E.J. DePeters

Relationships between chemical composition, dry matter degradation and in vitro gas production of several ruminant feeds

Abstract Thirty-eight samples of 12 feedstuffs were used to study relationships between in vitro true digestibility of dry matter (IVTD) and in vitro gas production. Influences of chemical constituents on gas and volatile fatty acid (VFA) production were investigated. There was a negative ( P P P P P P P

Bovine Milk Glycome

Bovine milk oligosaccharides have several potentially important biological activities including the prevention of pathogen binding to the intestinal epithelial and as nutrients for beneficial bacteria. It has been suggested that milk oligosaccharides are an important source of complex carbohydrates as supplements for the food and the pharmaceutical industries. However, only a small number of structures of bovine milk oligosaccharides (bMO) are known. There have been no systematic studies on bMO. High-performance mass spectrometry and separation methods are used to evaluate bMO, and nearly 40 oligosaccharides are present in bovine milk. Bovine milk oligosaccharides are composed of shorter oligomeric chains than are those in human milk. They are significantly more anionic with nearly 70%, measured abundances, being sialylated. Additionally, bMO are built not only on the lactose core (as are nearly all human milk oligosaccharides), but also on lactose amines. Sialic acid residues include both N-acetyl and N-glycolylneuraminic acid, although the former is significantly more abundant.

Variations in bovine milk oligosaccharides during early and middle lactation stages analyzed by high-performance liquid chromatography-chip/mass spectrometry

Milk oligosaccharides (OS) are not only a source of nutrition for newborns, but also provide numerous important biological functions including the prevention of pathogen binding to the intestinal epithelium and serving as nutritive sources for beneficial bacteria. High-performance mass spectrometry and separation methods were used to evaluate changes of bovine milk oligosaccharides (bMO) in different lactation stages. Previously, 40 bMO were identified in bovine milk with many consisting of short oligomeric chains that were less complex than human milk oligosaccharides (hMO). The bMO are also significantly more anionic than hMO, with nearly 70% in measured abundances containing either N-acetylneuraminic acid or N-glycolylneuraminic acid, and no fucosylated OS. In this study, we examined factors that could affect the abundances of bMO including stage of lactation and breed. The total concentrations dropped rapidly in the first several days of lactation. Moreover, the anionic oligosaccharides (including N-glycolylneuraminic acid) decreased more rapidly compared with the neutral oligosaccharides.

Impact of lameness on behavior and productivity of lactating Holstein cows

The impact of lameness on behavior and milk production of multiparity Holstein cows was examined on two commercial dairy farms. Pens of cows were selected based on distance from the milking parlor. Cows within each pen were locomotion scored to quantify lameness severity. Based on their locomotion score (i.e. 1–4), where an increasing number indicates an increased severity of lameness, cows were color marked and observed to quantify behaviors. Data recorded by cow was the return time from the milking parlor (i.e. time after the first cow returned; in minutes) after the morning milking and then, at hourly intervals until cows left for the afternoon milking, whether marked cows were lying or standing and their distance from the pen entrance. Milk production and composition was determined. In Experiment 1, the percentage of cows lying increased at an increasing rate (linear (L): P=0.02; quadratic (Q): P=0.07), distance from the pen entrance was highest in intermediate locomotion score groups (Q: P=0.02), return time tended to increase linearly (P=0.07), and milk (P=0.02) and protein production (P<0.01) decreased linearly as the locomotion score groups increased. In Experiment 2, the percentage of cows lying increased linearly (P<0.01), distance from the pen entrance decreased at an increasing rate (L: P<0.01; Q: P<0.01), and return time increased at an increasing rate (L: P=0.07; Q: P=0.05) as locomotion score groups increased. Percentage of cows lying was highest in the farthest pen (P<0.01), distance from the pen entrance decreased at an increasing rate (L: P<0.01 and Q: P<0.01), and cows return time increased linearly (P<0.01) as pen distance from the milking parlor increased. Increased locomotion score and pen distance were judged to have negatively impacted cow behavior and productivity. However, lack of interactions between locomotion score and pen distance do not support a recommendation to place lame cows in pens closer to the milking parlor to increase welfare and/or productivity.

Unique phospholipid metabolism in mouse heart in response to dietary docosahexaenoic or α-linolenic acids

Diet and fatty acid metabolism interact in yet unknown ways to modulate membrane fatty acid composition and certain cellular functions. For example, dietary precursors or metabolic products of n-3 fatty acid metabolism differ in their ability to modify specific membrane components. In the present study, the effect of dietary 22∶6n−3 or its metabolic precursor, 18∶3n−3, on the selective accumulation of 22∶6n−3 by heart was investigated. The mass and fatty acid compositions of individual phospholipids (PL) in heart and liver were quantified in mice fed either 22∶6n−3 (from crocodile oil) or 18∶3n−3 (from soybean oil) for 13 wk. This study was conducted to determine if the selective accumulation of 22∶6n−3 in heart was due to the incorporation of 22∶6n−3 into cardiolipin (CL), a PL most prevalent in heart and known to accumulate 22∶6n−3. Although heart was significantly enriched with 22∶6n−3 relative to liver, the accumulation of 22∶6n−3 by CL in heart could not quantitatively account for this difference. CL from heart did accumulate 22∶6n−3, but only in mice fed preformed 22∶6n−3. Diets rich in non-22∶6n−3 fatty acids result in a fatty acid composition of phosphatidylcholine (PC) in heart that is unusually enriched with 22∶6n−3. In this study, the mass of PC in heart was positively correlated with the enrichment of 22∶6n−3 into PC. The increased mass of PC was coincident with a decrease in the mass of phosphatidylethanolamine, suggesting that 22∶6n−3 induced PC synthesis by increasing phosphatidylethanolamine-N-methyltransferase activity in the heart.

Effects of dietary supplemental fish oil during the peripartum period on blood metabolites and hepatic fatty acid compositions and total triacylglycerol concentrations of multiparous Holstein cows

The objectives were to evaluate the effects of dietary fish oil on plasma metabolite, hepatic fatty acid composition, and total triacylglycerol concentrations. Multiparous Holstein cows (n = 42) were completely randomized to 1 of 3 treatments at 3 wk prepartum. Treatments were no supplemental lipid or supplemental lipid from either Energy Booster (Milk Specialties Co., Dundee, IL) or fish oil. Treatment diets were fed from -21 d relative to expected date of parturition until 10 d postpartum. Treatments were fed as a bolus before the a.m. feeding. The dose of lipid fed during the prepartum period was 250 g, whereas approximately 0.92% of the previous days dry matter intake was supplemented postpartum. Blood was collected 3 times weekly for determination of plasma metabolites. Liver biopsies were performed at 21 and 10 d before expected date of parturition and 1 and 14 d after parturition to determine fatty acid compositions and total triacylglycerol concentrations. Dry matter intake, milk yield, and loss of body weight or body condition score were not affected by supplementing the diet with lipid or by the source of lipid. Supplemental lipid tended to increase plasma glucose and decrease nonesterified fatty acids during the postpartum period. Furthermore, plasma beta-hydroxybutyrate was reduced during the postpartum period in the lipid-supplemented treatments. However, source of supplemental lipid had no influence on any blood metabolite. Supplemental fish oil altered the fatty acid composition of liver phospholipids and triacylglycerols, decreasing total saturated fatty acids and increasing total n-3 and long-chain polyunsaturated fatty acids (>20 carbon fatty acids). Despite the altered fatty acid composition, hepatic total triacylglycerol concentrations were unaffected by supplemental fish oil. Furthermore, the improved metabolic profile following lipid supplementation did not decrease hepatic total triacylglycerol concentrations.

Digestion kinetics of neutral detergent fiber and chemical composition within some selected by-product feedstuffs

Nine by-product feedstuffs (BPF) obtained from three different sources were evaluated for nutrient composition, estimated nonstructural carbohydrate (NSC) and TDN content, and total extent and rate of digestion of DM and NDF. The nine BPF evaluated included: beet pulp (BP), rice bran (RB), almond hulls (AI-I), citrus pulp (CT), bakery waste (BW), wheat mill run (WMR), brewers’ grains (BG), distillery grains (DG) and soy hulls (SH). Twenty-seven samples were evaluated and were a subset of a larger study reported previously. In sacco techniques were used to measure the amount of NDF and DM remaining in nylon bags after 0, 1, 2, 4, 8, 16, 24, 36, 48, and 72 h of incubation in the rumen of a rumen listulated cow. Chemical analyses measured included ash, crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein in the NDF (NDFCP) and ADF (ADFCP) fractions. Chemical composition differed among BPF source. This difference could be due to processing method or ingredients added to BPF during processing. The amount of CP associated with the NDF fraction varied among sources of each BPF. The amount of NDFCP also differed for each BPF. The NDFCP content of CT, O&l%, was low compared with DG, 14.5%, which was high compared with the other BPF evaluated. Correcting for the fiber-bound protein increased the estimate of NSC slightly for most BPF, but the NSC content of DG was increased 88%. The results indicate a correction for NDFCP is necessary for an accurate estimation of NSC in BPF. Within a given BPF, the extent and rate of digestion of NDF were different for each source. The TDN content of each sample was calculated using the rate of in sacco NDF digestion for each BPF at three theoretical rates of passage from

Extent of variability in nutrient composition within selected by-product feedstuffs

Abstract The nutrient composition of nine by-product feedstuffs (BPF) was determined. BPF were selected based on economic importance to the dairy industry, nutritional value, and availability. Three to nine different samples for each BPF were obtained throughout California. A total of 51 samples were collected: nine beet pulp (BP), eight rice bran (RB), seven almond hulls (AH), four citrus pulp (CT), five bakery waste (BW), eight wheat mill run (WMR), four brewers grains (BG), three distillery grains (DG), and three soy hulls (SH) samples. Chemical analyses measured included dry matter, ash, crude protein (CP), fiber fractions, macrominerals, and microminerals. The average chemical analyses determined for each BPF were compared with average values reported by the National Research Council (NRC). Considerable variation within a given BPF was observed in the present study. For example, BP was found to contain 18.81% acid detergent fiber (ADF) while the NRC reported an average composition of 25% ADF. The ether extract content of RB was found to be 20.48% compared with 15.1% reported by NRC. Much of this variability was related to how the commodity was handled during or after processing. In the second part of this study, two theoretical diets were formulated to calculate the effect of nutrient variability on diet composition. The BPF compositions of the two diets were 27% and 50% in Diet 1 and Diet 2, respectively. Specific by-products sources of BP, RB, DG, and SH were compared with the NRC diet composition used in the initial diet formulation. As the proportion of BPF in the diet was increased (Diet 2) nutrient composition of the diet was more variable with CP content ranging from 14.30 to 15.20%. Similar changes to those observed for CP were observed for the other chemical components. The effect of variability in by-product composition was more evident when evaluated on a concentrate mix basis. Variability in the chemical component of BPF influenced the composition of both the total diet and the concentrate mix, and the magnitude of effect depended upon the contribution of BPF to the total ration and the nutrient of interest.

In vitro rumen fermentation and gas production: influence of yellow grease, tallow, corn oil and their potassium soaps

The effect of addition of fat on in vitro gas production, volatile fatty acid (VFA) production, in vitro true digestibility (IVTD), and ammonia-N concentration was assessed by incubation of a simulated total mixed ration in buffered rumen fluid using an in vitro gas technique. Fat sources were corn oil (CO), tallow (TL), yellow grease (YG), and potassium soaps (K-soaps) of CO, YG, and TL. Addition of YG increased (P<0.001) in vitro gas production while TL had no effect. Neither YG nor TL affected IVTD and total VFA production. Addition of either YG or TL decreased acetate production and increased propionate production. Addition of CO increased in vitro gas production, but had no effect on IVTD and total VFA production. However, CO decreased acetate and increased propionate production with a concomitant decrease in the acetate to propionate ratio. Addition of K-soaps of CO, TL and YG depressed in vitro gas production, IVTD, VFA and ammonia-N concentrations. K-soaps also caused a marked decrease in acetate and increase in propionate production. The absence of negative effects on rumen fermentation parameters in response to the inclusion of fat in the form of triglycerides to an in vitro system at up to 25% DM suggests that triglycerides have much less effect on rumen fermentation parameters than corresponding free fatty acids. In contrast, the K-soaps of each respective fat had detrimental effects on in vitro rumen fermentations.

Supplementation with Calcium Salts of Linoleic and trans-Octadecenoic Acids Improves Fertility of Lactating Dairy Cows

Objectives were to evaluate effects of feeding a calcium salt rich in linoleic and trans-octadecenoic acids (LTFA) on synthesis of prostaglandin F(2alpha) based on its metabolite (PGFM), uterine involution and pregnancy rates in lactating dairy cows. Five hundred and eleven Holstein cows were blocked according to parity, body condition score and milk yield in the previous lactation. Primiparous and multiparous cows were randomly assigned to one of the two treatments consisting of calcium salt (2% diet dry matter) of either palm oil (PO) or LTFA from 25 days prepartum to 80 days of lactation. Cows were time-inseminated at 70 +/- 3 days postpartum. Feeding LTFA tended (p = 0.08) to decrease the incidence of puerperal metritis (15.1% vs 8.8%). Primiparous cows supplemented with LTFA showed larger increase in plasma PGFM concentration at day 1 postpartum (17018 vs 6897 pm). Pregnancy rate after first insemination tended (p = 0.07) to be greater at 27 days after insemination (37.9% vs 28.6%), and was greater (p = 0.05) at 41 days after insemination (35.5% vs 25.8%) for cows fed LTFA compared with PO. These results indicate that unsaturated fatty acids fed in a rumen inert form have the potential to modulate reproductive events and improve pregnancy rates in lactating dairy cows.