MULTIPLE TRAIT ANALYSIS OF GENOTYPE BY ENVIRONMENT INTERACTION FOR MILK YIELD TRAITS IN SLOVENIAN CATTLE

The objective of the study was to evaluate genotype by environment interaction (GxEI) for yield traits in Holstein, Simmental and Brown breed cattle in Slovenia using multiple trait analysis. Data from Slovenian milk-recording scheme was used. The lactation records on cows having first to third calving in the period 1990-2004 and milk, protein and fat yield in 305 days were studied. The variables used to characterize the environment were herd-year averages of each trait. The multiple trait analysis was done using the highest and lowest quartiles of the environments. To study the GxEI, animal model methodology and the genetic correlation between the traits were used. GxEI was generally smaller for fat and milk yield than for protein yield. The lowest genetic correlations between high and low environments were estimated for protein yield, especially in Simmental (0.81) and in Brown (0.86) breed. In Holstein the correlation was higher, 0.94. The genetic correlations for fat yield were 0.95 for Brown and Simmental breed and 0.96 for Holstein. For milk yield the estimated genetic correlations were 0.88, 0.92 and 0.96 in Brown, Simmental and Holstein breed, respectively. Differences between variance components obtained in low and high quartile result in the rank of heritabilities from 0.04 to 0.12 in low and from 0.12 to 0.22 in high quartile

Harvester operator learnig efficiency analysis

Članek obravnava načine učenja bodočih strojnikov za delo s strojem za sečnjo.Na prvem takšnem primeru v Sloveniji je opisan in analiziran potek učenja s simulatorjem in merjeni so časi posameznih postopkov pri dveh kandidatih. Opisano je delovanje simulatorja za učenje na stroju Timberjack 1270 D in potek enotedenskega tečaja. Narejena je primerjava med kandidatoma glede porabe časa in števila poškodb na virtualnem stroju in sestoju, ki jih je beležil program simulatorja. Podane so usmeritve za prihodnje študije in spremljanje učinkov strojnikov pri delu.The article considers the possibilities of training future harvester operators. The course of learning with a simulator is described and analysed on the first such example in Slovenia. The times of individual processes are measured in two candidates. The paper describes the operation of a learning simulator for work on the harvester Timberjack 1270 D and the proceedings of aone-week course. A comparison between candidates regarding the consumption oftime and number of damages to the virtual machine and the stand is derived from the data recorded by the programme of the simulator. Directions for future studies and monitoring of operatorsć efficiency at work are also given

SLOVENIAN EXPERIENCE IN PIG CARCASS CLASSIFICATION ACCORDING TO SEUROP DURING THE YEARS 1996 TO 2004

Slovenian results on pig carcass classifi cation according to SEUROP (average lean meat percentage, carcass weight, measurements of fat and muscle and their variability) are presented for years from 1996 to 2004. In these years, an important increase of average lean meat percentage was noted (51.9 % in year 1996 vs. 55.9 % in year 2004). As a consequence the percentage of pig carcasses being graded into S and E classes was almost tripled from 1996 to 2004 (21.3 to 58.2%, respectively). This improvement was initiated by the payment according to the lean meat percentage, to which pig breeders responded by better management of herds and partly by increased use of pietrain breed. Potential for further improvement remains in attaining genetically more uniform herds and reduction of carcass weight variability. A new method, introducing an optic probe Hennessy, adapted to changes of the EU legislation, is expected to shift up the average meat percentage close to 57%, which places Slovenian pigs into the EU average

SLOVENSKE IZKUŠNJE PRI OCENJEVANJU MESNATOSTI PRAŠIČEV PO SEUROP V LETIH 1996 DO 2004

Slovenian results on pig carcass classifi cation according to SEUROP (average lean meat percentage, carcass weight, measurements of fat and muscle and their variability) are presented for years from 1996 to 2004. In these years, an important increase of average lean meat percentage was noted (51.9 % in year 1996 vs. 55.9 % in year 2004). As a consequence the percentage of pig carcasses being graded into S and E classes was almost tripled from 1996 to 2004 (21.3 to 58.2%, respectively). This improvement was initiated by the payment according to the lean meat percentage, to which pig breeders responded by better management of herds and partly by increased use of pietrain breed. Potential for further improvement remains in attaining genetically more uniform herds and reduction of carcass weight variability. A new method, introducing an optic probe Hennessy, adapted to changes of the EU legislation, is expected to shift up the average meat percentage close to 57%, which places Slovenian pigs into the EU average.S prispevkom želimo predstaviti slovenske izkušnje pri ocenjevanju mesnatosti prašičjih klavnih trupov po SEUROP sistemu v letih 1996 do 2004. Metoda, ki je bila vpeljana leta 1996 upoštevajoč EU zakonodajo in imenovana DM5, temelji na izračunu odstotka mesa v prašičjem klavnem trupu na podlagi enačbe, ki vključuje dve meritvi na liniji razseka trupa; meritev F, ki je debelina slanine na mestu, kjer je ta najtanjša oziroma kjer se m. gluteus medius najbolj vrašča v slanino ter meritev M, ki je razdalja med kranialnim robom m. gluteus medius in dorzalnim robom hrbteničnega kanala, kot kazalcem debeline hrbtne mišice (slika 1). Zbrali smo mesečne statistične podatke (poprečja in standardne odklone) za obdobje od julija 1996 do decembra 2004 za lastnosti, ki se merijo ali izračunajo; za meritvi M in F, za odstotek mesa v trupih in klavno težo trupov. Zbrane podatke smo prikazali na letni osnovi (preglednica 1). Z regresijsko analizo, oziroma uporabo procedure REG statističnega paketa SAS, smo ocenili mesečne trende ter jih grafi čno prikazali. Rezultati ocenjevanja mesnatosti prašičev na klavni liniji kažejo na velik napredek v mesnatosti prašičev. Poprečni odstotek mesa v trupih se je dvignil iz 51,9 % v letu 1996 na 55,9 % v letu 2004 (preglednica 1), kar v obliki trendov predstavlja statistično značilen (p<0,001) pozitiven trend na ravni 0,045 % mesečno oziroma 0,54 % letno (slika 7). Ta napredek v mesnatosti pripisujemo predvsem uvedbi plačevanja na osnovi odstotka mesa v trupih ter posledično izboljšanju rejskega dela ter deloma tudi večji uporabi pasme pietrain pri križanju; ne moremo pa jih pripisati spremembam v teži klavnih trupov, saj se ta ni bistveno spremenila (preglednica 1). Rezerve za izboljšanje klavne kakovosti prašičev ostajajo v zagotavljanju večje izenačenosti populacije glede na klavno težo in mesnatost. Ugotavljamo namreč veliko variabilnost v klavni teži (preglednica 1), ki bi jo bilo mogoče izboljšati z ustrezno plačilno shemo (pribitki oziroma odbitki glede na klavno težo) ter veliko variabilnost v mesnatosti, ki je delno posledica variabilnosti v teži, delno pa velikega števila različnih genotipov v relativno majhni populaciji prašičev. V letu 2004 naj bi se uveljavila nova metoda, ki temelji na uporabi optične sonde Hennessy Grading Probe in je prilagojena spremembam EU zakonodaje. Pričakujemo, da bo nova metoda dvignila poprečno mesnatost blizu 57 %, ta rezultat pa uvršča mesnatost slovenskih prašičev v EU poprečje

Growth and Mortality of Suckling Rabbit

Rabbits are usually smaller and mortality is higher in large litters. The aim of the study was to estimate effects on mortality and growth in rabbits. The study was carried out in Slovenian SIKA sire line. In total, 430 kits of 60 does were included. In the analyses the effects of parity, number of liveborn kits and number of teats were analysed. Initial weight was included in the model for mortality, while age was included in the model for growth. Parity, litter size and teat number affected all traits, except on mortality. Body weight varied according to age. A total of 430 kits were observed, corresponding to an average litter size of 7.8 kits born, 7.3 kits born alive and 6.2 kits weaned. The birth to weaning mortality was 15.35% and mortality has steadily declined with age. Average weight up to age of three days was 75 g and at weaning 1035 g. Kits in smaller litters had a higher growth rate

Study of genetic diversity of Bisaro pigs breed by pedigree analysis

The objective of this work was to study the genetic diversity of the Portuguese autochthonous pig breed Bísaro by pedigree analysis. Data of Bísaro pigs breed was taken from the database of the National Breeders (Association Associação Nacional de Criadores de Suínos de Raça Bísaro - ANCSUB) concerning the period from 1997 to 2008. For both, pedigree and active population files completeness was evaluated. The number and the proportion of animals with both parents known, sire known, and dam known were computed using the SQL procedure. Population genetic diversity parameters were computed, using the PEDIG software package, for the active population which included animals born from 2003 to 2008. The effective number of founders was 78.8 for boars and 79.7 for sows, while the number of ancestors contributed with 50% of the genes in the breed pool gene was 24 for boars and 23 for sows. A high proportion (52.4%) of animals in the active population are inbred, and 43.9% of the inbreed animals presented inbreeding coefficient higher than 20%. These results suggest that genetic variability needs monitoring in order to avoid the losses of genes in the Bísaro pigs

The Effect of Dam Breed on Calf Mortality in the First Month of Life in Slovenia

The aim of this study was to estimate the perinatal and neonatal mortality rates from day 2 to 30 in Slovenian calves and to evaluate risk factors for increased losses. We analysed data on 1,333,765 calves of different dam breeds, born in Slovenia in the period from January 1 to December 31st, 2012. Data were obtained from the Central register of bovine animals. The average perinatal calf mortality, including abortions and stillbirths, was 5.57% and 2.68% from day 2 to 30. The most significant effects on perinatal calf mortality rate were the number of calves at calving, age of the dam at calving, the herd size, while herd size and calving season were the most influential in the following neonatal period from day 2 to 30. Calves from Holstein Friesian dams showed much higher perinatal and neonatal mortality rates than calves from Simmental, Brown and other dam breeds. With increased herd size, the perinatal and neonatal mortality rate increased. This increase was more pronounced in Simmental, Brown and other dam breeds than in Holstein Friesian dams

Modelling lactation curve in dairy sheep rose under extensive production system

The objective of this study was to compare the goodness-of- fit of four mathematical functions (Wilmink, 1987; Ali and Schaeffer, 1987; Guo and Swalve, 1995; and a cubic regression model) for modeling lactation curve on dairy ewes. Data comprising 53,428 test-day records of daily milk yield (DMY) of 11,251 ewes raised under extensive production system, collected during six consecutive years (2000 to 2005) by the milking recording program of the Churra da Terra Quente (CTQ) dairy sheep breed, were used. Test-day records registered before 30 and after 150 days in milk (DIM) were discharged. All models presented similar fitting quality, with coefficient of determination between 71.0 and 71.3%, and underestimate the DMY for high production levels; this trend was more pronounced for Wilmink model. All models presented similar data fitting-quality, and Wilmink model presented higher difficulties in modeling the beginning and the end of lactation curve, however, being a model with less parameters can present advantages in dairy ewes productions systems where small number of test days controls per ewe can occur