Milk Fat Content Research Articles

A comprehensive integration of factors affecting vitamin B12 concentration in milk of Holstein cows: genetic variability, milk productivity, animal characteristics, and feeding management

Daily vitamin B12 (VB12) requirements of humans can naturally be fulfilled by animal product consumption, especially products from ruminants because of bacteria dwelling in their rumen. Indeed, only bacteria can synthesize this vitamin. Milk is hence an excellent source of VB12. This cross-sectional study was undertaken to unravel factors, such as genetic variation, diet and cow characteristics, and milk production, explaining the large variation in milk B12 concentration among cows by using an integrative approach. Milk samples from 2 consecutive milkings were collected from 3,533 Canadian Holstein cows (1,239 first, 932 s, and 1,362 third and more lactations) located in 99 herds with various feeding management. For genetic variation analysis purpose, pedigrees were traced back for 3 complete generations for each sire and dam. A total of 10,021 identities were used in the subsequent genetic analyses. Milk VB12 averaged 4.2 ng/mL with a range between 0.7 and 9.0 ng/mL. Dietary fiber (NDF from forage, dietary NDF, ADF, and lignin) increased and dietary components related to energy (non-fiber carbohydrate, starch, net energy of lactation, and percentage of concentrate) decreased VB12 in milk. Milk VB12 varied with days in milk, with a similar pattern as milk fat and protein concentration lactation curves. Milk VB12 increased as age at calving increased. When disregarding the herd variance, heritability value was 0.37, meaning that milk VB12 can be modified by genetic selection. The final model including factors related to the diet, animal characteristics and milk productivity, and genetic variation explained 79% (pseudo-R2) of the milk VB12 variation. When excluding the random effect of the cow, i.e., excluding the animal and genetic relationships, the pseudo-R2 dropped to 43%, reinforcing the importance of genetic variation in explaining milk VB12 variation. To our knowledge, the present study is the most comprehensive evaluation of factors affecting milk VB12 variation including the greatest number of cows from various lactation stages.

Impacts of Non- and Whole-fat Milk Supplementation on Metabolism-Associated Fatty Liver Disease (MAFLD) in C57BL/6 Mice

Background: Metabolism-associated fatty liver disease (MAFLD) is a widespread metabolic disease affecting 25% of the global adult population following Westernized lifestyles. Lifestyle modifications, specifically adherence to healthy dietary patterns, are pivotal in preventing and mitigating this disease. Consuming milk and dairy products is considered a cornerstone of a healthy dietary pattern, gathering significant attention due to compelling evidence from observational studies. These studies suggest that a higher intake of milk and certain dairy products is associated with a reduced risk of MAFLD. However, the relative health benefits of high- compared to lower-fat milk is a current topic of interest, with ongoing debates about their equivalency in promoting metabolic health. Aims & Hypothesis: In a MAFLD mouse model, we aim to determine the dependence of milk’s fat content on hepatic steatosis and lipid metabolic pathways by comparing whole- (WFM) to non-fat (NFM) milk supplementation in high-fat diet-fed mice (HFD). We hypothesize that both WFM and NFM will significantly improve HFD-induced hepatic lipid accumulation but via differential molecular mechanisms. Methods: Two cohorts of n=24 and n=36 6-week-old male C57BL/6 mice were acclimatized for one week, then randomly assigned to a HFD (45 kcal% fat) or a low-fat diet (LFD; 10 kcal% fat) control group. The HFD mice were randomized to either a WFM or NFM treatment of 0.425 mL milk for 8 weeks. At the end of the study, mice underwent an insulin tolerance and pyruvate tolerance test and body composition was measured. The animals were then euthanized, tissues were collected, and hepatic lipid metabolism was compared using western blot, histology, hepatic lipid assays, gas chromatography, and qPCR. Statistics were then completed using GraphPad Prism software 7.0, utilizing T-test, one-way ANOVA, and Tukey’s post-hoc tests with a p-value ≤ 0.05 considered as statistically significant. Results: Body weight gain was significantly reduced in NFM groups compared to HFD and WFM, accounted for by a significant reduction in fat mass. ITT was unaltered when corrected to baseline, but NFM groups had significantly higher PTT values when corrected to baseline. Overnight-fasted blood glucose was significantly reduced in NFM animals compared to WFM animals, suggesting an altered metabolic state between the two treatment groups. Histological results indicate a significant reduction in lipid accumulation by the NFM group compared to the HFD group (p<0.05), with WFM trending towards a similar reduction (p=0.051). Hepatic triglyceride concentrations were significantly reduced in NFM animals compared to WFM and HFD animals, suggesting a greater effect of NFM in reducing hepatic steatosis. Hepatic molecular results display an enhancement of enzymes involved in fatty acid oxidation and export pathways in the NFM group. In contrast, WFM displays an enhancement of de novo lipogenesis, fatty acid uptake, and fatty acid oxidation. Conclusion: The findings suggest that NFM may be more effective at reducing hepatic steatosis through enhanced fatty acid oxidation and export. WFM may reduce steatosis less effectively because of counteractive effects on fatty acid uptake and de novo lipogenesis versus beta-oxidation. These results provide mechanistic evidence of the protective effects of milk on MAFLD. The funding sources for this project include the Alberta Diabetes Institute Studentship Grant, CIHR Canadian Graduate Studentship, and Dairy Farmers of Canada. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Feeding rumen-protected methionine during the peripartum period improved milk fat content and reduced the culling rate of Holstein cows in a commercial herd

Researchers have reported the benefits of feeding rumen-protected methionine (RPM) during the peripartum on the health parameters of dairy cows. Rumen-protected Met has reportedly improved milk yield, milk components, and liver health, but the literature is scarce on its effects in commercial herds. Therefore, we aimed to determine the effects of feeding RPM (Smartamine M, Adisseo Inc., Antony, France) prepartum (8 g/cow per day) and postpartum (15 g/cow per day) on performance, metabolic profile, and culling rate of Holstein cows in a commercial herd. One hundred sixty-six (n = 166) Holstein cows, 58 nulliparous and 108 parous, were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPM (RPMet; 2.35% and 2.24% Met of MP for close-up and fresh cows, respectively) or without (control [CON] 2.03% and 1.89% Met of MP for close-up and fresh cows, respectively), fed from 21 ± 6 d prepartum until 16 ± 5 d postpartum. From 17 DIM until dry-off, all cows received RPMet. Daily milk yield was recorded, and milk samples were collected in the first and second weeks after calving to determine their composition. Blood samples were collected before the morning feeding on -14, -7, +1, +7, and +14 d relative to calving. Mortality and morbidity were recorded during the first 60 DIM. Cows supplemented with RPMet had greater milk yield during the first 16 DIM (31.76 vs. 30.37 kg/d; SEM = 1.04, respectively), and had greater milk fat content (4.45 vs. 4.10%; SEM = 0.11, respectively), but not milk total protein (3.47 vs. 3.39%; SEM = 0.04, respectively) and casein contents (2.74 vs. 2.66%; SEM = 0.04, respectively) than CON cows. Cows in RPMet had increased plasma Met concentrations than cows in CON (24.9 vs. 21.0 µmol/L; SEM = 1.2, respectively). Although morbidity was similar between treatments, the culling rate from calving until 60 DIM was lower for RPMet cows than for CON cows (2.4% vs. 12.1%; SEM = 0.02). In conclusion, cows receiving RPMet have greater milk yield, improved milk fat content, and a lower culling rate at 60 DIM than CON cows.

Effect of Dietary Eicosapentaenoic and Docosahexaenoic Fatty Acid Supplementation during the Last Month of Gestation on Fatty Acid Metabolism and Oxidative Status in Charolais Cows and Calves.

Fatty acids (FAs) are of utmost importance in the peripartal period for the development of the central nervous and immune systems of the newborn. The transport of polyunsaturated fatty acids (PUFAs) through the placenta is considered to be minimal in ruminants. Nevertheless, the cow's FAs are the main source of FAs for the calf during gestation. This research aimed to investigate the influence of low-dose eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation during late gestation on the FA metabolism of cows and their calves. A total of 20 Charolais cows during the last month of their gestation were included in the feeding trial and were divided into a control group (CON) and an experimental group (EPA + DHA). The latter received a supplement in the amount of 100 g/day (9.1 and 7.8 g/cow/day of EPA and DHA, respectively). Supplementation of low-dose EPA and DHA alters colostrum and milk fatty acid composition through the elevation of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) without affecting milk fat and protein concentrations and oxidative status. Plasma composition in cows was significantly altered, while the same effect was not detected in calf plasma. No significant change in mRNA expression was detected for the genes fatty acid synthase (FASN) and acetyl-CoA carboxylase alpha (ACACA).

Association between production and reproduction parameters based on parity and breed of dairy cows in the Czech Republic

Abstract. Milk production and the efficiency of dairy cow breeding are significantly influenced by reproductive factors. The purpose of our research was to examine the relationships between selected milk production and reproductive parameters. We evaluated 659 dairy cows, including 444 purebreds from the Czech Fleckvieh and Holstein breeds and 215 crossbreds. Our primary objective was to assess the impacts of breed and parity on specific milk production and reproductive parameters. The study revealed significant results regarding the interaction between certain breed groups and parity. In particular, there was a noticeable increase in milk yield with parity. Furthermore, it was also evident that the highest milk yield values were related to the milk content. Breed group H, which represents cows with a more than 50 % Holstein bloodline, had the highest values of the monitored milk content. Our findings show that first-lactation crossbred Czech Fleckvieh cows had a reduced milk yield, decreased fat, and lactose content in milk. However, they had a more favourable calving interval when compared to purebred Czech Fleckvieh and higher-parity Holstein crossbreds. Crossbred H, in comparison to C100 and C50, whether purebred or crossbred with Czech Fleckvieh, showed a relatively higher content of some milk components. The results for service periods and calving intervals were not statistically significant. The findings of this study highlight the promising potential of higher-parity Holstein crossbred cows in terms of milk yield and the advantages of lower-parity ones concerning milk contents.

Exploring the cause of reduced production responses to feeding corn dried distillers grains in lactating dairy cows

An experiment was conducted to identify the factors that cause reduced production of cows fed a diet with high content of corn distillers grains with solubles (DDGS). We hypothesized that the factors could be high sulfur (S) content in DDGS, which may directly (S toxicity) or indirectly (DCAD) cause reduced production. We also hypothesized that high PUFA in DDGS could be another major factor. In a randomized complete block design, 60 lactating cows (15 primiparous and 45 multiparous; average ± SD at the beginning of the trial: milk yield, 44.0 ± 6.9 kg/d; DIM, 123 ± 50; BW, 672 ± 82 kg) were blocked, and cows in each block were randomly assigned to 1 of the following treatments: SBM (4.7% fatty acids [FA], 0.22% S, and 178 mEq/kg DM of DCAD), a diet containing soybean meal as the main protein source; DG, with SBM replacing mainly soybean byproducts and supplemental fat with distillers grains at 30% dietary DM (4.7% FA, 0.44% S, and 42 mEq/kg DM of DCAD); SBM+S, SBM with sodium bisulfate for additional dietary S (4.8% FA, 0.37% S, and 198 mEq/kg DM of DCAD); SBM+CO, SBM with corn oil (4.7% FA, 0.23%, and 165 mEq/kg DM of DCAD); and DG+DCAD, DG with increased DCAD (4.7% FA, 0.40% S, and 330 mEq/kg DM of DCAD). Due to the limited number of tiestalls, blocks 1 to 6 started the experiment first as phase 1, and the rest of the blocks, as phase 2, started the experiment after phase 1. All cows were fed the SBM diet for 10 d as a covariate period followed by the experimental period for 35 d. Data were analyzed using PROC MIXED of SAS (Version 9.4, SAS Institute Inc.); block and phase were random effects; and treatments, repeated week, and interaction were fixed effects. We found an interaction of week by treatment for DMI. Although milk yield did not change, milk fat concentration tended to decrease (2.78% vs. 3.34%) for DG compared with SBM. Dry matter, OM, NDF, and CP digestibilities were lower when cows were fed the DG diet compared with SBM. Additionally, cows fed DG had lower blood concentrations of HCO3-, base excess, and total (t)CO2 compared with SBM. The SBM+S diet did not affect production, nutrient digestibility, or blood parameters compared with SBM. The SBM+CO diet decreased milk fat concentration and yield compared with SBM. The DG+DCAD diet tended to increase milk fat yield and concentration (1.24 vs. 1.47 kg/d; 2.78% vs. 3.37%) and increased ECM (40.9 vs. 45.1 kg/d) compared with DG but did not improve nutrient digestibility. However, blood HCO3-, base excess, and tCO2 were greater for DG+DCAD compared with DG. In conclusion, the indirect role of S-, altering DCAD, along with the high PUFA content in DDGS, appear to be the factors causing reduced production responses to a high DDGS diet. Increasing DCAD to 300 mEq/kg DM in a high DDGS diet can be a feeding strategy to alleviate reduced production responses.

Substitution of human edible feeds with integrated use of reduced fat wheat distillers and high-quality forages in a diet for high production lactating dairy cows

This study has investigated the effect of the integration of wheat distillers, without solubles, after lipid extraction (RF-DDG) in a diet based on high-quality forages in partial substitution of human-edible feeds, i.e. corn and soybean meal (SBM), on milk production and quality, feed conversion efficiency and on the human-edible feed conversion efficiency of high producing dairy cows. The experiment was conducted on a commercial dairy farm for an 8-wk period, split into 2 periods, lasting 28 d each (2-wk adaptation and 2-wk experimental period with data collection) on 180 Holstein cows (averaging 130 DIM and 42.0 kg of milk/d at the start of the trial), randomly assigned to 4 pens (45 cows each). The cows, stratified by DIM, were split in two groups assigned two diets that differed according to the human edible feed inclusion: (1) a control diet (CON), based on alfalfa silage, grass silage, high moisture ear corn silage, and soybean meal (SBM) as a protein supplement, 2) a treatment diet (TREAT), in which the control diet was modified using RF-DDG at 13.0 % (dry matter basis) to totally replace soybean meal (SBM).The dry matter intake was similar across treatments, whereas the milk yield was 2.06 kg/d lower for the TREAT diet. The inclusion of wheat RF-DDG increased the milk fat concentrations (3.74 vs 3.54 %) and decreased the milk protein concentration (3.02 vs 3.18 %), milk protein yield (1.19 vs 1.31 kg/d), and milk urea nitrogen (3.63 vs 7.61 mg/dL). Cows fed the TREAT diet showed an increased aNDFom, ADF ADL, NDIN and ADIN intake compared with those fed the CON diet. The TREAT diet resulted in a reduced milk yield as well as a reduced milk protein concentration and yield, which were likely caused by a reduction in the apparent digestibility of the protein and by different essential AA and RDP contents in the TREAT diet compared to the control DIET. The TREAT diet also decreased serum glucose, albumin, as well as the urea nitrogen and total protein in the blood, compared with the CON diet. Furthermore, the TREAT diet led to a reduction in the milk production feed conversion efficiency (in terms of milk yield/DMI and FPCM/DMI) and in the nitrogen utilization of the milk production (28.3 vs 31.0 %). The inclusion of RF-DDG led to a substantial increase in the human-edible feed conversion index for the protein (1.19 vs. 0.74) and for energy (1.66 vs 1.39), thereby improving the net protein and energy food balance. It has been concluded that further research is needed to find an economical process to extract oil from DDG without causing any further thermal stress that could compromise the protein components and amino acid supply of RF-DDG.

Localized mammary gland changes in milk composition and venous blood metabolite concentrations result from sterile subclinical mastitis

Subclinical mastitis reduces milk yield and elicits undesirable changes in milk composition, but the mechanisms resulting in reduced milk production in affected mammary glands are incompletely understood. This study investigated the effects of sterile inflammation on mammary gland metabolism by assessing changes in milk and venous blood composition. Mid-lactation primiparous Holstein cows (n = 4) had udder halves randomly allocated to treatments; quarters of 1 udder half were infused with 2 billion cfu of formalin fixed Staphylococcus aureus (FX-STAPH) and quarters of the opposite udder half infused with saline (SAL). Blood samples were collected from the right and left subcutaneous abdominal veins in 2.6 h intervals until 40 h post challenge and analyzed for blood gas and metabolite concentrations. Milk from FX-STAPH udder halves had significantly increased SCS by first milking at 8 h post-challenge. By 16 h post-challenge, FX-STAPH udder halves had increased concentrations of protein and lactate and lower lactose concentrations than SAL udder halves. Milk fat concentrations, milk yields, energy corrected milk yields, and the ferric reducing antioxidant power of milk were not significantly different between SAL and FX-STAPH udder halves. Venous blood of FX-STAPH halves had marginally greater concentrations of saturated O2, partial pressures of O2, and glucose concentrations than SAL halves. Conversely, total and partial pressures of CO2 did not differ between udder half treatments suggesting a shift in local metabolite utilization in FX-STAPH udder halves. These results indicate that changes in milk composition resulting from mastitis are accompanied by changes in some key blood metabolite concentrations. The shift in venous blood metabolite concentrations, along with the marked increase in milk lactate, suggests that local mammary tissue and/or recruited and immune cells alters metabolite usage in mammary tissues. Future studies are needed to quantify the uptake of key milk precursors during mastitis.

Estimation of udder emptying based on milk constituents of strip samples after milking

Milk ejection disorders were induced by oxytocin receptor blockade. We tested the hypothesis that the degree of udder emptying at incomplete milk ejection can be estimated based on the concentration of various milk constituents in different milk fraction samples. To induce different levels of spontaneous udder emptying (SUE) 10 Holstein dairy cows were milked either with or without i.v. injection of the oxytocin receptor blocking agent atosiban (ATO). In ATOearly, 12 µg/kg BW ATO was injected immediately before and in ATOlate directly after a 1-min manual udder preparation. The normal milking routine served as the control treatment. In all 3 treatments the udder was completely emptied by the i.v. injection of 10 IU oxytocin (OT) at the end of spontaneous milk flow. During all experimental milkings 4 milk samples were taken in all treatments: at the start of udder preparation (foremilk; FM), immediately after cessation of spontaneous milk flow and cluster detachment by hand stripping (strip milk; SM), from spontaneous removed milk in bucket 1 (milk before OT; MBOT) and from the milk obtained after OT injection in bucket 2 (milk after OT; MAOT). Fat, protein, lactose, and electrolytes (Na, Cl, and K) were measured in each milk sample. In addition, electrical conductivity (EC) was determined in parallel to continuous milk flow recording. The treatments induced individual degrees of SUE; therefore, the final evaluations of data were based on SUE classes instead of treatments. The most pronounced differences of milk constituents at different degrees of SUE were found for the milk fat content. The fat content of SM and MBOT remained almost unchanged up to 60% SUE, but was considerably higher if >80% of the milk was spontaneously removed. The concentrations of Na and Cl were highest and of K lowest if less than 20% of milk was received in the different samples. The EC was higher in SM and MBOT if <20% of milk was received. In conclusion, the blockade of the OT effect influences primarily the fat content, which confirmed an OT-induced fat secretion during milking. Similar effects are likely found in situations of disturbed milk ejections, caused by a lack of or reduced release of OT in response to different degrees of tactile udder stimulation. Our results show that the measurement of fat content and the EC in SM samples collected after cluster detachment can be used to estimate the completeness of udder emptying.

Association of different milk fat content with coronary artery disease and myocardial infarction risk: A Mendelian randomization study.

Numerous observational studies have investigated on the correlation of whole, semi-skimmed, and skimmed milk with coronary artery disease (CAD) and myocardial infarction (MI) risk; However, no consensus has been reached and evidence on any causal links between these exposures and outcomes remains unclear. This study aimed to conduct univariate and multivariate Mendelian randomization (MR) analyses, using publicly released genome-wide association study summary statistics (GWAS) from the IEU GWAS database, to ascertain the causal association of milk with various fat content with CAD and MI risk. For the exposure data, 29, 15, and 30 single-nucleotide polymorphisms for whole milk, semi-skimmed milk, and skimmed milk, respectively, obtained from 360,806 Europeans, were used as instrumental variables. CAD and MI comprised 141,217 and 395,795 samples, respectively. We used inverse variance weighted (IVW), weighted median, MR-Egger regression, and MR Pleiotropy Residual Sum and Outlier analyses to determine whether pleiotropy and heterogeneity could skew the MR results. Sensitivity tests were conducted to verify the robustness of the results. After adjusting for false discovery rates (FDR), we discovered proof that skimmed milk intake is a genetically predicted risk factor for CAD (odds ratio [OR] = 5.302; 95% confidence interval [CI] 2.261-12.432; P < 0.001; FDR-corrected P < 0.001) and MI (OR = 2.287; 95% CI 1.218-4.300; P = 0.010; FDR-corrected P = 0.009). Most sensitivity assessments yielded valid results. Multivariable MR for CAD and MI produced results consistent with those obtained using the IVW method. There was no causal relationship between whole or semi-skimmed milk, and CAD or MI. Our findings indicate that the consumption of skimmed milk may increase the risk of CAD and MI. This evidence may help inform dietary recommendations for preventing cardiovascular disease. Further studies are required to elucidate the underlying mechanisms.

Preparation of polyoxometalate modified magnetic metal–organic framework and application to the enrichment of phosphopeptides

Herein, polyoxometalate modified magnetic metal–organic framework (Fe3O4@PDA@MOF-POM) was successfully prepared and then applied to the enrichment of phosphopeptides. Fe3O4@PDA@MOF-POM can bind with phosphopeptides through ZrO clusters provided by the MOF layer and metal oxide originated from Zr-W-POM. The magnetic nanomaterial had high sensitivity (0.1 fmol), good reusability (10 cycles), and high selectivity (α-casein: β-casein: bovine serum albumin = 1: 1: 5000). Coupling with MALDI-TOF MS determination, non-fat milk was selected to preliminarily explore the applicability of Fe3O4@PDA@MOF-POM. Furthermore, 241 phosphopeptides derived from 232 phosphoproteins and 99 phosphopeptides attributed to 89 phosphoproteins were identified in human serum and saliva by nano LC-MS. This work paves a new way for the recognition of phosphopeptides in bio-samples.

Effect of fat on physicochemical, rheological, textural and sensory properties of Ricotta cheese spreads

SummaryThe effect of different fat contents of milk and cheese whey mixture (20:80) on physicochemical, rheological and sensory properties of Ricotta cheese spread (RCS) was evaluated. Four types of product such as no‐fat milk (NFM)‐RCS, low‐fat milk (LFM)‐RCS, medium‐fat milk (MFM)‐RCS and full‐fat milk (FFM)‐RCS were prepared from Ricotta cheese curd added with salt (1.5%) and guar gum (0.4%). The NFM‐RCS had higher (P &lt; 0.05) protein, ash, acidity, dynamic modulus (G' and G"), critical stress, firmness, work of shear, stickiness, work of adhesion values and lower fat, and pH, L*, a*, b* values when compared with LFM‐, MFM‐ and FFM‐RCS. Except spreadability, highest sensory scores for all other attributes were found in MFM‐RCS when compared with other experimental samples. This study indicated that increase in fat content or decrease in protein content of RCS samples produced lower viscoelastic modulus values, firmness, stickiness, adhesiveness and higher spreadability, yield, solids recovery and highly acceptable sensory characteristics.

Feeding Balanced Ration for Improving Dairy Cattle Productivity: A Review

In India and similar subtropical regions, dairy livestock primarily consume various by-products derived from locally cultivated crops, fodder, and oilseeds. Approximately 65-70 per cent of the total milk production cost is attributed to feed expenses. Ensuring a balanced diet is pivotal for the success of dairy development initiatives across India. The optimal productivity of dairy animals is achieved when they are provided with a nutritionally balanced diet that matches their genetic potential. To enhance the productivity of livestock owned by small-scale farmers, a balanced ration program was introduced. Under this program, animals are categorized based on their milk production levels: low (&lt;8 kg/day), medium (8–12 kg/day), and high (&gt;12 kg/day) yielders. The program assessed milk yield, milk fat content, and the net daily income of milk producers before and after implementing a balanced diet regimen. The nutritional assessment revealed that 71 per cent of the animals consumed excessive amounts of crude protein and metabolizable energy, while 65 per cent exhibited lower intake levels of calcium and phosphorus than required. Implementing a balanced ration resulted in an improvement in milk production ranging from 2 to 14 per cent, along with a 0.2 to 0.15 per cent increase in milk fat content.

Capsaicin as a Dietary Additive for Dairy Cows: A Meta-Analysis on Performance, Milk Composition, Digestibility, Rumen Fermentation, and Serum Metabolites.

This study aimed to evaluate the effects of dietary supplementation with capsaicin (CAP) on productive performance, milk composition, nutrient digestibility, ruminal fermentation, and serum metabolites of dairy cows using a meta-analytical approach. The database included 13 studies, from which the response variables of interest were obtained. Data were analyzed using a random effects model, and results were expressed as weighted mean differences between treatments supplemented with and without CAP. Dietary supplementation with CAP increased (p < 0.05) dry matter intake, milk yield, feed efficiency, milk fat yield, and milk fat content. However, CAP supplementation did not affect (p > 0.05) milk protein and lactose yield, milk urea nitrogen, or milk somatic cell count. Greater (p < 0.05) apparent digestibility of dry matter and crude protein was observed in response to the dietary inclusion of CAP. Likewise, supplementation with CAP increased (p < 0.05) the rumen concentration of total volatile fatty acids. In contrast, CAP supplementation did not affect (p > 0.05) ruminal pH or the ruminal concentration of ammonia nitrogen, acetate, propionate, and butyrate. In blood serum, CAP supplementation increased (p < 0.05) the glucose concentration and decreased (p < 0.05) the concentration of non-esterified fatty acids. However, CAP supplementation did not affect (p > 0.05) the serum concentration of urea and beta-hydroxybutyrate. In conclusion, capsaicin can be used as a dietary additive to improve the productive performance, milk composition, and nutrient digestibility in dairy cows and, at the same time, improve the ruminal concentration of total volatile fatty acids and serum levels of glucose and non-esterified fatty acids.

The content of aflatoxin M1 in the milk of cows from Turkish farms: the effect on milk quality and the effectiveness of mycotoxin binding by a claybased adsorbent

The aim of this study was to evaluate the concentration of aflatoxin M1 (AFM1) in milk from Holstein-Friesian cows on local farms located in two different cities in Turkey, to investigate the effect of this mycotoxin on milk quality and seasonal variation, and to investigate the efficacy of a commercial clay-based binder. As part of the study, milk samples from 144 dairy cows were analyzed for the presence of AFM1 prior to the use of a clay-based toxin binder. As a result of this analysis, 26.9% of milk samples from individual animals had AFM1 levels exceeding the U.S. permissible limit of 0.5 µg/kg. In addition, AFM1 was detected in 36.5% of winter and 18.6% of summer milk samples. The presence of AFM1 caused a decrease in milk fat, dry matter, and protein levels. The affected animals were further divided into two groups: control group (n = 14) and experimental group (n = 26). The animals of the experimental group were fed 25 g/animal of clay-based binder toxin daily. The treatment group showed a gradual decrease in AFM1 levels by 24.4% on day 4 and 48.9% on day 7. In addition, the fat, non-fat solids, and protein content of milk increased significantly. As a result, a high level of AFM1 contamination in milk was detected, which can be assumed to negatively affect the quality of milk production. The use of clay-based toxin binders may be an effective method to improve milk quality and protect animal and consumer health.

Effects of supplementing cassava root silage to grazing dairy cows on nutrient utilization, milk production and composition in the tropics.

The current study evaluated the effects of supplementing cassava root silage (CRS) to dairy cows grazing on Megathyrsus maximus cv Mombasa on nutrient intake and digestibility, as well as on milk production and composition. Ten primiparous Girolando cows with average body weight ± (SEM) of 373.45 ± (63.55) kg were used in a replicated 5 × 5 Latin square. Animals were subjected to five treatments: (I) grazing cows without supplementation (WCS); (II) grazing cows provided with 5kg DM of supplement without CRS (0g/kg DM of CRS) or including (III) 260, (IV) 520, and (V) 780g/kg DM of CRS. Statistical analyses were performed using the PROC MIXED of SAS with significance at P < 0.05. Intake of neutral detergent fiber (NDF) and ether extract decreased (P < 0.01), while intake of non-fiber carbohydrates increased (P < 0.01), with increased CRS in the diets. Total DM intake and digestibility of DM, and digestibility of nutritional components were lower (P < 0.03) in WCS animals compared to supplemented animals, except for intake and digestibility of NDF, which was the opposite. Milk yield (MY) and fat corrected milk (FCM), as well as all milk components were unaffected (P > 0.05) by CRS inclusion. In contrast, MY, FCM, protein, lactose, casein, and non-fat milk solids (NFMS) were greater for animals that received supplementation (P < 0.05), compared to animals WCS. Milk fat and total dry extract (TMS) did not differ (P > 0.11) between two groups. In conclusion, CRS may be a potential corn meal replacer in the supplement of dairy cows under tropical conditions.

Mолочна продуктивність корів західного внутрішньопородного типу української чорно-рябої молочної породи в залежності від їх генетичної структури

The analysis of milk productivity indicators of cows of the western inbred type of the Ukrainian black-spotted dairy breed was carried out, depending on the milk productivity level of their mothers. Certain features of the influence of maternal and paternal heredity on milk yield, milk fat content, reproductive capacity and duration of economic use of cows have been established. First-born cows, which come from mothers of the modal class (milk yield for 305 days of lactation in the range of 3411–5129 kg) and mothers from the group of plus variants (milk yield more than 5129 kg) prevailed in terms of the weight of peers from mothers from the group of minus variants (milk yield less than 3411 kg) by 20 % and 25 %, respectively. In the following age periods (second to fifth), due to the culling of low-yielding animals, the differences in milk yield between the cows of the experimental groups are evened out. The rate of elimination from the main herd of cows from plus-variant mothers is significantly higher than that of cows of other groups. By the fifth lactation, 91.2 % of the initial herd dropped out for various reasons, in other groups this figure was 63–67 %. Cows from the minus-variants group had the most fatty milk, the fat content in the milk during the first three lactations was 0.05–0.09 percent higher than that of other groups. The significant influence of the genotype of the parents on the level of milk yield for 305 days, the fat content in milk and the duration of the service period after the first calving in the whole herd, as well as on milk yield and the duration of the service period in the modal class and on the duration of the service period in the minus group were established

Hydroponic barley supplementation fed with high-protein diets improves the production performance of lactating dairy cows

The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 crude protein (CP) levels [16.8% and 15.5% of dry matter (DM)], with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles (DDGS)) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 d in milk, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high protein diet (16.8% CP, HP), HP with HB (HP+HB), low protein diet (15.5% CP, LP), or LP with HB (LP+HB). An interaction between CP × HB on dry matter intake (DMI) was detected, with DMI being unaffected by HB inclusion in cows fed the high CP diets, but was lower in cows fed HB when the low CP diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and milk urea N content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low protein diets. In conclusion, feeding a low protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high CP diet, but compromised cow performance with a low CP diet.

MILK COMPOSITION EVALUATION IN DIFFERENT BREEDS OF LOCAL DAIRY TYPE ANIMALS IN PUNJAB

The current study was carried out during the reign of July 2022 to June 2023 involving 1682 collected milk samples to evaluate the effect of species on milk composition including fat, protein, solid not fat (SNF) and total solids (TS) from indigenous livestock species of Punjab, Pakistan kept for milk purpose under local conditions including cow, sheep, goat and camel. The study was carried out a Livestock Production Research Institute, Bahadurnagar, Okara. The objective of current study was to investigate the effect of species on composition of milk for. For this purpose the milk samples were collected from different species and breeds within including pure Sahiwal cow, cross bred Sahiwal cow with Friesian, local non-descript cow, Lohi sheep, goat and camels maintained at different livestock experiment stations under Livestock and Dairy development department Punjab, Pakistan. Results showed lacto meter reading (LR) was highest in Lohi sheep 30.02 followed by camel 29.59, buffalo 30.15 and then cow breeds. Milk fat was highest in Lohi sheep 7.17 percent followed by camel 5.63 percent, buffalo 6.76 percent and goat 4.73 percent. Milk fat content of purebred Sahiwal, cross bred Sahiwal and local Qadirabad cow is 4.77, 4.52 and 5.19 percent respectively. Solid not fat (SNF) content was highest in Lohi sheep 8.98 percent followed by Buffalo 8.84 and camel 8.51 percent. SNF content for goat is 7.55 and for purebred Sahiwal, cross bred Sahiwal and local Qadirabad cow is 7.50, 7.28 and 7.79 respectively. Total solids (TS) was found to be highest in Lohi sheep 16.12 followed by buffalo 15.83 and then camel 13.97 and cow. The milk protein content was found to be highest for goat 4.82 percent followed by sheep 4.75, camel 3.95 and then by cow and buffalo.

Comparative Studies on the Strength and Swell Characteristics of Cohesive Soils Using Lime and Modified Enzyme-Induced Calcite Precipitation Technique

Enzyme-induced calcite precipitation (EICP) emerges as a highly effective and well-established technique within bio-cementation approaches, offering notable advantages over traditional methods. Conversely, lime, known for its accessibility, cost-effectiveness, and efficacy, serves as a valuable material in enhancing the engineering properties of problematic soils. This study explores the application of EICP and lime treatments separately on two distinct soils (low-plastic and high-plastic soil) exhibiting different mineralogical and plasticity characteristics to assess their impact on strength and swell characteristics. Various combinations of treatments, including jack bean (JICP), soya bean (SICP), and bio-enhancer (BICP), were employed for EICP treatment. Bio-enhancer, rich in natural urea and urease enzyme, was particularly remarkable due to its compatibility with urea supplementation. Similarly, jack bean and soya bean exhibited high efficacy in natural urease enzyme content. The study has revealed that the unconfined compression strength (UCS) of red soil increased significantly by six times at the end of 21 days of the curing period with JICP treatment, while lime treatment was more effective for the black soil. Specifically, the UCS of black cotton soil increased by 11 and 17 times when treated with Enzyme-Induced Calcite Precipitation (EICP) and lime, respectively. Moreover, EICP with J2 solution (jack bean solution with 1M urea and 4 g/L non-fat milk powder) reduced swell pressure by 60% and 67.5% in low-plastic and high-plastic soil, respectively. Lime treatment, on the other hand, led to a swell pressure reduction of 47% and 70% in low-plastic and high-plastic soil, respectively. As a result, EICP proved efficient in mitigating swell pressure for red soil, whereas lime treatment performed exceptionally well for black soil, highlighting the soil-specific effectiveness of each method. Furthermore, a life cycle assessment revealed substantial carbon footprint emission savings with EICP treatment strategy. In brief, this paper contributes to understanding the phenomena and significance of these two treatment techniques on distinct mineralogical soils.