Productive Performance and Egg Quality of Laying Hens in Post-Moulting production Cycles

Martin HALAJ, Peter HALAJ, Branislav ROHÁČEK, Henrieta ARPÁŠOVÁ   (Slovak Agricultural University, Nitra)
Paper is in Slovak

    Repeating of egg-laying cycles was studied in the Shaver Starcross 288 laying hen hybrid. Experiment 1 involved laying hens at 18 weeks of age and moulted laying hens after a 10-month laying period included in the second cycle. For experiment 2, laying hens from experiment 1 were chosen, subjected to forced moulting using the traditional method, based on restriction of water /1 day/, feed /6 days/ and light /15 days/. A course of moulting, productive performance, and quality and standard of eggs were investigated during a 10-month laying period (first and second cycles) in experiment 1 and an 8-month period (first, second and third cycles) in experiment 2. During moulting the weight of hens was reduced by 30-32%. They stopped laying after 6-7 days from the beginning of forced moulting, and a total loss of feathers was observed after 13-15 days. The first egg was laid after 26-34 days and 50% of total laying was reached after 50-58 days from the start of moulting. Over 10 months, hens produced 233.42 eggs in the first cycle and 204.02 eggs in the second one. With an 8-month egg-laying pOeriod it was 180.1,171.6 and 165.6 eggs in the first, second and third cycles, respectively. In experiment 1, feed conversion (g/g) was 2,491 g in the first cycle and 2,783 g in the second cycle and in experiment 2, it was determined to be 1,952 g, 2,568 g and 2,825 g in respective cycles. With the appropriate organization of egg-laying cycles and utilization of the potential ability of hens to produce egg mass, effective production of market eggs can be obtained, i.e. 26.52 kg egg mass per hen in 2 cycles within a ten-month laying period and up to 33.06 kg egg mass per hen in 3 cycles within an 8-month period.

Key words: laying hens, forced moulting, productive performance, egg quality


Adress: Ing. Peter Halaj, CSc., Slovenská poľnohospodárska univerzita, Fakulta záhradníctva a krajinného inžinierstva, Hospodárska 7, 949 01 Nitra, Slovak Republic
e-mail:Peter.Halaj@uniag.sk

Effect of Calving Balance on Milk Production of Slovak Spotted Dairy Cows

Margita RYBANSKÁ, Jozef BUJKO   (Slovak Agricultural University, Nitra)
Paper is in Slovak

    A study was carried out to evaluate the milk yield in different seasons of calving in a set of 462 Slovak Spotted dairy cows and their crosses with red Holstein-Friesian cattle (a blood proportion up to 50 % and 25%. According to calving date (month), tested cows were divided by into 4 groups (seasons): 1. XII = I = II, 2. Ill - IV - V, 3. VI = VII = VIII, 4. IX = X - XI. Results from the analysis showed that in terms of milk yield the best time for cows to calve is the 1st and 2nd season when Slovak Spotted type dairy cows produced 4,600 kg and 4,740 kg of milk, 50% crossbred cows 4,650 kg and 5,015 kg and 25%, crossbred cows 4,537 kg and 4,663 kg of milk, respectively. There was a similar tendency of the changes in fat and protein content, depending on milk production.

Key words: Slovak Spotted cattle, Holstein-Friesian crossbred cows, milk production, calving of cows, seasonal calving


Adress: doc. Ind. Margita Rybanská, CSc., Slovenská poľnohospodárska univerzita, Fakulta agrobiológie a potravinových zdrojov, Katedra genetiky a plemenárskej biológie, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic

Nutria Fertility of Chosen Genotypes in Farm Breeding in Slovakia

Dušan MERTIN, Jana HANUSOVÁ, Pavol FĽAK   (Výskumný ústav živočíšnej výroby, Nitra)
Paper is in Slovak

    The aim of this work was to study the litter size of primiparous nutria females of different genotypes under conditions of farm breeding in west Slovakia over four years (1995-1998). The average number of offspring in the first litter ranged from 3.27 to 5.55. The biggest litter size was observed for Greenland and the lowest for silver nutrias. Out of the total number of fertile standard and Greenland females, 40.8% and 40.2%, respectively gave the birth to 5 young animals per litter. As far as silver females and crosses are concerned, most females (41.1% and 40.6%, respectively produced 4 young per litter. A comparison of frequencies of litter size occurrence among the studied genotypes showed the genetic determination of this parameter. The average litter size of primiparous female nutrias in farm conditions was 4.53±0.09 young. Based on these results, it can be concluded that the fertility of nutrias is highly significantly influenced by genotype, breeding, and year.

Key words: nutria, Myocastor coypus, genotype, fertility


Adress: Ing. Dušan Mertin, PhD., Výskumný ústav živočíšnej výroby, Ústav chovu malých hospodárskych zvierat, Hlohovská 2, 949 92 Nitra, Slovak Republic
e-mail:mertin@vuzv.sk

Changes in Botanical Composition of Grassland after Renovation

Ľubomír HANZES, Iveta ILAVSKÁ   (Výskumný ústav trávnych porastov a horského poľnohospodárstva, Banská Bystrica)
Paper is in Slovak

    Control of the botanical composition of a sward heavily infested with tufted hair grass (Deschampsia caespitosa L. (P. Beauv.) A trial was established at a site of an altitude of 1,300 m on grassland within the area of Nizke Tatry National Park (NAPANT) in 1997 and research was conducted over 1998-2000. Changes in the botanical composition were investigated after mechanical treatment of the sward, followed by drilling and sowing a grass-clover mixture. The sward was utilised by 2 cuts and the botanical composition was determined by the method of projective dominance before cuts. Mechanical and biological interventions influenced significantly the composition of phytocoenosis. A proportion of D. caespitosa decreased from 56% in the original sward to 8-18% in the third experimental year. Consequently, there were changes in the proportions of botanical groups, and diversity of valued forage species increased. From the viewpoint of feeding value, characteristics of the treated swards ranged from less valuable to semi-cultural ones. Efficiency of the sward improvement techniques used during research was satisfactory. Treatment 1 (rotary tilling of whole surface area prior to sowing, broadcasting) was found to be the most efficient in terms of the botanical composition changes of the sward and its feeding value. However, a long-term effect of the treatments may be expected only if adequate grassland management practices are applied.

Key words: Deschampsia caespitosa L. /P.Beauv/, phytocenosis, botanical composition, diversity, feeding value


Adress: Mgr. Ľubomír Hanzes, VÚTPHP, VP Poprad, ul. SNP 2, 058 01 Poprad, Slovak Republic, tel.:+421-52-776 70 82
e-mail:ppvutphp@isternet.sk

Effect of Fertilizing on Root System Changes of Grasslands

Ján JANČOVIČ, Ľuboš VOZÁR, Simona PETRÍKOVÁ, Pavol SLAMKA   (Slovak Agricultural University, Nitra)
Paper is in Slovak

    An amount of root mass created in a 0-100 mm soil profile of a grassland was investigated in a period covering three years (1993-1995). Three types of grassland, i.e. permanent grassland (TTP), temporary grassland (DTP), grassland (PTP) with added seed and four treatments of fertilization were tasted for dynamics of root mass growth. Nitrogen fertilizers were applied to respective growth periods of cuts in even doses, and P and K fertilizers in one-shot application in spring. The grasslands were exploited by mowing three times during the growing season. An interval root increment of three types of grasslands ranged from 0.06 kg/m² to 0.03 kg/m² in the experimental years. A significant effect of years on the accumulated root mass amount was confirmed when a sum of precipitation in the growing season (r=0.797+) seems to be the decisive factor. On the contrary, the effect of both different mineral nutrition and a type of grassland on root mass accumulation was not confirmed. Lower root mass increments in the grassland with added (PTP) can also be caused by the allelophaty effect.

Key words: grassland, fertilization, root system, root increments


Adress: Prof. Ing. Ján Jančovič, PhD., Slovenská poľnohospodárska univerzita, Fakulta agrobiológie a potravinových zdrojov, Katedra krmovinárstva, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic, tel.:+421-37-650 82 34
e-mail:Jan.Jancovic@uniag.sk

Effectiveness of Feed Mixtures with the Different Content of N-Substances in the One-Phase Fattening of Pigs

Roman GÁLIK, Jozef GARLÍK, Pavol MILLY   (Slovak Agricultural University, Nitra)
Paper is in Slovak

    Thirty four-bred hybrid pigs L (BuxL) x o-(Du x Pn) were used in a 115-day experiment to study the effect of feeding animals single feed mixture during whole fattening period. Pigs with a 30 to 100 kg live weight were divided into 3 groups of 10 heads each. Experimental groups (EG) I, II, and III were offerred food with a different content of N-substances (16.03,17.26 and 19.17% in dry matter (DM)) and of essential amino acids, and with an amount of lysine per MJ. Meo. Energy value of mixtures was calculated by means of average coefficients of digestibility as determined by the indicator method. Different levels of N-substances were obtained by a different proportion of soya-bean extracted groats in feed mixtures. The highest average daily gain (664 g) during all the experimental period was observed in the group which was offered diet with a middle content of N-substances (172.6 g N-substances or 7.24 g lysine per kg food DM). Food consumption per kg gain was 3.43 kg. According to the parameters of carcass quality and nutrient content in muscles DM, there was no significant difference between groups (P more than 0.05). The animals in EG III showed a higher DM content in liver (vs. EG I and II; P less than 0.05), the highest content of fat in DM (vs. EG I; P less than 0.01) and the lowest content of residual N-substances (vs. EG I; P less than 0.05). Differences in the relative proportion of fatty acid content in the fat of products were not statistically significant.

Key words: fattening experiment, feed mxtures, digestibility, metabolizable energy, N-substances, lysine, nitrogen parameters of fattening, carcass quality, chemical analysis of products, hybrid of pigs


Adress: Ing. Jozef Garlík, PhD., Slovenská poľnohospodárska univerzita v Nitre, Fakulta agrobiológie a potravinových zdrojov, Katedra výživy zvierat, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic, tel.:+421-37-6508 321
e-mail:Jozef.Garlik@uniag.sk