Milk Protein Content Research Articles

Supplementing Monosodium Glutamate in Sow Diets Enhances Reproductive Performance in Lactating Sows and Improves the Growth of Suckling Piglets.

In most current farm operations, lactating sows need to overcome reproductive and environmental stresses that have resulted in poor sow production performance and piglet growth. Therefore, this study aimed to investigate the effects of in-feed supplementation of monosodium glutamate (MSG) in sows during late gestation lactation in regard to litter performance. The study subjects were 12 multi-parity sows (Landrace × Large White), farrowing sows with an average parity of four (three with three parities, seven with four parities, and two with five parities). They were randomly divided into the following two diet groups: the basal diet as a control (CON) group based on corn and soybean meal; and the basal diet + 2% MSG group. The experimental time ranged from 109 days before delivery to 21 days after delivery. There were six sows in each group, and each sow served as the experimental unit. There were no significant differences (p > 0.05) in body weight (BW), back fat (BF) thickness and estrus interval between sows supplemented with 2% MSG in their diets before and after farrowing and during weaning (p > 0.05). However, MSG-treated sows tended to increase BW loss at farrowing more than the CON group (p = 0.093) but lost less weight during lactation than the CON group (p = 0.019). There were no significant differences in the body condition scores (BCSs) and BF loss of the two groups of sows before and after farrowing and at weaning (p > 0.05). There was no significant difference in the weight of newborn piglets between the two groups of sows (p > 0.05). The weaning weight (p = 0.020) and average daily gain (ADG) (p = 0.045) of suckling piglets were higher in the MSG treated group compared to the CON group. The daily milk production of sows in the MSG treatment group was higher compared to the CON group (p = 0.045). The protein concentration of milk at week 3 (p = 0.060) and fat concentration of milk at week 5 (p = 0.095) of the MSG-supplemented sows tended to increase more than the CON group. In summary, the dietary inclusion of MSG supplementation had a beneficial effect on the late gestating sows and their piglet's growth and milk production. Our research has shown that the addition of 2% MSG in late gestation and lactation diet would be beneficial for both sow and piglet production.

Comparing Nutritional Values and Bioactivity of Kefir from Different Types of Animal Milk.

The growing interest in fermented dairy products is due to their health-promoting properties. The use of milk kefir grains as a starter culture made it possible to obtain a product with a better nutritional and biological profile depending on the type of milk. Cow, buffalo, camel, donkey, goat, and sheep milk kefirs were prepared, and the changes in sugar, protein, and phenol content, fatty acid composition, including conjugated linoleic acids (CLAs), as well as antioxidant activity, determined by ABTS and FRAP assays, were evaluated and compared. The protein content of cow, buffalo, donkey, and sheep milk increased after 24 h of fermentation. The fatty acid profile showed a better concentration of saturated and unsaturated lipids in all fermented milks, except buffalo milk. The highest content of beneficial fatty acids, such as oleic, linoleic, and C18:2 conjugated linoleic acid, was found in the cow and sheep samples. All samples showed a better antioxidant capacity, goat milk having the highest value, with no correlation to the total phenolic content, which was highest in the buffalo sample (260.40 ± 5.50 μg GAE/mL). These findings suggested that microorganisms living symbiotically in kefir grains utilize nutrients from different types of milk with varying efficiency.

Reference Material Production and Milk Protein Concentration as Elements to Improve Bluetongue Serological Diagnosis in Bulk Tank Milk.

The serological surveillance of bluetongue in bulk tank milk is an efficient and cost-effective method for the early detection of bluetongue virus incursions in unvaccinated free areas of the disease. In addition, the availability of standardized and reliable reagents and refined diagnostic procedures with high sensitivity and specificity are essential for surveillance purposes. However, no available reference materials for bluetongue virus serological surveillance in bulk tank milk exist. This study shows the production and characterization of reference material for the implementation of a commercially available bluetongue milk ELISA test in official laboratories, as well as the evaluation of a procedure to increase the sensitivity in samples with low levels of antibodies. This procedure, based on milk protein concentration, allowed us to notably increase the ELISA test's analytical sensitivity, which is useful for milk samples from farms with low within-herd prevalence or pools of bulk tank milk samples. The standardized milk reference material produced here, together with the evaluated procedure to improve analytical sensitivity, could be applied as tools to ensure an accurate diagnosis by official laboratories in bluetongue unvaccinated free areas.

Milk protein concentrate supplementation improved appetite, metabolic parameters, adipocytokines, and body composition in dieting women with obesity: a randomized controlled trial

BackgroundDairy consumption is associated with many health benefits. However, to our knowledge, no clinical trials examined the effects of milk protein concentrate (MPC) on metabolic health in overweight and obese adults. This study investigated the effect of supplementation with MPC on glycaemic status, lipid profile, biomarkers of inflammation, and anthropometric measurements in women with obesity under a weight loss diet.MethodsThis is a single-blind, open-labelled, parallel-group, randomized trial. Forty-four healthy women with obesity were randomized into a control (n = 22) or MPC (n = 22) group. Participants in the MPC group were supplemented with 30 g of MPC per day for 8 weeks. Both groups were on a calorie-restricted diet plan with 800 Kcal lower intakes than their needs. Blood samples, dietary intake, and body composition were assessed before and after the intervention.ResultsMPC group had a significantly lower body mass index (P = 0.009), waist circumference (P = 0.013), fat mass (P = 0.021), appetite score (P = 0.002), fasting blood sugar (P < 0.001), insulin (P = 0.027), low-density lipoprotein cholesterol (P = 0.025), and leptin (P = 0.014) levels and higher high-density lipoprotein cholesterol (P = 0.001) and adiponectin (P = 0.032) compared to the control group after supplementation. Lean body mass, total cholesterol, and triglyceride did not differ significantly (P > 0.05).ConclusionDaily intake of 30 g of MPC for 8 weeks may improve several anthropometric and metabolic markers in women with obesity under a hypocaloric diet.

Food intake of breastfeeding mothers versus protein content of breastmilk in the coastal area of Bengkulu, Indonesia.

Maternal intake has a role in the composition of nutritional content, especially breast milk protein, but is rarely studied in fish producing areas (coastal). This study aimed to assess protein concentrations in human milk and evaluate their changes according to diet. The type of study was analytical observation, cross-sectional research design with a total sample of 50 from 313 breastfeeding mothers of infants 0-6 months domiciled at the Padang Serai Health Center. Dietary intake is collected using the food recall form 2 x 24 hours. Breast milk is collected in the morning as much as 30 ml using an electric breast pump. T-Test Independent analyzed the data. The results showed that as many as 10% of mothers had breast milk protein content above 0.9 g/100mL, and there was a relationship between maternal age, energy, and protein with breast milk protein content. Maternal diet, especially energy and protein, affects the protein content of breast milk. It is recommended that mothers improve their daily intake through nutritionally balanced and varied foods.

Performance in dairy cows and calves with or without cow-calf contact on pasture

Interest in dairy cow-calf contact (CCC) systems is growing, yet limited research had been focused on CCC in a pasture setting. Our study aimed to evaluate the performance of pastured dairy cows and calves with or without CCC through machine milk yield and composition, cow body condition score (BCS) and body weight (BW) decrease, and calf body weight gain (BWG). We also examined calf intake of concentrates, artificially reared calves’ milk intake, and the health of both cows and calves. Conducted on a commercial dairy freestall farm and summer farm in Norway from May to August 2021, the study included twenty cow-calf pairs: 17 Norwegian Red (NRF) and three NRF × Holstein crossbreeds. They were divided into two treatments: cow-calf contact (CC, n = 10) or early separation (ES, n = 10), each with two groups of five cow-calf pairs. CC pairs had full CCC on pasture until 6 weeks postpartum and part-time contact in weeks 7 and 8 (weaning). ES pairs were separated 1–3 h after birth, kept on separate pastures with no contact between ES cows and calves. ES calves’ received daily milk allowances of 12–14 L (weeks 0–6), reduced to 8 L (week 7) and further to 4 L (week 8). From week 9, all calves were denied access to any milk (ES) or cows (CC). During weeks 0–6, CC cows had a daily machine milk yield 23.7 kg lower/cow than ES cows. The difference was likely affected by nursing and other factors (parity and inhibited milk ejection), and persisted during weaning, with CC cows delivering 8.3 kg less/cow/day in weeks 10 and 11 postpartum. Fat and protein content in machine milk showed no significant difference, while lactose content was lower in milk from CC cows than ES cows (week 5 postpartum). CC cows had a lower BW decrease compared to ES cows (CC: 913 g/day, ES: 1415 g/day from pasture day one through week 9). ES calves had an average milk intake of 10.7 L/calf/day (weeks 0–6), and consumed more concentrates than CC calves. Calves’ daily BWG did not differ between treatments in weeks 0–6 (CC: 1340 and ES: 1250 g/day) and decreased for both treatments during weaning (CC: 1050 g/day, ES: 920 g/day in weeks 6–9). Inhibited milk ejection during machine milking was a challenge in CC cows, prompting oxytocin injections to prevent mastitis. Allowing calves full CCC or providing whole milk near ad libitum can result in similar BWG and health in calves. Further research should explore strategies to enhance milk ejection in pastured CCC cows.

Dynamics of variation of dairy characteristics in cows when using the feed additive “VivAktiv”

Relevance. Holstein dairy cattle are bred in the Sverdlovsk region, its improvement is carried out by selecting and selecting the best for further breeding. In order for them to display their genetic potential of productivity, it is necessary to ensure a balanced diet. The aim of the work was to assess the diversity of dairy characteristics in Holstein cows when using the “VivAktiv” feed additive.Methods. To conduct the study, 4 groups of calved heifers with 10 heads each were formed in a typical breeding plant for the region: a control group and three experimental ones based on the principle of pairs of analogues. The dairy productivity of cows was evaluated for the first lactation and for the calendar year by control milking once a month. The fat and protein content in milk was assessed in an average milk sample once a month from each cow. The coefficient of variability (variation) was calculated according to the generally accepted formula.Results. As a result of the conducted research, it was found that the use of the “VivAktiv” feed additive did not significantly affect the productivity of cows. The milk yield for lactation by group was 10582.3 ± 187.35, 10640.8 ± 163.89, 10293.9 ± 176.45 and 10080.1 ± 178.13 kg, respectively, the difference was unreliable and insignificant. Considering the changes in the coefficient of variation between the groups, we can note a lower variability of the trait in cows of the 2nd experimental group. The animals of the control group came in second place. The largest variety of the trait turned out to be in the 3rd experimental group. Thus, the variability of the trait is influenced by the period (month) of lactation, to some extent the duration of lactation, as well as the use of the feed additive “VivAktiv”, which had a stabilizing effect on cow yield when used at a dose of 20 g/head/day.

Study of Milk Souring Using Raman Scattering

The possibility of using Raman spectroscopy for diagnosing cow’s milk during its souring was investigated. Statistically reliable linear dependences of IR (pH) were obtained at high sensitivity. The use of the spectral range 1000-1130 cm-1 will make it possible to obtain statistically reliable linear dependences of the integral parameters of Raman scattering on the content of fat, protein and lactose in milk, as well as milk solids.

Farm-level risk factors associated with increased milk β-hydroxybutyrate and hyperketolactia prevalence on farms with automated milking systems

The objectives of this study were to determine the farm-level hyperketolactia (HKL) prevalence, as diagnosed from milk β-hydroxybutyrate (BHB) concentration, on dairy farms milking with an automatic milking system (AMS) and to describe the farm-level housing, management, and nutritional risk factors associated with increased farm-average milk BHB and the within-herd HKL prevalence in the first 45 DIM. Canadian AMS farms (n = 162; eastern Canada n = 8, Quebec n = 23, Ontario n = 75, western Canada n = 55) were visited once between April to September 2019 to record housing and herd management practices. The first test milk data for each cow under 45 DIM were collected, along with the final test of the previous lactations for all multiparous cows, from April 1, 2019 to September 30, 2020. The first test milk BHB was then used to classify each individual cow as having HKL (milk BHB ≥ 0.15 mmol/L) at the time of testing. Milk fat and protein content, milk BHB, and HKL prevalence were summarized by farm and lactation group (all, primiparous, and multiparous). During this same time period, formulated diets for dry and lactating cows, including ingredients and nutrient composition, and AMS milking data were collected. Data from the AMS were used to determine milking behaviors and milk production of each herd during the first 45 DIM. Multivariable regression models were used to associate herd-level housing, feeding management practices, and formulated nutrient composition with first test milk BHB concentrations and within-herd HKL levels separately for primiparous and multiparous cows. The within-herd HKL prevalence for all cows was 21.8%, with primiparous cows having a lower mean prevalence (12.2 ± 9.2%) than multiparous cows (26.6 ± 11.3%). Milk BHB concentration (0.095 ± 0.018 mmol/L) and HKL prevalence for primiparous cows were positively associated with formulated prepartum DMI and forage content of the dry cow diet while being negatively associated with formulated postpartum DMI, the major ingredient in the concentrate supplemented through the AMS, and the PMR-to-AMS concentrate ratio. However, multiparous cows' milk BHB concentration (0.12 ± 0.023 mmol/L) and HKL prevalence were positively associated with the length of the previous lactation, milk BHB at dry off, prepartum diet nonfiber carbohydrate content, and the major forage fed on farm, while tending to be negatively associated with feed bunk space during lactation. This is the first study to determine the farm-level risk factors associated with herd-level prevalence of HKL in AMS dairy herds, thus helping optimize management and guide diet formulation to promote the reduction of HKL prevalence.

Effect of milk stasis on mammary gland involution and the microRNA profile

The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 yr ago. To provide evidence for the existence of one or more autocrine factors, 10 multiparous cows in late lactation were quarter-milked for 7 d. Following this baseline period, the right front quarter of each cow was left unmilked, and the other quarters were milked for 7 d. Before the last milking of that period, milk (mammary secretions) was collected aseptically from both front quarters. After that milking, 250 mL of the collected samples were infused in the cows' respective rear quarters. No quarters were milked for the following 7 d (milk stasis period), and quarter milking was then resumed in all quarters for the last 7 d of the experiment (remilking period). Quarter milk samples were collected during the baseline period, before the milk stasis period, and during the remilking period. These samples were used for measuring milk components and the concentration of involution markers (SCC, BSA, and lactoferrin). Samples of mammary secretions were collected manually from the quarters during the milk stasis period for involution marker determination. We extracted RNA from samples collected from front quarters before the last milking before the milk stasis period for microRNA (miRNA) determination. As anticipated, the longer milk stasis period implemented for the right front quarter resulted in a more advanced involution than in the left front quarter, based on the concentration of involution markers in the mammary secretions, lower milk production recovery, and changes in milk composition during the remilking period. All 3 involution marker concentrations in the mammary secretions increased in both rear quarters, but were greater in the right quarter secretions than in the left quarter secretions. Resuming milking reinitiated milk production in all quarters, but milk production recovery in the right rear quarters was less robust than that in the left rear quarters (54.3 ± 1.4% vs. 61.6 ± 1.4%, respectively). Milk from the quarters infused with mammary secretions (right rear) had a lower lactose content, but a higher milk protein content and higher SCC than the quarters infused with milk. We detected a total of 359 miRNAs, 76 of which were differentially expressed in milk and mammary secretions. Expression of bta-miR-221 and bta-miR-223 was upregulated in mammary secretions 34- and 40-fold, respectively. The results of the present experiment support the contention that milk stasis leads to the accumulation of one or more factors that trigger involution. The results also indicate that milk stasis leads to changes in the miRNA profile of the milk, but whether such changes are a cause or a consequence of the involution process remains to be established.

The use of improved premix recipes in rations of cattle

Complete balanced feeding of farm animals cannot be organized without the use of various balancing additives, in particular premixes. It is important to note that the greatest eff ect from the use of premixes is observed when their recipes are developed taking into account specifi c feeding and housing conditions. The purpose of this work was to study the eff ectiveness of using improved premix recipes based on an analysis of the actual nutritional value of feed in the rations of lactating cows and calves. During the research, two experiments were carried out. The experiments were carried out at the Staraya Chigla livestock complex in the Anninsky district of the Voronezh region. In the experiment on cows, 20 animals were selected, which were divided into two groups (control and experimental) of 10 heads in each using the method of analogue pairs. In an experiment to study the eff ectiveness of the premix in feeding of young animals, two groups of calves of 12 heads in each were similarly formed. Animals of the control groups received farm rations with the premix developed without taking into account the analysis of the nutritional value of the rations. In the experimental groups, cows and calves received new and improved premixes developed based on these specific feeding conditions. The use of the premix with an improved recipe in the rations of cows made it possible to increase the average daily milk yield by 5,61 %, the fat content by 0,05 abs.% and the protein content in milk by 0,15 abs.%. At the same time, there was an increase in the level of digestibility of dry matter by 1,25 abs.%, organic matter by 1,07 abs.%, crude protein by 1,56 abs.%, crude fat by 1,63 abs.%, crude fi ber by 1,08 abs.%, nitrogen-free extractive substances by 1,87 abs.%. Calculation of feed intake for the synthesis of 1 kg of milk showed that they were lower in the experimental group by 0,31 MJ of net lactation energy and 2,97 g of digestible protein. Positive results were also obtained in experiments on calves. The use of the premix developed on the basis of the actual nutritional value of feed and rations, made it possible to increase the live weight of heifers at 12 months of age by 5,04 %, the average daily gain in live weight during the experimental period by 5,74 %, the relative gain by 1,91 abs.%.

Asparagopsis taxiformis inclusion in grass silage-based diets fed to Norwegian red dairy cows: Effects on ruminal fermentation, milk yield, and enteric methane emission

Efforts to mitigate enteric methane (CH4) emission from ruminants by using the red macroalgae Asparagopsis taxiformis (AT) have demonstrated promising results both in vitro and in vivo. We assessed the effects of wild harvested and freeze-dried AT inclusion in the grass silage-based diets of Norwegian Red dairy cows on feed intake, milk yield and composition, rumen fermentation and CH4 emission. Fifteen (9 rumen cannulated and 6 intact) multiparous cows with an average (±SD) covariate period milk yield (MY) of 33.0 (3.8) kg/day were used in the experiment. The cows were divided into three groups (n = 5) after blocking for cannulation, and initial MY. After feeding on a common diet for 21 days (i.e., Covariate period), the groups were randomly allocated to three treatments: Control (no seaweed), 0.125%AT (Control + 0.125%AT, on organic matter (OM) basis) and 0.25%AT (Control + 0.25%AT, on OM basis). The cows were adapted to their diets for 13 days, followed by 39 experimental days for data collection. Inclusion of AT at 0.125% level did not affect dry matter intake (DMI, kg/d) but signicantly reduced both MY and energy corrected milk yield (ECM, kg/d) (P < 0.05) with a tendency for lower CH4 production (g/d) relative to the control group. Dry matter intake, ECM and CH4 production were reduced (P < 0.05) by 0.25%AT inclusion relative to the Control group. Apparent total tract nutrient digestibility (%), ECM per kg DMI, CH4 yield (g CH4/kg DMI) and CH4 intensity (g CH4/kg ECM) were not affected by AT inclusion. Inclusion of AT, at both levels, significantly reduced (P < 0.05) ruminal fluid total short chain fatty acids and molar proportions of actate, while increasing (P < 0.05) the molar proportion of propionate and isovalerate. Inclusion of AT decreased contents (%) of milk fat (P = 0.018) and protein (P = 0.010) resulting in significanly lower fat and protein yields. Lactose content (%) was higher for the AT groups (P = 0.021) but this did not compensate for lower MY resulting in lower milk lactose yield. Milk iodine content increased in a dose dependent manner with AT inclusion. In conclusion, AT inclusion at 0.25% level reduced CH4 emission from dairy cows with a grass silage-based diets. However, the reduced DMI for the 0.25%AT group along with reduced MY and elevated milk iodine content for both AT groups, for this particular harvest of AT, would suggest possible constraints for large scale inclusion of AT in dairy cow production.

Effect of source and frequency of rumen-protected protein supplementation on mammary gland amino acid metabolism and nitrogen balance of dairy cattle

The AA profile of MP affects mammary gland metabolism and milk N efficiency of dairy cattle. Further, the frequency of dietary protein supplementation may influence N partitioning leading to reduced N excretion. This study investigated the effect of source and frequency of rumen-protected (RP) protein supplementation on apparent total-tract digestibility, milk production, mammary gland AA metabolism, and N balance of dairy cattle. Twenty-eight Holstein-Friesian cows (2.3 ± 0.9 lactations; 93 ± 27 DIM; mean ± SD) were used in a randomized complete block design and fed a basal TMR consisting of 41% corn silage, 32% grass silage, and 27% concentrate (DM basis) and formulated to meet 100% and 95% of net energy and MP requirements, respectively. Cows were adapted to the basal TMR in a freestall barn for 7 d, moved to individual tiestalls for 13 d of adaptation to dietary treatments, and then moved into climate respiration chambers for a 4-d measurement period. Treatments consisted of the basal TMR (CON; 159 g CP/kg DM) or the basal TMR including 1 of 3 iso-MP supplements: (1) 315-g mixture of RP soybean meal and RP rapeseed meal fed daily (ST-RPSR), (2) 384-g mixture of RP His, RP Lys, and RP Met fed daily (ST-RPAA), and (3) 768-g mixture of RP His, RP Lys, and RP Met fed every other day (OS-RPAA). The basal TMR with the addition of treatment supplements was designed to deliver 100% of required MP over a 48-h period. The mixture of His, Lys, and Met was formulated to deliver digestible AA in amounts relative to their concentration in casein. Compared with ST-RPSR, ST-RPAA increased milk protein and fat concentration, increased the arterial concentration of total His, Lys, and Met (HLM), decreased mammary clearance of HLM, and increased clearance of Phe, Leu, and Tyr (tendency for Leu and Tyr). Rumen-protected protein source did not affect N balance, but the marginal use efficiency (efficiency of transfer of RP protein supplement into milk protein) of ST-RPAA (67%) was higher than that of ST-RPSR (17%). Milk protein concentration decreased with OS-RPAA compared with ST-RPAA. Arterial concentration of HLM increased on the nonsupplemented day compared with the supplemented day with OS-RPAA, and there was no difference in arterial HLM concentration across days with ST-RPAA. Mammary uptake of HLM tended to increase on the nonsupplemented day compared with the supplemented day with OS-RPAA. Supplementation frequency of RP AA did not affect N balance or overall milk N efficiency, but the marginal use efficiency of OS-RPAA (49%) was lower compared with ST-RPAA. Overall, mammary glands responded to an increased supply of His, Lys, and Met by reducing efflux of other EAA when RP His, RP Lys, and RP Met were supplemented compared with RP plant proteins. Mammary glands increased sequestration of EAA (primarily HLM) on the nonsupplemented day with OS-RPAA, but supplementing RP AA according to a 24-h oscillating pattern did not increase N efficiency over static supplementation.

Evaluation of protocols to determine urine output and urinary urea nitrogen excretion in dairy cows with and without dietary salt supplementation

Urine output and urinary urea-N excretion (UUNe) excretion are critical measures to accurately evaluate N metabolism in lactating dairy cows and environmental concerns related to manure N. The objectives of this study were: (1) to compare estimates of UUNe, urine output, and related variables from 3 pre-established measurement protocols (bladder catheterization, external collection cup, and spot sampling) and from dietary salt supplementation, (2) to study temporal variation in UUNe, urine output, and related variables as affected by measurement protocol, and (3) to evaluate urine specific gravity as a predictor of urine output. Twelve multiparous Holstein cows were used in a split-plot, Latin square design. Cows were randomly assigned to a diet (main plot) containing either 0.7% or 1.6% NaCl (DM basis) and then assigned to a sequence of 3 protocols (subplot) in a balanced 3 × 3 Latin square with 14-d period. For each protocol, measurements were conducted every 4 h for 3 consecutive days. Urine output was determined gravimetrically for bladder catheterization and external collection cup or based on measured cow BW, measured urinary creatinine concentration, and the assumed creatinine excretion of 29 mg/kg BW per day for spot sampling. Urine specific gravity was measured by refractometry. When averaged over a 3-d measurement period and compared with bladder catheterization, spot sampling underestimated urine output (6.8 kg/d; 20%) and UUNe (26 g/d; 13%) but exhibited greater concentration of urinary urea-N (+58 mg/dL; 10%). There were no differences in any measurements determined via bladder catheterization or external cup device protocols, except for urine output that tended to be 3.7 kg/d lower for collection cup compared with bladder catheterization. The 2 gravimetric protocols yielded lower urinary creatinine concentration than spot sampling (64.7 vs. 88.1 mg/dL) and lower creatinine excretion (25.3 mg/kg BW per day) than the value of 29 mg/kg BW per day generally assumed in the spot sampling protocol. Salt supplementation tended to increase urine output (+5.2 kg/d) and decrease urinary urea-N concentration (-93 mg/dL), urinary creatinine concentration (-9.5 mg/dL), milk protein concentration (-0.19 percentage unit) and milk protein yield (-70 g/d). There was greater temporal variation of urine output when measured via the collection cup compared with bladder catheterization in the first 2 d but not the third day of sampling, suggesting that an extended period of adaptation might have improved data quality of the collection cup protocol. The R2 of the linear regression to predict urine output with urine specific gravity was 67%, 73%, and 32% for bladder catheterization, collection cup, and spot sampling, respectively. In this study, spot sampling underestimated both urine output and UUNe, but UUNe determination did not differ between external collection cup and bladder catheterization. However, our data suggested the need to investigate the adaptation protocol, required days of measurements and the conversion of urine mass to urine volume to improve accuracy and precision of urine collection protocols.

Description of Ewiss cheese, a new ewe milk cheese processed by Swiss cheese manufacturing techniques: Microbiological, physicochemical, and sensory aspects

Typically, Swiss-type cheese is made from cow milk. However, in the present work an attempt to expand the sheep supply chain and product offering in this field was made by developing a new type of cheese using Swiss-type cheese technology. The cheese was manufactured under industrial conditions, and fermentations were carried out using freeze-dried commercial starters that are traditionally used in the production of Swiss cheese. Two experimental "Ewiss cheese" (EC) products were produced using raw milk (RM) and pasteurized milk (PM), respectively. Fourteen microbial groups were investigated by plate counts from curd until ripened cheeses. According to microbiological analyses, no statistically significant differences were found between the 2 productions with respect to the group of lactic acid bacteria (LAB). The curds were mainly characterized by mesophilic LAB cocci (7.45 log10 cfu/g in RM-EC and 7.33 log10 cfu/g in PM-EC). However, at the end of the ripening period (9 mo), the cheeses exhibited a higher presence of mesophilic LAB rods. Undesired microbiological groups were found only in the curd of raw milk cheese in the range of 104 to 105 cfu/g, but they were reaching undetectable levels by plate count in the cheese at the end of ripening. The RM-EC and PM-EC were characterized by 76% and 68% of DM, respectively. These cheeses contained 29.30% and 34.36% of protein, and 51.31% and 50.38% of fat, respectively. Textural analysis showed differences in terms of hardness, chewiness, and gumminess between the experimental cheeses and Swiss cheese sold on the market. These differences could be attributed to the higher protein content of ewe milk. The main fatty acids in the cheeses were palmitic acid, myristic acid, oleic acid, and capric acid. Among the organic acids, RM-EC had higher concentrations of lactic acid, whereas PM-EC was higher in propionic acid. The ewe cheeses emitted 46 volatile compounds, including acids, aldehydes, ketones, esters, alcohols, and other compounds. The PM-EC was characterized by the main compounds of Swiss-type cheese: acetic acid, butyric acid, ethyl butyrate, ethyl caproate, propanoic acid, and tetramethylpyrazine. Sensory evaluation showed that the new dairy products were generally appreciated, and PM-EC was the most preferred by the judges. This research has enabled the development of new ewe milk products, which could stimulate the valorization of a sector that has been long neglected and still has a large margin of improvement.

Composition and fatty acid profile of milk from cows fed diets supplemented with raw and n-3 PUFA-enriched fish oil

Dietary supplementation of ruminants with fish oil is a strategy for favorably modifying the fatty acid composition of milk fat. This study investigated the effect of supplementing cows’ diet with fish oil after low-temperature crystallisation (LTC-FO) compared to its raw form (FO) on milk yield, milk components (fat, protein, and lactose), and milk fatty acid profile. Twenty-four mid-lactating multiparous Polish Holstein–Friesian cows fed a total-mix ration were randomly assigned to two homogeneous groups (n = 12 cows each) and supplemented with LTC-FO or FO at 1% of dry matter. Milk samples were collected on days 14 and 30 of the 30-day experiment. No significant differences between the groups in terms of milk yield, milk protein, and lactose content were found, however, the fat yield and content decreased in the LTC-FO group. Milk fat from cows in the LTC-FO group contained significantly higher levels of C18:1 trans-11, C18:2 cis-9, trans-11, C18:3n − 3, C20:5, and C22:6, and lower levels of saturated fatty acids compared to the FO group (p < 0.05). Therefore, LTC-FO may be a more efficient feed additive than FO and may serve as a practical way to modify the fatty acid composition of milk fat.

Effect of pH and Shear on Heat-Induced Changes in Milk Protein Concentrate Suspensions.

The effect of shear on heat-induced changes in milk protein concentrate suspensions was examined at different pH levels, revealing novel insights into micellar dissociation and protein aggregation dynamics. Milk protein concentrate suspensions, adjusted to pH of 6.1, 6.4, 6.8, or 7.5, underwent combined heat (90 °C for 5 min or 121 °C for 2.6 min) and shear (0, 100, or 1000 s-1) treatment. The fragmentation of protein aggregates induced by shear was evident in the control MPC suspensions at pH 6.8, irrespective of the temperature. At pH 7.5, shear increased the heat-induced micellar dissociation. This effect was particularly pronounced at 121 °C and 1000 s-1, resulting in reduced particle size and an elevated concentration of κ-casein (κ-CN) in the non-sedimentable phase. At pH 6.1 or 6.4, shear effects were dependent on sample pH, thereby modifying electrostatic interactions and the extent of whey protein association with the micelles. At pH 6.1, shear promoted heat-induced aggregation, evidenced by an increase in particle size and a significant decline in both whey proteins and caseins in the non-sedimentable phase. At pH 6.4, shear-induced fragmentation of aggregates was observed, prominently due to comparatively higher electrostatic repulsions and fewer protein interactions. The influence of shear on heat-induced changes was considerably impacted by initial pH.

97 Effects of crude protein content and supplementing probiotics in late gestation and lactation sow diets on performance of sows and suckling pigs

Abstract The objective of this study was to investigate the effects of crude protein (CP) content and supplementation with Bacillus-based probiotics (PRO) in late gestation and lactation sow diets on performance of sows and suckling pigs. Pregnant sows (n = 120; 60 gilts and 60 2+ parity) were assigned to 4 dietary treatments in a 2 x 2 factorial arrangement (2 CP levels, with or without probiotics) from d 85 of gestation to d 21 of lactation. The experiment was conducted in 4 consecutive periods (half sows and half gilts per period). The diets consisted of 1) a corn-soybean meal (SBM)-based low CP (LCP; 12% CP) diet; 2) LCP + 0.05% probiotic (LCP-PRO); 3) a corn-SBM-based high CP (HCP; 15% CP) diet; and 4) HCP + 0.05% probiotic (HCP-PRO). The diets were formulated for 2 phases: gestation (d 85 – 115) and lactation (d 1 – 21). Sow body weight (BW) and backfat thickness were recorded on d 85 and 111 of gestation and on d 1 and 21 of lactation. Sow blood and milk were sampled on d 1 and 21 of lactation to analyze plasma urea nitrogen (PUN) concentration, and milk fat, protein, and lactose, respectively. Data were analyzed using the PROC MIXED of SAS. The statistical model included diet as fixed effect and period as random effect. There were no significant effects of CP and PRO on sow BW or backfat thickness. There was an interaction (P &amp;lt; 0.05) between CP and PRO on the number of stillbirths, where the number of stillbirths did not differ between LCP and LCP-PRO groups, while the number decreased in sows fed HCP-PRO diet compared with HCP diet. Sows fed LCP diets had reduced (P &amp;lt; 0.05) PUN concentrations on d 1 and d 21 of lactation compared with those fed HCP diets. However, no difference was found in fat, protein, or lactose content in both colostrum (d 1) and milk (d 21). Piglets from the sows fed LCP diets showed heavier (P &amp;lt; 0.05) birth weights (1.58, 1.57, 1.53, and 1.52 kg for diets 1 to 4) than those in HCP groups, however, the average daily gain (ADG) of week 1 (188, 166, 187, and 187 g for diets 1 to 4) was less (P &amp;lt; 0.05) for piglets in LCP groups than HCP groups. No other effects were observed on piglet growth. In conclusion, CP and PRO did not affect sow BW and backfat thickness. There was an interaction effect of CP and PRO on reproductive performance, where stillbirths did not differ between LCP and LCP-PRO groups; however, stillbirths decreased with PRO in HCP diet. Moreover, feeding LCP diets to sows did not influence milk nutrient contents and overall growth performance in suckling piglets.

PSV-9 Effects of increasing amounts of high-oleic or conventional soybeans in diets fed to mid-lactation dairy cows on measures of dry matter intake and lactation

Abstract The objective of the study was to determine effects of increasing amounts of conventional (CONV) or high-oleic (HO) soybean in diets fed to mid-lactation dairy cows on dry matter intake (DMI) and performance. Rumen and duodenally cannulated cows (n = 8) were split into two groups and placed in a split-plot design. The whole plot factor was type of soybean (CONV vs. HO) and was provided to cows in a crossover arrangement so that each cow was provided both types of soybeans throughout the experiment. The subplot factor was amount of soybeans (0, 4, 8, 12%). Each group of cows receiving the same type of soybean were placed in a 4 x 4 Latin square with treatment sequences balanced for carryover effects. Diets were formulated to contain 18.5% crude protein and to slightly exceed requirements for ruminally degradable protein. Additions of soybeans replaced soybean meal and soybean hulls so that diets provided similar amounts of soy-based protein and fiber. During the last 4 d of each 14-d period, spot samples of feed, orts, and milk were collected together with measures of milk production and feed intake. Data were analyzed using the MIXED procedure of SAS. There were no interactions of soybean type and amount on lactation or DMI except for measures of milkfat, milk energy concentration and milkfat yield. Increasing amounts of HO resulted in a quadratic response in milkfat and energy concentration together with measures of milkfat yield. Specifically, these measures were greater (P ≤ 0.02) when cows were fed diets containing 4 and 8% HO compared with diets containing 0 or 12% HO; increasing amounts of CONV had no impact (P ≥ 0.32) on milkfat and energy concentration or milkfat yield. Measures of milk yield were not affected by type or amount of soybean (P ≥ 0.54), but measures of energy corrected milk yield (ECM) tended to respond differently to increasing amounts of soybean from either CONV or HO (P = 0.07). Interestingly, ECM responded quadratically (P = 0.02) to increasing amounts of HO but not to increasing amounts of CONV (P ≥ 0.58). Overall, however, ECM tended (P = 0.06) to be slightly greater with HO compared with CONV (42.5 vs. 41.1 kg/d). Yet, DMI was also greater (P ≤ 0.01) with HO compared with CONV (26.6 vs. 24.4 kg/d). Differences in DMI, therefore, resulted in a tendency (P = 0.07) for greater efficiency of ECM production when cows were fed CONV vs. HO. Overall, treatments had no effect on measures of milk protein, urea-nitrogen, solids-not-fat or lactose concentrations or yields. These data seem to indicate that performance responses among lactating cows to increasing amounts of HO are dynamic but that responses to CONV are not.

Dairy goat performance in two grazing regimes: silvopastoral rangeland or abandoned agricultural land, and two supplementation treatments in central Mexico.

Twenty Saanen third parturition dairy goats were used in an on-farm 2 × 2 factorial arrangement that ran for 12 weeks, with two grazing regimes and two concentrate types. The grazing regimes evaluated were an extensive silvopastoral native rangeland (SPR) and grazing in an abandoned agricultural land (AAL). Grazing happened between 9:00 and 17:00h. The two types of concentrate supplement were a high protein concentrate (HP = 180g CP/kg DM and 13MJ ME/kg DM) or high energy concentrate (HE = 110 g CP/kg DM and 14.3MJ ME/kg DM). Goats were milked once a day, providing 250g of concentrate supplement per goat and day. Animal variables were fat and protein corrected milk yield recorded every day, and milk composition determined for two consecutive days at the end of each experimental week. Flora in the experimental paddocks was characerised and sampled, including grasses, shrubs, trees, legumes and cacti. The data was analysed with the R software using a mixed model with day nested in period as random effect and goat as repeated measure. The SPR had greater (P = 0.002) fat and protein corrected milk yield than AAL, with no differences between concentrate type and no interaction (P > 0.05). There was an interaction (P < 0.01) between grazing regime and concentrate type for fat content in milk, where a reduction in fat content was notorious in the SPR regime. Protein content of milk was greater (P < 0.01) in SPR with no significant effects of concentrate type or the interaction. The number of plant species in SPR was greater. The native silvopastoral system supplemented with the high energy concentrate was the strategy with higher milk yield, and protein and milk fat content, although the interaction between grazing regime and supplement was significant only for milk fat content.