Poor Breeding Performance Research Articles

Behavioral solutions to breeding cheetahs in captivity: Insights from the wild

AbstractKnowledge of cheetahs' behavior is increasingly seen as the key to solving the mystery of cheetahs' poor breeding performance in captivity. In the absence of zoos' maintaining systematic records of individuals' behavior during introductions, behavior of free‐living animals can be informative. In the wild, most female cheetahs probably mate with males living in small groups or coalitions; thus, zoos may benefit from replicating these social conditions, provided injuries can be minimized. Relations between free‐living coalition members are amicable, and escalated aggression was never witnessed during 4 years of observation. Some antagonism was seen in newly formed trios, although this had disappeared in longer established coalitions. Minor aggression occurred over carcasses, being greater at small and intermediate sized kills than at large ones. In the presence of females, mild intramale aggression was only seen within 1 of 7 coalitions. Free‐living females showed similar rates of behavior in the presence of different numbers of males, aside from more frequent growling at large groups. These findings suggest that captive institutions should be less nervous about housing male cheetahs together and introducing females to groups of males for purposes of breeding. © 1993 Wiley‐Liss, Inc.

Breeding performance in captivity of meadow voles (Microtus pennsylvanicus) from decline- and increase-phase populations

A major enigma in understanding microtine cycles is the failure of decline-phase animals to increase. We compared the performance of wild-caught meadow voles and their progeny from Pinawa, Manitoba, collected from a decline year (1985) with that of animals from an increase year (1986) by breeding them in the laboratory in Pinawa (animals from both years) and in the field and laboratory in Toronto (only F1 and F2 animals from 1985). Overall only 35% of the 1985 females or their progeny bred in the laboratory in Pinawa compared with 100% of the 1986 females. The interval between pairing with a male and birth of litters was 2–7 months for the 1985 females compared with 3–4 weeks for the 1986 females. The poor breeding performance of 1985 females occurred only in the laboratory; in small field enclosures in Toronto all F1 and F2 females conceived and had litters within 3–4 weeks. In contrast, 1985 males readily sired litters either with 1986 females in the laboratory or with Toronto females in the field. We conclude that the prior experience of decline-phase females had long-term detrimental consequences for the performance of the first two generations under laboratory conditions.

Path Model of Reproductive Disorders and Performance, Milk Fever, Mastitis, Milk Yield, and Culling in Holstein Cows

Path analysis was used to model the direct and indirect relationships among age, previous lactation yield or estimated transmitting ability for milk, body weight, days dry, reproductive disorders, milk fever, mastitis, reproductive performance, current milk yield, and culling. Prospective data were from 784 primiparous and 2,066 multiparous Holstein lactations from 33 herds.Heifers that were older, of lighter weight, or who had lower estimated transmitting ability for milk had more problems, less milk, and poorer survival. Dystocia in heifers had several detrimental consequences including 2.9 to 4 times more retained placenta, metritis, and culling and +7.4 d more to first service. Cystic ovaries were associated directly with 376 kg greater milk yield and with a 16.5-d delay in first service. Failure to conceive at first service and mastitis increased risk of culling 5.2 to 10 times.In multiparous cows, milk fever increased risk of reproductive disorders by 1.6 to 4.2 times and indirectly contributed to poor breeding performance and increased culling. Risk of culling was increased 2.1 to 3.7 times directly by mastitis and dystocia and by poor breeding performance.

Proliferation and migration of primordial germ cells during compensatory growth in mouse embryos

Primitive-streak-stage mouse embryos were treated with Mitomycin C injected intraperitoneally into pregnant females at 6.75--7.0 days post coitum. The newborn mice developed poorly and mortality was high during the suckling period. Many weaned survivors showed impaired fertility and poor breeding performance. Histological examination revealed a paucity of germ cells in the adult gonads. The deficiency was mainly caused by a severe reduction of the primordial germ cell population in early embryonic life, which was not fully compensated for during the compensatory growth phase of the Mitomycin C-treated embryo. Also contributing to such impaired fertility were retarded migration of the primordial germ cells into the genital ridges, poor development of the foetal gonad and secondary loss of the germ cells during gametogenesis in males.

Some aspects of lameness in dairy herds

Abstract Excessive wear of the sole of the claws was a common cause of lameness in 2-year-old Friesian heifers. The lameness in older cattle frequently resulted from lesions sited in the interdigital space and in soft tissue structures elsewhere. Lameness was usually noted from 2–12 weeks after calving. Wear began soon after animals entered the herd and lameness resulted when animals walked long distances in wet conditions and after abrasive materials had accumulated on concrete holding yards. The time spent in yards, and the movement of animals on abrasive surfaces at each yarding, was influenced by the animal's ranking order of dominance and her sequence in the milking order. Lameness was often followed by delayed oestrus, poor breeding performance, shortened lactation, low yield of milk fat and a sudden drop in body weight. These animals were often culled. Preventative measures were extremely successful when directed at minimising wear, reducing the period heifers were confined in yards during milking ...

The microflora of the cervix of the thoroughbred mare: a clinical and bacteriological survey in a large-animal practice in Hastings.

Abstract Extract Many reports concerned with the microflora of the genital tract in thoroughbred mares stress the potential pathogenic significance of the haemolytic streptococci. Many years ago, Dimock (1929 Dimock, W. W. 1929. Breeding diseases of the horse. J. Am. vet. med. Ass., 74: 327–335. [Google Scholar], 1939 Dimock, W. W. 1939. Equine breeding hygiene. J. Am. vet. med. Ass., 94: 469–478. [Google Scholar]) and Dimock and Edwards (1928) Dimock, W. W. and Edwards, P. R. 1928. The pathology and bacteriology of the reproductive organs of mares in relation to sterility. Ky agric. exp. Stn Bull., 286: 287–339. [Google Scholar] associated the haemolytic streptococci with persistent endometritis, sterility and deaths in foals up to 2 to 4 weeks after birth. In Holland, Ressang (1954) Ressang, A. 1954. “Sterility in Mares. A clinical, bacteriological and histopathological investigation”. In Thesis, State University of Utrecht. [Google Scholar] isolated haemolytic streptococci of Lancefield's Group C from 34 of 153 (22%) mares offered for examination because of poor breeding performance. Ressang noted that mares with streptococcal endometritis were not likely to show satisfactory fertility even after the infection had apparently been eliminated. Haemolytic streptococci have also been associated with infertility in mares in Turkey (Pusat, 1955 Pusat, M. M. 1955. Kisraklarin sikit amili streptococlarin tipleri ve streptococcus genitalium uzerinde bir munakasa. Turk vet. Hekim. Dern. Derg., 24: 2,039–2,047. [Google Scholar]), in the United Kingdom (Moran and Cronin, 1957 Moran, A. B. and Cronin, M. T. 1957. Organisms isolated from the uteri of thoroughbred mares. J. comp. Path., 67: 106–109. [Google Scholar]) and in Ireland (Farrelly and Mullaney, 1964 Farrelly, B. T. and Mullaney, P. E. 1964. Cervical and uterine infection in thoroughbred mares. Ir. vet. J., 18: 201–212. [Google Scholar]). In Australia, Bain (1966) Bain, A. M. 1966. The role of infection in infertility in the thoroughbred mare. Vet. Rec., 78: 168–173. [Google Scholar] noted that 12% of infected mares at stud in the Hunter district of New South Wales harboured beta-haemolytic strepotcocci in the genital tract. This organism was considered the most serious pathogen encountered as only 40% of these mares infected with haemolytic streptococci produced a live foal in the first year following infection: 35% had still not completed a successful pregnancy within the subsequent 3-year period.