interaction with CP level. Especially at the high CP level, milk urea concentration was higher with fava bean compared with rapeseed meal indicating better utilization of protein from the rapeseed meal. The apparent total-tract organic matter digestibility did not differ between treatments at the low CP level, but digestibility was higher for fava bean than for rapeseed meal at the high CP level. Plasma concentrations of essential amino acids, including methionine and lysine, were lower for fava bean than for rapeseed meal. Compared with rapeseed meal, the use of fava bean in dairy cow diets as the sole protein supplement decreased silage intake and milk production in highly digestible formic acid-treated grass silage-based diets.

Effect of cultivated or semi-natural pasture on changes in live weight, body condition score, body measurements and fat thickness in grazing Finnhorse mares

Two groups of Finnhorse mares, 11 horses in each group, were grazed on cultivated pasture (CG) or semi-natural grassland (NG) from the end of May to the beginning of September 2011 and the effect on possible development of obesity was followed. The observations of live weight, body condition score (BCS), cresty neck score (CNS), body measurements and fat thickness were made during the grazing season. At the end of the grazing season, the horses grazing CG were significantly heavier (P<0.05) compared to the horses grazing NG. On average, the live weight change was +71 kg in CG and +31 kg in NG pastures. The waist (abdominal) circumference started to grow rapidly at the beginning of the grazing season in CG group and it ended up being different (P<0.05) from NG group at the end of grazing season. The BCS at the end of the grazing season averaged 1.35 points higher for the CG group compared to the beginning of the trial. The neck circumference was 4.1 cm more in CG group compared to NG at the end of grazing season. Results showed fat deposition in both experimental groups and in all measured spots during the grazing season. The most significant difference between groups in fat deposition was in the shoulder and tailhead areas (P<0.05). These preliminary results show, that fat accretion was greater in animals grazing the cultivated, high yielding pastures compared to those grazing semi-natural grasslands. Several parameters can be used to measure the development of obesity, but some seem to be more reliable than others.