Economic analysis of high-oleic soybeans in dairy rations.

We evaluate the potential economic impact of using high-oleic soybeans (HOS) in dairy rations based on a synthesis of results from 5 prior feeding trials. Milk income less feed costs (MILFC) per cow per day is calculated based on assumed increases in milkfat production and increased cost of rations including HOS. The effects of changes in MILFC are evaluated for herds with different numbers of milking cows, and the total volume of HOS required to support different proportions of US dairy cows is calculated.

Effect of feeding increasing levels of whole cottonseed on milk and milk components, milk fatty acid profile, and total-tract digestibility in lactating dairy cows.

Dietary fat is fed to increase energy intake and provide fatty acids (FA) to support milk fat production. Oilseeds contain unsaturated FA that increase the risk for biohydrogenation-induced milk fat depression, but FA in whole cottonseed (WCS) are expected to be slowly released in the rumen and thus have a lower risk for biohydrogenation-induced milk fat depression. Our hypothesis was that increasing dietary WCS would increase milk fat yield by providing additional dietary FA without induction of milk fat depression.

A review of recent studies on the enrichment of eggs and poultry meat with omega-3 polyunsaturated fatty acids: novel findings and unanswered questions.

Studies from our laboratory over the past decade have yielded new information with regard to the dietary enrichment of eggs and poultry meat with omega-3 (n-3) polyunsaturated fatty acids (PUFA) but have also generated a number of unanswered questions. In this review, we summarize the novel findings from this work, identify knowledge gaps, and offer possible explanations for some perplexing observations. Specifically discussed are: 1) Why feeding laying hens and broilers an oil rich in stearidonic acid (SDA; 18:4 n-3), which theoretically bypasses the putative rate-limiting step in the hepatic n-3 PUFA biosynthetic pathway, does not enrich egg yolks and tissues with very long-chain (VLC; ≥20 C) n-3 PUFA to the same degree as obtained by feeding birds oils rich in preformed VLC n-3 PUFA; 2) Why in hens fed an SDA-rich oil, SDA fails to accumulate in egg yolk but is readily incorporated into adipose tissue; 3) How oils rich in oleic acid (OA; 18:1 n-9), when co-fed with various sources of n-3 PUFA, attenuates egg and tissue n-3 PUFA contents or rescues egg production when co-fed with a level of docosahexaenoic acid (DHA; 22:6 n-3) that causes severe hypotriglyceridemia; and 4) Why the efficiency of VLC n-3 PUFA deposition into eggs and poultry meat is inversely related to the dietary content of α-linolenic acid (ALA; 18:3 n-3), SDA, or DHA.

Direct Comparison of 18 Carbon n-3 and n-6 Fatty Acids at Equal Levels in an Oil Blend on Tissue Enrichment of Long-Chain Polyunsaturated Fatty Acid in Broiler Chickens.

Background: Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs) are of interest because of their health effects. However, most experiments use natural oils and are confounded by PUFA concentrations and other fatty acids (FAs) that impact biosynthesis of the very long-chain derivatives (VLC).

Objectives: To directly compare the effect of 18 C n-3 or n-6 FA fed at similar rates on their elongation and desaturation to VLC PUFA and their incorporation into tissues.

Effects of the timing of protein infusion on the daily rhythms of milk synthesis and plasma hormones and metabolites in dairy cows.

Milk synthesis exhibits a daily rhythm that is modified by the timing of feed intake. However, it is unknown how specific nutrients entrain this daily rhythm. Amino acids have an important role in milk synthesis, and may have a role in entrainment of mammary circadian rhythms.

Kinetics of omega-3 fatty acid transfer to milk differs between fatty acids and stage of lactation in dairy cows.

Fatty acids (FA) differ in their transfer efficiencies and metabolic partitioning and lactating cows provide a robust model to investigate kinetics of FA transport. The objective was to compare kinetics of n-3 polyunsaturated FA (PUFA) trafficking through plasma and into milk. In the first experiment, ten ruminally cannulated multiparous Holstein cows were used in a crossover design with 7 d periods.

Comparison of Ahiflower oil containing stearidonic acid to a high-alpha-linolenic acid flaxseed oil at two dietary levels on omega-3 enrichment of egg yolk and tissues in laying hens.

Enrichment of egg yolks with very long chain omega-3 fatty acids (VLCn-3 FA) is of interest because of their beneficial effects on human health. The ability of Ahiflower® oil (AHI; Buglossoides arvensis), which is naturally rich in stearidonic acid (SDA), and a high-alpha-linolenic acid (ALA) flaxseed (FLAX) oil to enrich eggs and tissues of laying hens with VLCn-3 FA was investigated. Forty 54-week-old Hy-Line W-36 White Leghorn hens were fed a diet that contained soybean oil (control; CON) or AHI or FLAX oils at 7.

Feeding laying hens docosa hexaenoic acid-rich microalgae oil at 40 g/kg diet causes hypotriglyceridemia, depresses egg production, and attenuates expression of key genes affecting hepatic triglyceride synthesis and secretion, but is rescued by dietary co-supplementation of high-oleic sunflower oil.

The primary goal of this study was to investigate the effect of feeding White Leghorn hens graded levels of a docosahexaenoic acid (DHA)-rich microalgae oil (MAO) on productive performance and enrichment of eggs with very long-chain (VLC) omega-3 (n-3) polyunsaturated fatty acids (PUFA). Forty-nine-week-old hens (8 per diet) were fed the following diets for 28 d: 1) A corn-soybean meal-based diet with no supplemental oil (CON); 2) CON + 10 g/kg MAO; 3) CON + 20 g/kg MAO; 4) CON + 30 g/kg MAO; 5) CON + 40 g/kg MAO; 6) CON + 40 g/kg MAO + 20 g/kg high-oleic sunflower oil (HOSO); and 7) CON + 40 g/kg MAO + 40 g/kg HOSO. Diets 6 and 7 were included because we previously reported that co-feeding high-oleic acid oils with n-3 PUFA-containing oils attenuated egg yolk n-3 PUFA contents vs.

Changes in plasma fatty acids profile in hyperketonemic ewes during early lactation: a preliminary study.

The transition from late pregnancy to early lactation is characterized by marked changes in energy balance of dairy ruminants. The mobilization of adipose tissue led to an increase in plasma non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). The aim of this study was to analyze the total plasma fatty acids of healthy and hyperketonemic dairy ewes in early lactation through gas chromatography (GC) to evaluate metabolic alterations.

Fatty Acid Transfer from Blood to Milk Is Disrupted in Mothers with Low Milk Production, Obesity, and Inflammation.

Background: Obesity is associated with chronic inflammation and is a risk factor for insufficient milk production. Inflammation-mediated suppression of LPL could inhibit mammary uptake of long-chain fatty acids (LCFAs; >16 carbons).

Objectives: In an ancillary case-control analysis, we investigated whether women with low milk production despite regular breast emptying have elevated inflammation and disrupted transfer of LCFAs from plasma into milk.

Evaluation of the metabolomic profile through H-NMR spectroscopy in ewes affected by postpartum hyperketonemia.

Ketosis is one of the most important health problems in dairy sheep. The aim of this study was to evaluate the metabolic alterations in hyperketonemic (HYK) ewes. Forty-six adult Sardinian ewes were enrolled between 7 ± 3 days post-partum.

Validation of an alternate method for monitoring the presence of cows at the feed bunk in a Calan Broadbent Feeding System using a 3-axis, data-logging accelerometer.

Daily dry matter intake is a key observation in dairy nutrition, and observation of feeding behavior provides insight into the physiological control of hunger and satiety that regulate intake. The objective of the study was to develop and validate an alternative method to observe feeding behavior, including meal length and frequency, in a Calan Broadbent Feeding System (American Calan) using a 3-axis accelerometer (Hobo Pendant G, Onset Computer Corp.).

TRB3 Deletion Has a Limited Effect on Milk Fat Synthesis and Milk Fat Depression in C57BL/6N Mice.

Background: Regulation of the endoplasmic reticulum (ER) stress pathway is critical to mammary epithelial cell function throughout pregnancy, lactation, and involution. Treatment with -10, -12 conjugated linoleic acid (t10c12CLA) suppresses mammary lipogenesis and stimulates the ER stress pathway. The ER stress pathway includes tribbles pseudokinase 3 (TRB3), a protein that regulates cellular energy and insulin signaling.

Comparison of Ahiflower oil containing stearidonic acid to a high-alpha-linolenic acid flaxseed oil at two levels on tissue omega-3 enrichment in broilers.

Enrichment of broiler meat with very long-chain omega-3 fatty acids (VLCn-3 FA) is of interest because of their beneficial effects on human health. The ability of Ahiflower® (AHI) oil (Buglossoides arvensis), which naturally contains stearidonic acid (SDA), and a high-alpha-linolenic acid (ALA) flaxseed (FLAX) oil to enrich VLCn-3 FA contents in broilers tissues was investigated. Fifty-five Cobb 500 chicks were fed from days 12 to 35 of life either a control (CON) diet that contained 27.

Meta-analysis of rumination behavior and its relationship with milk and milk fat production, rumen pH, and total-tract digestibility in lactating dairy cows.

Time spent ruminating is affected by diet and affects the rumen environment. The objective of the current study was to conduct a meta-regression to characterize the variation in rumination time and its relationship with milk and milk fat yields and variables mechanistically associated with milk fat synthesis, including rumen pH and total-tract digestibility. The analysis included 130 journal articles published between 1986 and 2018 that reported 479 treatment means from lactating Holsteins cows during established lactation.

Supplemental dietary oils rich in oleic acid or linoleic acid attenuate egg yolk and tissue n-3 polyunsaturated fatty acid contents in laying hens co-fed oils enriched in either stearidonic acid or α-linolenic acid.

We previously reported that when laying hens were fed diets supplemented with oils enriched in α-linolenic acid (ALA) and oleic acid (OA), the deposition of n-3 PUFA in egg yolk was attenuated as compared to feeding hens a diet supplemented with the ALA-rich oil alone. The present work extends those findings to another n-3 PUFA-rich oil (stearidonic acid [SDA]-enriched soybean oil) and two other high-OA oils, suggesting that the effect is not plant oil-specific. Feeding hens a supplemental linoleic acid (LA)-rich oil plus an oil rich in either SDA or ALA also attenuated egg yolk ALA and SDA contents (Experiment 1), or egg yolk and liver ALA contents (Experiment 2), respectively, as compared to feeding the SDA- or ALA-rich oils alone.

Dietary SFAs and ω-6 Fatty Acids Alter Incorporation of ω-3 Fatty Acids into Milk Fat of Lactating CD-1 Mice and Tissues of Offspring.

Background: Methods to increase the amount of omega-3 (n-3) PUFAs in milk are desirable for neonatal health. The n-3 PUFA, α-linolenic acid (18:3n-3), can be elongated to EPA (20:5n-3) and DHA (22:6n-3). n-6 PUFAs suppress tissue n-3 PUFA incorporation, but the effect of SFAs is not clear.

Physical characterization of fatty acid supplements with varying enrichments of palmitic and stearic acid by differential scanning calorimetry.

Saturated fatty acid supplements commonly fed to dairy cows differ in their fatty acid (FA) profile. Some supplements with very high enrichments of palmitic acid (PA) or stearic acid (SA) have been reported to have low total-tract digestibility. Saturated FA have the potential to form crystalline structures at high purity that may affect digestibility.

Short communication: Diet digestibility measured from fecal samples and associations with phenotypic and genetic merit for milk yield and composition.

Selection for improved feed utilization is of high interest globally but is limited by the high cost of obtaining feed intake for individual cows and relies on indirect measures of feed efficiency. Supplementing selection with mechanistic measures of feed use could make selection for feed utilization more direct and effective. The objectives of this study were to evaluate fecal sampling as a method of determining digestive efficiency of individual cows and to evaluate associations of digestive efficiency with genetic and phenotypic merit for milk yield and composition.

Dietary Fat Does Not Overcome trans-10, cis-12 Conjugated Linoleic Acid Inhibition of Milk Fat Synthesis in Lactating mice.

Trans-10, cis-12 conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis in the cow and similarly reduces milk fat in rodents. The objective of this study was to determine whether dietary fat can overcome CLA inhibition of milk fat concentration in lactating mice. Wild type C57Bl/6J mice (n = 31) were fed semipurified diets containing either low fat (LF; 4% fat) or high fat (HF; 23.

Night-restricted feeding of dairy cows modifies daily rhythms of feed intake, milk synthesis and plasma metabolites compared with day-restricted feeding.

The timing of feed intake can alter circadian rhythms of peripheral tissues. Milk synthesis displays a daily rhythm across several species, but the effect of feeding time on these rhythms is poorly characterised. The objective of this experiment was to determine if the time of feed intake modifies the daily patterns of milk synthesis, plasma metabolites and body temperature in dairy cows.

Both Dietary Fatty Acids and Those Present in the Cecotrophs Contribute to the Distinctive Chemical Characteristics of New Zealand Rabbit Milk Fat.

The relationship between the fatty acid (FA) profile of cecotrophs and that of the milk fat was evaluated in nine multiparous New Zealand does during the first 12 days of lactation. Milk samples were obtained manually on days 6, 8, 10, and 12 postpartum and cecotrophs and feces were collected on days 7, 9, and 11 postpartum. The FA profiles of feed, milk, cecotrophs, and feces were determined using gas chromatography.

Kinetics of trans-10, cis-12-conjugated linoleic acid transfer to plasma and milk following an abomasal bolus in lactating dairy cows.

Trans-10, cis-12-conjugated linoleic acid (CLA) is a potent bioactive fatty acids (FA) that causes milk fat depression in lactating animals. FA are transferred to milk directly through chylomicrons and indirectly by recycling through other tissues. The objective of this study was to characterise the kinetics of trans-10, cis-12 CLA transfer to plasma and milk after a single bolus infusion.

Time-dependent effect of trans-10,cis-12 conjugated linoleic acid on gene expression of lipogenic enzymes and regulators in mammary tissue of dairy cows.

Trans-10,cis-12 conjugated linoleic acid (CLA) has been identified as an intermediate of rumen fatty acid biohydrogenation that caused milk fat depression (MFD) in the dairy cow. Previous studies in cows experiencing CLA- and diet-induced MFD have identified reduced mammary expression of the master lipogenic regulator sterol response element transcription factor 1 (SREBF1) and many of its dependent genes. To distinguish between primary mechanisms regulating milk fat synthesis and secondary adaptations to the reduction in milk fat, we conducted a time-course experiment.