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The aim of the research was to determine the influence of Limousine cow body condition scores (BCS) before calving on the course of calving. 371 purebred Limousin cows in Poland were the material of the investigations. The body condition score was estimated using a 9 point scale according to Richards (24) directly before the planned calving day. The following levels were used: 1 - bad (notes of 1, 2, 3); 2 - suitable (notes of 4, 5, 6, 7); 3 - more than adequate (notes of 8, 9). All the animals were weighted. The calving course was qualified to one of the following categories: N - easy, without any assistance; T difficult, with farmer’s help or mechanical means used. The ratio of different calving courses of Limousin cows depending on their body weight and condition (BCS) just prior to calving was analysed. The correlation coefficient between calving course and Limousin cows BCS was low (r = -0.17), but statistically significant. The highest ratio of difficult calvings was noticed for cows for which the body weight did not exceed 500 kg (36.1%) as well as for the heaviest ones - exceeding 800 kg (25%). BCS notes 5, 6, 7 proved to be optimal (the majority of calvings were examined as easy). All of calvings from cows with notes of 1, 2, 3 had to be assisted.
Badano koncentrację Ca, Mg, P, Na, K, Cl i Fe w surowicy krwi krów przed porodem (w 9. miesiącu ciąży) - grupa A. Wyniki porównano z wartościami otrzymanymi w grupie krów laktujących (niezacielonych) - grupa B - przy tym samym systemie utrzymania obydwu grup. Wszystkie badane biopierwiastki u krów w okresie przedporodowym mieściły się w granicach wartości referencyjnych dla bydła. Duże niedobory jo nów chlorkowych stwierdzone u krów w okresie laktacji prawdopodobnie miały związek z intensywną produkcją mleka. Istotne różnice pomiędzy badanymi grupami zwierząt wystąpiły również w poziomie magnezu. Wyższa zawartość Mg w surowicy krów laktujących mogła wynikać z większej objętościowo dawki paszy treściwej przysługującej krowom w okresie laktacji.
Magnesium (Mg) is an activator of more than three hundred enzymes and a cofactor in synthesis and release of hormones. Currently, magnesium deficiency occurs in dairy cows most frequently in subclinical form, with symptoms limited to decreased appetite and decreased milk yield. The study covered 75 cows: 50 cows, which were diagnosed with magnesium deficiency in the antenatal period. The control group consisted of 25 healthy cows. In group I (n = 25) increased supplementation was not applied; in group II (n = 25) the intake of Mg was increased, using a 7% magnesium supplement. Blood samples for tests were taken 2 weeks prepartum and 1 and 2 weeks postnatally, indicating the concentration of: total magnesium (Mg), total calcium (Ca), inorganic phosphorus (Pi), copper (Cu), zinc (Zn), total bilirubin (tB), total protein (TP), glucose (Glu) and cholesterol (TC) as well as the activity of aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGTP). In group 1, the highest number of cows with decreased appetite and postpartum weakness was identified, which exhibited the lowest increase rate of milk production and significantly lower mean blood calcium concentration. The highest mean concentrations of tB and the decrease in TC and Glu concentrations were also recorded in this group. Our own studies confirm the need to monitor mineral deficiencies not only during lactation but also before delivery, as well as the effectiveness of appropriate prophylactic regimen, based on oral administration of magnesium preparations which cause the slightest biochemical changes in blood. Lack of supplementation in the subclinical form of antenatal Mg deficiency may cause severe gastrointestinal and reproductive disorders in the postnatal period.
This study examined the effect of the body condition of Polish Holstein-Friesian cows in the last month before calving and in the first week of lactation and of the rate of the body condition loss in the early lactation on basic fertility indicators. Body condition of a total 327 cows was evaluated using the 5-point BCS scale. Five fertility indices were included. The fertility indicators analysed depended less on the BCS of cows in the last month before calving and in the first week of lactation, and more on the size of body condition loss and its duration. Scores of over 3.5 both before parturition and at the start of lactation were associated with the longest service periods and with the lowest percentage of conceptions after one insemination procedure. The length of the days open and calving intervals and the number of services per conception increased as the length of the decline in BCS after parturition increased. The most favourable values for the fertility indicators analysed can be expected in cows whose BCS before parturition and at the start of lactation was 2.75-3.5. A smaller energy deficit with a shorter duration after parturition was also more favourable for these traits.
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