Volume 12 (2012): Issue 2 (March 2012)

The bond between the mare and her newborn foal is usually a strong one. However, some factors can lead to aberrations of maternal behaviour. Failure to protect and nurse the foal is defined as foal rejection. With a long period of gestation and increasingly high value of foals, foal rejection causes severe losses to breeders. Horse owners and breeders should have knowledge of risk factors, types, prevention rules and treatment of inadequate maternal behaviour. In the case of foal rejection it is important to use fostering techniques in raising such foals.

Recently increasing interest in stem cells of mammalian ovary has been observed. Potential somatic stem cells for the follicular theca and ovarian surface epithelium have been demonstated. On the other hand, despite intensive research, difinitive evidence for stem cell characteristics of granulosa cells is still to be found. Elucidation of stem cell properties of follicular granulosa cells may have important implications both from scientific and clinical point of view. The aim of this work is to review the current knowledge about stem cell properties of cells constituting main somatic compartment of the mammalian ovary, namely granulosa cells.

The objective of the present study was to compare the slaughter value of young bulls of two breeds included in the genetic resources conservation programme, namely Polish Black-White and White-backed with young Polish Holstein-Friesian (dairy type) and Limousin (beef type) bulls. This is the first study to evaluate the meat performance traits of White-backed cattle in several-centuries history of the breed in Poland. It was determined that populations of White-backed and Polish Black-and-White cattle represent the dual-purpose type desirable in the genetic resources conservation programme. The indices obtained for the analysed traits of slaughter value from young Polish Black-and-White and White-backed bulls were intermediate between Polish Holstein-Friesian (dairy type) and Limousin (beef type), but closer to those of the Polish Holstein-Friesian breed. The analysed muscles of young bulls had a very similar content of basic chemical components. The relatively high amount of proteins (22.85-23.23%) in musculus longissimus lumborum and in musculus semintendinosus (22.43-23.06%) should be emphasized.

The aim of the study was to determine the level of basic fattening and slaughter traits (growth rate, level of meatiness and fatness, age at slaughter) depending on different levels of intramuscular fat that determine different sensory perceptions of consumers. Subjects were 4430 gilts from pedigree farms, which were tested in performance stations. The breed composition of the animals was as follows (head): Polish Large White - 1240, Polish Landrace - 2083, Puławska - 104, Hampshire - 35, Duroc - 152, Pietrain - 208, line 990 - 608. Animals were kept in individual pens and fed standard diets. Intramuscular fat (IMF) content of the longissimus dorsi muscle was determined by Soxhlet using the SOXTHERM SOX 406 system (Gerhardt). The level of IMF served as a basis for dividing the test animals into three groups: below 2% (group I), between 2% and 3% (group II) and above 3% (group III). Animal breed had the highest and highly significant effect on the level of all traits analysed. As regards age at slaughter and carcass meat percentage, an interaction was found between animal breed and the group factor determined based on IMF level (P≤0.001). The factor expressed as IMF group had no effect on the level of analysed traits (P>0.05). Therefore, the results of this analysis concerning the parameters obtained from live evaluation do not permit these data to be used in selection for improved IMF levels. The high rate of lean deposition in the modern breeds prevented genetic differences in the level of IMF to fully manifest themselves at a slaughter weight of about 100 kg. This unfavourable information leads one to look for other factors that determine variation of this trait.

The aim of the study was to determine the effect of sex ratio in the litter in which Polish Large White (PLW) and Polish Landrace (PL) sows were born on the number of piglets born and reared to 21 days of age. Results obtained in nucleus herds from one breeding region were analysed. A total of 518 multiparous sows (179 PLW and 339 PL) were evaluated based on data from their litters (790 PLW and 1540 PL litters). The proportion of females in the litter in which the sow was born served as a basis for dividing the females into groups: group 1 <40%, group 2 - 40-50%, group 3 - 50-60%, group 4 - 60-70%, group 5 >70%. Significant differences in the average number of piglets born were found between the groups for PLW sows; compared to sows from groups 1, 2 and 3, females from group 5 gave birth to 8.0% (P≤0.05), 9.4% (P≤0.01) and 6.6% more piglets (P≤0.01), respectively, and compared to sows from group 2, those from group 4 gave birth to 5.1% more piglets (P≤0.05). The average number of piglets born and reared to 21 days by PL sows did not differ significantly between groups. The greater the proportion of females in the litter in which the PLW sow was born, the greater the preweaning mortality of piglets: 0.79, 0.87, 0.99, 1.02 and 1.24 piglets in groups 1 to 5, respectively. Preweaning mortality of PL piglets (0.93, 0.89, 0.81, 0.76 and 0.65 in groups 1 to 5, respectively) decreased with increasing proportion of females in the litter of origin and was lower than that of PLW piglets. It seems appropriate to account for the sex ratio of the litter in which the gilts were born when selecting them as mothers of the next generation as part of herd replacement; this parameter may improve fertility and production efficiency.

Three hydrated monocalcium phosphates differing in purity (with or without monetite, or monetite and calcite) and in crystalline structure were used in broiler chickens diets. The performance indices, concentration of Ca, P and Mg and activity of alkaline phosphatase in blood plasma, the content of these mineral elements in bones, and physico-mechanical parameters of femur and tibia bones were recorded. Body weight on 35th day of life, feed intake and mechanical parameters of bone quality were slightly affected by the type of phosphates used. Higher Ca and P concentration in blood was stated in chickens fed diets with greater purity of phosphates, but activity of alkaline phosphatase has increased with the admixture of monetite or calcite used in phosphates. The best parameters of bone quality were found in the treatment in which hydrated monocalcium phosphate (MCP) with admixture of monetite and calcite was applied. Higher concentration of both Ca and Mg in bone was determined in chickens fed diets with pure phosphates.

The research material consisted of 42 sows divided into 3 feeding groups, 14 individuals in each group, which received feed mixtures with different protein levels. Protein and amino acid levels in the control group were in accordance with recommendations contained in Polish standards. The level of protein in experimental groups was decreased by 10 and 20%, respectively, and the levels of lysine, methionine, threonine and tryptophan were adjusted to those of the control group. During the gestation and lactation periods all sows were fed individually. The content of dry matter, nitrogen, fibre, fat and ash was determined in samples of faeces collected at 60 and 105 days of pregnancy, and the total nitrogen content was assessed in urine. Blood from sows was collected on day 14 of lactation, and indices of protein, fat transformation and mineral components content were determined in blood serum. The results of the analysis of faeces and urine prove that pregnant sows from the experimental groups excreted 7% and 10% less nitrogen in faeces, and 18% and 23% less urine in faeces. The reduced protein level in feed mixtures did not significantly influence the content of dry matter, fibre and ash in faeces. A significant decrease in the content of total protein, globulins, urea and an increase in cholesterol level was observed in the blood serum of sows from both experimental groups. No influence of the reduced protein level in feed on the content of mineral compounds in blood serum or haematological parameters of the sows' blood was noted.

Three experiments were conducted to compare the effect of a decreasing vitamin premix amount in diets from 29 to 42 days of age on performance and immunocompetence of broiler chickens in floor (experiments 1 and 2) and battery cage (experiment 3) systems. The diets were based on corn/soybean meal (experiment 1) and wheat/barley (experiments 2 and 3). On day 34, two birds from each replicate were selected and antibody responses to inoculated sheep red blood cells were determined. The results of experiments 1 and 2 showed that vitamin premix reduction/withdrawal at 29 days of age did not impair performance during the final rearing period. However, the results of experiment 3 showed that from 29 to 42 days of age, performance of birds fed the diet without vitamin premix (T1) was significantly lower than other treatments. The results of three experiments demonstrated that immunocompetence response was not affected by treatments in the finisher period. In conclusion, the results of the present study indicated that in the battery cage system it is possible to reduce dietary vitamin premix during the finisher period but withdrawal can negatively affect performance of broilers. While in the floor system it is possible to withdraw vitamin supplements from finisher diets.

The aim of this study was a complex analysis of organizational and technological factors affecting somatic cell count (SCC) and total microorganism count (SPC) in bulk tank milk produced in the area of Łódź Voivodeship. The study was conducted on the basis of a questionnaire completed directly in 205 family farms, maintaining Polish Black-and-White Holstein-Friesian cows. The data were analysed statistically using multifactor analysis of variance. The following factors decreased SCC in milk: application of mechanical ventilation in the cowshed; disinfection of stalls for cows; frequent inspection of milking equipment efficiency by a specialized service (twice vs. once a year); application of manual pre-milking udder massage; dry period of a standard length of 6-8 weeks (vs. 2-5 weeks); application of concentrates in amounts of at least 3 kg/day/cow; application of meadow hay and straw or hay only among roughages in cow feeding (vs. straw only); addition of vitamin E and Cu to feeding ration for cows and individual housing of replacement heifers between 1-3 months of age (vs. group system). In turn, the following factors decreased SPC: participation of milkers in specialist trainings; cleaning of teats before milking using wet towel or washing with water containing a disinfectant; "dry" storage of milking equipment between milkings; culling of cows due to mastitis; application of vitamin A and Zn; no use of milk from mastitic cows in calf feeding; and individual housing of replacement heifers during the first month of life.

Birth weight (BW) is frequently considered as an indicator to detect possible restrictions of intrauterine development. This study evaluated the effect of breeding season (BS) across year: spring (SP), summer (SM), fall (FL) and winter (WT) upon the expression of BW. This meta-analysis considered records (n = 1,084) collected from a commercial herd kept under intensive conditions (22° NL, 1,835 m). The definitive statistical model for BW analysis considered the independent variables kidding year, (KY), genetic group (GT), litter size (LS), gender (GN), breeding season (BS), kidding season (KS) plus the interactions (KY^*GT) and (GN^*BS). BW expression was affected (P<0.05) by KY, GN, LS, KS, and KY^*GT. Interestingly, while BW expression was not affected (P>0.05) by kidding season, it was affected (P<0.05) by breeding season. The highest and lowest BW values were observed in SP and WN (3.34 vs. 3.10 kg; P<0.05), respectively. This physiological scenario could be the result of embryonic-fetal adaptive responses representing homeostatic adaptations due to alterations including doe nutritional status, available quantity and quality of food to both the embryo and the fetus as well as to a changing external environment.

The objective of the study was to evaluate laying performance and quality indices of consumption and hatching eggs in hens from conservation flocks fed a diet containing maize distillers dried grains with solubles (DDGS). A total of 360 Greenleg Partridge (Z-11) and Rhode Island Red (R-11) hens, included in the genetic resources conservation programme in Poland, were investigated. The good performance obtained by layers fed the DDGS diet indicates that maize distillers dried grains with solubles can serve as a useful source of protein in the nutrition of hens from conservation flocks, partly replacing imported soybean meal. The dietary inclusion of DDGS improved laying performance while maintaining hatchability traits and the quality of consumption eggs. The DDGS diet had an effect on nutritionally important egg quality traits, i.e. increased protein content of egg albumen and increased concentration of oleic and linoleic acids in yolk lipids, with a simultaneous increase in n-6:n-3 PUFA ratio. Dietary inclusion of DDGS also increased yolk colour intensity and Haugh units while having no effect on eggshell quality.

The objective of the present study was to evaluate the effect of breed and feeding system on the content of selected whey proteins in cow's milk collected in the spring-summer and autumn-winter periods. A total of 2,278 milk samples from Black- and Red-and-White variety of Polish Holstein-Friesian cows and Simmental and Jersey cows were examined. In each sample the content of selected whey proteins, i.e. alpha-LA, beta-LG, lactoferrin, BSA and lysozyme, was analysed by RP-HPLC method. Evaluation of the simultaneous effect of breed and production season on whey protein content showed significant interactions (P≤0.05 and P≤0.01) for all analysed whey proteins. The milk of Simmental cows kept in the conventional system was characterized by a higher content of whey proteins (with the exception of BSA), in comparison to the cows managed under TMR system. Furthermore, for most of the evaluated components, except the content of BSA and lysozyme and the alpha-LA/beta-LG ratio, the simultaneous effect of feeding system and production season was also found.