The influence of selenium and zinc addition in food on concentration of these elements in blood and milk, on somatic cells number and histological characteristics of cows udders

The experiment included 30 cows of Holstein-Friesian breed, out of which 15 were receiving selenium and zinc in optimal doses before calving, while the others had never been supplemented with these micronutrients. There was analysed the concentration of selenium and zinc in blood and milk serum as well as the average number of somatic cells in corresponding lactation. After the cows exclusion from production, histological characteristics of cows udders were examined. The results of the investigation have shown that addition of selenium and zinc before calving has a positive effect on the values of these microelements in the blood and milk during the period of early lactation, that is, the concentration of these elements was significantly higher in the blood and milk of the cows that obtained selenium and zinc supplements. Also, in these cows there was significantly lower number of somatic cells during the following lacation period. In the parenchyma of the udder there was found less pronounced infiltration of leukocytes, notably thicker keratin layer of ductus papillaris and less expressed repairing processes that indicate a chronic inflammation of the udder in the samples after exclusion of the cows from production. There was a significant positive correlation between selenium in blood and milk, while there was not observed such a correlation for zinc. On the other hand, there was a significant negative correlation between the concentration of selenium in the blood and milk with the average number of somatic cells and the degree of infiltration of leukocytes, while its influence on the keratin layer of ductus papillarus was not shown. Zinc from blood and udder had a negative correlation with the number of somatic cells, had a positive correlation with the thickness of ductus papillaris keratin layer and had no influence on the level of leukocyte infiltration of udder parenchyma. Zinc demonstrates a positive influence on the formation of ductus papillaris keratin layer and protects the udder from pathogens penetration, while selenium stimulates the immunological response of the udder. Their positive impact can be defined as additive, because athough they have effect on two morphologically separate udder parts, adding both of them significantly decreases the number of somatic cells in milk. [Projekat Ministarstva nauke Republike Srbije, br. TR31062

Metabolic changes and mammary uptake of metabolites in milk in heat stressed cows

Toplinski stres je veliki ekonomski problem u mliječnom govedarstvu, jer dovodi do smanjene proizvodnje i kvalitete mlijeka. Smanjena proizvodnja i kvaliteta mlijeka nastaje kao posljedica smanjenog unosa hrane i promjena u postapsorpcijskom metabolizmu hranjivih tvari. Cilj ovog rada bio je utvrditi postapsorpcijsku upotrebu glukoze, neesterificiranih masnih kiselina (NEFA), beta hidroksibutirata (BHB) i uree u procesu proizvodnje mlijeka, određivanjem postprandijalne koncentracije metabolita i stupnja ekstrakcije metabolita u mliječnoj žlijezdi. Glukoza se povećano koristi u energetske svrhe u organizmu tijekom djelovanja toplinskog stresa, pa manja količina glukoze dolazi do mliječne žlijezde. Zbog toga opada koncentracija laktoze u mlijeku. Mliječna žlijezda se adaptira na smanjen dotok glukoze i povećano koristi NEFA i BHB za svoje potrebe, što negativno utječe na mliječnu mast i proteine. Urea koja je u povećanoj koncentraciji tijekom toplinskog stresa lako prolazi kroz mliječnu žlijezdu i pokazuje negativan utjecaj na proteine mlijeka. Sve navedeno smanjuje količinu proizvedenog mlijeka. Smanjen dotok glukoze u mliječnu žlijezdu, povećano iskorištavanje NEFA i BHB za proizvodnju mlijeka i povišena koncentracija uree tijekom toplinskog stresa direktno utječu na proizvodnju i kvalitetu mlijeka.Heat stress is a major economic problem in dairy cattle because it leads to reduced milk production and quality. Reduced milk production and quality is the result of reduced feed intake and changes in post-absorptive metabolism of nutrients. The aim of this study was to investigate the post-absorptive use of glucose, non-esterified fatty acids (NEFA), betahydroxybutyrate (BHB) and urea in milk production by determination of postprandial concentration of metabolites and the degree of metabolites extraction in milk glands. The use of glucose for energy production was increased during heat stress, and a small amount of glucose was transported to the mammary gland. Therefore, it decreased concentration of lactose in milk. The uptake of NEFA and BHB in mammary gland was significantly greater during heat stress, due to adaptation to decreased supply of glucose. This adaptation has shown a negative impact on the percentage of milk fat and protein. Elevated concentration of urea is the result of heat stress; it easily passes through the mammary gland and shows a negative impact on milk proteins. All these changes show a negative effect on the amount of milk produced during heat stress. Reduced influx of glucose in the mammary gland, increased utilization of NEFA and BHB in milk production and increased concentrations of urea during heat stress directly affect the production and quality of milk

Utjecaj selena u krvnom serumu na zdravstvene karakteristike vimena krava

The aim of this study was to determine the effect of selenium concentration in early lactation on mammary gland health and histological characteristics of the udder. The experiment included 30 high-yielding Holstein-Friesian cows. Selenium concentrations in blood and milk serum, and the average somatic cell count in the first and sixth months of lactation were analyzed. After exclusion of the experimental cows from the herd, histological characteristics of the udder were examined (the degree of leukocyte infiltration and the number of granulomas in the parenchyma). The mean selenium concentration in the blood serum was 0.62±0.11 mmol/L and that in the milk serum was 0.12±0.07 mmol/L. Optimal blood levels of selenium were found in 19 cows and suboptimal levels in 11 cows. A significant negative correlation was observed between blood and milk selenium concentrations and somatic cell count in early and mid lactation. There was no relationship between blood selenium concentration, milk selenium concentration and the amount of milk produced. Selenium-deficient cows had a significantly higher milk somatic cell count in early and mid lactation and significantly lower levels of selenium in milk. Upon histological analysis, 120 samples of individual quarters of the udder were grouped according to the degree of leukocyte infiltration and number of granulomas. Results showed that an increase in the degree of leukocyte infiltration and number of granulomas leads to an increase in the proportion of quarters from selenium-deficient cows and a decline in the percentage of quarters from cows exhibiting normal blood selenium concentrations. Selenium has a significant impact on udder health. Changes caused by selenium deficiency occur due to marked inflammation process in the mammary gland.Cilj rada bio je istražiti utjecaj koncentracije selena u ranoj laktaciji na zdravlje mliječne žlijezde i histološke karakteristike vimena krava. U istraživanje je bilo uključeno 30 visokomliječnih krava holštajn-frizijske pasmine. Analizirana je koncentracija selena u krvnom i mliječnom serumu, kao i prosječan broj somatskih stanica u prvom i šestom mjesecu laktacije. Nakon isključenja krava iz proizvodnje istraživana su histološka svojstva vimena krava (stupanj leukocitne infiltracije i broj granuloma u parenhimu). Prosječna koncentracija selena u krvnom serumu krava iznosila je 0,62±0,11 µmol/L, a u mliječnom 0,12±0,07µmol/L. U ogledu je utvrđeno 19 krava s optimalnom koncentracijom selena u krvi i 11 sa suboptimalnom koncentracijom. Utvrđena je značajna negativna korelacija koncentracije selena u krvi i mlijeku s brojem somatskih stanica u ranoj i srednjoj laktaciji. Nije utvrđena veza između koncentracije selena u krvi s koncentracijom selena u mlijeku i količinom proizvedenog mlijeka. Krave koje su deficitarne u selenu imaju značajno veći broj somatskih stanica u mlijeku u ranoj i srednjoj laktaciji i značajno nižu koncentraciju selena u mlijeku. Kada se nakon histološke analize 120 uzoraka pojedinačnih četvrti vimena grupiraju prema stupnju leukocitne infiltracije, odnosno prema broju granuloma, može se zaključiti da s porastom stupnja leukocitne infiltracije, odnosno broja granuloma u tkivu, raste udio onih četvrti koje potječu od krava deficitarnih u selenu, dok opada udio četvrti koje potječu od krava s normalnom koncentracijom selena u krvi. Selen značajno utječe na zdravlje vimena, a promjene koje izaziva deficit selena nastaju kao posljedica izražene inflamacije i reparacije u tkivu mliječne žlijezde

Revidirani kvantitativni indeks osjetljivosti na inzulin: povezanost sa metaboličkim statusom krava tijekom rane laktacije

The revised quantitative insulin sensitivity check index (RQUICKI) is the most commonly used indicator of insulin resistance in dairy cows. The aim of this study was to examine the characteristics of metabolic status in cows with different RQUICKI index values during early lactation. The experiment included 40 Holstein-Friesian cows in the first week of lactation. The cows were classified into four groups according to quartile (Q 1 to 4) values of RQUICKI indexes: Q1 = 0.35-0.41 (most insulin resistant), Q2 = 0.42-0.52, Q3 = 0.53-0.67, Q4 = 0.68-0.77 (most insulin sensitive). Metabolic parameters were significantly different in early lactation cows, classified according to the values of the RQUICKI index. The cows that were the most resistant to insulin (Q1) had higher levels of non-esterified fatty acid (NEFA), cortisol, somatotropic hormone (STH), beta-hydroxybutyrate (BHB), total bilirubin, aspartate aminotransferase (AST), malondialdehyde (MDA) and body condition score (BCS) in comparison to the cows that were the least resistant to insulin (Q4). The cows also had lower levels of insulin-like growth factor I (IGF-I), triiodothyronine (T3), thyroxine (T4), albumin, cholesterol, triglycerides, Ca and P as well as a tendency towards lower insulin and glucose concentrations. Metabolic parameters were strongly regressed by RQUICKI in the most insulin resistant cows (Q1) in relation to the cows in the other groups, Q2-4. The cows with a higher number of metabolic abnormalities in their metabolic profiles had lower RQUICKI values: 0.56 ± 0.045 (no abnormalities); 0.52 ± 0.041 (1 abnormality); 0.47 ± 0.042 (2 abnormalities) and 0.4 ± 0.043 (≥3 abnormalities). We concluded that the RQUICKI index could be applied in order to accurately identify metabolic status in cows during early lactation. However, the kinetics of insulin sensitivity should be further studied using more animals per group, as well as in other breeds of cowsRevidirani kvantitativni indeks provjeravanja osjetljivosti na inzulin (RQUICKI) najčešće se koristi kao pokazatelj otpornosti na inzulin u krava. Cilj ovoga istraživanja bio je ustvrditi karakteristike metaboličkog statusa u krava s različitom vrijednosti RQUICKI indeksa u ranoj laktaciji. Pokus je uključivao 40 krava Holstein-Friesian pasmine. Krave su razvrstane u četiri skupine prema kvartilima (Q 1 do 4) vrijednosti RQUICKI indeksa: Q1 = 0,35-0,41 (najrezistentnije na inzulin), Q2 = 0,42-0,52, Q3 = 0,53-0,67, Q4 = 0,68-0,77 (najosjetljivije na inzulin). Metabolički parametri bili su znakovito različiti u krava u ranoj laktaciji razvrstanima prema vrijednostima RQUICKI indeksa. Krave koje su bile najrezistentnije na inzulin (Q1) imale su i veće razine NEFA, kortizola, STH, BHB, ukupnog bilirubina, AST, MDA i bolju tjelesnu kondiciju u usporedbi s kravama koje su bile najmanje osjetljive na inzulin (Q4). Također, te su krave imale niže koncentracije IGF-I, T3, T4, albumina, kolesterola, triglicerida, Ca i P te sklonost smanjenju koncentracije inzulina i glukoze. U skupini krava koje su najrezistentnije na inzulin (Q1) regresijska analiza je pokazala jaču povezanost između metaboličkih parametara i RQUICKI nego što je to bio slučaj u ostalim skupinama krava (Q2, Q3 i Q4). Krave s većim brojem metaboličkih abnormalnosti profila imale su nižu vrijednost RQUICKI: 0,56 ± 0,045 (bez abnormalnosti); 0,52 ± 0,041 (jedna abnormalnost); 0.47 ± 0.042 (dvije abnormalnosti) i 0.4 ± 0.043 (≥3 abnormalnosti). Zaključujemo da bi se RQUICKI indeks mogao primijeniti za točnije identificiranje metaboličkog statusa krava tijekom rane laktacije. Međutim, kinetika osjetljivosti na inzulin trebala bi se dodatno istražiti na većem broju životinja kao i u krava različitih pasmina

Thermal comfort of cows and temperature humidity index in period of 2005-2016 in Vojvodina region (Serbia)

The aim of this study is to determine value of temperature-humidity index (THI) in period of 2005-2016. in Vojvodina and their correlations with milk production and temperature of body surface of animals. THI index is calculated according to the following formula THI=(1,8×Temperature)-(1-Relative Humidity) × (Temperature- 14,3)+32. Temperature and humidity data were collected directly from Hydrometeorological Institute of Serbia. Average THI values were calculated for every month for every year from 2005 to 2016. Measuring spots were cities Vršac, Zrenjanin, Kikinda, Palić, Sombor, Rimski Šančevi and Sremska Mitrovica. Temperature and humidity are noted at 14h, so they represented maximal average values of THI index. Trend of THI values was represented for each day in every month in years from 2005. to 2016. Average production of drinking milk for year of 2016 was calculated. This year was chosen because is the last year of research and represents cumulative effect of heat stress in cows. Data were collected from Statistic Institute of R. Serbia. Thermo-vision camera was used for determining skin temperature of udder and skin in eye region. Results were showed that temperature ranged from 40.3 in January to 77.5 in July. Average maximal THI value in period of 2005-2016 showed that heat stress was presented in May, June, July and August. Drinking milk production was the greatest in January. After that it started dropping. The lowest production of drinking milk was noted in August with an increase afterwards till December. Body surface temperature was ranged from 34.1 to 38.5ºC. The highest body temperature was measured at August and the lowest in winter time. Significant negative correlation between ten-year average THI value and milk production was noted. Positive correlation was noted between THI and body temperature. From 2005 to 2016 positive linear trend of THI values that were measured in hottest period of day was noted. In every month statistically significant linear trend of rising THI value was founded, except in January, October and November. Extremely hot summers in Serbia appear in every five years when cows are affected the most. Showed data indicated global warming and climate changes which affect biological adaptation of cows

Relationship between milk production and metabolic adaptation in dairy cows during heat stress

The aim of this study is to determine correlation between change in milk production and metabolic adaptation of cows during heat-stress. Experiment included 30 Holstein-Frisian cows. Cows exposed to heat-stress, which is expressed in high THI index, have lower milk production, higher concentration of insulin and lover concentrations of glucose and NEFA. Indexes of insulin resistance-RQUICKI, insulin: glucose and insulin: NEFA relations are higher in cows under heat stress. Grouping cows in accordance to reduced milk yield have showed that trend of reduction of glucose and NEFA levels, followed by increased insulin level, higher RQUICKI, greater insulin: glucose and insulin: NEFA ratios, started and increased during the reduction in milk production. Among this, significant correlation was founded between these parameters and milk yield. Significant correlation was also noted between those parameters. Change in metabolic value is of great importance for prediction of cows that would have decreased milk yield (above 18%). With almost 90% certainty cows with great reduction in milk yield can be detected. These cows have had following relative changes in values of metabolic parameters during heat-stress compared to thermo-neutral period: insulin increased for ≥12.5%, reduction in NEFA values for ≤14.1%, reduction in glucose for 21.5%, RQUICKI index increased for ≥9.6%, insulin: NEFA ratio increased for ≥20.1% and insulin: glucose for ≥20.3%. Dynamical changes in metabolites and insulin resistance values have great influence on milk yield in cows under heat stress. Decreasing in glucoses followed by increased insulin level and increased insulin sensitivity indicate that glucose is transferred from udder to other tissues which can cause decreased milk production

Insulin resistance in cows during the periparturient period (review)

Insulin resistance is a state in which the biological effect of insulin is reduced when its concentration decreases or when a compensatory mechanism increases its concentration. Insulin resistance is characterized by reduced insulin response to glucose, i.e. decreased pancreatic beta cell function (insulin hyporesponsiveness) and/or reduced sensitivity of glucose to insulin (reduced intake of glucose by peripheral tissues under the influence of insulin - eng. insulin sensitivity). Methods for estimating insulin resistance include direct methods (hyperinsulinaemic-euglycaemic clamp, golden standard), indirect methods (intravenous glucose tolerance test) and surrogate methods (indices calculated from basal concentrations of insulin, glucose, NEFA and BHB-HOMA, QUICKI, RQUICKI and RQUICKI- BHB). Surrogate indices show correlations with direct and indirect test results but they are inconsistent. Inconsistency occurs because the dependence of glucose concentrations on the degree of hepatic gluconeogenesis should be kept in mind when evaluating insulin resistance in ruminants. Therefore, the hyperinsulinaemic-euglicaemic clamp method is particularly suitable as it excludes gluconeogenesis in hepatocytes from analysis. Our results have shown a correlation between HOMA, QUICKI and RQUICKI indices and metabolic profile parameters. The correlation between dynamic and basal responses of NEFA, BHB, insulin, glucose and inorganic phosphorus is significantly dependent on RQUICKI-BHB index values in ketotic cows. RQUICKI index of insulin resistance is substantially dependent on NEFA values in early lactation as well as on insulin and glucose values in the dry period. Further investigations should focus on the practical evaluation of the use of insulin resistance indices

THE IMPROVEMENT OF THE BODY AND UDDER HYGIENE INFLUENCE ON THE MILK SAFETY AND COMPOSITION ON SMALL DAIRY FARMS IN SERBIA

The hygienic condition of dairy cows and their udders in 128 small household farms in different regions of Serbia, producing mostly milk, having 5–15 cows, a milk cooler and at least one milking machine, was evaluated by the following indicators: 1. general assessment of body cleanliness, 2. visual inspection of teats and udder base, and 3. maintenance of udder cleanliness, rated on a scale of 0 and 1 or 1 to 5. The samples were taken at each visit to the farm after cooling and tested for milk protein and fat content, somatic cell count (SCC) and the total number of microorganisms (TNM). The milk fat content was determined by the Gerber method, the protein content by the Kjeldahl method, the TNM according to the ISO 4833-1:2013 method and the SCC using Fossomatic TM. The IBM SPSS program was used for statistical data processing. Capacity, housing system, breed, milking system, number of cows, and capacity occupancy mostly had a very significant or significant impact on hygiene parameters, protein and fat content, SCC and TNM in milk. The hygiene parameters showed a continuous trend of improvement in relation to the visits. TNM mean scores increased after each visit, with significant differences between visits (F=9.63, P<0.0001). SCC scores varied very significantly between visits (F=5.17, P<0.0001). The number of visits tended to show a significant influence on the milk fat rate (F=2.221; P<0.1), but no influence on the milk protein rate (P=0.480; F=0.901). Copyright©2023 by authors, all rights reserved

Comparison of the content of lean meat in pigs on farm and slaughter line

Measurement of lean meat on slaughter line and formation of price on the basis significantly contribute to the overall improvement of the quality and profitability of production and distribution of pork. The content of lean meat on live pigs was measured on farm using ultrasound device PIGLOG 105. While in slaughterhouse, the content of lean meat measured using Fat-O-Meater (FOM), two-point method (TP) and partial dissection. 59.30% of lean meat in vivo was estimated by the apparatus PIGLOG-105 one day before slaughter. It is 0.91% more then partial dissection and when compared to FOM and TP it is more 4.86% and 4.02%. Great deviation between PIGLOG-105 on one side and FOM and TP on other side indicated some error, and then partial dissection solved this mystery. After this study, slaughterhouse constructed new formulas for FOM in pig carcass classification. Regarding that, slaughterhouses which used FOM or similar equipment for measuring percentage of lean meat, should control results of the equipment described in this study, minimum twice a year

Influence of niacin administration on lipid peroxidation in cows in early lactation

Niacin is a reactive part of NAD and NADP, which are co-enzymes in numerous oxidative and reductive reactions. In early lactation, there is an increased lipid mobilization, accompanied by inflammatory response and oxidative stress. The aim of this study was to examine the effect of niacin administration in cows during early lactation in reducing lipid peroxidation i.e. MDA (malondialdehyde) concentration. Niacin was administered through feed two weeks before and two weeks after calving. Blood samples were taken in the week preceding calving and in the first and second week after calving. MDA concentration was significantly lower in cows receiving niacin compared to the control group during all three samplings: 1.89±0.33:1.42±0.13 (calving, week 0); 2.37±0.41:1.64±0.15 (first week) and 2.6±0.45:1.8±0.17µmol/L (second week). In control cows, no significant correlation between MDA and NEFA concentrations was found compared to cows fed niacin. In cows receiving niacin, the concentration of MDA linearly increased, as did the NEFA concentration. Niacin supplementation in early lactation can decreaselipid peroxidation in cows. Reduced lipid peroxidation in cows can be a consequence of the antilipolytic effect of niacin