Milk Protein Content Research Articles

Portable Protein and Fat Detector in Milk Based on Multi-Spectral Sensor and Machine Learning

To address the challenges of a long measurement period, high testing cost, and environmental pollution of traditional milk composition detection methods, a portable detection instrument was developed by combining multi-spectral sensors, machine learning algorithms, and an embedded system to rapidly detect the main components of milk. A broadband near-infrared (NIR) LED constant-current driver circuit and multi-spectral sensor module were designed to obtain six NIR features of milk samples. Based on a comparison of several machine learning algorithms, the XGBoost model was selected for training, and the trained model was ported to a Raspberry Pi unit for sample detection. The validation results showed that the coefficients of determination (R2) for the investigated protein and fat models were 0.9816 and 0.9978, respectively, and the corresponding mean absolute errors (MAE) were 0.0086 and 0.0079. Accurate measurement of protein and fat contents of milk can be facilitated in a short time interval by using the proposed low-cost portable instrument.

Effect of feeding Pleurotus pulmonarius-treated empty fruit bunch on nutrient digestibility and milk fatty acid profiles in goats.

This study aimed to evaluate the effect of feeding P. pulmonarius-treated empty fruit bunch (FTEFB) on the nutrient intakes, digestibility, milk yield and milk profiles of lactating Saanen goats. A total of nine lactating Saanen goats were used in an incomplete cross-over experimental design. The balanced dietary treatments contain different replacement levels of Napier grass with FTEFB at 0% (0-FT), 25% (25-FT) and 50% (50-FT). The FTEFB contained crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) at 4.10, 94.6, 70.8 and 19.4% DM, respectively. The replacement of FTEFB in 25-FT did not alter dry matter, NDF, hemicellulose, ADL, ether extract and gross energy intakes when compared to the control fed group (0-FT). The ADF and cellulose intake was higher in 25-FT than in the others (P < 0.001). The digestibility of hemicellulose, cellulose and ADL were not changed in 25-FT compared to the control group (P < 0.05) whereas when 50% FTEFB was incorporated to the diet, intermediate digestibility was decreased significantly (P < 0.05). Milk yield and protein content did not differ between the goat received 25-FT and the control group (P > 0.05). There are no differences in milk fatty profiles between dietary treatments (P > 0.05), except for OCFA. Goat fed with 25-FT had the lowest OCFA (P < 0.01) and significantly reduced the lauric acid concentration (P < 0 .05) when compared to the control group. Thus, replacement of NG in 25-FT does not adversely affect nutrient intake, fibre digestibility (cellulose and hemicellulose), milk yield, milk composition and milk fatty acid profiles. Overall, FTEFB may have potential to be used in the dairy goat diet as a roughage source to replace Napier grass.

Lactation modeling and the effects of rotational crossbreeding on milk production traits and milk-spectra-predicted enteric methane emissions

Rotational crossbreeding has not been widely studied in relation to the enteric methane emissions of dairy cows, nor has the variation in emissions during lactation been modeled. Milk infrared spectra could be used to predict proxies of methane emissions in dairy cows. Therefore, the objective of this work was to study the effects of crossbreeding on the predicted infrared proxies of methane emissions and the variation in the latter during lactation. Milk samples were taken once from 1,059 cows reared in 2 herds, and infrared spectra of the milk were used to predict milk fat (mean ± SD; 3.79 ± 0.81%) and protein (3.68 ± 0.36%) concentrations, yield (21.4 ± 1.5 g/kg dry matter intake), methane intensity (14.2 ± 2.0 g/kg corrected milk), and daily methane production (358 ± 108 g/d). Of these cows, 620 were obtained from a 3-breed (Holstein, Montbéliarde, and Viking Red) rotational mating system, and the rest were purebred Holsteins. Milk production data and methane traits were analyzed using a nonlinear model that included the fixed effects of herd, genetic group, and parity, and the 4 parameters (a, b, c, and k) of a lactation curve modeled using the Wilmink function. Milk infrared spectra were found to be useful for direct prediction of qualitative proxies, such as methane yield and intensity, but not quantitative traits, such as daily methane production, which appears to be better estimated (450 ± 125 g/d) by multiplying a measured daily milk yield by infrared-predicted methane intensity. Lactation modeling of methane traits showed daily methane production to have a zenith curve, similar to that of milk yield but with a delayed peak (53 vs. 37 d in milk), whereas methane intensity is characterized by an upward curve that increases rapidly during the first third of lactation and then slowly till the end of lactation (10.5 g/kg at 1 d in milk to 15.2 g/kg at 300 d in milk). However, lactation modeling was not useful in explaining methane yield, which is almost constant during lactation. Lastly, the methane yield and intensity of cows from 3-breed rotational crossbreeding are not greater, and their methane production is lower than that of purebred Holsteins (452 vs. 477 g/d). Given the greater longevity of crossbred cows, and their lower replacement rate, rotational crossbreeding could be a way of mitigating the environmental impact of milk production.

Effects of Hemp Seed on the Production, Fatty Acid Profile, and Antioxidant Capacity of Milk from Goats Fed Hay or a Mixed Shrubs-Grass Rangeland.

The research objective was to evaluate the effect of dietary incorporation of hemp seeds in goats fed with hay or mixed shrubs-grass rangeland on the production, FA profile and health-related lipid indices, antioxidant content and total antioxidant capacity of milk, with the purpose to increase the content of beneficial ingredients in milk and to improve its functional activity. Forty indigenous Carpathian goats were allocated into two groups according to the type of basic forage in their diet: hay (H) or mixed shrubs-grass rangeland (SG); each of them was further divided into two subgroups according to the presence of Hs in the concentrate mixture (250 g/kg) or not. Milk production was determined, and milk samples were collected and analyzed for fat, protein, lactose, and cholesterol content, as well as FA profile, lipophilic antioxidant content (α-tocopherol and retinol), and milk TAC. SG goats gave less milk (p < 0.01) but with higher milk fat (p < 0.001) and lower cholesterol content (p < 0.01) than H goats, while milk protein and lactose contents were not affected. Supplementing the diet with Hs caused a significant increase in milk production (p < 0.05) and milk fat content (p < 0.001) and a decrease in cholesterol content (p < 0.05). Grazing compared to indoor feeding but also supplementing the diet with Hs had the effect of decreasing the proportion of SFAs and increasing the concentrations of polyunsaturated FA (PUFA) in goat milk fat (p < 0.01). Fats in the milk of SG goats compared to H, but also in those supplemented with Hs, showed significantly higher proportions of vaccenic acid (VA), rumenic acid (CLA c-9,t-11) and omega-3 FA (α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA)) which are considered healthy for consumers. The feeding system based on SG and the diet supplementation with Hs ensured the best nutritional and functional quality of milk, confirmed by the FA profile, antioxidant content, and by the value of health-related lipid indices (n-6/n-3 FA ratio and hypo-/hypercholesterolemia, atherogenic index (AI), thrombogenic index (TI), and health promotion index (HPI)). The results of our work will be useful for the development of optimal nutritional strategies that improve the FA profile and the antioxidants content in goat milk, with beneficial effects on human health.

PSVIII-A-6 Effects of Feeding Ground Whole Flaxseed, Defatted Flaxseed Meal and Organic Flaxseed Meal on Production Performance, Rumen Fermentation, and Total-Tract Nutrient Digestibility in Dairy Cows

Abstract This study aimed to determine the effects of feeding ground whole flaxseed and two types of mechanically extracted flaxseed meals on dry matter intake (DMI), milk production and composition, ruminal fermentation characteristics, and total-tract nutrient digestibility in dairy cows. Twelve multiparous Holstein cows [122 ± 20 days in milk (DIM) at the start of the study] were used in a replicated 4 × 4 Latin square design with 4 dietary treatments. One square had 4 ruminally cannulated cows that were used to determine dietary effects on ruminal fermentation characteristics and total tract nutrient digestibility. The 4 dietary treatments tested were a barley silage-based diet with canola meal (CM; 21.1% of diet DM) as the main protein source (designated CON), and diets containing ground whole flaxseed (designated GWF; 4.92% of diet DM), defatted flaxseed meal (designated DFM; 19.7% of diet DM), or organic flaxseed meal (designated OFM; 20.2% of diet DM) as partial replacements for CM. The crude fat contents of CM, GWF, DFM, and OFM were 3.20, 37.7, 9.9, and 12.9% (DM basis), respectively, and experimental diets were balanced for crude fat content (4.51%; DM basis). Experimental periods consisted of 18 d of dietary adaptation and 10 d of data and sample collection. Orthogonal contrasts were used to test for the following treatment differences: CON vs. GWF; CON vs. [DFM + OFM]; and GWF vs. [DFM + OFM]. Dry matter intake was lower (P &amp;lt; 0.01) for cows fed CON compared with those fed GWF and [DFM + OFM]. Milk yield tended to be greater (P = 0.06) for cows fed CON compared with those fed GWF (P = 0.06) and [DFM + OFM] (P = 0.06). Milk fat content and yield were unaffected by diet; however, milk protein content was reduced for cows fed CON compared with those fed GWF (P = 0.001) and [DFM + OFM] (P &amp;lt; 0.001). Milk urea-N (MUN) concentration was greater (P ≤ 0.001) in cows fed CON compared with those GWF and [DFM + OFM]. Also, MUN concentration was decreased for cows fed GWF compared with those fed [DFM + OFM]. Ruminal NH3-N concentration was less (P ≤ 0.04) in cows fed CON than those fed GWF and [DFM + OFM], but ruminal pH and short-chain fatty acid concentrations were unaffected by diet. Fecal N excretion (g/d) was greater (P &amp;lt; 0.01) for cows fed CON compared with those fed GWF and [DFM + OFM] and, therefore, total-tract CP digestibility was reduced (P &amp;lt; 0.001) in cows fed CON compared with those fed GWF and [DFM + OFM]. In conclusion, partial replacement of CM with GWF or [DFM + OFM] increased DMI; however, it tended to reduce milk yield.

287 Effect of Diet Supplementation with Omega-3 Fatty Acids on Reproduction and Milk Production in Cattle

Abstract The aim was to assess the effects of omega-3 fatty acid supplementation on reproduction and milk production in cattle. Holstein cows (primiparous; n = 22], multiparous; n = 28) housed at the Kansas State University dairy were randomly assigned to two diets: omega-6:omega-3 ratio of 6:1 (Control, n = 26), or 2:1 (OMG3, n = 24), and allocated randomly into 6 pens (3 controls and 3 OMG3). Diets were isocaloric and isonitrogenous. GreatOPlus, which is an extruded feed containing flaxseed and Nannochloropsis oculata algae, was used in OMG3. Cows were milked 3x/d, and fed fed experimental diets from 15 days in milk (DIM) until ~140 DIM 1x/d. Data were analyzed using the Glimmix procedure (SAS 9.4). Body condition score was not different (P = 0.15) between Controls and OMG3 diets at –21, 0, 21, 50, 75, or 110 DIM. Multiparous OMG3 cows (60.8 ± 2.2 kg) tended (P = 0.1) to produce more milk (15 to 140 DIM) than multiparous Controls (55.6 ± 2.2 kg). Primiparous (41.5±1.7 kg) produced less (P &amp;lt; 0.01) milk than multiparous, with no difference between diets. Based on milk and blood samples from 15, 50, 75, and 110 DIM, milk protein (2.84 ± 0.34%) and fat (3.27 ± 1.08%) were not different between diets (P &amp;gt; 0.45), but plasma ratio omega-6:omega-3 was reduced (P &amp;lt; 0.001) in the OMG3 at 50, 75, and 110 DIM compared with Controls. Thus, hypothesis 1 was supported, that OMG3 would not influence milk protein or fat content but would have greater omega-3 concentration. Oocyte quality was assessed by a single oocyte harvest at 50 DIM, and number of follicles (&amp;gt; 3 mm) or recovered oocytes did not differ between diets (P &amp;gt; 0.3), but a diet-by-parity interaction was detected (P = 0.0007) for the number of grade I and II oocytes/total recovered oocytes: primiparous-Controls = 58.5 ± 8.6%; multiparous-Controls = 59.7 ± 7.9%; primiparous-OMG3 = 31.2 ± 7.8%; multiparous-OMG3 = 70.5 ± 7.5%. Cows received first and second TAI at 75 and 110 DIM, respectively, and weekly ovarian ultrasound was performed from day 11 post-TAI until day 30 to evaluate CL volume and blood flow. On day 30 post-TAI, pregnancy was diagnosed by an embryo with heartbeat. From days 30 to 60 post-TAI, pregnant cows had CL, embryo, and amniotic vesicle evaluations. Only pregnant primiparous-Controls (n = 6), primiparous-OMG3 (n = 7), and multiparous-Controls (n = 9) were compared post-TAI due to lack of representation in the multiparous-OMG3. CL volume did not differ (P &amp;gt; 0.3) among groups, but CL blood flow was less in primiparous-Controls on days 25 and 39 post-TAI. Finally, embryo and vesicle size did not differ among groups (P &amp;gt; 0.7). Thus, hypothesis 2 was partially supported, that omega-3 enhances oocyte quality and in vivo embryo development. In conclusion, omega-3 supplementation increases omega-3 in blood and enhanced oocyte and CL quality, but it is unclear if this can translate into direct benefits on embryos from day 30 to 60 of gestation.

PH-induced physiochemical and structural changes of milk proteins mixtures and its effect on foaming behavior

Milk proteins are well known to produce aerated food due to the amphiphilicity. However, milk proteins are commonly added in blends for the desirable properties in food industry. In this study, the foaming properties of milk protein mixtures (MPM), a mixtures of whey protein isolated (WPI) and milk protein concentrate (MPC), was studied through foaming capacity (FC), foam stability (FS), and foam morphology at pH 3.0–9.0. Physiochemical, structural, surface properties, and Pearson correlation analysis were measured to gain insight into foaming behavior. Results indicated that MPM showed excellent FC (113.0–114.3 %) and FS (90.7–93.0 %) at pH 6.0–9.0, and foam displayed a smaller size and uniform distribution. MPM solutions showed smaller particles, higher solubility, and lower apparent viscosity at pH 6.0–9.0, which resulted in an increase in surface pressure and adsorption rate (Kdiff), facilitating more protein absorbed to interface. To further investigate structural changes, various spectral methods were used, in which the structure of MPM was changed with pH. Correlation analysis further suggests that Kdiff and solubility positively affect the formation of foam, while free sulfhydryl and β-sheet contributed to stabilizing foams. These findings provide valuable information on MPM as ingredients for aerated foods under acidic, neutral, and alkaline conditions.

Detection of 11 carbamate pesticide residues in raw and pasteurized camel milk samples using liquid chromatography tandem mass spectrometry: Method development, method validation, and health risk assessment

This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw and pasteurized camel milk samples collected from the United Arab Emirates. A method was developed and validated by evaluating limits of detection, limits of quantitation, linearity, extraction recovery, repeatability, intermediate precision, and matrix effect. Due to the high protein and fat content in camel milk, a sample preparation step was necessary to avoid potential interference during analysis. For this purpose, 5 different liquid-liquid extraction techniques were evaluated to determine their efficiency in extracting carbamate pesticides from camel milk. The established method demonstrated high accuracy and precision. The matrix effect for all carbamate pesticides was observed to fall within the soft range, indicating its negligible effect. Remarkably, detection limits for all carbamates were as low as 0.01 μg/kg. Additionally, the coefficients of determination were >0.998, demonstrating excellent linearity. A total of 17 camel milk samples were analyzed, and only one sample was found to be free from any carbamate residues. The remaining 16 samples contained at least one carbamate residue, yet all detected concentrations were below the recommended maximum residue limits set by Codex Alimentarius and the European Union pesticide databases. Nonetheless, it is worth noting that the detected levels of ethiofencarb in 3 samples were close to the borderline of the maximum residue limit. To assess the health risk for consumers of camel milk, the hazard index values of carbofuran, carbaryl, and propoxur were calculated. The hazard index values for these 3 carbamate pesticides were all below 1, indicating that camel milk consumers are not at risk from these residues.

Relationship of body condition and milk parameters during lactation in Simmental cows in Bavaria, Germany.

In dairy cows the body condition forms a reflection of the energy reserves of the organism. Health, welfare and productivity of dairy cows are strongly associated with changes in body condition. As lactation puts substantial demands on the metabolism of dairy cows, farm management aims at avoiding either a deficient body condition or a substantial loss of body condition within a short period of time. A body condition higher or lower than recommended (over- and underconditioning in the following) compromises dairy cow productivity. While the body condition of Holstein Friesian cows has been thoroughly explored, few is known about the consequences of deviations from a target body condition for health and productivity of cows from other breeds. This study explores the percentage of over- and underconditioned cows at different days post partum [dpp] and their association with production parameters i.e., milk yield, milk fat and milk protein content of Simmental cows on Bavarian farms, categorized by parity (primi- or multiparous). Our study displays that in Simmental cows, overconditioning is more prevalent than underconditioning. While the middle of lactation (dpp = 100-199) resulted in higher percentage of overconditioning, the dry period (dpp = < 0 & > 299) indicated a higher percentage of underconditioned cows. The dry period and the middle of lactation are therefore the most challenging lactation stages for Simmental cows. We found milk protein content to have the strongest association with over- and underconditioning in Simmental cows. The probability of overconditioning was higher with higher milk protein content for every lactation stage and the probability of underconditioning was lower with higher milk protein content in every lactation stage. This study provides a theoretical basis for potential improvements in stockbreeding, which, if implemented, could improve not only the milk yield of Simmental dairy cows, but also their health and welfare.

The effect of diet restriction on raw milk stability: a meta-analytical approach.

This research communication was designed to evaluate the effects of different levels of diet restriction on the composition and ethanol stability (MES) of raw bovine milk. This research was carried out using three electronic databases: Scopus, Pubmed and Web of Science. The main inclusion criteria were: (i) original research, (ii) use of alcohol (ethanol) test as a method to assess milk stability, (iii) measure different levels of feed restriction and (iv) allow access to the raw data of articles. Of the nine publications that addressed the subject filtered by the systematic review, seven fitted the selection criteria and were selected to perform the meta-analysis. Feed restriction (reduction of 20, 30, 40 and 50% of the dietary dry matter offered) decreased (P < 0.01) milk yield (-18%), ethanol stability (-5%), acidity (-4%), protein (-3%) and lactose (-2%) concentrations, but did not affect the values of pH, density, fat and total solids concentrations, nor somatic cell count. The correlation between milk yield and MES was low but positive and numerically higher in the control group compared with the restriction group. The milk of cows fed the control diet presented greater ethanol stability (76.5%) compared with milk of cows fed the restrictive diet (72.8%). This decrease by up to 4 percentage units due to restriction levels ranging from 20 to 50% of diet intake may cause limitations in milk processing at the dairy industry, increasing milk rejection.

Age at first calving and productive performance of primiparous Holsteins.

This study investigated the age at first calving in Holstein heifers and its impact on various production parameters. A sample of 737 Holstein heifers born between 2015 and 2018 and finishing their first lactations between 2018 and 2020 was included. Cluster analysis revealed three groups based on age at first calving: high precocity, medium precocity and low precocity. Medium-precocity group exhibited the highest 305-day milk yield and peak milk production. Additionally, the same group demonstrated superior mean production per lactation, 305-day milk protein content, and 305-day milk yield. The lowest somatic cell count was found in the low-precocity group. In conclusion, medium-precocity cows showed better results such as higher 305-day milk yield and peak milk production.

Effect of ultrafiltration on the cheesemaking properties of donkey milk

The effect of ultrafiltration on the cheesemaking properties of donkey milk was assessed. Milk was coagulated by rennet with or without modification of some technological parameters, i.e., preacidification with lactic acid or EPS-producing starter, addition of small amount of bovine milk. After assessing the gross composition, the milk samples were processed and coagulation was monitored with a viscosimeter. The obtained cheeses were subjected to chemical analyses, calculation of the yield and electrophoretic characterisation of the protein profile. The results indicated that the milk protein concentration was the main limiting factor for coagulation and that pre-acidification played a minor role. The most satisfactory results were obtained for milk with added EPS-producing starter, since the cheese showed the highest yield (about 11%) and the firmest texture. The outcomes of the study could be easily transferred to the dairy level, after suitable economic evaluation.

315 Awardee Talk: Late Gestational Nutrient Restriction Alters Postnatal Nutrient Delivery and Calf pre-Weaning Growth in the Primiparous Beef Female

Abstract Nutrient requirements increase dramatically in the late gestation beef female to allow for proper growth and function of the uteroplacenta, fetus, and mammary gland. In fall- and spring-calving systems, late gestation grazing beef cattle often have limited forage nutrient availability. Late gestational nutrient restriction research generally associates decreased prenatal nutrient delivery with programming fetal growth and development, resulting in poor postnatal outcomes. However, the effects gestational nutrient partitioning may have on programming the mammary gland to decrease postnatal nutrient delivery is far less understood. In a fall-calving experiment, primiparous females were individually fed either 100% or 70% of energy and protein requirements from d 160 of gestation until parturition. Nutrient restricted females lost body weight and condition and had less nutrients in maternal circulation during late pregnancy. Calf birth weight was not affected, but nutrient restricted dams had less vigorous calves and 40% less colostrum yield. Colostrum of nutrient restricted females was more concentrated with IgG, and calf 48-h serum IgG indicated that offspring of both treatments had successful passive transfer of immunity. Colostrum of nutrient restricted females had less total lactose, but similar total protein and triglycerides compared with control females. Even when females were fed to meet their energy and protein requirements during lactation, late gestational nutrient restriction reduced milk yield by 15% and decreased milk protein concentration during the first 150 d of lactation. Reduced milk production was partially explained by a 19% reduction in blood flow supplying the mammary gland during this time. Less total lactose, protein, and triglycerides provided by the milk resulted in calf body weight diverging by 42 d of age, and calves born to nutrient restricted dams were 13% smaller at weaning. Interestingly, calf metabolic status pre-weaning was not as severely altered as expected considering milk nutrient and calf growth differences. By d 21 of lactation, metabolic status of previously nutrient restricted dams had returned to concentrations similar to control dams. During lactation, previously nutrient restricted females gained maternal weight faster and increased body condition, but had still not fully recovered to that of control females by weaning. Females were managed together and followed through their second parity to examine effects during the subsequent parity. Previously nutrient restricted dams still weighed less, were in thinner body condition, and had less mammary blood flow during their second lactation. Lactational performance and second parity calf growth were similar between treatments. While late gestational nutrient restriction may not always reduce fetal growth, our results illustrate that impaired postnatal nutrient delivery mechanisms in the cow and calf deserve continued consideration. Additionally, persisting effects in the second parity on maternal size, fleshing ability, and mammary blood flow demonstrate the possibility of long-term programming effects on the dam.

The Performance and Metabolism of Dairy Cows Receiving an Ultra-Diluted Complex in the Diet during the Transition Period and Early Lactation.

This study evaluated the effects of feeding an ultra-diluted complex to dairy cows during the transition period and early lactation. Thirty multiparous pregnant dairy cows were blocked and randomly assigned to either a placebo control (CON) group or ultra-diluted complex (UD) group. The CON group received a placebo (basal diet + 40 g/cow/day of expanded silicate), while the UD group received the ultra-diluted complex (basal diet + 40 g/cow/day of PeriParto Transição-RealH, composed of ultra-diluted substances + vehicle: expanded silicate). Cows were evaluated from 30 days before the expected calving date until 60 days in milk (DIM) for sample and data collection. Post-partum dry matter intake (DMI) was not affected by the treatment. Cows fed UD had higher DMI relative to BW. Feeding UD increased milk lactose content and decreased milk protein content. Cows fed UD had lower somatic cell counts in the third and fourth week of lactation. Cows fed UD showed a tendency for higher liver health index. Using UD during the transition period and early lactation may benefit liver and udder health of dairy cows with no detrimental effect on milk performance.

Influence of Actinidin-Induced Hydrolysis on the Functional Properties of Milk Protein and Whey Protein Concentrates.

The main aim of the study was to establish the impact of limited proteolysis by actinidin on the functionality of selected milk protein systems. The plant protease actinidin was used to produce hydrolysates (MPHs) from milk protein concentrate (MPC) and whey protein concentrate (WPC) to 0, 5, 10 or 15% of the degree of hydrolysis (DH) at an enzyme-to-substrate ratio of 1:100 (5.21 units of actinidin activity g-1 of protein). The functionalities assessed included solubility, heat stability, emulsification and foaming properties. In general, significant changes in the functionalities of MPH were associated with the extent of hydrolysis. Solubility of hydrolysates increased with increasing %DH, with WPC showing about 97% solubility at 15% DH. Emulsifying properties were negatively affected by hydrolysis, whereas heat stability was improved in the case of WPC (~25% of heat stability increased with an increase in DH to 15%). Hydrolysates from both WPC and MPC had improved foaming properties in comparison to unhydrolysed controls. These results were also supported by changes in the FTIR spectra. Further adjustment of hydrolysis parameters, processing conditions and pH control could be a promising approach to manipulate selected functionalities of MPHs obtained using actinidin.

Responses of boerka goats during transition period to low or high fat concentrate diets containing palm fatty acid distillate

This experiment was aimed to study the responses of Boerka does (Boer × Kacang crosses) during the transition period to low or high fat concentrates. Thirty nine multiparous pregnant Boerka does with average BW and BCS of 40.6 ± 5.28 kg and of 3.21 ± 0.28, respectively were used. The animals were divided into three groups (n = 13 does), and individually housed in a raised-floor pens (1.2 × 1.5 m2/doe). Each group was randomly assigned to one of three concentrate diet treatments: LFD (low fat concentrate without palm fatty acid distillate/PFAD), HSFD (high fat concentrate with saponified PFAD), and HUFD (high fat concentrate with unsaponified PFAD). Brachiaria ruziziensis was offered as forage. Diet treatments were offered along 3 weeks prior to expected parturition to 3 weeks after parturition. Data were analysed as a completely randomized design and were averaged before statistical analyses. Diet effect on DMI was detected (P = 0.01). During the prepartum period the DMI in the HSFD group was consistently greater (P = 0.01) than in the HUFD group, while the DMI in the LFD group was not different (P = 0.56) to both the HSFD and HUFD groups. At parturition and postpartum period DMI in the HUFD group was consistently lower (P = 0.01) as compared to the LFD and HSFD groups. Body weight was not affected by dietary treatments (P = 0.41). Litter weight tended to be affected by diet treatments (P = 0.08). Birth weight of twins was affected by diet treatments (P = 0.03). The ratio of litter weight/does weight at parturition was not affected by diet treatments (P = 0.49). The milk fat contents were not different (P = 0.834) among the dietary groups, but milk protein content was highest (P = 0.03) in the LFD group. Blood NEFA and BHBA were greater (P = 0.04) in the HSFD or HUFD group at week 2 and 3 postpartum, while blood glucose level was highest in the LFD group at parturition (P = 0.01). Blood insulin and thyroxin were greater in the LFD group. It is concluded that during transition period the Boerka does responded better to low-fat concentrate compared to high fat concentrates when unsaponified PFAD was used, but reponded comparably to high fat diet when saponified PFAD was used.

Use of probiotic preparations to increase productive qualities in goats: a review

An analytical review of scientific publications on probiotics in goat breeding was carried out. It has been established that the most popular probiotic microorganisms in goat farming are bacteria of the species Bacillus subtilis, Bifidobacterium bifidum, Enterococcus faecium, Lactobacillus acidophilus, Lactobacillus plantarum and single-celled yeast of the species Saccharomyces cerevisiae. Including probiotic microflora in the diet increases the number of bacteria in the rumen contents of goats. Reducing the number of Clostridia and Escherichia coli in animal faeces is achieved by replacing the native faecal microflora with streptococci and lactic acid bacteria. It has been shown that feeding probiotic preparations is accompanied by an improvement in the metabolic status in the body of goats and is expressed by an increase in the concentration of total protein and its fractions, haemoglobin, erythrocytes, macro- and microelements in the blood of animals, and optimisation of lipid metabolism. Probiotics help preserve villi and inhibit inflammation of the intestinal epithelium of animals, exhibit antimutagenic and anticarcinogenic properties, and help reduce putrescine concentration in faeces. Feeding probiotics ensures an increase in daily milk yield, fat and protein content by increasing the digestibility of diet solids, primarily crude fibre. The probiotic potential of some microorganisms is expressed in increased concentrations of unsaturated fatty acids in goat milk and meat with a decrease in the atherogenic index of raw materials. The use of drugs helps to increase the absolute increase in live weight of goat kids against the background of the harmonious development of the physique of young animals due to the production of microbial phytase, a decrease in the redox potential of chyme and an increase in the number of microorganisms that consume lactic acid. Some authors report the absence of a significant effect when using probiotics in feeding lactating animals and raising goat kids.

Влияние уровня углеводов в рационах высокопродуктивных коров на молочную продуктивность

The influence of the level of readily available carbohydrates in the diets of cows of the Kholmogorsky breed on the production efficiency and qualitative characteristics of milk has been studied. A twofold increase in the sugar-protein ratio in diets at the height of lactation contributed to an increase in milk productivity by 4,6 %. There was a significant effect (P=0,95) of an increase in the level of carbohydrates on an increase in the protein content in milk by 0,14 abs. % and the content of dry skimmed milk residue by 0,128 abs. %. The dependence on the level of sugars in the diet of cows was determined, expressed in a positive correlation of the protein content in milk at the beginning and end of the experiment (r=0,54), and the content of sugars and dry skimmed milk residue (r=0,76). When cows consume an additional amount of readily available carbohydrates, the service period is reduced by 14,9 days. The biochemical analysis of blood revealed a more intensive course of metabolic processes. The level of alpha- and gamma-globulins responsible for the formation of immunity in animals of the experimental group increased by 0,74–0,79 % compared to the control group. During the experiment, there was a pronounced tendency to increase the concentration of glucose by 10,6 %, which indicates a positive energy balance in the body of experimental animals. The additional introduction of 741 g per day of readily available carbohydrates into the diet increases the biological value of milk, has a positive effect on economic indicators. The research results show the importance of balancing diets by the level of readily available carbohydrates in order to obtain high-grade dairy products.

Streptococcus thermophilus JM905-Strain Carbon Source Utilization and Its Fermented Milk Metabolic Profile at Different Fermentation Stages.

The metabolic utilization of different carbon sources by Streptococcus thermophilus JM905(S. thermophilus JM905) was determined using a high-throughput microbial phenotyping system, and changes in fermentation characteristics of S. thermophilus JM905 fermented milk were investigated at different fermentation periods, with changes in pH, water-holding capacity, viscosity, nuisance odor, and viable bacteria count being used to define the fermentation characteristics of the strain. Changes in the key metabolites, 2-hydroxybutyric acid, folic acid, L-lactic acid, D-glycerol-D-galactose-heptanol, (R)-leucine, L-aspartic acid, L-proline, D-arginine, L-isoleucine, hydra starch, L-lysine, L-tryptophan, and D-galactose, were clarified. Correspondingly, the fermented milk protein, amino acid, and fermented milk fat quality nutrient contents were determined to be 3.78 ± 0.054 g per 100 g, 3.405 ± 0.0234 g per 100 mL, and 0.161 ± 0.0030 g per 100 g, respectively. This study addressed strain carbon source utilization, changes in fermentation characteristics and metabolites during fermentation, with the aim of investigating the link between fermentation characteristics and metabolite quality components of Streptococcus thermophilus JM905 and its fermented milk with fermentation potential and to provide a useful reference for the screening of superior fermentation strains.

Relationship between rate of glucose or propionate infusion and milk protein yield and concentration in dairy cows: A meta-regression

Although postruminal glucose infusion into dairy cows has increased milk protein yield in some past experiments, the same trend has not been observed in others. A meta-regression of 64 sets of observations from 29 previously published glucose and propionate infusion studies in dairy cattle, treating study and experiment (study) as random effects, was performed to establish the general effects of glucose equivalent (GlcE) infusion rate on milk true protein (MTP) yield and content, if any, and to identify independent, fixed-effect variables that accounted for the changes in MTP yield and content that were observed. Candidate explanatory variables included rate and site of infusion, diet composition and intake, body weight and lactation stage of the cows, and the change in nutrient intake between GlcE and control treatments. Across all studies, according to a model containing only the random effects of study and experiment, GlcE infusion at an average of 954 g/d increased MTP yield by 26 g/d, on average, whereas mean MTP content was not affected. Backward stepwise elimination of potential explanatory variables from a full mixed model produced a final, reduced model for MTP yield that retained a positive, second-order quadratic effect of infusion rate of GlcE and a positive, linear effect of the change in crude protein intake (CPI) between GlcE treatment and control. This change in CPI due to GlcE infusion ranged from -0.546 to 0.173 kg/d in the dataset. The model fit indicated that when CPI was allowed to drop during GlcE infusion, the effect of GlcE on MTP yield was smaller than when CPI was maintained or increased, in a manifestation of the classic protein:energy interaction. The final reduced model for MTP content contained the same explanatory variables as for MTP yield, plus a negative effect of intravenous compared with gastrointestinal infusion. Overall, the meta-analysis revealed that both MTP yield, and content were positively related to GlcE infusion rate and to the change in CPI between glucose treatment and control.