Hill country sheep production: II. Lamb mortality and birth weights in Romney and Border Leicester × Romney flocks
01 Nov 1970-New Zealand Journal of Agricultural Research (Taylor & Francis Group)-Vol. 13, Iss: 4, pp 735-752
TL;DR: Analysis of variance of birth weight showed that first-cross lambs were the heaviest and that birth weights decreased with inter-flock variability, which increased with increasing age of dam for both single- and multipleborn lambs.
Abstract: Factors associated with mortality in 7,727 lambs born to 7,091 twoto five-year-old ewes over the 9 years 1959–67 were studied. The lambs were from two Romney flocks and first-, second-, third-, and fourthcross Border Leicester × Romney flocks. Lamb survival rate (lambs weaned as a percentage of all lambs born) increased with increasing age of dam for both single- and multipleborn lambs. Variation in survival rate between flocks and between female and male lambs was large. In 60% of the dead lambs, 44.6% of single-born lambs died of dystokia and 15.1 % from physiological starvation. Of the multiple-born lambs autopsied, 16% died from dystokia and 41.7% from starvation. Infections accounted for 11.6% and pre-natal deaths for 10.3% of the remaining deaths. Most of the deaths occurred within 3 days of birth, and relatively more single- than multiple-born lambs died at birth Analysis of variance of birth weight showed that first-cross lambs were the heaviest and that birth weights decreased with inter...
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TL;DR: The authors exploit newly available massive natu- ral language corpora to capture the language as a language evolution phenomenon. But their work is limited to a subset of the languages in the corpus.
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Cites background from "Hill country sheep production: II. ..."
...Animals can choke to death (e.g. young lambs occasionally die from choking on milk; Hight and Jury, 1970), but I have been unable to find reliable statistics on the rate of choking, or of death by choking, in nonhuman animals....
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TL;DR: This review compares three well-studied species (the rabbit, pig and sheep) that differ in their parental strategies and in the problems that neonates have to overcome.
Abstract: The defining characteristic of mammals is that females nurse and care for their young; without this, the neonate has no chance to survive. Studies on wild and domestic species show that the neonatal period is the most critical step in the lifetime of a mammal. This review compares three well-studied species (the rabbit, pig and sheep) that differ in their parental strategies and in the problems that neonates have to overcome. As a general trend, mother-young interactions vary according to the maturity of the newborn, and the size of the litter. Neonatal survival relies to a great extent on an environment that is ecologically appropriate for the developmental stage of the neonate, and on optimum interactions with the mother. Adaptive maternal care supposes that the mother provides the basic needs of the neonate: warmth (in pigs and rabbits) or shelter, food, water and immunological protection (via colostrum) and, in some instances, protection from predators and other conspecifics. A major risk facing all neonates, other than the birth process itself, is inadequate colostrum intake owing to delayed suckling or competition with siblings, which leads to starvation, hypothermia or even crushing, as has been observed in pigs.
296 citations
TL;DR: Major science-based improvements in the management of pregnancy and birth have markedly reduced the overall amount of welfare compromise experienced by newborn farm animals and further improvements may be expected as knowledge is refined and extended in the future.
Abstract: Much has been learnt during the last 50 years about the causes of neonatal mortality and morbidity and about practical means for minimising them in newborn lambs, kids, bovine calves, deer calves, foals and piglets. The major causes of problems in these newborns are outlined briefly and include hypothermia due to excessive heat loss or to hypoxia-induced, starvation-induced or other forms of inhibited heat production. They also include maternal undernutrition, mismothering, infection and injury. The published literature reveals that the scientific investigations which clarified these causes and led to practical means for minimising the problems, involved iterative successions of self-reinforcing laboratory and field or clinical investigations conducted over many years. These studies focused largely on solutions to the problems, not on the suffering that the newborn might experience, so that an analysis of the associated welfare insults had not apparently been conducted until now. The present assessment focuses on potentially noxious subjective experiences the newborn may have. The account of the causes of neonatal mortality and morbidity outlined early in this review indicates that the key subjective experiences which require analysis in animal welfare terms are breathlessness, hypothermia, hunger, sickness and pain. Reference to documented responses of farm animals and, where appropriate, to human experience, suggests that breathlessness and hypothermia usually represent less severe neonatal welfare insults than do hunger, sickness and pain. Major science-based improvements in the management of pregnancy and birth have markedly reduced the overall amount of welfare compromise experienced by newborn farm animals and further improvements may be expected as knowledge is refined and extended in the future.
257 citations
TL;DR: Strategies to improve neonatal survival should be aimed at maximising lamb vigour, colostrum production, and mutual mother-young bonding through adequate feeding in late pregnancy and selection on behaviour.
Abstract: New-born lambs have limited energy reserves and need a rapid access to colostrum to maintain homeothermy and survive. In addition to energy, colostrum provides immunoglobulins which ensure passive systemic immunity. Therefore, getting early access to the udder is essential for the neonate. The results from the literature reviewed here highlight the importance of the birth site as the location where the mutual bonding between the mother and her young takes place. Attraction to birth fluids by the periparturient ewe leads to intense licking of the lamb. Grooming not only dries, cleans and stimulates the newborn it also facilitates bonding through learning of its individual odour. Ewes having twins should ideally stay on the birth site for at least six hours in order to establish a strong bond with both lambs and favour lambs survival. However, primiparous ewes or ewes having high levels of emotivity are more likely to exhibit poor maternal behaviour. In addition, difficult parturition and weather conditions have an indirect effect on the behaviour of the mother and are other major causes of lamb death. On the lamb's side, rapid access to the udder and early suckling are extremely important. Delayed lactation or insufficient colostrum yield may be fatal especially since suckling has strong rewarding properties in the establishment of a preference for the mother, which in turn increases lamb survival. Insufficient access to the udder in mothers leaving the birth site too soon after parturition, especially in twin-bearing ewes, could also partly account for the high incidence of loss of mother-young contact and subsequent death in such lambs. Strategies to improve neonatal survival should be aimed at maximising lamb vigour, colostrum production, and mutual mother-young bonding through adequate feeding in late pregnancy and selection on behaviour.
257 citations
References
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Book•
01 Jan 1981
TL;DR: The genetic constitution of a population: Hardy-Weinberg equilibrium and changes in gene frequency: migration mutation, changes of variance, and heritability are studied.
Abstract: Part 1 Genetic constitution of a population: Hardy-Weinberg equilibrium. Part 2 Changes in gene frequency: migration mutation. Part 3 Small populations - changes in gene frequency under simplified conditions. Part 4 Small populations - less simplified conditions. Part 5 Small populations - pedigreed populations and close inbreeding. Part 6 Continuous variation. Part 7 Values and means. Part 8 Variance. Part 9 Resemblance between relatives. Part 10 Heritability. Part 11 Selection - the response and its prediction. Part 12 Selection - the results of experiments. Part 13 Selection - information from relatives. Part 14 Inbreeding and crossbreeding - changes of mean value. Part 15 Inbreeding and crossbreeding - changes of variance. Part 16 Inbreeding and crossbreeding - applications. Part 17 Scale. Part 18 Threshold characters. Part 19 Correlated characters. Part 20 Metric characters under natural selection.
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TL;DR: Advances in Genetics as discussed by the authors provides the latest information on the rapidly evolving field of genetics, presenting new medical breakthroughs that are occurring as a result of advances in our knowledge of the topic.
Abstract: Advances in Genetics provides the latest information on the rapidly evolving field of genetics, presenting new medical breakthroughs that are occurring as a result of advances in our knowledge of the topic. The book continually publishes important reviews of the broadest interest to geneticists and their colleagues in affiliated disciplines, critically analyzing future directions. * Critically analyzes future directions for the study of clinical genetics* Written and edited by recognized leaders in the field* Presents new medical breakthroughs that are occurring as a result of advances in our knowledge of genetics
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Book•
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TL;DR: Quantitative genetics in sheep breeding, Quantitative geneticsIn sheep breeding , مرکز فناوری اطلاعات £1,000,000 to £2,500,000 per year is spent on research into quantitative sheep breeding.
Abstract: Quantitative genetics in sheep breeding , Quantitative genetics in sheep breeding , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
348 citations