N.E. Odongo

Effects of Monensin and Dietary Soybean Oil on Milk Fat Percentage and Milk Fatty Acid Profile in Lactating Dairy Cows

The objective of this study was to investigate the effect of monensin (MN) and dietary soybean oil (SBO) on milk fat percentage and milk fatty acid (FA) profile. The study was conducted as a randomized complete block design with a 2 x 3 factorial treatment arrangement using 72 lactating multiparous Holstein dairy cows (138 +/- 24 d in milk). Treatments were [dry matter (DM) basis] as follows: 1) control total mixed ration (TMR, no MN) with no supplemental SBO; 2) MN-treated TMR (22 g of MN/kg of DM) with no supplemental SBO; 3) control TMR including 1.7% SBO; 4) MN-treated TMR including 1.7% SBO; 5) control TMR including 3.4% SBO; and 6) MN-treated TMR including 3.4% SBO. The TMR (% of DM; corn silage, 31.6%; haylage, 21.2%; hay, 4.2%; high-moisture corn, 18.8%; soy hulls, 3.3%; and protein supplement, 20.9%) was offered ad libitum. The experiment consisted of a 2-wk baseline, a 3-wk adaptation, and a 2-wk collection period. Monensin, SBO, and their interaction linearly reduced milk fat percentage. Cows receiving SBO with no added MN (treatments 3 and 5) had 4.5 and 14.2% decreases in milk fat percentage, respectively. Cows receiving SBO with added MN (treatments 4 and 6) had 16.5 and 35.1% decreases in milk fat percentage, respectively. However, the interaction effect of MN and SBO on fat yield was not significant. Monensin reduced milk fat yield by 6.6%. Soybean oil linearly reduced milk fat yield and protein percentage and linearly increased milk yield and milk protein yield. Monensin and SBO reduced 4% fat-corrected milk and had no effect on DM intake. Monensin interacted with SBO to linearly increase milk fat concentration (g/100 g of FA) of total trans-18:1 in milk fat including trans-6 to 8, trans-9, trans-10, trans-11, trans-12 18:1 and the concentration of total conjugated linoleic acid isomers including cis-9, trans-11 18:2; trans-9, cis-11 18:2; and trans-10, cis-12 18:2. Also, the interaction increased milk concentration of polyunsaturated fatty acids. Monensin and SBO linearly reduced, with no significant interaction, milk concentration (g/100 g of FA) of short- and medium-chain fatty acids (

Effects of supplementing glycerol and soybean oil in drinking water on feed and water intake, energy balance, and production performance of periparturient dairy cows

The objective of this study was to determine the effects of supplementing glycerol and soybean oil in drinking water on feed and water intake, calculated energy balance, and production performance of periparturient dairy cows. Ninety multiparous Holstein dairy cows were randomly assigned to 1 of 3 treatments: 1) no nutrients supplemented in the drinking water (control); 2) 20 g/L of glycerin supplemented in the drinking water (glycerol); and 3) 10 g/L of soybean oil supplemented in the drinking water (SBO). The trial lasted from 7 d prepartum to 7 d postpartum. Cows were offered a close-up and milking cow TMR for ad libitum intake, pre- and postpartum, respectively. The dry matter intake of cows supplemented with glycerol and SBO was lower than for the control cows throughout the experimental period but not different from each other. Water intake for the control cows was greater than the average for the glycerol and SBO cows prepartum, and greater than for SBO cows but similar to that of glycerol cows postpartum. Glycerol cows consumed more water than SBO cows. There were no differences in energy intake and energy balance of the cows pre- and postpartum. Serum triacylglycerol concentration for glycerol cows was lower than for the control and SBO cows prepartum and was lower than for the SBO cows postpartum. There were no differences in the serum nonesterified fatty acids and glucose concentrations throughout the experiment. There were no differences in the serum beta-hydroxybutyrate (BHBA) concentrations at parturition, but serum BHBA concentration of the glycerol cows was greater than for control and SBO cows during the prepartum period. However, during the postpartum period, serum BHBA concentrations of the control cows were greater than for glycerol and SBO cows. There were no differences in calf birth weights or milk yield and composition. Although the glucogenic property of glycerol supplemented in the drinking water at 20 g/L may not have been sufficient to elicit a milk yield response, it did reduce the concentration of BHBA postpartum.

Fatty acid composition of yak (Bos grunniens) cheese including conjugated linoleic acid and trans-18:1 fatty acids.

The esterified fatty acid composition of cheese (YC) from yak ( Bos grunniens), reared in the highlands of the Nepalese Himalayas, was studied using capillary gas-liquid chromatography and compared with that of dairy cow Cheddar cheese (DC) purchased in a local market. The YC was collected from Dolakha, Nepal. The YC had a lower (P<0.001) myristic acid (C14:0; 6.7 vs 10.3%, YC vs DC, respectively) and palmitic acid content (C16:0; 23.3 vs 29.2%, YC vs DC, respectively) compared to DC. The YC had a lower (P<0.01) total medium-chain saturated fatty acids (C10:0-C16:0) content compared to DC (36.7 vs 47.3%, YC vs DC, respectively). On the other hand, the YC had a 24.8% higher (P<0.01) level of total long-chain saturated fatty acids (C17:0-C26:0) and a 3.2 times higher (P<0.001) content of total n-3 PUFA than DC. The ratio of n-3 PUFA to n-6 PUFA in YC was 0.87 compared to 0.20 in DC. YC had a 2.8 times higher (P<0.001) total trans-18:1 (9.18 vs 3.31%, YC vs DC, respectively) content. The percentage of vaccenic acid ( trans-11-C18:1) in YC was 4.6 times higher (6.23 vs 1.35% of total fatty acids, YC vs DC, respectively) than in DC. Vaccenic acid constituted 67.9% of total trans-C18:1 in YC. The Delta9-desaturase index for YC was lower than that of DC. The total conjugated linoleic acid (CLA) content in YC was 2.3% of total fatty acids compared to 0.57% in DC. The cis-9, trans-11 CLA isomer in YC constituted 88.5% of the total CLA. The results suggest that cheese from yak, grazed on Himalayan alpine pastures, may have a more healthful fatty acid composition compared to cheese manufactured from dairy cattle fed grain-based diets.

Selenium uptake by ruminal microorganisms from organic and inorganic sources in dairy cows

The objectives of this study were (i) to determine the amount of time required for microbial Se concentration to reach a plateau and the half-life of Se in the ruminal microorganisms (exp. 1) and (ii) to compare Se uptake by ruminal microorganisms from organic and inorganic sources (exp. 2). In exp. 1, four dry ruminally cannulated Holstein dairy cows (863 ± 98 kg of BW, mean ± SD) housed in a tie-stall facility were used in a completely randomized design with a 14-d adaptation and 9-d measurement period. Cows were offered 10 kg of timothy hay (divided in 12 equal portions and delivered at 2-h intervals) supplemented with 500 g of dry-cow mineral and vitamin premix at 0800 daily. The treatments were inorganic and organic Se that were each enriched with Se stable isotopes (inorganic 82Se and organic 77Se Sel-Plex®). The Se treatments were supplemented at 0.3 mg kg-1 DM and administered directly into the rumen under the rumen mat every 6 h. Rumen samples (both fluid and solid) were collected before treatmen...

Fatty acid profile of bovine milk naturally enhanced with docosahexaenoic acid.

Recent studies have shown that the fatty acid profile of dietary lipid has the potential for improving the health of consumers. The present study was conducted to determine the fatty acid composition of commercial milks, namely, Dairy-Oh! Homo-Milk (DOHM), which is naturally enhanced with docosahexaenoic acid (DHA), or regular Homo-Milk (HM). The milk was collected from local supermarkets. The most abundant saturated fatty acids in the milk were butyric (C4:0), lauric (C12:0), myristic (C14:0), palmitic (C16:0), and stearic (C18:0) acids. Among unsaturated fatty acids, oleic acid (cis-9-C18:1) was also considerably high (502.7 mg/100 mL of milk). The concentration of total trans-18:1 was higher (P < 0.05) in DOHM than in HM (134.7 vs 107.0 mg/100 mL of milk, respectively), whereas total cis-18:1 was higher (P < 0.05) in HM than in DOHM (566.4 vs 508.4 mg/100 mL of milk, respectively). The concentration of DHA was 24.0 times higher (P < 0.05) in DOHM than in HM. DOHM contained 2.8 times higher (P < 0.05) eicosapentaenoic acid (EPA) compared to HM. Milk fat from DOHM contained a greater concentration of cis-9,trans-11 conjugated linoleic acid (CLA, 16.4 vs 11.6 mg/100 mL of milk, DOHM vs HM, respectively). The total omega-3 polyunsaturated fatty acids content was 2.23 times greater (P < 0.05) in DOHM compared with HM, due to an increase in C18:3n-3, EPA, and DHA. The result of the milk fatty acid analyses indicates that milk fat from DOHM had increased contents of EPA, DHA, and cis-9,trans-11 CLA, which could have a more favorable impact on diet composition and healthfulness.

Long-term effects of feeding diets without mineral phosphorus supplementation on the performance and phosphorus excretion in high-yielding dairy cows

The objective of this study was to assess the long-term effects of feeding a diet with no mineral phosphorus (P) supplementation on performance and P excretion in high-yielding dairy cows. In exp. 1, 24 primiparous (PP) and 40 multiparous (MP) Holstein cows were allocated to one of two treatments at calving: (1) regular corn silage and alfalfa haylage based milking cow total mixed ration (TMR; 0.42% P diet) or (2) milking cow total mixed ration (TMR) without supplemental mineral P (0.35% P diet) in a completely randomized design. The trial lasted until after two lactations were completed or the cow was culled. In exp. 2, eight MP Holstein cows (108 ± 8.0 d in milk) were used to determine P digestibility and retention in a completely randomized block design. In exp. 1, the 0.35% P diet cows had lower body weight, body condition score and milk urea nitrogen and higher faecal P than the 0.42% P cows. The dry matter intake (DMI) of PP cows on the 0.35% P diet was lower than that of PP cows on the 0.42% P diet...

Effect of monensin on meal frequency during sub-acute ruminal acidosis in dairy cows

Two experiments were conducted to determine the effects of monensin (Rumensin® controlled-release capsule; exp. 1 and Rumensin® Premix; exp. 2) on meal frequency during grain-induced sub-acute ruminal acidosis (SARA) in Holstein dairy cows. SARA was induced by restricting total mixed ration intake to 85% of ad libitum intake and replacing the remaining 15% with a grain pellet consisting of 50% wheat and 50% barley. In both experiments, meal frequency during SARA was lower (P < 0.05) than meal frequency during the adaptation and recovery periods. In exp. 2, monensin increased meal frequency during SARA (6.0 vs. 7.2, P = 0.04) and meal frequency during the recovery period (7.5 vs. 9.0, P = 0.004). These results suggest monensin premix may increase meal frequency in lactating dairy cows under conditions of SARA. Key words: dairy cows, monensin, ruminal acidosis, meal frequency

Effects of nutritionally induced metabolic acidosis with or without glutamine infusion on acid-base balance, plasma amino acids, and plasma nonesterified fatty acids in sheep.

This study characterized the effects of nutritionally induced metabolic acidosis with or without Gln infusion on acid-base balance, plasma AA, and plasma NEFA in sheep. In a randomized complete block design with a 2 x 2 factorial arrangement of treatments, 24 fully fleeced sheep (Rideau-Arcott, 63.6 +/- 5.9 kg of BW) were fed a control supplement (CS; 300 g/d of canola meal) or an acidosis supplement (AS; 300 g/d of NutriChlor; HCl-treated canola meal), offered twice daily at 0700 and 1100 h. Sheep were infused at 1400 h daily with 0.3 g of L-glutamine per kg of BW or saline via jugular vein catheters for 7 d. The sheep were individually housed and limit-fed a basal diet of dehydrated alfalfa pellets (1.75 kg/d; 90% DM, 22% CP, and 1.2 Mcal of NE(g)/kg on a DM basis) offered twice daily at 1000 and 1300 h. Blood and urine was sampled daily between 1100 and 1130 h, and blood samples were analyzed for hematocrit, plasma pH, gases, strong ions, AA, and NEFA, whereas urine was analyzed for pH. The AS reduced (P < 0.01) DMI, urine and plasma pH, blood urea, partial pressure of CO(2), strong ion difference, and plasma HCO(3)(-), and increased (P < 0.01) plasma K(+), Ca(2+), and Cl(-). The AS with saline infusion increased (P <or= 0.03) partial pressure of O(2) and plasma glucose, whereas AS with Gln infusion reduced (P < 0.01) partial pressure of O(2) and plasma glucose. The AS increased (P < 0.01) plasma lysine and reduced (P < 0.01) plasma taurine. Glutamine infusion increased (P = 0.04) plasma leucine with the CS treatment but had no effect (P = 0.89) with the AS treatment. Plasma 16:0, 18:2n-6, 18:3n-3, 20:4n-6, and total NEFA were increased and 18:0 was decreased (P < 0.001) in AS sheep compared with CS sheep. Infusion of Gln decreased (P < 0.05) 16:0, 18:2n-6, 18:3n-3, 20:4n-6, and total NEFA compared with saline infusion. Plasma cis-9, trans-11 CLA was elevated (P = 0.001) in AS sheep, whereas plasma cis-9, trans-11 CLA, regardless of the diets, was decreased (P < 0.02) with Gln infusion. These results show that despite some improvement in overall mobilization of NEFA, Gln infusion did not ameliorate the negative responses associated with metabolic acidosis.

Data capture: development of a mobile open-circuit ventilated hood system for measuring real-time gaseous emissions in cattle.

This chapter describes a mobile, open-circuit ventilated hood system for measuring real-time gaseous exchange in large ruminants at the farm level. It uses improvements in technology for the determination of O2, CO2 and CH4 contents, measurements of air flow, absolute pressure, temperature and relative humidity, system control and data acquisition. Details of the three experiments conducted to test the calorimetry system are presented. All animals adapted easily to confinement in the hoods and there were no indications of discomfort or stress in the animals.

Phosphorus status of lactating dairy cows fed total mixed rations containing 0.24% vs. 0.36% phosphorus

The effect of dietary P content on P balance was evaluated using 14 lactating dairy cows fed a corn silage based total mixed ration (TMR) containing either 0.24% P or 0.36% P. The animals were paired by calving date at dry-off with one cow from each pair randomly assigned to either dietary treatment. All cows were fed a common TMR containing 0.34% P prepartum, and then 0.41% P for 2 wk postpartum. Experimental diets were fed from 3 to 13 wk postpartum. Phosphorus balance was conducted at week 13 postpartum. Cows fed 0.36% P diet consumed more (P 0.05) affected by treatments. These results suggest that short-term P balance in lactating dairy cows can be maintained on a diet supplying 26% below National Research Council 2001 recomm...