Teat-seeking behaviour in newborn lambs. I. Evidence for the influence of maternal skin temperature

Animal welfare implications of neonatal mortality and morbidity in farm animals

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.

Effect of Milk Source on Welfare and Weight Gain of Lambs

The possibility of lessening the adverse welfare impact of artificial rearing was assessed in thirty Comisana lambs under conditions of ad libitum feeding. The lambs were assigned to a control dam-suckled group (DS) or to one of two test groups, each consisting of 10 animals. 18-24h after parturition, test lambs were separated from their dams: during the first postseparation week 10 subjects (EM) were offered ewe milk and the other 10 (MX) a 50:50 mix of ewe milk and a milk substitute. An artificial feeding system, to which the test lambs had free access, was filled with milk twice daily. After the first week, a transition from EM or MX to 100 per cent (reconstituted) milk substitute was carried out over 3 days in both test groups, gradually reducing the proportion of ewe's milk. In vivo cell-mediated immune response of lambs to phytohemagglutinin percutaneous injection were evaluated at 5, 15 and 25 days of age. At 10 and 20 days of age, all lambs were subjected to 15min isolation tests, during which latency to move, duration of movement and number of bleats were recorded. Blood samples were collected immediately before the test and 15 and 60min after, in order to assess the effect of differential rearing on the Cortisol response of animals at different ages. In addition, the weight gain of lambs was recorded during the first 35 days of age at weekly intervals. Latency to move and duration of movement were not significantly affected by the experimental treatment, whereas the number of bleats was higher (P < 0.001) in dam-suckled lambs compared to test lambs at both 10 and 20 days of age. Neither immune response nor Cortisol levels were affected by milk source. Although weight gain increased with increasing amounts of ewe's milk in the diet, the overall differences between the three groups were small and not significant. These findings suggest that the provision of ewe milk or a mix of ewe milk and a milk substitute during the first post-separation week can be a suitable strategy to sustain the welfare and production performance in the artificially reared lamb.

A Breeding Goal to Improve the Welfare of Sheep

A polled sheep with a short tail, and devoid of wool on the head, legs, belly and breech, has been proposed as a breeding goal (Scobie et al 1997). This paper examines the practical and welfare implications of such an objective. Mean shearing times were significantly (P < 0.001) slower for control Romney (97s) and Coopworth (88s) ewe hoggets compared to times for both breeds after they were ‘trimmed’ to resemble the breeding goal (47s). Romney wethers were slower to shear than ewes (P < 0.001), but trimmed wethers (53s) were much faster to shear than the untrimmed controls (99s). Trimmed sheep produced less wool (pooled mean weights of fleece wool for trimmed sheep vs total wool for controls being 2.5 vs 3.5 kg; P < 0.001), half the difference (ie 500g) consisting of lower value oddment wools from the untrimmed controls. Tails were docked to 0, 20, 40, 60, 80 and 100 per cent of the distance between the base of the tail and the hock of Perendole lambs, and 0, 20, 40 and 60 per cent on Coopworths. More dags accumulated as the tail stump increased in length, although significance was dependent on the time of year and management system. No flystrike (cutaneous myiasis) was observed in Perendales given physical and chemical protection, while a small proportion of all tail lengths were flystruck in Coopworths given only physical protection. When shorn as hoggets, the time taken to shear Perendole ewes increased with increasing tail length (P < 0.001). Provided the undocked short tail is bare of wool, the proposed breeding goal should deliver an economic solution to sheep breeders attempting to satisfy markets conscious of chemical residue and animal welfare issues in the new millennium.