A technology that allows for manipulating of oestrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management due, at least in part, to savings in labour and the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such a technology is now available. It covers procedures for synchronising oestrus based on the use of altrenogest in gilts and of batch-wise weaning in sows, for stimulating follicle development using eCG and for inducing of ovulation using hCG or LH as well as GnRH analogues. While the procedures for oestrus synchronisation stand alone, other procedures require additional treatments. If fixed-time insemination is the goal, oestrus needs to be synchronised and follicular development and ovulation induced by the use of GnRH analogues and hCG with ovulation occurring within 36-42 hrs. It is a general recommendation to inseminate those animals twice, i.e. 24 and 40 hrs after ovulation induction. However, the aforementioned technology requires healthy animals and a solid management and cannot be used to compensate for poor management.

The objective of this study was to determine the chemical composition and fatty acid content in m. longissimus dorsi (MLD) of two indigenous pig breeds (ML -Swallow-belly Mangalitsa and M -Moravka) reared in free range farm conditions and fed complete mixtures used for commercial meat pig genotypes. The body mass of ML and M pigs at slaughter was,on average, 107.14 and 107.61 kg, respectively. In MLD of M pigs, more total fat was measured compared to ML breed (6.96 % compared to 5.10 %, P<0.05). Protein content in MLD of ML pigs was higher by +0.92 % (P<0.01) compared to M pigs. Male castrates of M pigs had more fat compared to gilts of the same breed (8.64 compared to 5.29 %), and the 3.35 % difference between mean values was statistically significant (P<0.05). The breed of pigs influenced the total saturated fatty acids (P=0.011) and mono-unsaturated fatty acid (P=0.003) contents, but not the content of polyunsaturated fatty acids (P=0.325). In the case of saturated fatty acids in the MLD of ML and M pigs, the most common were C16:0 (25.05 % and 25.53 %) and C18:0 (12.73 % and 14.40 %). The MLD of M pigs contained 1.67 % more stearic acid compared to ML pigs (P=0.004). Pigs of ML, compared to M pigs, had more C18:1cis-9 (+2.31 %), C16:1 (+0.49 %), C17:1 (+0.10 %) and less C20:1cis-11 (-0.25 %). The content of two essential fatty acids, C18:2n-6 and C18:3n-3, did not vary according to breed or sex of pigs (P>0.05). The n-6/n-3 ratio was higher than optimal (18.7 for breed ML and 13.7 for M).

In the primiparous lactating sow undernutrition affects LH, but the effect on FSH is less clear. This study was conducted to investigate the effect of ad libitum (AL; n = 5) and restricted (RE; 70% of the AL feed; n = 5) feeding on the secretion patterns of FSH and LH, and on follicular development in primiparous lactating sows. Body side fat thickness (BSFT) was measured prior to farrowing and at weaning on day 21 postpartum (pp). Sows had an intravenous catheter fitted on day 6 or 7 pp. Blood samples were taken on days 12, 15 and 18 pp, every 15 min starting at 0700 h for 11 h, and plasma analysed for FSH and LH by radioimmunoassay (RIA). Daily transcutaneous ultrasonography of the ovaries was performed between days 10 and 20 pp to monitor follicular growth. Reduction in BSFT was higher in RE than in AL sows (p < 0.05). Mean and basal LH were significantly higher in AL than in RE sows on days 12 and 15 pp. (p < 0.05), and LH pulse frequency tended to be higher (p < 0.1). Mean FSH was higher in AL than in RE sows on days 15 and 18 (p < 0.05), and had a tendency to be higher on day 12 (p = 0.1). Follicle size increased in AL sows between days 10 and 20 of lactation (p < 0.05; r = 0.71), but remained unaffected in RE sows. In conclusion, the study demonstrates that feed restriction of primiparous sows during lactation affects not only LH, but also FSH, as well as lactational follicular growth. An association between those events is suggested.

A technology that allows for manipulating of estrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management. Such technology at least in part, saves labor and permits the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such a technology is now available. This 'biotechnology of reproduction' will be reviewed. It covers procedures for synchronizing estrus based on the use of altrenogest in gilts and of batch-wise weaning in sows, for stimulating follicle development using eCG and for inducing of ovulation using hCG or LH as well as GnRH analogues. While the procedures for estrus synchronization stand alone, other procedures require additional treatments. If fixed-time insemination is the goal, estrus needs to be synchronized and follicular development and ovulation induced by the use of GnRH analogues and hCG with ovulation occurring within 36-42 hrs. It is a general recommendation to inseminate those animals twice, i.e. 24 and 40 hrs after ovulation induction. However, the aforementioned technology requires healthy animals and a solid management and cannot be used to compensate for poor management.

Influence of heat stress and age on the percentage of calcium carbonate in eggshell and the percentage of broken and cracked eggs AbstractThe influences on eggs of high temperatures and age were examined in hens that were from a poultry farm situated in the south of the Republic of Macedonia where the average summer temperatures were always the highest. The experiment lasted for 9 months and comprised a period of three seasons: summer, autumn and winter. Maximum and minimum temperatures and relative humidity were recorded every day. Layers were of two different ages. During the research, all production parameters were recorded for the flocks: egg production, mortality, feed-consumption, body weight and the percentage of broken and cracked eggs. Once a month 50 eggs out of each age group were examined. An analysis of egg mass, eggshell mass and percentage of calcium carbonate in the eggshell was performed. At the end of the research the results underwent statistically analysis according to the Least Squares Means method. High temperatures in the region had a highly significant influence (<0.01) over egg size, which was smaller than the average. The heat stress showed high significance (<0.01) in relation to the percentage of calcium carbonate in the egg shell, which was lowest in the summer months and highest during the winter months. The age of the layers did not exhibit significant differences in any parameter examined. The percentage of broken and cracked eggs per month was highest in the summer period.