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Hawkins Lausen posted an update 6 months, 1 week ago
postpartum diets can decrease fat mobilization and serum indicators of systemic inflammation and increase milk production even with the transition from a low-starch prepartum diet.Milk protein concentrate (MPC) is a preferred ingredient to provide nutritional and functional benefits in various dairy and food products. Altering the protein configuration and protein-protein interactions in MPC can provide a novel functionality and may open doors for new applications. The fibrilization process converts the globular structure of whey proteins to fibrils and consequently increases viscosity and water holding capacity compared with the native protein structure. The objective of the current work was to selectively convert the whey proteins in MPC as fibrils. For this purpose, simulated control model MPC was prepared by combining solutions of micellar casein concentrate (MCC) and milk whey protein isolate (mWPI) to give casein and whey protein in an 8020 ratio. The mWPI solution was converted to fibrils by heating at low pH, neutralized, and combined with MCC solution similar to control model MPC and termed “fibrillated model MPC.” Thioflavin T fluorescence value, transmission electron microscopy, and gel electrophoresis confirmed the fibril formation and their survival after neutralization and mixing with MCC. Further, the fibrillated mWPI showed significantly higher viscosity and consistency coefficient than nonfibrillated mWPI. Similarly, fibrillated model MPC showed significantly higher viscosity and consistency coefficient compared with control model MPC. Hence, the fibrillated model MPC can be used as ingredient to increase viscosity. Heat coagulation time was found to be significantly higher for control model MPC compared with fibrillated model MPC.Next to rumen acidosis, other forms of acidosis may also affect lactational performance of cows. Therefore, the effects of hindgut acidosis, induced via abomasal infusion of ground corn, and metabolic acidosis, induced via abomasal infusion of NH4Cl, were studied in cows in early lactation. Observations were made on intake and digestibility of nutrients, lactation performance, energy and N partitioning, blood acid-base status, and rumen and hindgut fermentation characteristics. In a 6 × 6 Latin square design, 6 rumen-fistulated, second-lactation Holstein-Friesian dairy cows (48 ± 17 d in milk) were subjected to 5 d of continuous abomasal infusions of water as control, or solutions of 2.5 mol of NH4Cl/d, 5.0 mol of NH4Cl/d, 3.0 kg of ground corn/d, or the combination of ground corn with either of the 2 NH4Cl levels, followed by 2 d of rest. Treatment solutions were administered via peristaltic pumps through infusion lines attached to the rumen cannula plug and an abomasal infusion line with a flexible disk (eqestibility of several nutrients increased with 5.0 mol of NH4Cl/d, likely as a result of decreased intake. Abomasal ground corn infusion resulted in hindgut acidosis, where fecal pH decreased from 6.86 without ground corn to 6.00 with ground corn, regardless of NH4Cl level. The decrease in fecal pH was likely the result of increased hindgut fermentation, evidenced by increased fecal volatile fatty acid concentrations. Hindgut acidosis was associated with decreased digestibility of nutrients, except for starch, which increased, and crude fat, which was not affected. No systemic inflammatory response was observed, suggesting that the hindgut epithelium was not severely affected by the more acidic conditions or barrier damage. Abomasal infusion of ground corn increased milk yield, milk protein and lactose yield, fecal N excretion, N use efficiency, and total energy retained as well as energy retained in fat, and reduced milk fat content and urine N excretion.The hindgut epithelial barrier plays an important role in maintaining absorption and immune homeostasis in ruminants. However, little information is available on changes in colon epithelial barrier structure and function following grain-induced subacute ruminal acidosis (SARA). The objective of this study was to investigate the effects of grain-induced SARA on colon epithelial morphological structure, permeability, and gene expression involved in epithelial barrier function. Twelve mid-lactating (136 ± 2 d in milk; milk yield = 1.68 ± 0.15 kg/d) Saanen dairy goats with 62.13 ± 4.76 kg of body weight were randomly divided into either the control (CON) treatment (n = 6) or SARA treatment (n = 6). The CON goats were fed a basal diet with a nonfiber carbohydrates to neutral detergent fiber ratio of 1.15 for 60 d. The SARA goats were fed 4 diets with increasing nonfiber carbohydrates to neutral detergent fiber ratio at 1.15, 1.49, 2.12, and 2.66 to induce SARA, with each diet (referred to as period) being fed for f the colonic epithelium at both structural and functional levels, which is associated with severe epithelial structural damage and increased permeability and changes in the expression of tight junction proteins.The aim was to study the effects of rumen N balance (RNB), dietary protein source, and their interaction on feed intake, N partitioning, and rumen microbial crude protein (MCP) synthesis in lactating dairy cows. click here Twenty-four lactating Holstein cows were included in a replicated 4 × 4 Latin square experimental design comprising four 20-d periods, each with 12 d of adaptation to the experimental diets and 8 d of sampling. The dietary treatments followed a 2 × 2 factorial arrangement (i.e., 4 treatments) with 2 main protein sources offered at 2 dietary RNB levels each . The RNB was calculated as the difference between dietary crude protein (CP) intake and the rumen outflow of undegraded feed CP and MCP and divided by 6.25. Composition of concentrate mixtures was adjusted to create diets with desired RNB levels. Each of these protein sources supplied ≥35% of total dietary CP. Both diets for each protein source were isoenergetic but differed in CP concentrations. The DM intake (kg/d) was lower for RNB- than for RNB0 in diets containing FB, whereas no differences were seen between the RNB levels for SP diets. The RNB- decreased N intake and urinary N excretion but increased milk N use efficiency in both FB and SP diets, with greater differences between the RNB levels for FB diets than for SP diets. Similarly, duodenal MCP synthesis (g/kg of digestible organic matter intake) estimated from purine derivatives in the urine was lower for RNB- than for RNB0 in FB diets but similar between the RNB levels in diets containing SP. Low RNB of approximately -65 g/d (approximately -3.2 g/kg of DM) in diets reduced feed intake, N balance, and performance in high-yielding dairy cows with possibly more pronounced effects in diets containing rapidly degradable protein sources.