Reproductive patterns and problems in Swedish and Finnish Lapphund bitches;
A comparative study
L-M. Berglundh1, K. Andersson2 and C. Linde Forsberg1
1Department of Clinical Sciences and 2Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden. E-mail: catharina.linde-forsberg@kv.slu.se.
Introduction and aims. The Swedish (SLH) and Finnish Lapphund (FLH) breeds are old native spitz breeds that belong to the FCI group 5: Spitz and Primitive Types. The aims of this study were to document and compare the reproductive patterns, including seasonal variations, and reproductive problems in bitches of these two closely related primitive breeds.
Materials and methods. Three sets of data were used: 1. The SKK data base (www.skk.se) for the years 1990-2007 to calculate mean registered litter sizes and changes in inbreeding coefficients. 2. All litter registration forms (n= 718) for SLH (243) and FLH (475) submitted to the Swedish Kennel Club (SKK) during the years 2000-2007 to determine seasonal differences, effects of parity, gestation lengths, litter sizes at the time of birth, and numbers of stillborn or euthanized pups. 3. A questionnaire survey to breeders (data from 30 breeders on 30 SLH and 28 FLH bitches), for details about the kennels, oestrus cycles, matings and whelpings, reproductive problems etc. The year was divided into 4 seasons (Dec-Febr, March-May, June-Aug, Sept-Nov). The GLM procedure was used and data given as LSMEAN.
Results. SLH gave birth to fewer pups, had more stillborn/euthanized pups and therefore fewer registered pups per litter than FLH (p<0.001). The average change in inbreeding coefficient during the studied period was always higher in the SLH than in the FLH. A seasonal reproductive pattern was found in both breeds. Most SLH litters were born in Dec-Febr., while most FLH litters were born in March-May. For both breeds, however, the largest litters (no. of pups born, and registered) were born in Sept-Nov. Fewest pups born and the highest no. of stillbirths/euthanized pups per litter were seen in the bitches’ first litter in both breeds, while the largest number of pups born and registered per litter were seen in the bitches’ third or more litter. There was a negative regression (p = <0.001) between litter size and gestation length in the FLH. Each extra pup above the average litter size caused a shortening of the gestation length with 0.25 days, and for each pup less the gestation length increased accordingly. In the SLH the regression on gestation length was almost significant (p = 0.052), where each extra pup above the average litter size decreased gestation length with 0.18 days and for each pup less the gestation length increased accordingly. The interoestrus interval was shorter in the SLH than in the FLH (p<0.01). Regular oestrus cycles were seen in 86.7% of SLH and in 100% of FLH (n.s.). Silent heats had been observed in 6.7% of SLH and 3.6% of FLH (n.s.), and split heats in 3.3% of SLH and 7.1% of FLH (n.s). In SLH 16.7% of bitches had refused mating on some occasion, compared to 10.7% in FLH (n.s.). Whelping rates were 91.3% in SLH and 96.6% in FLH (n.s.). Dystocia occurred in 9.5% of 63 SLH whelpings and 12.3% of 57 FLH whelpings (n.s.), and Caesarian sections in 1.6% and 5.3%, respectively (n.s.).
Conclusions. SLH and FLH are breeds with normal reproductive functions, although the more inbred SLH produce smaller litters. Like previously shown for several other breeds (1,2,3) SLH and FLH both show seasonal variations in their reproductive patterns, and their litter sizes varies with parity of the bitch, and influence the gestation length, larger litters shortening it and vice versa.
References: 1) Bobic Gavrilovic et al., Theriogenology 2008;70:783-794. 2) Linde Forsberg et al., Proc 6th I.S.C.F.R., Vienna, Austria 2008;pp132-3. 3) Wikström c & Linde Forsberg C. Proc 5th EVSSAR Congr, Budapest, Hungary 2006; p294.