N. Maksimovic

The effects of crossing Balkan and Saanen goat breeds on carcass traits and certain quality parameters of kid meat.

The Effects of Crossing Balkan and Saanen Goat Breeds on Carcass Traits and Certain Quality Parameters of Kid Meat The possibility for improvement of carcass traits and quality of kid meat of the autochthonous Balkan goat breed by crossing with Saanen breed was investigated in this study. The trial was carried out on one group of Balkan goat kids and three groups of kid crosses of Balkan and Saanen goats with different proportion of Saanen genes: 25, 50 and 75%. Each group had 16 male kids, which were slaughtered at the average body weight of 18 kg. With the increase in the proportion of Saanen genes, the age of kids that reached preslaughter weight decreased, the chilling loss increased and the proportion of fat tissue (kidney and pelvic fat) in the carcass side decreased (P≤0.05). The crossing also increased the proportion of carcass parts of the first category (leg and loin section), as well as muscle tissue in those parts. The highest proportion of muscle tissue in the thigh (74.91%) and loin section (75.66%) was determined in kids from the group with 75% of Saanen genes, and kids from this group also had the highest proportion of intramuscular fat (2.48%) in samples of m. longissimus dorsi. Slight differences between kid groups were established in indicators of technological meat properties, such as water binding capacity and tenderness, with the increase in the proportion of Saanen genes in the genotype. Sensory score for roasted meat was high, and scores for tenderness and juiciness were slightly higher in kid crosses with 50% and 75% of Saanen genes (P≤0.05). Results presented in this study confirm the positive effect of crossing the Saanen breed with the Balkan breed on carcass traits and for obtaining meat of more desirable quality. Wpływ krzyżowania kóz rasy bałkańskiej i saaneńskiej na cechy tuszy i niektóre parametry jakości mięsa koźląt Badano możliwość poprawy cech tuszy i jakości mięsa koźląt autochtonicznej rasy bałkańskiej poprzez krzyżowanie z rasą saaneńską. Doświadczenie przeprowadzono na jednej grupie koźląt rasy bałkańskiej i trzech grupach koźląt pochodzących z krzyżowania kóz bałkańskich i saaneńskich o różnym udziale genów rasy saaneńskiej: 25, 50 i 75%. W każdej z grup znajdowało się 16 samców koźląt, które ubijano przy średniej masie ciała wynoszącej 18 kg. Wraz ze wzrostem udziału genów rasy saaneńskiej wiek koźląt, które osiągnęły przedubojową masę ciała, zmniejszał się, straty masy tuszki podczas schładzania rosły, a udział tkanki tłuszczowej (tłuszcz nerkowy i miednicowy) w półtuszy ulegał zmniejszeniu (P≤0,05). Krzyżowanie zwiększyło także udział części tuszy pierwszej kategorii (udziec i polędwica) oraz udział tkanki mięśniowej w tych wyrębach. Najwyższy udział tkanki mięśniowej w udzie (74,91%) i polędwicy (75,66%) stwierdzono u koźląt z grupy o 75% udziale genów rasy saaneńskiej. Koźlęta te charakteryzowały się także największym udziałem tłuszczu śródmięśniowego (2,48%) w próbkach mięśnia najdłuższego grzbietu. Niewielkie różnice pomiędzy grupami koźląt wraz ze wzrostem udziału genów rasy saaneńskiej w genotypie, stwierdzono we właściwościach technologicznych mięsa, takich jak zdolność wiązania wody i kruchość. Mięso pieczone uzyskało wysoką ocenę sensoryczną, a ocena punktowa za kruchość i soczystość była nieznacznie wyższa u krzyżówek koźląt o 50 i 75% udziale genów rasy saaneńskiej (P≤0,05). Wyniki uzyskane w tym doświadczeniu potwierdzają pozytywny wpływ krzyżowania rasy saaneńskiej z rasą bałkańską na cechy tuszy i uzyskanie mięsa o bardziej pożądanej jakości.

Relationship between birth weight and body growth characteristics of lambs.

Research was carried out in population of R2 generation Pirot pramenka x Pirot improved sheep during period of three years. Lambs were divided into three groups: I from 2.5 kg to 3.5 kg; II from 3.6 kg to 4.5 kg; III from 4.6 kg to 5.5 kg. Weight of lambs was controlled at birth, with 30, 60 and 90 days of age. Average body weight at birth of the tested lambs was 3.35 kg in the first group, 4.30 kg in the second group and 5.06 kg in the third group. At 30 days of age, the body weight of the lambs was 10.19 kg in the first group, 11.39 kg in the second and 12.49 kg in the third group. All these differences in body weight of lambs at birth were statistically highly significant (P_ 0.01). With 60 days of age, average body weight was 16.48 kg in the first group, 19.01 kg in the second and 20.49 kg in the third group. Differences between groups of lambs at this age were statistically very significant (P_0.01).On the end of experiment at 90 days of lambs age, we have found the following values of the body weight of lambs: 26.35 kg in the first group, when the second 30.49 kg and 28.93 kg in the third group. Differences between groups of lambs at this age were statistically very significant (P_0.01). At the age of 90 days maximum weight of the body was in the second group of lambs, or a group which body weight at birth occupied the mean of the population. Correlations between body weights of lambs vary from weak to midsized values. The highest values of correlation coefficients were found between body weight at birth and weight of lambs at 30 days of age.

Eco-fish meal as an alternative to fish meal in diets for lambs

The effect of Eco-fish meal, as an alternative to fish meal, on the production performance of the lambs of the Mis population in the intensive fattening, was investigated. The experiment was carried out on 40 lambs, the average age of 30 days, divided in 2 groups. In addition to mother’s milk, the lambs were given a concentrated mixture and a lucerne hay, at will. Isoprotein forage mixtures (16% of total proteins) differed in terms of the protein component. The protein source for treatment I had fish meal, while the animals on treatment II consumed EcoFish, a herbal substitute for fish meal, which consisted of domestic foods of known origin such as genetically unmodified and thermally treated meal of decorticated soybean grains, soybean protein isolates, gluten, livestock yeast with the addition of minerals, amino acids, vitamins, enzymes and other additives. Statistical processing of the obtained data was done using the SPSS STATISTICA, Version 20. On treatments I and II, the average daily lamb gain was 320 and 283 g, respectively, without statistical significance. The consumption of dry matter and proteins in analogue treatments was 0.819 and 0.823 kg, and 152.62 and 157.04 g, respectively. The dry matter consumption per kilogram of gain (kg/kg of gain) was 2.56 and 2.91; of energy (MJ NEM/kg): 17.65 and 20.25; of total proteins: 476.9 and 554.9 g, respectively. The protein efficiency ratio PER (g of gain/g of consumed protein) in analogue treatments was: 2.09 and 1.80. There were no statistically significant differences between examined treatments (P> 0.05). Considering that the source of protein did not significantly affect the intensity of growth and the use of food by lambs of Mis population in intensive fattening (P>0.05), fish meal can be replaced by Eco-fish meal plant protein, since according to Commission Decision 9/2001 on BCE protection (OJEC, 2001), there is a distance to the use of fish meal, as a source of protein.

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.