Effect of Oestrous Synchronization with Estradiol 17β and Progesterone on Follicular Wave Dynamics in Dairy Heifers

An experiment was designed to evaluate the effects of estradiol‐17β (E17β) on follicular wave dynamics and ovulatory response in Holstein heifers receiving either a progestogen ear‐implant (Crestar^®; Intervet International b.v. Boxmeer, The Netherlands) or an intravaginal progesterone‐releasing device [controlled internal drug release‐bovine device (Eazibreed, CIDR‐B^®; Bodinco BV, Alkmaar, The Netherlands)]. For comparison, another group of heifers was also synchronized using Crestar plus an injection of estradiol valerate (EV) and norgestomet as recommended by the pharmaceutical company. Twenty 20–22‐month‐old cycling Holstein heifers were allocated to one of the following treatment groups at random stages of the oestrous cycle: (I) simultaneous insertion of Crestar and intramuscular injection of 3 mg norgestomet and 5 mg EV (Crestar 9 + EV 9); (II) simultaneous insertion of Crestar and intramuscular injection of 5 mg E17β (Crestar 9 + E17β 9); (III) insertion of Crestar followed 2 days later by intramuscular injection of 5 mg E17β (Crestar 9 + E17β 7); or (IV) insertion of CIDR‐B device followed 2 days later by intramuscular injection of 5 mg E17β (CIDR 9 + E17β 7). The CIDR‐B or Crestar implants were removed after 9 days and all heifers received 500 μg Cloprostenol (Estrumate^®, Pitman‐Moore Nederland BV, Houten, The Netherlands). Ovarian ultrasonographic examinations were performed once daily during the synchronization period using a B‐mode scanner equipped with a 7.5 MHz linear‐array transrectal transducer. In addition, heifers were scanned every 12 h after implant/device withdrawal until 3 days after ovulation in order to monitor follicular activity, detect ovulation and subsequent early luteal formation. Detection of oestrus was performed every 6 h for 4 days after device/implant removal. Oestrus was observed 24–32 h before ovulation in all heifers. The mean hours interval from treatment withdrawal to ovulation was not significantly different (84.0 ± 16.5, 77.6 ± 4.1, 73.6 ± 4.1 and 64.0 ± 4.4 h for treatments I, II, III and IV, respectively; p > 0.1). However, the variance for heifers treated with EV + norgestomet was significantly larger (Levene’s Test; p < 0.01) than those treated with E17β. All E17β treatments resulted in dominant follicle suppression and a new wave emerged 4.1 days after treatment compared with 6.6 days for the EV + norgestomet treatment (p < 0.05). The time from emergence of the new ovulatory wave to ovulation was longer for the new wave that emerged after E17β treatment (9.2 ± 0.3 days) than after EV + norgestomet treatment (6.9 ± 0.4 days; p < 0.05). The results of this study suggest that the four treatments used were effective in inducing synchronous behavioural oestrus and ovulation. However, a higher degree of oestrus and ovulation synchrony was observed in heifers treated with E17β than in heifers treated with EV + norgestomet. Synchronization treatments with exogenous E17β or EV + norgestomet at the time of progestin device insertion (Crestar or CIDR‐B) or 2 days later in heifers can regulate a different emergence pattern of ovarian follicular development in randomly cyclic heifers. The E17β was effective in inducing follicular suppression and resulted in the consistent emergence of a new follicular wave.     

Transgenic cattle constitute a breakthrough in production of innovative medicine. From milk to medicine

The continuously increasing demand for biomolecules, e.g. human proteins, for applications in human health care, is one of the main driving forces for the development of safe, large-scale production systems. One very promising approach is the production of biomolecules in the milk of transgenic cattle. By using nuclear transfer technology, transgenic cattle can be generated in a very safe and efficient manner, thereby offering a significant time reduction when compared to conventional breeding methods. As a result, that the transgenic cattle platform offers an efficient, safe and cost-effective method for producing large amounts of biopharmaceuticals, which is essential to the development of innovative health care products.     

A comparison of two techniques for the synchronisation of oestrus in dairy heifers.

Seventy-four heifers in four separate breeding groups were allocated into two treatment groups for oestrus synchronisation. Group 1 was given a combination of an initial injection of norgestomet and oestradiol valerate together with a norgestomet ear implant left in place for nine days. Group 2 was given two injections of the synthetic prostaglandin luprostiol 10 days apart. The animals in group 1 were artificially inseminated once 48 hours after the removal of the implant and those in group 2 were inseminated once 72 hours after the second injection of luprostiol. Subsequently any returns were rebred by either AI or natural service. There was no significant difference between the numbers of animals in the two treatment groups which were diagnosed pregnant 33 to 35 days after insemination, although the implant treatment gave a higher overall proportion of pregnancies (70 per cent, 51 per cent). It also gave significantly smaller numbers of 'open' days over the whole of the breeding period. A study of individual animals by progesterone assay and investigation of ovarian structures by real-time ultrasound showed that some of them had unusual progesterone profiles but nevertheless became pregnant. It would appear that a corpus luteum may be responsive to prostaglandins even though it is secreting only a low level of progesterone.     

Isolation, identification and dyeing studies of betanin on modified acrylic fabrics

Mature red fruits of Opuntia ficus-indica contain two soluble pigment, betanin and indicaxanthin. The optimal conditions for dye extraction were to mix 50 g of juice from cactus pears with 100 mL of acidified water as solvent for dye extraction. Two main dyes were purified from the pigment extract by chromatography and identified by UV-vis, HPLC and LC-MS techniques as indicaxanthin (15 mg per 100 g) and betanin (280 mg per 100 g). The effect of dye bath pH, salt concentration, dyeing time and temperature was studied. The optimal conditions for dyeing modified acrylic fabrics with betanin dye were carried out at 50 °C for 45 min at pH 5. Un-mordanted samples have good properties of water and washing fastness. Mordant CoSO₄ was found to give good light fastness (rating 5).     

Genetic diversity of some Mediterranean populations of the cultivated alfalfa (Medicago sativa L.) using SSR markers

This species study was to investigate the differentiation level among 26 populations in which 12 are locals originating from the Tunisian South and 14 introduced from Italy, Austerely, France and Morocco with two SSR markers. These highly polymorphic and co dominant markers, together with recent population genetic statistic extended to autotetraploids, offer tools to analyse genetic diversity in alfalfa. The number of alleles per locus varied between 8 and 9. The genetic similarity between these various populations is estimated by the index of Rogers and Tanimoto. Genetic diversity is analysed by two statistical procedures: Hierarchical classification and Correspondence Factorial Analysis (CFA). Four large groups were obtained.     

Dyeing properties and colour fastness of wool dyed with indicaxanthin natural dye

This research work involves the dyeing of wool with indicaxanthin, a natural dye extracted from fruits of Opuntia ficus-indica. The optimal conditions for dye extraction were to mix 50 g of Juice from cactus pears with 100 mL of 80% aqueous ethanol as solvent for dye extraction. Liquid chromatography was applied for the separation. Two main dyes were obtained, which were identified as indicaxanthin (75 mg per 50 g) and betanin (5 mg per 50 g). The effect of dye bath pH, salt concentration, dyeing time and temperature were studied. The optimal conditions for wool dyeing with indicaxanthin dye were carried out at 70 °C for 90 min with the pre-treatment of various metal salts as mordant. The colour yields of the dye on the wool were found to be highly dependent of the pH, optimum results being obtained at pH 4. The K/S of wool increased in the order of the dyeing using KAl (SO₄)₂ > MnSO₄ > CoSO₄ > FeSO₄ > none > ZnSO₄ > CuSO₄. Un-mordanted samples have good properties of water and washing fastness. Mordants KAl (SO₄)₂ and CoSO₄ were found to give good light fastness (rating 5).