More effective synchronization of oestrus in pigs using the Crestar and CIDR G preparations

Synchronization of sexual cycle in pigs is at present performed with tried methods of peroral application of preparations on the basis of progestagens (Trombolon, Oxolven, Regumate porcine). Their advantage is that their application can start on an arbitrary day of the sexual cycle. Their disadvantage is that they must be applied in accurate doses for some days. The preparations Crestar and CIDR G, which are used to synchronize oestrus in cows and goats, were tested because they are applied only once. The sexual cycle was synchronized by applying the subcutaneous implantate Crestar (Intervet, Holland) to 20 sows and gilts (n=30) of the White Meaty breed (WM). 10 animals were given the inserts EAZI-breed CIDR G (New Zealand) intravaginally. The preparations operated for 18 days, and after 48 hours following removal 1000 i.u. PMSG i.m.,(Serum gonadotropin, Bioveta, Ivanovice na Hane), and 500 i.u. HCG i.m. (Praedyn, Leciva Praha) were applied. Insemination was performed according to the occurrence of oestrus. A positive reaction to the treatment was observed in 28 animals (93.30 %) out of the total number of 30 synchronized animals (16 sows and 14 gilts) of WM breed. Fourteen sows (87.50 %) and eight gilts (57.14 %) farrowed (Table 1). The average numbers of piglets born and number of live piglets in individual groups as well as in the control group are given in Table 2. The control group was made up of 12 randomly chosen sows of WM breed. They mated at the same time as the animals in the experimental groups. The results in table show that the most piglets were born and the most remained alive in the group of sows treated with EAZI-breed CIDR G (11.75 +- 1.18 or 11.5 +- 1.70). Higher average numbers of born and live young (10.90 +- 0.90 or 9.90 +- 0.90) were also noticed in the group of sows treated with Crestar compared with the control group (9.83 +- 0.91 or 8.50 +- 0.88). The results in gilts treated with Crestar were 9.66 +- 2.84 or 6.66 +- 1.33, and 10.75 +- 1.54 or 8.00 +- 2.58 in gilts treated with EAZI-breed CIDR G. The number of born or live youngs was identical or lower in both groups compared with the control group. Lower litter size with gilts can be substantiated by the fact that the sows had already borne litters and therefore their reaction to the preparation was better compared with gilts. The tested preparations applied once give the possibility to make oestrus synchronization more effective in practice compared with classically used preparations for synchronization.