Predrag Perisic

Simmental cattle breed in different production systems

The paper gives the analysis on the state in population of Simmental cattle reared in Europe with a special review on the state in Simmental cattle in our country which makes about 80 % total cattle fund in Serbia, and is characterized by a negative trend in the number of cattle, as well as by a low average milk production per cow. The most important results obtained by both domestic and foreign authors by means of various methods of improving Simmental breed and its raising in different systems have been shown. The directions for improving Simmental cattle according to the productive directions have been analyzed. Possible methods of improving the Simmental cattle in our country have been pointed out, which should be in accordance with already existing genetic potential of each actual population, its purpose (registered breeding stock, production breeding stock), as well as with the market needs for cow milk, milk products and meat (primarily beef meat, for export). A special emphasis has been given to the importance of organizing the production of meat in the cow-calf system in which Simmental breed, following the model of many European countries, should have good performance also in our country, if the same production should be organized in deserted hilly and mountainous regions. In this way we could contribute to more significant increase in overall beef production, and to reactivate unused natural resources as well.

The state in the sector of milk production in European Union and in our country

The paper gives an analysis of the state in milk production from the aspect of total produced quantities of milk and total purchased quantites of milk by the diaries in EU. The number of farms engaged in cattle production has been analysed, along with the farms engaged in milk production. Trend in development of cattle breeding in EU is going in the direction of decreasing the number of farms raising the breeding stocks of dairy cows and to the simultaneous increase in the number of cows per farm for milk production with constant increase of the quantity of milk produced per cow. In 2008 the number of cows per farm in EU27 was on average 9.8 cows, in EU25 on average 16.6 cows, with great variation among member countries observed. Average milk yield in total cow population in 2008 in EU15 was 6646 kg, in EU25: 6357 kg and in EU27: 6133kg. In Serbia the average milk yield in registered cows of Simmental breed is about 4500 kg, and in Holstein Friesian breed around 8700 kg. It is important to emphasize that in Serbia there is a far less number of cows under controlled milk yield (around 5.5% Simmental cows in total number), and that there is a decline observed in the number of cattle in Serbia in the last decade per average rate of 2-3 % annualy.

The influence of age at first fertilization on some reproductive and performance traits of Simmental cows in first three lactations

Certain reproductive and performance traits of Simmental cows, as well as the demonstration of those traits depending on the effect of age at first fertilization, were investigated. The investigation included 606 cows, divided according to age at first fertilization, in 10 groups (one month difference among groups). Statistical analysis of data was done by method of Least squares (LSMLMW, Harvey, 1989), the model with fixed influence of factors on observed traits was applied. Established results have shown that the age of head of cattle at first fertilization had highly significant effect (P 0,05).

The effect of level of non-degradable protein in diet on fattening parameters and digestibility of nutrients in lambs.

Results of the study of the effect of the level of non- degradable protein in diet on fattening performance and digestibility of nutrients in weaned lambs are presented in the paper. Objective of the study was to establish the optimal level of non-degradable protein in diets for weaned and intensively fattened lambs. Experiment was conducted on 60 lambs of F1 generation: Pirot Pramenka x Wurttemberg x Ile de France, weaned at the age of 60 days and divided into three groups. The effect of use of three concentrated mixtures which differed in the share of protein non-degradable at the level of rumen: 43% (I), 51% (II) and 58% (III). Average daily gain of lambs fed types of mixtures I:II:III was 0.169: 0.205 : 0.227 kg, respectively. Dry matter conversion (kg/kg of gain) on analogue treatments was: 4.54 : 3.71: 3.30, respectively, of energy (MJ NEM/kg) : 33.77: 29.37 : 26.25, and of total proteins (g/kg): 732 : 596 : 549. Level of intake of proteins was not influenced by the treatment considering that the digestibility coefficients recorded were: 52.58% : 51.30% : 55.12%. With the increase of the share of non-degradable protein in concentrate mixtures, the tendency of increase of the digestibility of fat was present: 76.13 : 77.98 : 87.17%, as well as of decrease of the intake of fibre: 67.40 : 45.87: 22.39% and NFE: 83.87 : 76.05 : 82.96%. Values of the dressing percentage of warm carcass with giblets according to nutrition types I:II:III were: 58.70 : 58.02 : 57.42%, respectively.

Changes in body proportion of roe deer with age

The aim of the present study was to estimate the development of body and some body parts and internal organs of roe deer, from 1 year of age (fawn) to 2-3 years of age (Buck). Average body mass of fawn was 16.6 kg and of buck 26.4 kg. Body mass of buck was by 1.6 times greater than body mass of fawn. Similar growth intensity was established for body parts (thighs shoulders, loin and back). The proportion of parts in body and carcass mass was same in fawn and buck. The mass of internal organs (liver, lungs, heart and spleen) increased with age, but proportion in regard to body mass was same in case of fawn and buck. During the first three years of age, no significant changes in body proportion of roe deer were registered.