Milk Protein Content Research Articles

Temperature correction of near-infrared spectra of raw milk

Accurate milk composition analysis is crucial for improving product quality, economic efficiency, and animal health in the dairy industry. Near-infrared (NIR) spectroscopy can quantify milk composition quickly and nondestructively. However, external factors, such as temperature fluctuations, can alter the molecular vibrations and hydrogen bonding in milk, altering the NIR spectra and leading to errors in predicting key constituents such as fat, protein, and lactose. This study compares the effectiveness of Piecewise Direct Standardization (PDS), Continuous PDS (CPDS), External Parameter Orthogonalization (EPO), and Dynamic Orthogonal Projection (DOP in correcting the impact of temperature-induced variations on predictions in milk long-wave NIR spectra (LW-NIR, 1000–1700 nm).A total of 270 raw milk samples were analyzed, collecting both reflectance and transmittance spectra at five different temperatures (20 °C, 25 °C, 30 °C, 35 °C, and 40 °C). The experimental setup ensured precise temperature control and accurate spectral measurements. PLSR models were calibrated at 30 °C to predict milk fat, protein, and lactose content. The performance of these models was assessed before and after applying the temperature correction methods, with a primary focus on reflectance spectra.Results indicate that EPO and DOP significantly enhance model robustness and prediction accuracy across all temperatures, outperforming PDS and CPDS, especially for lactose prediction. These orthogonalization methods were compared against PLSR models calibrated with spectra from all temperatures. EPO and DOP showed comparable or superior performance, highlighting their effectiveness without requiring extensive temperature-specific calibration data. These findings suggest that orthogonalization methods are particularly suitable for in-line milk quality measurements under farm conditions where temperature control is challenging. This study highlights the potential of advanced chemometric techniques to improve real-time, on-farm milk composition analysis, facilitating better farm management and enhanced dairy product quality.

Macronutrients in Human Milk and Early Childhood Growth-Is Protein the Main Driver?

Infant growth trajectories reflect current health status and may predict future obesity and metabolic diseases. Human milk is tailored to support optimal infant growth. However, nutrient intake rather than milk composition more accurately predicts growth outcomes. Although the role of protein leverage in infant growth is unclear, protein intake is important for early infancy growth. This study of exclusively breastfeeding mothers with allergies (n = 161) from the Infant Fish Oil Supplementation Study assessed relationships between intake of human milk macronutrients and infant growth. Human milk fat, protein and lactose concentrations were measured at 3 months postpartum, and infant daily intakes were estimated using an average milk intake of 800 mL/day. Higher human milk protein:energy ratio was associated with higher weight-for-age z-score at 2.5 years compared to 3 months and higher body mass index-for-age z-score change (6 months to 1 year compared to 3-6 months). Maternal atopy and birth season (summer) were negatively associated with human milk lactose concentration. Passive smoke exposure was associated with reduced energy and fat concentrations and increased lactose:energy ratio. Our results indicate that intake of human milk macronutrients may impact early childhood growth.

Study of the Effects of Alfalfa Bioactive Substances and Polysaccharides on the Lactation Performance and Immune Function of Dairy Cows

Background: The aim of this study was to investigate the effects of alfalfa polysaccharides on the lactation performance and immune function of dairy cows. Methods: A total of 84 healthy Holstein cows were selected and randomly divided into 7 groups, including the control Group A0, the alfalfa polysaccharide groups (AP1, AP2, AP3) and the alfalfa extract groups (AE1, AE2, AE3). Each group had three replicates and each replicate had four cows. The daily rations of the dairy cows in the AP group and the AE group were supplemented with alfalfa polysaccharide powder and alfalfa extract at concentrations of 1, 2 and 3 kg/t, those in the A0 group served as a control. Result: (1) the milk production of dairy cows in the AE groups was extremely significantly greater (p less than 0.01) than that in A0 group and AP groups. The milk protein content of cows in the AP2 and AE2 groups was significantly greater (P less than 0.05) than that in the A0 group (2) The interleukin-2 (IL-2) levels in the serum of cows in the AP2, AP3, AE2 and AE3 groups were greater than those in the A0 and AP1 groups and the IgM antibody levels in the AP group and the AE group were extremely significantly greater than those in the A0 and AP1 groups (P less than 0.01). The IgA antibody level in the serum of dairy cows in the AP2, AP3, AE2 and AE3 groups was significantly (P less than 0.01) greater than that in the A0, AP1 and AE1 groups. In summary, the alfalfa extract improved both the lactation performance and immunity of dairy cows, indicating comprehensive effects. Alfalfa polysaccharides at a concentration of 2 kg/t improved the immunity of dairy cows.

Impact of diferent types of selection on the milk productivity of Kostroma breed cows

The article studies the influence of homogeneous and heterogeneous selection on the milk productivity of first-calf cows (milk yield, fat and protein content in milk). The object of research is cattle of the Kostroma breed. The research methods were zootechnical, population-genetic and analytical using computer programs IAS “SELEX” Multifarm and BON-MilkRegion. The modern cattle breeding base in the Kostroma region is represented by three breeding plants and two breeding reproducers. In 2022, the Karavaevo Breeding Farm JSC received 9,297 kg of milk per cow, the Minskoe LLC pedigree reproducer received 7,371 kg of milk, and the Rodina collective farm, Gridino and Agrofirma Planet LLC received more 6000 kg of milk. Record milk yields reach 15,000 kg of milk or more in 305 days of lactation. The following lines have been identified as promising in the Kostroma breed: lines Ladka 2537 and Kursa 3722, related groups Master 106902, Meridian 90927 and Concentrate 106157. To improve the productive qualities of dairy cattle, it is necessary to use both intraline selection and cross-lines, taking into account their compatibility. In breeding farms, using homogeneous selection, high productivity indicators were obtained: in terms of milk yield - from first-calf heifers of the related groups Laird, Concentrate and Meridian, in terms of fat and protein content in milk - Laird and Ladka. With heterogeneous selection, the best combinations were identified across farms.

Dielectric spectroscopy technology combined with machine learning methods for nondestructive detection of protein content in fresh milk.

To quickly achieve nondestructive detection of protein content in fresh milk, this study utilized a network analyzer and an open coaxial probe to analyze the dielectric spectra of milk samples at 100 frequency points within the 2-20GHz range, focusing on the dielectric constant ε' and the dielectric loss factor ε''. Feature variables were extracted from the full dielectric spectra using the successive projections algorithm (SPA), uninformative variables elimination (UVE), and the combined UVE-SPA method. These variables were then used to develop partial least squares regression (PLSR), support vector machine (SVM), decision tree (DT), random forest (RF), and least squares boosting (LSBOOST) models for predicting protein content. The results showed that ε' decreased monotonically with increasing frequency, while ε'' increased monotonically. The UVE-SPA method for feature extraction demonstrated superior performance, with the UVE-SPA-PLSR model being the best for predicting milk protein content, achieving the highest RC 2=0.998 and RP 2=0.989 and the lowest RMSEC=0.019% and RMSEP=0.032%. This study provides a theoretical reference for evaluating milk quality and developing intelligent detection equipment for natural milk.

Linseed oil supplementation alters milk fatty acid profile, mitigates heat stress, and improves summer milk yield in grazing dairy cows.

Dietary supplementation of fat can be an important source of energy to compensate for the reduction in dry matter intake in dairy cows during heat stress periods. Studies have reported that supplementing dairy cow diets with linseed oil (LO) can increase milk yield and enhance the levels of beneficial fatty acids, such as omega-3 fatty acids, in the milk. The objective of this research was to evaluate the effect of LO supplementation on milk fatty acids profile, milk yield and composition, and physiological parameters of grazing cows. The study was conducted in two seasons, one in spring and one in summer. A 2 × 2 Latin square design was used in each experiment. Twelve Holstein and crossbred Holstein x Jersey cows were involved in each season. Cows were divided into two groups: control (TC) with no supplementation and treatment (TL) supplemented with 400g/day of LO. The results showed that LO supplementation altered the milk fatty acid profile: decreased concentrations of short and medium-chain fatty acids (C10:0 - C17:1) except for C13:0 and increased concentrations of long-chain fatty acids (C18, C18:1 (both trans and cis isomers), C18:2 (specific conjugated linoleic acid - CLA isomers), and C18:3 n3 (omega-3)). Additionally, milk yield increased by 1.5l per day during summer in LO-supplemented cows, while milk fat, protein, and casein content decreased. Milk stability increased by 2.2% in the LO-supplemented group. LO-supplemented cows reduced internal body temperature and heart frequency in the afternoon and increased daily rumination time by 20min. In conclusion, LO supplementation can be an effective strategy to improve the nutritional profile of milk by altering fatty acid composition towards potentially healthier fats, mitigate the negative effects of heat stress on grazing cows during summer, as evidenced by reduced body temperature and heart frequency and increase milk yield.

Dietary thiamine supplementation modulates ruminal microbiota and partly restores lactation performance in lactating Hu ewes under heat-stress conditions

This study aimed to investigate the impact of dietary thiamine supplementation on milk production, rumen microbiota profile and inflammatory response of Hu ewes under heat-stress conditions. Twenty-seven multiparous pregnant and lactating Hu ewes of 71.6 ± 1.4 kg body weight, 11 ± 0.5 months gestation age, 31 ± 1 days in milk, 1.68 ± 0.15 L/d milk yield, and 2.14 ± 0.12 kg of daily dry matter intake (DMI), were used in the study. Following an acclimation period of 7 days, ewes were divided into 3 blocks of 9 each (one Hu ewe per pen), in a complete randomized design and assigned to one of three environmental temperature conditions for 15 days: thermoneutrality without supplementation (CON), heat-stressed without supplementation (HS) or heat-stressed with dietary thiamine supplementation (200 mg/kg of DMI; HST). The results indicated that the HS group experienced notable declines in milk protein, fat, and lactose content from day 10–15 (P < 0.05) compared to the CON group. In contrast, thiamine supplementation significantly elevated milk protein content from day 13–15 and raised milk fat and lactose content on days 14 and 15 (P < 0.05) compared to the HS group, thereby enhancing milk quality to a certain extent. Additionally, thiamine supplementation (HST group) significantly increased the circulating thiamine and Immunoglobulin A (IgA) concentrations accompanied by a significant decline in LPS-binding protein, interleukin-1 (IL-1), and serum amyloid A protein (SAA) levels compared to the HS group (P < 0.05). Rumen microbial composition analysis revealed that thiamine supplementation increased the abundance of Pyramidobacter, Butyrivibrio, Bacteroides, and Saccharofermentans. In conclusion, heat exposure during lactation in Hu ewes lowered milk production and quality, affecting rumen microbes. Dietary thiamine supplementation could improve rumen fermentation, mitigate heat stress-induced inflammation, and restore milk production in Hu ewes under heat stress conditions.

The effects of dietary supplementation with red grape pomace treated with ozone gas on ruminal fermentation activities, nutrient digestibility, lactational performance, and blood metabolites in dairy ewes

This study aimed to investigate the effect of red grape pomace (RGP) treated with ozone (O3) gas as a substitute of low-quality alfalfa hay on the ruminal fermentation, nutrient digestibility, and milk production performance of fat-tailed, fed RGP substituted high fibrous alfalfa hay. Present study was performed in two experimental phases: 1) In situ and in vitro phase: Four Ghezel ewes in their third gestation (30 months old; weighing 51 ± 2 kg) with surgically implanted cannulas in their rumen were used to assess the in situ degradability and to obtain ruminal fluid to assay the in vitro gas production; the treatments were RGP not-processed (control; T0), and RGP processed with O3 for 6 (T1), 12 h (T2), and 24 h (T3). Processing RGP with O3 gas reduced (P < 0.05) neutral detergent fiber (NDF) and acid detergent fiber (ADF), although the processing time did not show differences. Ozone-treated RGP caused a reduction (P < 0.02) in total phenolics, total tannins, condensed tannins, protein-bound tannins, and fiber-bound tannins, compared to the control. Processing RGP with O3 for 12 h improved the nutritional value of RGP because of the reduction of the concentration of phenolic compounds, the increase of the in vitro gas production and the dry matter (DM) degradability, and improved fermentation parameters and it was chosen for the second phase of the experiment. 2) In vivo phase: Forty-eight healthy multiparous fat-tailed Ghezel ewes received the control diet (0 % RGP), or diets that substituted 20, 40, and 60 % of the dietary alfalfa hay with RGP processed with O3 for 12 h. Incremental dietary replacement of RGP with alfalfa hay did not influence the ruminal total volatile fatty acids but increased (P < 0.03) propionate. The digestibility coefficients of the DM and the NDF increased (P < 0.001) in diets containing RGP versus the control, but not for the crude protein and ether extract. The ruminal protozoa population exhibited a linear increase with the addition of O3-treated RGP (P < 0.001). Plasma glucose and albumin concentration increased (P < 0.04), and milk production and milk fat, protein, and lactose contents also increased (P < 0.05) with the alfalfa substitution with O3-processed RGP. In conclusion, replacing high-fibrous alfalfa hay with RGP treated with O3 for 12 h improved the apparent digestibility of DM and NDF and maintained the performance of the ewes.

High-pressure processing and heat treatment of Murrah buffalo milk: Comparative study on microbial changes during refrigerated storage

This study aims to evaluate the effect of high-pressure processing (HPP) (500 and 600 MPa for 3 min and 5 min) on the microbial changes of Murrah buffalo milk in comparison to heat treatment (72 °C for 15 s of holding time) during refrigerated storage of 28 days. The results indicated that the total plate count (TPC) of raw milk at day 0 was 5.5 ± 0.6 log10 CFU/mL. At day 0, heat treatment lowered TPC to 3.9 ± 0.6, while HPP treatment was in the range of 4.1 ± 0.3 to 4.8 ± 0.6 log10 CFU/mL. Similarly, lowered yeast and mold count and lactic acid bacteria were noted in heat- and HPP-treated milk samples compared to the control sample during refrigerated storage. There were no Staphylococcus aureus and Escherichia coli detected in heat and HPP-treated samples. Heat or HPP treatment at 600 MPa for 5 min significantly extended the shelf-life of Murrah buffalo milk for three weeks at the refrigerated storage. In addition, HPP treatment did not alter the pH, lightness (L* value), protein, or fat content of Murrah buffalo milk during refrigerated storage. Hence HPP at 600 MPa for 5 min could be a suitable alternative to conventional heat treatment.

A comprehensive analysis of the effects of DGAT1 K232A polymorphism on milk production and fertility traits in Holstein Friesian and Jersey cows reared in Türkiye

Abstract. Research on the diacylglycerol acyltransferase 1 (DGAT1) K232A marker in cattle shows inconsistent results across regions, largely due to small sample sizes, limited genetic variation, and data restricted to few lactations, which complicates establishing a reliable genotype–phenotype correlation. This research aimed to determine the effect of the K232A polymorphism of the bovine DGAT1 gene on milk production and quality traits in dairy cattle. We used 1104 cattle, including 828 Holstein Friesian and 276 Jersey cows. The analysis utilized extensive data from six lactations of cows raised on four commercial dairy farms. We genotyped the population using the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) technique and Sanger sequencing for verification. We then evaluated the 305 d and test-day milk yields as well as fat and protein yields and percentages. The number of inseminations per conception and calving ease were also assessed as reproduction indices. Genotype–phenotype associations were quantified using linear mixed models. The AA genotype was absent in Jersey cows, and the heterozygous genotype was predominant in both breeds. The K232A marker was significantly associated with test-day milk yield, fat, and protein content in Jersey cows. Further, it substantially affected the fat percentage of milk in Holstein Friesian cows (p&lt;0.001). We found that the KK genotype is highly desirable for milk quality and especially fat content. This comprehensive assessment demonstrated that the KK genotype of the DGAT1 K232A polymorphism significantly influenced fat and protein contents in dairy cattle.

Comparative analysis of different methods for protein quantification in donated human milk.

Human milk is the best option for feeding newborns, especially premature infants. In the absence of breast milk, milk from a human milk bank can be a suitable alternative. However, the nutritional content of human milk may be insufficient to meet these high requirements and milk fortification is needed. To facilitate the implementation of simpler and faster analyzers in neonatal healthcare facilities, this study focuses on the concordance analysis of two different analyzers, one based on mid-infrared and the other on ultrasound, in comparison to the Bradford method for determining protein concentration in human milk. Mature milk samples from donor mothers were collected and pasteurized at the Human Milk Bank of Barcelona and protein quantification was performed using mid-infrared (MIRIS-HMA), ultrasound (MilkoScope Julie27), and the classical Bradford reference methods. The intraclass correlation coefficient (ICC) with 95% confidence interval and Bland-Altman plots were used to assess the agreement between methods. The mean protein concentration of 142 milk samples calculated using MIRIS-HMA, MilkoScope, and the Bradford assay were 1.38, 1.15, and 1.19 g/100 ml, respectively. The ICC was 0.70 for MIRIS-HMA vs. Bradford and 0.37 for MilkoScope vs. Bradford. MIRIS-HMA obtained a better agreement with the Bradford technique and is a promising method for developing new devices based on MIR transmission spectroscopy principles. This study confirms how MIRIS-HMA can be used to accurately calculate the protein concentration of human milk.

Genetic parameters for methane production, intensity, and yield predicted from milk mid-infrared spectra throughout lactation in Holstein dairy cows

Genetic selection to reduce methane (CH4) emissions is a promising solution for reducing the environmental impact of dairy cattle production. Before such a selection program can be implemented, however, it is necessary to have a better understanding of the genetic determinism of CH4 emissions and how this might influence other traits of interest. In this study, we performed a genetic analysis of 6 CH4 traits predicted from milk mid-infrared spectra. We predicted 4 CH4 traits in g/d (MeP, calculated using different prediction equations), one in g/kg of fat- and protein-corrected milk (MeI), and one in g/kg of dry matter intake (MeY). Using an external data set, we determined these prediction equations to be applicable in the range of 70 to 200 DIM. We then estimated genetic parameters in this DIM range using random regression models on a large data set of 829,025 spectra collected between January 2013 and February 2023 from 167,514 first- and second-parity Holstein cows. The 6 CH4 traits were found to be genetically stable throughout and across lactations, with average genetic correlations within a lactation ranging from 0.93 to 0.98, and those between lactations ranging from 0.92 to 0.98. All 6 CH4 traits were also found to be heritable, with average heritability ranging from 0.24 to 0.45. The average pairwise genetic correlations between the 6 CH4 traits ranged from -0.15 to 0.77, revealing that they are genetically distinct, including the 4 measurements of MeP. Of the 6 traits, 2 measures of MeP and MeI did not present antagonistic genetic correlations with milk yield, fat and protein contents, and SCS, and can probably be included in breeding goals with limited impact on other traits of interest.

Productivity and nitrogen metabolism of lactating cows fed pistachio hull with soybean meal partially replaced by slow-release urea.

Pistachio hull (PH), a rich source of tannin, may interact with nitrogen (N) and affect N metabolism in dairy cows. This investigation aimed to assess the effects of feeding PH and two N sources (soybean meal: SBM or slow-release urea: SRU) on milk production, digestibility, and N metabolism in lactating dairy cows. The study utilized a 4 × 4 Latin square design with 12 Holstein dairy cows (body weight = 611 ± 39kg; 84 ± 14 days in milk; 45.6 ± 5.3kg/d milk), with treatments arranged in a 2 × 2 factorial configuration. The main factors were (1) the tannin source [without or with dried PH included at 76.5g/kg of diet DM] and (2) two N sources [SBM vs. SRU]. Crude protein and total phenolic and tannin contents were greater, but NDF was lower in PH than in sugar beet pulp. Feeding diets containing 7.65% PH resulted in reductions in milk yield, milk urea N, and milk efficiency but milk fat and protein concentration increased. Milk yield was similar between SBM and SRU. Feeding PH in replacement to sugar beet pulp did not interact with N sources, except for feed intake, as the PH + SRU diet tended to decrease feed intake (P = 0.09). Feeding PH was also associated with decreased dry matter, crude protein, and NDF digestibility. Dry matter digestibility decreased when a portion of SBM was replaced by SRU. Feeding PH in replacement to sugar beet pulp lowered ruminal ammonia-N concentration and increased acetate-to-propionate proportion. Feeding PH vs. sugar beet pulp had no effect on N intake and N excretion in urine and milk, but it increased the amount of N excretion in feces and decreased apparent N efficiency (milk N/N intake). Alanine aminotransferase was lower in cows fed SRU only in PH- but not sugar beet pulp-containing diets. Blood creatinine was lower when SRU was included in the PH-containing diet, but the opposite was observed in diets containing sugar beet pulp. Feeding PH instead of sugar beet pulp did not affect blood urea-N but resulted in lower glucose and aspartate aminotransferase concentrations. Overall, cows fed PH in replacement to sugar beet pulp were less efficient in converting feed nutrients into milk production, likely because of its negative effect on nutrient digestion. Partial replacement of SBM with SRU had no influence on lactation productivity and urea-N concentration in milk and blood. This may imply the suitability of SRU in providing a sustained supply of N in the rumen, likely qualifying it as a viable source of N to replace a portion of SBM in dairy diets.

Effect of Cavitation and High-Temperature Nanofiltration of Ultrafiltered Skim Milk on the Functionality of Milk Protein Concentrate Powder

Both hydrodynamic cavitation (HC) and temperature elevation are important pretreatments for improving the performance of liquid food processing by reducing viscosity. In this study, we assessed the impact of HC and elevated temperature on the functionality of milk protein concentrate powder with 80% protein (MPC80) prepared from nanofiltration (NF) of ultrafiltration (UF) retentate. Skim milk was concentrated using UF, and the retentate was further subjected to HC and concentrated using NF, then spray dried to obtain MPC80 powder. The functionality of these powders processed using NF at 22 °C, NF at 50 °C, HC and NF at 22 °C, and HC and NF at 50 °C were evaluated. Rennet coagulation time of reconstituted MPC80 from different NF treatments was like skim milk when treated with 0.1% CaCl2. High-temperature NF reduced the water solubility of MPC80 powder (70.03 to 79.20%) at room temperature, but it was similar when measured at 50 °C (86.05 to 92.91%). The HC improved foaming (92.22 to 112.89%) but did not impact the emulsifying capacity (59.58 to 61.38%) and heat stability (18.04 to 20.22 min). Results showed that the HC and high-temperature NF utilized to increase the production efficiency of MPC80 also maintained the functionality of the powders after spray drying.

Pre- and postpartum metabolizable protein supply: I. Effects on feed intake, lactation performance, and metabolic markers in transition dairy cows.

The objective of this study was to investigate the effect of increasing MP supply in the prepartum, postpartum, or both diets on intake, performance, and metabolic indicators. Multiparous Holstein cows (n = 96) were assigned to 1 of 4 treatment groups at 28 d before expected calving following a randomized block design. Prepartum diets were formulated to contain either a control (C; 85 g of MP/kg DM) or high (H; 113 g of MP/kg DM) level of estimated MP. From calving to 21 DIM, diets were formulated to contain either a control (C; 104 g of MP/kg DM) or high (H; 131 g of MP/kg DM) level of estimated MP. To control the potential confounding effect of Met and Lys supply, diets were formulated to supply an equal amount at 1.24 and 3.84 g/Mcal of ME in both prepartum diets and 1.15 and 3.16 g/Mcal of ME in both postpartum diets, respectively. The combination of a pre- and postpartum diet resulted in 4 treatment groups: 1) CC (n = 23), 2) CH (n = 24), 3) HC (n = 22), and 4) HH (n = 23). A common lactation diet (113 g of MP/kg DM) was fed from 22 DIM to the end of the observation period at 42 DIM. Milk yield and DMI were collected daily, and plasma metabolic indicators (BHB, fatty acids [NEFA], urea nitrogen [PUN], and glucose) were determined twice weekly from -28 to 28 d relative to calving and once weekly from 29 to 42 DIM. Samples with BHB ≥1.2 mmol/L between 3 and 10 DIM were considered hyperketonemia events. Milk composition was determined weekly. Milk yield during 1 to 21 DIM was greater in HH (44.7 ± 1.0 kg/d) compared with CC (39.2 ± 1.0 kg/d) and HC (38.0 ± 1.0 kg/d) and milk yield in CH (42.4 ± 0.9 kg/d) was greater than HC, respectively. From 22 to 42 DIM, milk yield was greater in CH (53.3 ± 1.0 kg/d) and HH (54.1 ± 1.0 kg/d) compared with CC (49.6 ± 1.0 kg/d) and HC (49.3 ± 1.0 kg/d). Dry matter intake (% of BW) and concentrations of milk protein, fat, and total solids were not affected by treatment. Prepartum concentrations of PUN were greater in H compared with C. From 1 to 21 DIM, PUN concentrations were greater in CH and HH compared with CC and HC. From 1 to 21 DIM, glucose concentrations were lower in HH compared with HC and BHB were greater in CH and HH compared with HC. Concentrations of NEFA, as well as the number of hyperketonemia events did not differ by treatment during this time. From 22 to 42 DIM, concentrations of NEFA were greater in HH compared with HC and concentrations of BHB were greater in CH and HH compared with HC. Overall, feeding CH or HH increased lactation performance without altering intake or hyperketonemia events. Results from this study support formulating a fresh diet to reduce the negative MP balance during early lactation.

Formulation and characterisation of protein-rich custard-like soft food intended for the elderly with swallowing difficulties

Swallowing problem is prevalent in the elderly which requires high intake of protein through soft foods. This study developed protein-rich custard-type soft foods for elderly with dysphagia and evaluated the impact of milk protein content (3.9% to 8.9%) on the physicochemical properties of the formulations. Kappa-carrageenan and inulin were incorporated as a thickener and dietary fibre. Textural and rheological characteristics including viscosity, hardness, and deformation resistance, were measured using texture analyser and rheometer to compare with international standards for swallowing-friendly foods. The microstructure was visualised by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which influenced custard's ease of swallowing. Results showed that the increasing kappa-carrageenan, inulin, and milk protein content increased the gel strength, viscosity, resistance to deformation and storage stability. The swallowability of the formulations was tested using the International Dysphagia Diet Standardization Initiative's (IDDSI) fork pressure and spoon tilt tests, classifying the products as Level 6 – Soft & Bite-Sized Foods. The instrumental IDDSI fork pressure test generated reliable data to optimise formulations. The custard formulation containing 0.7% kappa-carrageenan, 2.4% inulin, and 8.9% milk protein was found to be optimal. This work provides insights for developing high-protein soft foods for the elderly with swallowing difficulties.

An agroecological approach to preparation and use of a milk protein production baseline.

Commercial dairy production occurs in a complex management environment, but increasingly, the dairy manager is expected to provide detailed reporting of productivity and environmental outcomes, for which conventional research methods double-blind crossover or case:control trials are inappropriate. This paper demonstrates the development of a milk protein production monitoring tool using a temporal (baseline) control in longitudinal, census-type investigations of modulation of system performance in response to factor change. It utilises farm-derived current and historical data, and contrasts seasonal responses with those achieved on neighbouring farms in a 2×2 contingency table. The approach is then shown to be useful in assessing the effect of two approaches to moderating milk urea concentration. Firstly, milk urea content can be monitored as it falls due to reduced feed protein content, and this fall can be arrested when milk protein content starts to decline relative to the value expected for the herd at any lactation stage. Secondly, by providing a dietary intervention aimed at increasing the availability of metabolic energy in the last month before calving, udder development can be augmented, leading to greater protein secretion capacity, meaning greater utilisation of circulating amino acids, and thus more limited substrate for urea synthesis. Thus, the changing impact of differing nutrition practices on dairy herd nitrogen excretion to environment can be followed with daily precision. In principle this approach can provide useful insights into a wide range of practical management interventions.

Investigation of near infrared and Raman fibre optic process sensors for protein determination in milk protein concentrate

This study investigated the potential of two fibre optic process sensors based on near infrared (NIR) or Raman spectroscopic technology for protein measurement in milk protein concentrate (MPC). Partial least squares (PLS) models were developed using NIR, Raman, and fusion of NIR and Raman spectra data. Calibration models developed were optimized by selecting different spectral pre-treatment methods and spectral regions. Overall, the three optimal models (NIR, Raman, fused NIR and Raman) yielded R2p values >0.9 and RMSEP values in the range of 0.168–0.185 %. The optimised fusion model outperformed all Raman models and had a similar protein prediction accuracy (R2p = 0.911 and RMSEP = 0.178 %) compared to the optimised NIR model (R2p = 0.917 and RMSEP =0.168 %). Results of the study demonstrated that both NIR and Raman process probes can be used as process analytical technology (PAT) tools for inline protein measurements of MPC post membrane filtration.

Helminth co-infections have no additive detrimental impact on milk yield and milk quality compared to mono-infections in German dairy cows

BackgroundInfections with (tricho-)strongyles, Dictyocaulus viviparus or Fasciola hepatica have been shown to reduce milk production in dairy cows. However, the current published studies focused on one single helminth infection by neglecting helminth co-infections and their possible (additive) effects on host performance. Hence, for the first time, we investigated differences in the impact of patent helminth co-infections versus mono-infections on milk production parameters in individual cows.MethodsA total of 1583 dairy cows from 27 herds were included in this study. Faecal samples were examined in 2015 and 2021/2022 to determine the number of eggs/larvae per gram faeces for (tricho-)strongyles, D. viviparus, F. hepatica and rumen flukes. The cows were classified as non-infected, mono-infected and co-infected. Linear mixed models were applied to analyse the association between infection status (non-infected vs. mono-infected vs. co-infected) with milk yield, milk protein and milk fat content by including potential confounders.ResultsInfections with (tricho-)strongyles, D. viviparus, F. hepatica and rumen flukes were detected in 100%, 28.6%, 50.0% and 21.4% of herds, and 27.4%, 2.6%, 10.8% and 0.8% of faecal samples in 2015, while 100%, 0.0%, 86.7% and 60.0% of herds and 52.3%, 0.0%, 13.3% and 26.8% of faecal samples were positive in 2021/2022. Co-infections with two or more helminth taxa were detected in 74.4% of herds and 5.0% of faecal samples in 2015, and in 93.3% of herds and 21.7% of faecal samples in 2021/2022. The correlations between strongyle EPG, D. viviparus LPG and F. hepatica EPG were significantly positive in 2015. Significantly higher mean EPGs were identified in 2015 in faecal samples presenting co-infections with F. hepatica and one or two other helminth taxa than in faecal samples presenting F. hepatica mono-infections (P = 0.013). Although expected, the infection status (mono- or co-infected) had no significant impact on milk yield, milk protein and milk fat content in the linear mixed model analyses based on individual faecal examinations.ConclusionsPatent helminth co-infections had no additive detrimental impact on milk production parameters in the present study. This might be a result of presumably low worm burdens, but should be confirmed in future studies.Graphical

Screening of mtr-miR156a from exosomes of dairy cow blood to milk and its regulatory effect on milk protein synthesis in BMECs

MicroRNA (miRNA) is a type of endogenous non-coding small RNA, which is abundant in living organisms. miRNAs play an important role in regulating gene expression and myriad cellular processes by binding to target messenger RNAs through complementary base pairing, and cross-species regulation mammalian cells by plant-derived xeno-miRNAs has been described. Here, we examined the miRNA species in two alfalfa (Medicago sativa, lucerne) cultivars commonly grown in Ningxia, China: cv. Zhongmu 1 and cv. Xinyan 52. Both cultivars have good salt and drought resistance. We found that the miRNA profiles were similar between the cultivars, with a slightly higher number of miRNAs present in the newer cv. Xinyan 52, which may contribute to its improved salt and drought tolerance. miRNAs were stable during drying, and some miRNAs were increased in dry versus fresh alfalfa, suggesting some miRNAs may be upregulated during drying. Alfalfa-derived miRNAs could be detected in exosomes from serum and whey collected from dairy cows, confirming the ability of the exogenous miRNAs (xeno-miRNAs) to enter the circulation and reach the mammary epithelium. In vitro studies confirmed that overexpression of mtr-miR156a could downregulate expression of Phosphatase 2 Regulatory Subunit B'gamma ( PPP2R5D) and Phosphoinositide-3-kinase Regulatory Subunit 2 (PIK3R2). Overexpression of mtr-miR156a also modulated PI3K–AKT–mTOR signaling as well as the casein content of milk produced by bovine mammary epithelial cells. Based on the known roles of PPP2R5D and PIK3R2 in regulating the PI3K–AKT–mTOR pathway as well as the effect of PI3K–AKT–mTOR on milk protein content, our findings implicate alfalfa-derived miR156a as a new cross-species regulator of milk quality in dairy cows.