Uticaj vremena zrenja i CaCl2 na kvalitet junećeg mesa

Investigations were carried out on four muscles (M. longissimus dorsi, M. semimembranosus, M. semitendinosus, M. biceps femoris) taken from five young cattle (crosses Domestic Spotted x Limousine) of average body mass prior to slaughtering of 587 kg. On all muscles, 24 h after slaughtering, sensory evaluation was carried out and the following parameters determined: pH value, colour, water binding ability, cooking loss and tenderness (initial values). The remaining part of each muscle was divided into 6 parts, 3 were packaged in plastic foil (control samples), and other 3 were soaked in solution containing 0,4% CaCl2 and 0,4% NaCl and packaged in plastic foil. Pieces of meat prepared in this way were left on temperature of + 40C 7, 14 and 21 days to mature. After this period, all mentioned analyses were carried out on meat samples. It was established that pH value during maturation increased, that meat packaged in plastic foil after 14 days of maturation becomes unusable, whereas the increase of pH values of meat whose maturation occurred in solution CaCl2 and NaCl was slower and therefore meat was still usable after 21 days. Color of meat in control samples was slightly lighter compared to initial condition, whereas the color of meat whose maturation occurred in solutions of salt was statistically considerably lighter (P (lt) 0,05 after 7 days, a P (lt) 0,001 after 14 and 21 days). Water binding ability in control samples was slightly better (P>0,05) after 7 days and after 14 days it was statistically significantly better (P (lt) 0,05) compared to initial state, whereas in meat whose maturation occurred in salt solution this ability was at initial level even after 21 days. Cooking loss in control samples was lower compared to initial values whereas in meat soaked in salt solution cooking loss was higher. Meat tenderness in control samples was statistically considerably better after 14 days of maturation (when meat was not fit for use) and in meat soaked in salt solution it was statistically highly significantly better after 14 and 21 days. According to sensory evaluation, control samples of meat, after 14 days of maturation are not fit for use, whereas meat whose maturation occurred in solution of CaCl2 and NaCl even after 21 days is acceptable from the sensory aspect.Ispitivanja su obavljena na četiri mišića (M. longissimus dorsi, M. semimembranosus, M. semitendinosus, M. biceps femoris) uzetih od pet junadi (melezi domaće šareno goveče x limuzin), prosečne mase pred klanje 587 kg. Na svim mišićima 24 sata posle klanja obavljena je senzorna ocena i određeni su: pH vrednost, boja, sposobnost vezivanja dodate vode, kalo kuvanja i mekoća (početne vrednosti). Ostatak svakog mišića podeljen je na 6 delova od kojih su po 3 upakovani u plastičnu foliju (kontrolni uzorci), a ostala 3 dela su potopljena u rastvor koji sadrži 0,4% CaCl2 i 0,4% NaCl i upakovani u plastičnu foliju. Ovako pripremljeni komadi mesa ostavljeni su pri temperaturi od + 40C 7, 14 i 21 dan na zrenju. Posle isteka zadatog vremena urađena su na komadima od svih mišića navedena ispitivanja.Utvrđeno je da se pH vrednost tokom zrenja povećava i da u mesu koje je upakovano u plastičnu foliju posle 14 dana zrenja dospeva u oblast kad je meso neupotrebljivo, dok je povećanje pH vrednosti kod mesa čije se zrenje odvijalo u rastvoru CaCl2 i NaCl sporije tako da je meso i posle 21 dan upotrebljivo. Boja mesa kod kontrolnih uzoraka bila je neznatno svetlija u odnosu na početno stanje, dok je boja mesa čije se zrenje odvijalo u rastvoru soli bila statistički značajno svetlija (P (lt) 0,05 nakon 7 dana, a P (lt) 0,001 nakon 14 i 21 dan). Sposobnost vezivanja vode kod kontrolnih uzoraka bila je neznatno (P>0,05) bolja nakon 7 dana dok je nakon 14 dana bila statistički značajno bolja (P (lt) 0,05) u poređenju sa početnim stanjem, dok je kod mesa čije se zrenje odvijalo u rastvoru soli i posle 21 dan bila na nivou početnog stanja. Kalo kuvanja kod kontrolnih uzoraka bio je manji u poređenju sa vrednostima na početku ogleda dok je kod mesa potopljenog u rastvor soli bio veći. Mekoća mesa kod kontrolnih uzoraka bila je statistički značajno bolja nakon 14 dana zrenja (kad je meso bilo neupotrebljivo) dok je kod mesa potopljenog u rastvor soli bila statistički visoko značajno bolja posle 14 i 21 dan. Prema senzornoj oceni kontrolni uzorci mesa nakon 14 dana zrenja postaju neupotrebljivi, dok je meso čije se zrenje odvijalo u rastvoru CaCl2 i NaCl i nakon 21 dan zrenja senzorno veoma prihvatljivo

Heritability and genetic correlation of production and reproduction traits of Simmental cows

Improvement of production capacity of cattle in terms of increasing the production of milk, milk fat and number of calves, greatly depends on phenotype and genotype variability, heritability and correlation between desirable traits, as well as on the production level of the cattle population. Heritability, as a value expressing and measuring average additive gene effect, is one of the major characteristic of quantitative traits from the point of view of creating genetically high-value cattle populations. Knowledge of the heritability is necessary in the estimation of the beeeding value of cattle and has significant impact on the selection of breeding method. Genetic correlations are very important in indirect selection where changes in one trait are induced through selection of other traits between which a genetic correlation exists. Genetic correlations can be determined in all cases where heritability coefficient can be calculated. This research included 3.461 first calving Simmental cows under control, with lactation concluded within one year. All first-calvers were reared on individual farms in the territory of Republic of Serbia. In this study, heritability and genetic correlations between the the following milk and fertility traits were investigated: duration of lactation (days)- DL, milk yield in standard lactation (kg)- MY, milk fat content in standard lactation (%)- MFC, milk fat yield in standard lactation (kg)- MFY, yield of 4% FCM in standard lactation (kg)- 4%FCM, age at first calving (days)- AC and duration of service period (days)- DSP.Key words: Heritability, genetic correlations, milk yield, fertility, Simmental breed

Ocena priplodne vrednosti bikova simentalske rase za osobine mlečnosti u Srbiji

The basis for selection work is knowledge of the quality of bull sires used for conception, as well as how the major traits are passed on to the progeny. BLUP method (Best Linear Unbiased Prediction) is the basis of the most favourable solution for evaluation of additive gene value in cattle production, and it is implemented in various variants depending on the structure of data used. This research included 2.121 Simmental first cavers under control, with lactations completed within one year. All first calvers were located on holdings of individual agricultural producers on the territory of the Republic of Serbia. Evaluation of the bull breeding value for lactation duration, milk production, milk fat yield, yield of 4% FCM and percentage of milk fat, was carried out by using the mixed model (BLUP), the calculation included random effect of bull sire and fixed effect of the region, year and season of calving. In this study, bull sires which had in two or three regions over 20 daughters - first calvers of Simmental breed. Number of first calving heifers ranged from 22 to 215 animals per bull sire. By using BLUP method in evaluation of breeding value of bulls in terms of yield of milk, milk fat, content of milk fat and 4% FCMI and by ranking, results were obtained showing superiority and inferiority of breeding males.Osnovu za svaki selekcijski rad predstavlja poznavanje kvaliteta bikova očeva koji se koriste za oplodnju, kao i način prenošenja važnijih svojstava na potomstvo. U osnovi najpovoljnijeg rešavanja problema ocene aditivne genotipske vrednosti osobina u govedarstvu leži BLUP metod (Best Linear Unbiased Prediction), koji se primenjuje u raznim varijantama zavisno od strukture podataka. Ovim istraživanjem je obuhvaćena 2.121 kontrolisana prvotelka simentalske rase, sa laktacijama zaključenim u toku jedne godine. Sve prvotelke su se nalazile na imanjima individualnih poljoprivrednih proizvođača na području Republike Srbije. Ocena priplodne vrednosti bikova za osobine trajanje laktacije, proizvodnju mleka, mlečne masti, 4% MKM i procenat mlečne masti, izračunata je pomoću mešovitog modela (BLUP), u čiju jednačinu je uključen slučajni uticaj bika-oca i fiksni uticaj regiona, godine i sezone telenja. Ispitani su bikovi-očevi koji u dva ili tri regiona imaju 20 i više kćeri prvotelki simentalske rase. Broj prvotelki je bio od 22 do 215 po biku-ocu. Korišćenjem BLUP metoda za ocenu priplodne vrednosti bikova na prinos mleka, mlečne masti, sadržaja mlečne masti i 4% MKM i formiranjem ranga dobijeni su rezultati koji pokazuju znatnu superiornost ili inferiornost priplodnjaka

GENETIC AND PHENOTYPIC TRENDS FOR UDDER TRAITS AND ANGULARITY OF HOLSTEIN FRIESIAN COWS

The present research aimed to investigate the genetic trends for udder traits (fore udder attachment; rear udder height; udder depth; front teat placement; rear teat placement; front teat length and rear teat length) and angularity of Holstein Friesian cows in Serbia. A multi-trait animal model was used to estimate genetic parameters, through REML procedures. In the study 10403 first-lactation cows Holstein type from 12 different regions in Serbia were included. The cows were daughters of 221 Holstein Friesian sires. The age at first calving was from 19 to 44 months, and there were 10 stages of lactation. Udder type traits and angularity were classified by 24 classifiers on a linear scale of 1 to 9. Udder type traits had heritability estimates ranging from 0.03 for rear teat placement to 0.12 for fore udder attachment, and angularity had heritability 0.10. Genetic trend for angularity of Holstein Friesian cows in Serbia shows that ribs are becoming less angular and extremely rounded, while genetic trends for udder traits show that teat lengths are becoming longer and inside of quarter, and udder is shallow. The genetic trend for fore udder attachment indicates there is indirect selection for weaker udders. © 2022, Pakistan Agricultural Scientists Forum. All rights reserved

THE EFFECT OF TIME OF MATURATION AND CaCl2 ON QUALITY OF YOUNG BEEF **

Abstract: Investigations were carried out on four muscles (M. longissimus dorsi, M. semimembranosus, M. semitendinosus, M. biceps femoris) taken from five young cattle (crosses Domestic Spotted x Limousine) of average body mass prior to slaughtering of 587 kg. On all muscles, 24 h after slaughtering, sensory evaluation was carried out and the following parameters determined: pH value, colour, water binding ability, cooking loss and tenderness (initial values). The remaining part of each muscle was divided into 6 parts, 3 were packaged in plastic foil (control samples), and other 3 were soaked in solution containing 0,4 % CaCl2 and 0,4 % NaCl and packaged in plastic foil. Pieces of meat prepared in this way were left on temperature of + 4 0 C 7, 14 and 21 days to mature. After this period, all mentioned analyses were carried out on meat samples. It was established that pH value during maturation increased, that meat packaged in plastic foil after 14 days of maturation becomes unusable, whereas the increase of pH values of meat whose maturation occurred in solution CaCl2 and NaCl wa

Validation and application of FTIR spectroscopy in raw milk analysis

The aim of this study was to investigate whether FTIR spectroscopy is an accurate and valid technique for the assessment of quality parameters in raw cow's milk: fat, protein, lactose, and total solids. The assessment was based on calibration series and comparison with reference material. Furthermore, it takes into account the results obtained in the inter-laboratory comparisons (proficiency testing). The calibration samples were purchased from the accredited regional reference laboratories. The validation parameters included linearity, accuracy, repeatability, reproducibility, and robustness. The linearity ratio was 0.95%. The biases calculated for the fat, protein, lactose and dry matter were -0.33, 0.31, -0.25, and 0.06 respectively. The F value from the F-test was used to determine the significant differences between two independent sets of the results. The obtained results were as follows: 1.469 for fat, 1.634 for protein, 1.192 for lactose, and 0.528 for dry matter. The intra-laboratory reproducibility calculated as the Horwitz Ratios for all parameters were within the criterion limits (0.5 to 0.8). The data obtained for carry-over were 0.27% for fat, 0.52% for protein, 0.47% for lactose, and 0.47% for dry matter. Based on the obtained results it can be concluded that the FTIR spectroscopy is a reliable instrumental technique for the determination of fat, protein, lactose and total solids in raw cow's milk