Milk Fat Content Research Articles

Quality of raw cow’s milk intended for processing and retail sale from Eastern Poland

The study assessed the quality of raw cow’s milk intended for processing and retail sale (n = 595 samples and n = 19 production batches, respectively) and the relationship between the number of somatic cell and the fat and protein contents. All milk samples were tested for total bacteria count, somatic cell count, antibiotic residues, and fat and protein contents. Additionally, raw drinking milk samples were tested for counts of Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci, enterococci, and the presence of Listeria monocytogenes and Salmonella spp. In raw milk samples, TBC, SCC, and fat and protein contents ranged from 4.9 × 103 to 2.3 × 105 CFU mL–1, from 9.9 to 407.8 thou. mL–1, from 3.2% to 5.9% and from 3.0% to 4.8%, respectively, while TBC, SCC, and fat and protein contents in raw drinking milk samples ranged from 1.8 × 106 to 3.3 × 106 CFU mL–1, from 454 to 696.9 thou. mL–1, from 1.67% to 2.88% and from 3.11% to 3.41%, respectively. The mean counts of Enterobacteriaceae, E. coli, coagulase-positive staphylococci, enterococci in raw drinking milk were 4.0 × 105 CFU mL–1, 1.4 × 102 CFU mL–1, 2.4 × 104 CFU mL–1, and 2.2 × 105 CFU mL–1, respectively. L. monocytogenes, Salmonella spp., and antibiotic residues were not detected in any of the samples tested. The study showed that 95% of the raw milk samples were of satisfactory quality, while 100% of the raw drinking milk samples were of unsatisfactory quality in relation to the regulatory thresholds. Additionally, raw drinking milk samples were a vehicle of potentially pathogenic bacteria. The somatic cell count did not affect the fat and protein content in the analysed milk.

Supplementing a Bacillus-based direct-fed microbial improves feed efficiency in lactating dairy cows.

This experiment was conducted to evaluate the effects of feeding a Bacillus-based direct-fed microbial (DFM) on performance and nutrient digestibility of lactating dairy cows. Seventy-six lactating (42 ± 6 days in milk[DIM]) Holstein-Friesian primiparous and multiparous cows were enrolled to a 16-wk experiment. Cows were blocked by lactation number and DIM and within blocks, assigned to 1 of the 2 treatments: 1) basal partial-mixed ration (PMR) without DFM addition (n = 38; CON) or 2) basal PMR with the addition of 3g/head/d of a DFM containing B. licheniformis 809 and B. subtilis 810 (n = 38; BOVACILLUS, Chr. Hansen A/S, Hørsholm, Denmark; DFM). The DFM was mixed in a protein-based pellet, whereas the CON group was fed the same pellet without DFM (0.6kg/cow/d). The PMR contained (dry matter [DM] basis) 50% of forage and 48% of a concentrate feed based on corn meal, soybean meal, wheat meal, wheat middlings, and a mineral-vitamin premix, with the remaining part of the diet being represented by the pellet used as a carrier for the treatments (CON and DFM). Dry matter intake (DMI), milk yield, and production efficiency were recorded daily, whereas milk protein and fat concentrations were recorded using electronic milk meters. An additional milk sample was collected every second week of the study for milk composition. On week 15 of the study, fecal samples were collected from each cow for apparent nutrient digestibility calculation. All data were analyzed using the MIXED procedure of SAS (version 9.4; SAS Inst. Inc., Cary, NC). No treatment effects were observed on cow final body weight, daily DMI, milk yield, energy-corrected milk (ECM), ECM efficiency, milk composition (yield or content), and somatic cell count (SCC) (P ≥ 0.12). However, cows fed DFM had a greater feed and N efficiency (P ≤ 0.03) compared to cows fed CON. Moreover, DM digestibility tended to be greater for DFM-fed cows when compared to CON (P = 0.10), whereas no further nutrient digestibility differences were observed (P ≥ 0.24). In summary, supplementing a DFM containing Bacillus licheniformis and B. subtilis benefited feed efficiency of lactating dairy cows fed a PMR, while also tending to improve the digestibility of DM.

The effect of reducing starch bioavailability using organic acids on rumen fermentation and ruminant performance: A meta-analysis

Starch is an important nutrient in ruminants as an energy source. Utilizing organic acids to reduce starch bioavailability offers a safer approach to sustainable ruminant health and productivity. However, the inconsistent results obtained from published studies necessitate integration through meta-analysis to determine the actual effects. This study aimed to evaluate the effect of reducing starch bioavailability using organic acids on rumen fermentation and ruminant performance by meta-analysis. Hedges’ meta-analysis was conducted by using a random effect. A total of 14 articles were selected from the Scopus platform, with 23 comparative studies. This meta-analysis revealed that starch modification using organic acids influenced rumen fermentation. In vitro studies demonstrated a significant increase (p<0.01) in rumen pH and a reduction in ammonia (NH3) and total volatile fatty acids (VFA) levels (p<0.01). Partial VFA components, including butyrate, iso-butyrate, valerate, and iso-valerate, also showed significant decreases (p<0.01). Total protozoa also obtained a significant decrease (p<0.001). Moreover, in vivo trials indicated ruminant performance with increased milk fat content (p<0.05). In conclusion, the intervention of organic acids for reducing the bioavailability starch in rumen is effectively optimizes rumen health by maintaining fermented products within the normal range and increasing ruminant productivity.

Synbiotic Soygurt Tempe Extract as A Functional Drink for Stunting Prevention

Stunting is a chronic malnutrition problem caused by insufficient nutritional intake for a long time due to the provision of food that does not meet nutritional needs. Toddlers with stunting are a chronic nutritional problem which can be caused by many factors, socioeconomic conditions, maternal nutrition during pregnancy, illness in infants, and lack of nutritional intake in infants. Synbiotics (prebiotics and probiotics) as an effective alternative for stunting Analyzing the effectiveness of prebiotic tempeh soyghurt as a functional drink for stunting prevention. The research method is an experimental research including fermenting prebiotic tempeh and prebiotic tempe extract, making prebiotic tempeh soygurt, and analyzing the nutritional content and product quality of probiotic tempeh soygurt referring to SNI 7552:2009 concerning flavored fermented milk including chemical physics analysis, namely the hedonic method organoleptic test, pH, acidity, protein, fat, ash content, fiber, water content and microbiological tests, namely MPN coliform and Salmonella sp. Data analysis used bivariate and multivariate Anova tests. Organoleptic test results for prebiotic soygurt extract of tempeh product with the addition of chitosan (0.5%; 1.0%; 1.5%; 2.0%) using lactic acid bacteria (LAB) inoculum in the rather dislike category (value 3.00) to rather like (value 4.50) . Physical test results showed liquid texture, yellowish color, aroma of tempeh extract, sour taste. Chemical test results (w/b) fat content 3.34%; milk solids 13.19%, non-fat milk solids 9.25%; proteins 0.69%; ash content 0.19%, acidity 0.69% and sugar content 0.59%. Microbiological tests showed MPN coliform &lt;3 cells/100 ml sample and Salmonella sp/25 ml negative results. CONCLUSION: Soygurt extract tempe prebiotic product meets the physical, chemical and microbiological requirements so that it can function as a functional drink for stunting prevention can be concluded that the accuracy of measuring body weight depends on gender.

INFLUENCE OF CALVING SEASON OF COWS ON THEIR PRODUCTIVITY UNDER ORGANIC AND CONVENTIONAL MILK PRODUCTION

The aim of the research was to study the impact of the first calving season of Simmental cows on their future milk productivity and reproductive capacity in conditions of both organic and conventional milk production.&#x0D; Research materials and methods. The research was conducted in Simmental breed herds of PE "Galex-Agro" (organic milk production, n = 272) and STOV "Myroslavel-Agro" (conventional milk production, n = 120) in the Zviahel district of Zhytomyr region, Ukraine. First-calving cows in the two farms were categorized into four groups based on the calving season: Group I – Winter (n = 83 and 42 cows in PE "Galex-Agro" and STOV "Myroslavel-Agro" respectively); Group II – Spring (59 and 26);Group III (45 and 12); Group IV (85 and 40 cows).&#x0D; Research results. First-calving cows in organic production demonstrated a higher expression of quantitative traits of milk productivity, regardless of the calving season, compared to their counterparts in conventional conditions, albeit with slightly lower qualitative traits. However, statistically significant differences were found only in 305-day milk yield between autumn-calving cows in favor of first-calving cows from PE "Galex-Agro."&#x0D; It is worth noting that, in both farms, the first calving in the autumn season was found to be the most favorable, while the summer season was the least favorable, which provides grounds for planning calving in the autumn period. Our research results indicate that animals under organic management, regardless of the calving season, exhibited statistically significantly (P &lt; 0.01–0.001) older age at first calving and longer calving intervals. No statistically significant intergroup differences were found in other reproductive traits.&#x0D; The season of first calving in both organic and conventional milk production conditions accounted for 0.3 to 4.7% and 0.2 to 3.3% of the total phenotypic variability in milk productivity traits, as well as 1.0 to 2.9% and 0.6 to 2.5% of the reproductive capacity. Statistically significant effects of the calving season were only observed in PE "Galex-Agro" and exclusively on productivity traits, including lactation duration (3.2%), 305-day milk yield (4.3%), milk fat content (4.7%), milk protein content (4.3%), milk fat, and protein content (4.7%), as well as the duration of dry period (2.9%) (P &lt; 0.05–0.001).&#x0D; Conclusion. Our research results highlight the importance for specialists in both farms to pay attention to the seasonality of first calving in cows and, if possible, take these aspects into account when planning breeding and technological measures in the farms.

MILK PRODUCTIVITY OF COWS OF THE UKRAINIAN RED-AND-WHITE DAIRY BREED DEPENDS ON THE ORIGIN AND COMPATIBILITY OF THE BULLS

We studied the effectiveness of the bulls selection to the cows of the Ukrainian Red-and-White dairy breed (n = 490 mother-daughter pairs) different bloodlines and related groups. The level of milk productivity of first-borns cows (n = 490 mother-daughter pairs) for 305 days of the first lactation, obtained as a result of the compatibility of the bulls. The parents of the first-borns cows were four breeding bulls (bloodline Regal 352882, RG Valiant 1650414 and R. Sovereign 198998) of the Ukrainian Red-and-White dairy breed and one bull (Jornado Red 114386106, RG Chief 1427381) of the Holstein breed, and their mothers – from 11 bulls of three origin bloodlines (Dynemik 359742, Leader 1926780 and Hanover 1629391) and 4 related groups. A total of 29 combinations of interbloodline selection were investigated. The highest level of milk productivity was characterized by the daughters of bull Viter 4444 of the bloodline Regal 352882 (7191.5 ± 75.90), Jornado Red 114386106 of the Holstein breed of foreign selection, which belonged to the related group Chief 1427381 (the milk yield for 305 days of the first lactation was 7188.7 ± 31.05 kg), and Artek 344 related group Valiant 1650414 (the yield for 305 days of the first lactation was 7052.5 ± 75.51 kg). A statistically significant difference was established between milk yield indicators for 305 days of the first lactation between the groups of cows of the bull Jornado Red (related group Chief 14273381) and Luchnov 471 (r. g. R. Sovereign 198998) – +380 kg (td = 4.22 p &lt; 0.001) in favor Jornado Red. Between cows of the bull Viter 4444 (bloodline Regal 352882) and Luchnov 471 (R. Sovereign 198998) – +383 kg (td = 3.38 p &lt; 0.001) in favor of Viter 4444. Animals of the bulls Kanzler and Viter 4444 have the highest fat content in milk (3.71%), and cows of the related groups Valiant 1650414 characterized by the lowest fat content in milk (3.68%). A statistically significant difference was established between the amount of total milk fat and protein in the milk of cows of different bulls.&#x0D; A total 20 successful combinations of bulls were found, the first-borns cows of which were characterized by an increased milk yield on average across all successful compatibility by +96 kg (1.5%), milk fat yield – by +6,1 kg (2.3%) and total protein – by +5.3 kg (2.3%) from the average level of phenotypic manifestation of milk productivity traits of the daughters of all 5 evaluated bulls. The increasing of daughters milk yield of some successful combinations was from +42 kg (0.6%, sire Jornado 114386106 RG Chief 1427381) up to +296 kg (4.1%, sire Viter 4444,), milk fat from +2 kg (0.7%, sire Artek 344, RG Valiant) up to +8 kg (3%, sire Viter 4444) and protein from +1 kg (0.4%, sire Artek 344) up to +12 kg (5%, sire Viter 4444). The data, which we received, confirm the influence of the origin of cows by father on the level of their milk productivity and the high combining ability of individual improver bulls with the mothers of other genealogical formations.

CHARACTERISTICS THE OFFSPRING OF SIRES BY LONGEVITY TRAITS OF THE HERD FOR BREEDING UKRAINIAN BLACK-AND-WHITE DAIRY BREED

Based on studies of the offspring of sires in a herd for breeding the Ukrainian Black-and-White dairy breed (UBWD), a significant influence of their heredity on the variability of longevity traits has been established. According to the duration of productive use, the variability between extreme options was 1061 days, and in terms of the number of lactations used during life, it was ‑ 2.7, with high reliability for both traits (P &lt; 0.001). The variability of longevity traits did not depend on the origin of the sires, among whom there are purebred Holsteins and bulls of domestic selection of Ukrainian Black-and-White dairy breed of different genotypes and lines. It was found that the quantity of days of productive use and the number of used lactations during the life of cows of different origins are positively correlated with indicators of productive longevity ‑ lifetime milk yield and milk fat, and milk yield per day of productive use. Variability in lifetime milk yield varied widely, from 14934 (daughters of the sire Katka 5218, Metta line, UBWD), to 33031 kg (daughters of the sire Marcellus 136057831, line P. F. A. Chief, Holstein breed), with a high reliable difference between them, which amounted to 18097 kg (P &lt; 0.001). The milk fat content of the daughters of the assessed sires also differed in significant, at a reliable level, variability within the range of 3.72–3.85% with a difference between the extreme options of 0.13% (P &lt; 0.001). Similar variability in sire offspring, regardless of origin, was observed in lifetime milk fat yield, with variation ranging from 570.5–1197.9 kg, with the highest indicator in daughters of Holstein bull Caprice 401393 and the lowest in daughters of domestic sire Katka 5218.

Evaluation of ELISA Test Kits for Detection of Milk Protein in Frying Oil Treated at Different Temperatures

Milk is a common ingredient in fried foods. Allergen cross-contact can occur through the reuse of frying oil. To enable assessment of the allergy risk of reused oil, methods for quantification of milk protein in oil are needed. This study evaluated four commercial ELISA test kits in comparison with the 660 nm total protein assay for the detection of milk protein in oil after frying. Corn oil spiked with nonfat or whole milk powder were fried at 150 °C or 180 °C for 3 min and were analyzed by ELISA kits either directly or after preextraction with phosphate-buffered saline containing 0.05% Tween (PBST). All four ELISA kits performed well in quantifying milk protein in unheated oil, achieving normalized recoveries of 72.1–115.9% compared with that determined in reference solutions (PBST spiked with nonfat or whole milk powder, 100%). Frying lowered the amount of protein detected, but the extent of reduction differed between test kits. In nonfat milk powder-spiked oil fried at 150 °C, normalized recoveries determined by Veratox Total Milk and BioKits BLG Assay (49.9% and 43.6%, respectively) were higher than that determined by the 660 nm assay (25.4%). Normalized recoveries determined by ELISA Systems Casein and Beta-Lactoglobulin (BLG) kits were substantially lower (9.7% and 2.4%, respectively). In samples fried under typical frying temperature (180 °C), very little protein (0.1–7.4%) was detected. Inclusion of PBST preextraction improved the detection of the two test kits targeting BLG but lowered the level of protein detected by Veratox and ELISA Systems Casein in fried samples. Overall, the ELISA kits evaluated could effectively quantify milk protein in unheated oil without the need to remove the oil phase prior to analysis. Heat treatment was the key factor negatively affecting protein quantitation. Such impact needs to be considered when ELISA test results are used for assessing the allergy risk of reused frying oil.

Influence of Somatic Cell Removal on Milk Quality and Yield

This investigation aimed to assess how the somatic cell count (SCC) impacts milk production and the physicochemical quality of milk, including the effects of centrifugation and microfiltration on SCCs and the yield of fresh cheese. Milk production was analysed at different somatic cell counts (SCCs) to observe how centrifugation and microfiltration affected the removal of SCs from the milk and the yield of fresh cheese. Tukey’s test was employed at a 5% significance level to compare the chemical composition of the milk, milk production, and fresh cheese yield when using microfiltered and/or centrifuged milk. Milk with an SCC of ≤200,000 somatic cells (SCs) per mL exhibited higher yields. Although centrifugation and microfiltration influenced milk fat content, total dry extract and SCC, they did not impact fresh cheese yield. It is important to note that these processes reduced the fat content and SCC, making skim milk a potential option for future research studies.

Perbandingan jumlah total bakteri, kadar lemak, dan protein susu segar pada penyimpanan suhu rendah (4 – 6° C) dan suhu ruang

The method and duration of storage are crucial factors determining quality of fresh milk, as assessed by total bacterial, fat content, and protein content of fresh milk. This research aims to determine the comparison of the total bacterial count, fat content, and protein content of fresh milk stored at a low temperature and at room temperature. The research subjects used were fresh milk obtained from a single cow in a single milking process, stored at a low temperature of 4 – 6 ℃ and at room temperature, and then tested and compared for the total bacterial count, fat content, and protein content after storage for the 2nd, 4th, and 6th hours. The data obtained was statistically analyzed using the student’s t-test at a confidence level of α = 95%. The result showed that there a significant difference (p&lt;0,05) in total bacterial and fat content. Within 6 hours, at a low temperature, total bacterial increased from the initial 3,07 × 105 cfu/ml to 5,95 × 105 cfu/ml, while at room temperature, it rose to 21.02 × 105 cfu/ml. The initial fat content was 4,14%, and after 6 hours of storage, at a low temperature, fat content decreased to 3,35%, whereas at room temperature, it dropped below the SNI standard of 3 to 2,91%. As for the protein content of the milk, both at low and room temperatures, the protein did not decrease and did not show a significant difference (p&lt;0,05). It can be concluded that up to two hours of storage, the quality of milk is not affected by temperature. However, after being stored for more than two hours, the storage temperature does impact the total bacterial count and the fat content of the milk.

Экономическая эффективность инновационных разработок, направленных на увеличение производства молока

Purpose. Assessment of the economic efficiency of using scientific developments in milk production. Materials and Methods. Scientific and economic experiments were carried out in three farms in the Volgograd region: breeding farm named after Lenin of Surovikinsky district; Agricultural Enterprise "Donskoye" LLC of Kalachevsky district and JSC "named after Kirov" of Staropoltavsky district. The object of research is lactating cows of Holstein, Red Steppe and Black-and-White breeds. The amount of fat, protein and other indicators contained in cows’ milk was determined in the conditions of the complex analytical laboratory of VRIMMP using standard methods. The calculation of economic indicators was carried out on the basis of data from summary reports on the results of livestock judgement, cards of breeding farms using methods of a systematic approach, analysis and calculation. Results. At the breeding farm named after Lenin, thanks to the use of lactulose-based feed additives in feeding cows, the milk yield of cows in the experimental groups increased by 5.59 and 8.09%, respectively, the fat content of milk – by 6.91 and 9.57%, protein – by 5.01 and 6.35 % compared to the control group. More profit was received from cows of experimental groups I and II compared to analogues in the control group by 1473.2 and 2131.0 rubles. The experimental groups exceeded the control group in terms of production profitability by 1.2 and 2.1%. In Agricultural Enterprise "Donskoye" LLC, the milk yield of cows during the highest lactation increased until the 3rd calving, and its increase was 1474.1 kg (15.4%). The animals that showed the greatest productivity (11,000.8 kg) after the first calving were 0.3 lactation higher than the animals that showed the greatest productivity in the second lactation. The introduction of modern scientific approaches made it possible to achieve a level of production profitability in 2022 of 30.0%, which is 2.6% higher than in 2018. At JSC "named after Kirov" produced 400 kg more milk per lactation, or 5.23%; profit – by 2980 rubles, or 8.5%; production profitability increased by 2.2%. Conclusion. The implementation of new scientific developments and intensive technologies at large dairy complexes makes it possible not only to improve the quality of the resulting dairy products, increase the productivity of animals, but also the overall profitability of industrial milk production.

Cactus Cladodes and Sugarcane Bagasse Can Partially Replace Earless Corn Silage in Diets of Lactating Dairy Cows

This study aimed to evaluate the effects of replacing earless corn silage (ECS) with cactus cladodes (CC; Opuntia spp.) and sugarcane bagasse (SB) on nutrient intake, digestibility, feeding behavior, milk yield (MY), and composition of lactating dairy cows. Ten Holstein cows, weighing 571 ± 97.0 kg and producing 23.0 ± 4.4 kg of milk per day, were assigned to two contemporaneous 5 × 5 Latin squares. Treatments consisted of five levels of ECS replacement with CC plus SB (0, 25, 50, 75, and 100%). The results showed a linear increase in dry matter (DM) intake (p &lt; 0.05) (15.98 and 18.73 kg/day) and a quadratic increase (p &lt; 0.05) in crude protein and energy intake (2.97 kg/day and 27.52 Mcal/day at 95.4 and 88.6% substitution, respectively). Apparent DM digestibility increased (p &lt; 0.05), but fiber digestibility decreased linearly (p &lt; 0.05). Treatments had a quadratic effect (p &lt; 0.05) on MY and fat-corrected MY (24.17 kg/day and 21.9 kg/day at 63.9% and 38.6% CC plus SB, respectively). Milk fat (3.26 and 2.35%) and total solids content decreased linearly (p &lt; 0.05), whereas the percentages of protein, lactose, and nonfat solids increased (p &lt; 0.05). Additionally, the CC–SB diets linearly reduced the time spent on feeding and rumination and total chewing time. For Holstein cows fed common semiarid diets, milk production can be maximized by replacing 38.6% of ECS with CC plus SB.

Variations in Casein Genes Are Associated with Milk Protein and Fat Contents in Sarda Goats (Capra hircus), with an Important Role of CSN1S2 for Milk Yield.

This work aimed to assess the variability of casein genes in a population of 153 bucks and 825 lactating does of the Sarda breed, and to perform association analysis between polymorphic sites and milk yield and composition traits. To genotype the casein genes, we chose an SNP panel including 44 SNPs mapping to the four casein genes CSN1S1, CSN2, CSN1S2, and CSN3. Genotyping (made by KASP™ genotyping assay, based on competitive allele-specific PCR) revealed the high variability of the Sarda goat, and haplotype analysis revealed linkage disequilibrium (LD) between CSN1S1 and CSN2 genes, in addition to two LD blocks within the CSN1S2 and two LD blocks within the CSN3 gene, in bucks and does. Association analysis revealed that variability at all four casein genes was associated with milk protein content, total solids, and milk energy. The three Ca-sensitive casein genes were associated with lipid content, and CSN1S2 showed a unique pattern, with intron variants associated with milk yield, in addition to milk pH, NaCl, and SCS (Somatic Cell Score). This information might prove useful in selection schemes and in future investigations aiming to better understand the biology of lactation, and the direct link between genotype and phenotype.

Optical detection of fat and adulterants concentration milk using TMDC (WS2 and MoS2)-surface plasmon resonance sensor via high sensitivity and detection accuracy

This paper introduces a surface plasmon resonance sensor for milk fat and melamine concentration detection, utilizing a transition-metal dichalcogenide (TMDC: WS2 and MoS2) based framework and incorporating an Ag–Pd bimetallic layer. The aim is to provide an innovative approach to monitor fat and melamine levels in milk. The palladium layer offers chemical stability and enhances sensitivity alongside the TMDC layer. Compared to the conventional SPR sensor, the maximum sensitivity, and detection limit are 409.36, 248.96°/RIU, and 0.0085, 0.0140 RIU, for detection of fat and melamine as sensing layer, respectively, related to the WS2 layer. The sensivity of sensor was expanded, due to the expanded field concentrated and profundity of infiltration of the sensor layer, coming about in a bigger interaction volume. The existence of the WS2 layer, with its notable imaginary component of the dielectric constant, enhances sensitivity while simultaneously enlarging the SPR curves. This study concludes that TMDC-Ag-Pd, offer a highly sensitive and efficient means of detecting fat cancentrion and melamine of milk. These findings suggest that TMDC-Ag-Pd optical sensor have great promise for application in the food industry.

The past and present of breeding in dairy cattle breeding in the Far North-East

Based on historical facts and past achievements, the work is designed to update the importance and prove the possibility of successful breeding work at the regional level in order to increase the production of high-quality, socially significant food products to ensure food security. At the beginning of the formation of agricultural science in the Magadan region, scientists were faced with the task of selecting the optimal breeds for the region. More than 4000 cows were examined during 1964–1967. It was found that in extreme natural and climatic conditions of the Magadan region the Kholmogory breed proved to be the best one. In 1967, in order to further improve the Kholmogory breed, the first attempt was made to study the genealogical structure of the herd, to identify and evaluate highly productive lines. In 1974, in order to increase the milk fat content of crossbred cows of the Kholmogory breed, introductory crossing with the bulls of the Ayrshire breed, tested for the quality of the offspring, was used. In order to improve dairy herds, the selection of cows for hereditary traits is combined with checking them for the first lactation. Since 1976, state farms began to study the breeding and productive qualities of the Ayrshire cattle, which were distinguished by high milk production and high fat content in milk. Since 1982, the Ayrshire breed has been approved as a planned breed for breeding in the farms of the Okhotsk zone. In the same year, absorptive crossbreeding of the animals of the Kholmogory breed with the sires of the Ayrshire breed began. In order to increase the efficiency of breeding for abundant milk production, work began on the farms to increase the hereditary variability of this trait through breeding along lines and families. At the same time, the work on improving the Kholmogory cattle by introductory crossbreeding with the purebred bulls of the Holstein-Friesian breed continued. By the 1990s, the main vector of development was the creation of highly productive herds of dairy cattle, but the difficult financial situation at farms in the 1990s led to a sharp decrease in the number of cattle and the productivity of the remaining animals.

Effects of heat stress on feed intake, milk yield, milk composition, and feed efficiency in dairy cows: A meta-analysis

Heat stress compromises dairy production by decreasing feed intake and milk yield, and it may also alter milk composition and feed efficiency. However, little information is available for evaluating such effects across different levels of heat stress and cows enrolled in heat stress studies. The objectives of this study were to evaluate the effects of heat stress on dry matter intake (DMI), energy-corrected milk (ECM), milk composition, and feed efficiency (kg ECM/kg DMI) and to investigate the relationship between such effects and heat stress intervention and animal characteristics by using meta-analytical approaches. Data from 31 studies (34 trials) fulfilled the inclusion criteria and were used for analysis. Results showed that heat stress decreased DMI, ECM, and milk protein concentration, but did not alter milk fat concentration or feed efficiency. Meta-regression confirmed that such reductions in DMI and ECM were significantly associated with increasing temperature-humidity index (THI). Over the period of heat stress, for each unit increase in THI, DMI and ECM decreased by 4.13% and 3.25%, respectively, in mid-lactation cows. Regression models further revealed the existence of a strong interaction between THI and lactation stage, which partially explained the large heterogeneity in effect sizes of DMI and ECM. The results indicated a need for more research on the relationship between the effect of heat stress and animal characteristics. This study calls for the implementation of mitigation strategies in heat-stressed herds due to the substantial decrease in productivity.

Validation of the FSTestTM Aerobic Count Plates Method for Enumeration of Aerobic Bacteria in a Variety of Matrixes and Stainless Steel Environmental Surface: AOAC Performance Tested MethodSM 112301.

The FSTestTM Aerobic Count (AC) Plates are ready-to-use culture media containing nutrients, a cold-water-soluble gelling agent, and a chromogenic indicator. The objective of this study was to validate the FSTest AC plate method for AOAC INTERNATIONAL Performance Tested MethodsSM (PTM) certification for a variety of foods and stainless steel. The performance of the FSTest AC plates were compared to the appropriate reference method, for the detection of total aerobic bacterial in a variety of foods matrixes (raw ground beef, raw ground pork, cooked ham, raw chicken breast, raw shrimp, frozen tuna, shredded bagged lettuce, cherry tomato, pasteurized liquid milk, nonfat milk powder) and on stainless steel surfaces. Robustness, consistency, and stability studies of the FSTest AC plate were also conducted. The results of the matrix study showed the standard deviation of repeatability (sr) was similar in both the FSTest AC plate method and the reference method. The 90% confidence interval of the difference between means between the two methods was found to fall within -0.5 to 0.5 log10 for all matrixes at all levels in the method developer and independent laboratory studies. The data in the report also support that the FSTest AC plate method is robust, manufactured in a consistent manner, and can be stable for 18 months at 4-10°C. The FSTest AC method is validated to be equivalent to the appropriate reference methods for the enumeration of aerobic bacteria in a variety of food matrixes and on stainless steel surfaces at 36 ± 1°C, and 32 ± 1°C (for dairy matrixes) in 24 ± 1 h. The FSTest AC plate method offers the advantage of saving labor, space, and time, as results are available within 24 h for all tested matrixes.

EFFECTS OF A SACCHAROMYCES CEREVISIAE FERMENTATION PRODUCT ON GROWTH PERFORMANCE OF LITTERS, MILK COMPOSITION AND HEMATOLOGY PROFILE OF PRIMIPAROUS SOWS

A total of 16 gilts (158,158±3.5 kg) were assigned to one of two treatments to determine the effect of a Saccharomyces cerevisiae fermentation product (SCFP) supplementation during lactation on performance of sows and litters. The treatments were: CT) formulated to meet the nutritional requirements according to the National Research Council, NRC (2012); SCFP) similar to CT, plus 0.88% SCFP. Feed intake (FI) was recorded daily from farrowing until day 21 of lactation. At birth and on days 7, 14, and 21 of lactation, the weight of the litters was recorded to determine body weight gain (BWG), and milk samples were taken to determine the nutritional composition of the milk. The FI of the sows and the BWG of the litters were stratified into three phases with 7 days per phase [phase 1 (P1: d1-7); phase 2 (P2: d8-14); phase 3 (P3: d15-21)]. Blood samples were collected from the sows on days 7, 14, and 21 of lactation to determine the hematological profile. A treatment per day interaction was obtained in the FI, with a higher FI in sows fed SCFP during P1 and P2, with no differences in P3 (p&lt;0.05). No differences were found in the BWG of the litters during lactation (p&lt;0.05). Furthermore, there were significant differences in the treatment per day interaction for leukocyte concentration (p&lt;0.05). Sows supplemented with SCFP had a higher percentage of milk fat compared to CT sows (p&lt;0.05). In conclusion, SCFP supplementation stimulated sow feed intake, milk fat content and leukocyte profile of primiparous sows during lactation, without exerting productive improvements in litter performance.

Heritability and Repeatability Estimates for Milk Production Traits Using Phenotypic, Pedigree-Based and Genomic Data of Serbian Holstein Cows

Summary This research aims to estimate heritability and repeatability based on the data on milk production traits (MY – milk yield; FY – milk fat yield; FC – milk fat content; PY – milk protein yield and PC – milk protein content) as well as pedigree and genomic information. A total of 6,041 animals were included in the research, while 2,565 of them had data for milk production traits. In order to form a genomic relationship matrix, 58K SNP data were used for a total of 1,491 cows. Several software tools were used in the preparation and analysis of data, which were provided by the Central Breeding Organization, Department of Animal Science, Faculty of Agriculture, University of Novi Sad. PreGSF90, in combination with RENUMF90, was used for quality control of genomic information. Genetic analysis was performed in WOMBAT software by the REML using standard repeatability univariate analysis (BLUPpe) and repeatability models for genomic prediction (GBLUPpe and ssGBLUPpe). In all three analyses, the highest heritability (0.410, 0.378 and 0.389, respectively) and repeatability (0.449, 0.429 and 0.440, respectively) were calculated for FC. Heritability estimates for all other traits were lower. Heritability ranged from 0.158 to 0.185 for MY, from 0.166 to 0.178 for FY, from 0.141 to 0.154 for PY and from 0.135 to 0.221 for PC. Heritability estimates indicate that it is possible to achieve genetic improvement but it is necessary to introduce the best model for prediction of breeding values of cow.

Concentrations of Amino Acids and their Concerned with some Blood and Milk Contents of Awassi Ewes

Nineteen ewes with single and twins birth were used to study the correlation between amino acids concentration and contents of milk (fat, protein, and nonfat solid materials) with contents of blood (WBC, RBC, PCV, HB concentration, total protein and Triglyceride). The results showed significant differences (p<0.05) in levels of amino acids in the age 2.5 years as compared with 3.5 years (4.13±0.12) mg/100 ml, (3.89±0.01) mg/100 ml, respectively. Increase levels of white blood cells and packed cell volume in both ewe’s twins and single birth. Significant differences (p<0.05) in total protein concentration in ewes with twins birth51.57±0.59 dl/g as compared with single bird. There were no significant differences (p<0.05) in (red blood cell, hemoglobin concentration and triglyceride). the results proved significant differences (p<0.05) in minerals (calcium, magnesium, zinc and phosphore) in ewes of both births single and twins. there were significant differences (p<0.05) in milk fat of ewes with twin’s birth than single birth.