Martin Ptáček

Relationships between milk fatty acids composition in early lactation and subsequent reproductive performance in Czech Fleckvieh cows.

Increase of milk yield after calving causes changes in milk fatty acids (FA) composition and simultaneously corresponds with reproduction performance decrease. The objective of this study was to evaluate the relationships between milk FA group composition (SFA, saturated fatty acids; MUFA, monounsaturated fatty acids; and PUFA, polyunsaturated fatty acids) during the first 5 lactation weeks and subsequent reproductive results (INT, calving to first service interval; NUM, number of services per conception, and DO, days open) in Czech Fleckvieh cows. A total of 1231 individual milk samples from 382 cows were collected and subsequently analyzed. Simultaneously, body condition score (BCS) was weekly evaluated as well. Software SAS 9.1 was used for statistical analysis. Daily milk yields increased whereas BCS, milk fat and protein contents decreased during period observed. The reduction of basic milk components (% of fat, % of protein) was associated with increased SFA and decreased MUFA, respectively PUFA contents. Significant (P<0.01-0.05 days) increase in NUM (+0.15 to +0.29 AI dose) and DO (+8.16 to 15.44 days) were detected in cows with the lowest SFA content. On the contrary, cows with the highest content of MUFA presented significantly (P<0.01-0.05) higher values of NUM (+0.13 to +0.30) and DO (+7.26 to +15.35 days). Milk FA groups composition in early lactation potentially used as NEB indicators, especially SFA and MUFA proportion, affected subsequent reproductive results of Czech Fleckvieh cows. Therefore, its post-partum values could serve as predictors of potential fertility of dairy cows.

Effects of age and nutritional status at mating on the reproductive and productive traits in Suffolk sheep kept under permanent outdoor management system

Ptáček M., Ducháček J., Stádník L., Fantová M. (2017): Effects of age and nutritional status at mating on the reproductive and productive traits in Suffolk sheep kept under permanent outdoor management system. Czech J. Anim. Sci., 62, 211–218. This study examined the variability of reproductive and productive traits in Suffolk sheep (a commercial flock, n = 316 ewes) with regard to the dams’ age or the nutritional status of sheep at mating under a year-round outdoor management. Data were collected across a 3-year monitoring period (totally 655 observations). The fixed effects of dam’s age (dams grouped as: 2, 3, 4, 5, 6 years and older), ewe’s live weight (LW; ewes grouped as: < 72 kg; 72–83 kg; > 83 kg), and backfat thickness at mating (BT; ewes grouped as: < 7.9 mm; 7.9–10.5 mm; > 10.5 mm) were evaluated. The dam’s age influenced reproductive and productive traits such that 2and 6-year and older ewes reached the lowest values. Ewes with LW > 83 kg had significantly higher lambing rate (11.8%) compared to those with LW < 72 kg. The group of ewes with LW < 72 kg gave birth to a significantly lower number of live lambs in litter (–8.9%) in comparison with LW < 83 kg group. An increase (9.9%; P < 0.01) of total litter weight at birth or an increase (12.5%; P < 0.05) of total litter weight at 100 days of age were detected in LW > 83 kg group compared to LW < 72 kg group. BT > 10.5 mm ewes had by 8.9% lower lambing rate (P < 0.05), by 6.8% lower litter size (P < 0.05), by 14.5% lower number of live lambs in litter (P < 0.01), and by 8.6% lower total litter weight at birth compared to BT < 7.9 mm ewes. A significantly lower total litter weight at 100 days of age (–10.8%) and a significantly lower total litter gain from birth to 100 days of age (–11.5%) were detected in BT > 10.5 mm ewes in comparison to BT 7.9–10.5 mm ewes.

Influence of selected factors on growth performance of Suffolk lambs and their crossbreds

The monitoring was performed in one year period in selected population of Suffolk sheep (SF, n = 257) and their crossbreds with Merinolandschaf (SF × ML, n = 87). Total of 627 lambs (SF, n = 463; SF × ML, n = 164) were observed in breeding conditions of two semi-extensive flocks. Lambs’ live weight at 100 days of age (LW100); musculus longissimus lumborum et thoracis (MLLT100) depth and backfat thickness (BT100) at the same age were assessed. Effects of breed, ewes’ live weight at mating, litter size, sex of lambs and ewe’s age as linear regression were evaluated using SAS 9.1. Significant differences (P < 0.05) in LW100, MLLT100 and BT100 between SF and SF × ML were observed. All the evaluated traits of growth performance were also influenced (P < 0.05) by ewes’ live weight at mating. The highest lambs’ growth performance traits were detected in lambs of ewes with highest live weight at mating (group of ≥ 80.7 kg). Significant differences (P < 0.05) were observed among singles, twins and triplets lambs as well. Significantly higher LW100 was marked in ram lambs compared to ewe lambs (P < 0.05).

The comparison of milk production and quality in cows from conventional and automatic milking systems

The objective of this study was to evaluate the effects of two different types of milking systems (conventional parlour vs. automatic milking system) and the season of the year on the composition and hygienic quality of milk from Czech Fleckvieh cows. A total of 500 cows were involved; 200 and 300 in conventional and automatic milking systems, respectively. Bulk milk samples were collected for 12 months from July 2010 to June 2011. The following milk components and quality indicators were determined: % of fat, % of protein, % of lactose, % of fat-free dry matter (FFDM), % of casein, urea content, somatic cell count (SSC), total germ count (TGC) and milk freezing point (FP). The data were processed and evaluated with MS Excel and the statistical software SAS 9.1. Significantly higher (P<0.05 – 0.01) contents of fat, protein, FFDM and casein and increased TGC were observed in the automatic milking system, whereas SCC and FP were significantly lower (P<0.01). The highest contents of fat, protein and casein, and the lowest lactose content were found in the winter season. The highest contents of FFDM, urea and SCC were observed in autumn, whereas TGC was highest in summer (P<0.05 – 0.01). Only FP was not influenced by the season.

Histochemical Muscle Fiber Characteristics of Texel Meat

The trial was performed on 12 Texel lambs (6 males and 6 females) in selected flock. The lambs were slaughtered at the age of 180 days and samples of musculus longissimus lumborum et thoracis (MLLT) and musculus quadriceps femoris (QFM) were collected. The histochemical traits of fiber cross sectional area, diameter and perimeter were monitored. Subsequently the fiber type distribution was calculated and evaluated. The dataset was evaluated using SAS. Significantly higher pH value (+0.88; P < 0.01) was marked in females, while significantly higher L* attribute was observed in males. No differences between males and females were detected in histochemical evaluation. On the other hand significant differences (P < 0.05 to 0.01) were observed in fiber type distribution and cross sectional area parameters of MLLT and QMF muscles. In praxis the results are usable for meat scientists, sheep breeders or the meat industry.

Development of the body size in stallions of selected Bohemian-Moravian Belgian horse, Silesian Noriker and Noriker breeds in the Czech Republic

The aim of this work was to evaluate the basic body measurements (stick height at withers - KVH, tape height at withers - KVP, chest perimeter - OHR, shin perimeter - OHOL) from data available from the 40th years of the 20th century in the Bohemian- Moravian Belgian horse, Silesian Noriker and Noriker breeds. The evaluation included a total of 1,080 stallions aged 2-3 years, used in mating and breeding. Processing and evaluation of a data set was done using Microsoft Office Excel and the statistical program SAS 9.3. Numerous statistically significant differences were found among the evaluated breeds (P < 0.05 to 0.01). The highest values of KVH, KVP and OHR were achieved by stallions of Bohemian-Moravian Belgian horse. The increase of the basic dimensions from 40´s years to 70´s – 90´s years was found during a detailed evaluation focusing on decade of stallions’ birth year. After year 2000, there was a dramatic drop in the values of the fundamental physical dimensions. Statistically significant differences (P < 0.05 to 0.01) were evaluated primarily between stallions born in the 70´s years, and most other decades. A declining tendency in all assessed dimensions was observed during evaluation of the race and decade interaction effect mainly for the Czech-Moravian Belgian horse stallions born from 70´s, respectively 80´s. Apparent downward trend between the 90´s and stallions born after year 2000 was detected especially for stallions of Silesian Noriker breed. Decline of body size parameters was not observed for stallions of Noriker breed. The more likely slightly increased tendencies for KVH, KVP, OHR and OHOL were determined in Noriker stallions.