1,721,214 research outputs found
Milk intake studies in llamas ('Lama glama') using the "dose-to-the-mother" technique
No full textThe knowledge of milk and milk nutrient intakes in suckling young is essential for giving recommendations on adequate nutrient supply. In a study involving 6 lactating llama ('Lama glama') dams and their suckling young, milk intake and total water turnover were measured at three different stages of lactation (wk 3–4, 10–11 and 18–19 post partum (PP)) using the 'dose-to-the-mother' (DTTM) technique. The method involved the application of the stable hydrogen isotope Deuterium (²H) to the lactating dam. In suckling llamas, total water turnover increased with age (
Relationships between integumental characteristics and thermoregulation in South American camelids
No full textHair fibre is regarded as a unique mammalian feature with an important role for endothermy. Artificial selection for hair characteristics resulted in marked changes with regard to follicle number, type, distribution, growth and natural shedding. This review focuses on the fine fibre-producing South American camelids (SACs) and the relationship between their hair coat and thermoregulation. SACs have developed several special integumental characteristics. While the hair coat of the wild lamoids vicuna (Vicugna vicugna) and guanaco (Lama guanicoe) is formed by two types of hair (the coarse outer guard hairs and a finer undercoat), the domesticated llamas (Lama glama) and alpaca (Lama pacos) exhibit variably double coat and predominantly single coat, respectively. The distribution of the hair coat across the body is not homogenous. Thermal windows with shorter hair or thinner skin can be identified at the ventral abdomen, axillary space and inside of the thighs (about 20% of the skin), thus allowing to modulate heat dissipation. In contrast to sheep wool, lamoid fibres are mainly medullated. The thermal conductance of summer pelage was higher than that of the winter fleece and highest for the axillar and lower flanks. Lamoids have developed behavioural strategies to modify heat loss by adopting specific postures according to ambient conditions by closing or opening the thermal windows. Energy savings of 67% attributed to posture were calculated. SACs have shown to be able to adapt to a broad range of different climatic conditions. The specific integumental characteristics of SACs indicate that they have developed adaptation mechanisms particularly suited for cooler climates. Accordingly, hyperthermia might become a problem in hot, humid areas outside of their original habitat. Several studies showed the beneficial effect of shearing against heat stress. In particular, fertility in males exposed to heat stress may be improved by shearing. Infrared thermography reveals that in shorn animals the heat is radiated across the entire body surface and is not restricted to the thermal windows. However; shearing also changes the conditions of the protective layer; resulting in a loss of thermal conductance that may result in adverse effects when animals are kept under cold temperatures. The length of residual fibre appears to be crucial in avoiding excessive heat loss in a cold environment, as demonstrated by shearing experiments with different shearing machines. There is, therefore, potential for welfare considerations to conflict with industrial demands for fibre length or homogenous quality
Measurements of the bodyweight and other physical characteristics of II llamas (Lama glama) from birth to weaning
No full textChanges in Llama (Lama glama) Milk Composition During Lactation
No full textMilk samples were collected weekly from 10 llamas during the first 27 wk after parturition under controlled stable conditions. Mean values for the concentrations of the major milk components across the lactation period were 4.70% fat, 4.23% protein, 5.93% lactose, 15.61% dry matter, and 22.62 mg/dL of milk urea N. All constituents were affected by the stage of lactation. There was an increase in fat to protein ratio as protein concentration declined and fat concentration increased. Fat, protein, and lactose concentrations changed during the transition from colostrum to milk. In the first month postpartum, fat concentration remained constant, protein decreased, and lactose increased. Starting with wk 5 postpartum, fat and protein increased and lactose decreased until the end of lactation. Among the major constituents fat had the highest variation. The mean gross energy concentration of milk was 3.88 kJ/g and showed a similar course as protein. Fat contributed 48.0%, protein 26.3%, and lactose 25.7% to the gross energy in the milk. Milk urea N values were higher than those found in ruminants and increased with stage of lactation, whereas the pH decreased. The analyzed milk components were not affected by the lactation number of the animal, except milk urea N. Somatic cell counts indicated the absence of mastitis and revealed that the average somatic cell count of uninfected llamas is lower than in animals usually used for milk production. The 2 algebraic models fitted by a nonlinear regression procedure to the data resulted in suitable prediction curves for the constituents (R-2 = 0.76 to 0.94). The courses of major milk constituents in llamas during lactation are similar to those in domesticated ruminants, although different in their values. The established curves facilitate the composition of milk replacers at different stages of lactation for nursing llamas whose dams died or are agalactic
Temporal stability of social structure and behavioural synchronization in Shetland pony mares (Equus caballus) kept on pasture
No full textThe temporal stability of synchronization was studied for two consecutive years in a herd of 10 Shetland pony mares kept on pasture. Direct field observations lasted 1.5-2.5 h per session between 8:00 am and 8:00 pm, adding up to an observation time of 74 h in the first and 134 h in the second year. Behaviour, nearest neighbour identity and distance were recorded individually every 15 min by point sampling. Rank order remained very stable between years (tau(b) = 0.91; P < 0.01). All mares showed preferences for the proximity of primarily one specific group member. K-coefficients of synchronization, i.e. non-random synchronization, were higher in the second year of observation (2010: kappa = 0.22; 2011: kappa = 0.54; t = 2.69; P = 0.007). Among the different parameters evaluated, the Kappa coefficient proved to be most reliable for assessment of synchronization at the group level, because it is not inherently affected by time budgets. A high degree of behavioural synchronization might be the basis of stable group cohesion. Preferences between individuals should be considered for re-groupings in managed horse groups.H. Wilhelm Schaumann Stiftung, Hamburg, German
Deuterium oxide dilution accurately predicts water intake in sheep and goats
No full textThe aim of this study was to test whether the deuterium oxide dilution technique accurately predicts water intake in sheep and goats. Two other issues were also studied: (i) a comparison of water intake in sheep and goats and (ii) an assessment of whether observations of drinking behaviour can accurately measure the water intake. In this study, eight dry Boer goats and eight dry German Black Head Mutton ewes were kept under controlled stable conditions. Animals had access to hay and water ad libitum. Diurnal drinking behaviour was recorded by video. Individual daily water intake was measured and estimated for 2 weeks by re-weighing water buckets and from water kinetics using the deuterium oxide dilution technique, respectively. In addition, dry matter intakes were directly measured and were significantly higher in sheep than in goats. The average daily water consumption by drinking differed significantly between the two species, with higher intakes in sheep than in goats. Total body water expressed as a percentage of body mass did not differ between species. Measurement methods of total water intake (TWI) using deuterium oxide dilution and re-weighing water buckets did not differ significantly in both species (P = 0.926). Results obtained for measured and estimated TWI confirm that the isotope dilution technique gives reliable results for estimates of water intake in sheep and goats. The higher amount of water intake in sheep was also reflected by their drinking behaviour. Sheep spent approximately 0.3% per 24-h drinking, while Boer goats spent only 0.1%. However, measured and estimated TWIs were only moderately correlated to the daily time spent drinking. The lower water intake found in Boer goats confirms a superior water management capacity compared with Black Head Mutton sheep even under temperate conditions.German Academic Exchange Service (DAAD
Seasonal changes of total body water and water intake in Shetland ponies measured by an isotope dilution technique
No full textWater is an essential nutrient necessary to support life, and adequate water supply is crucial for animal survival and productivity. The present study was designed to determine seasonal changes in the water metabolism of horses under outdoor conditions. Total body water (TBW) and total water intake (TWI) of 10 adult Shetland pony mares were estimated at monthly intervals for 14 mo by using the deuterium dilution technique. During the last 4 mo, 5 ponies were fed restrictively to simulate natural feed shortage in winter, and 5 ponies served as controls. The TBW (kg) was closely related to body mass [TBW (kg) = -2.86 + 0.67 x body mass (kg); P 0 degrees C. Therefore, removing TWI values measured at T-a < 0 degrees C from the analysis resulted in high correlations with locomotor activity (r = 0.87), T-a (r = 0.86), and resting heart rate (r = 0.88). The multiple regression among TWI, T-a, and heart rate explained 84% of the variation in TWI [TWI (mL.kg(-1).d(-1)) = -13.38 + 1.77 x heart rate (beats/min) + 2.11 x T-a (degrees C); P < 0.001]. Feed restriction had no effect on TWI and TBW. The TBW content was unaffected by season and physical activity. The established regression equation for TBW and body mass can be used to predict TBW from body mass in ponies under field conditions. The comparison of TWI with published data on drinking water intake revealed that ponies had 1.7 to 5.1 times greater total water intakes when other sources of water such as feed and metabolic water were included. The TWI was highly influenced by environmental conditions and metabolic rate. Contrary to expectation, water supply during the cold seasons might be more critical than under summer conditions when water content of grass is high to allow for the compensation of limited availability of drinking water
Measurement of Milk Intake in Suckling Llamas (Lama glama) Using Deuterium Oxide Dilution
No full textThe objective of the study was to estimate daily milk intake in llama crias and relate nutrient intakes at peak lactation to growth data. Milk intake in 11 suckling llamas was estimated from water kinetics using deuterium oxide ( D(2)O) at d 17, 66, and 128 postpartum. Daily milk intakes averaged 2.6, 2.3, and 2.0 kg at 17, 66, and 128 d postpartum, respectively. Milk intake decreased with age when expressed as daily amount, percentage of body weight ( BW), or per kilogram of metabolic size, but the influence of age was eliminated when expressed per gram of daily gain. Because llamas only have one young per parturition, milk intake was equivalent to the daily milk output of the dam, which ranged from 27.6 to 96.9 g/kg of maternal BW(0.75). Compared with different ruminant species, milk production in llamas appears to lie between wild and domestic ruminants used for meat production. Nutrients ( dry matter, fat, protein, and lactose) and energy intakes from the milk calculated by combining milk intake and milk composition data decreased with age when expressed as daily amount or per 100 g of BW, but when expressed per gram of daily gain, no clear trend was observed. Maintenance requirement for suckling llamas at peak lactation ( 17 d postpartum) was 312 kJ of ME/kg of BW(0.83). Combined with milk composition data, the present milk intake estimations at different stages of the lactation can be used to establish recommendations for nutrient and energy requirements of suckling llamas
Effects of a higher incubation temperature between embryonic day 9 and 12 on growth and meat quality characteristics of turkeys
No full text1. The study investigated the influence of manipulating incubation temperature for a short period on the post-hatch development up to week 16 in male and female BUT Big 6 turkeys. 2. Eggs were incubated at a control temperature of 37 center dot 5 degrees C and 55% RH until d 18 when transferred to a hatcher at 37 center dot 5 degrees C and 85% RH. For a 4 d period between embryonic day 9 (ED 9) and 12, eggs were incubated at 38 center dot 5 degrees C and 55% RH (HT). 3. Birds were slaughtered at 16 weeks of age to analyse meat quality parameters of the Musculus pectoralis superficialis (MPS). 4. Across both incubation treatments, the turkey males had significantly higher live and breast weights, but lower breast yields than the females. The sex of the animals only influenced the yellowness of the MPS with lower values in the males. 5. Temperature manipulation resulted in significantly decreased live weights of HT birds compared with the control animals across all ages in both sexes. No impact of incubation treatment on meat quality characteristics was found. 6. The results indicate a negative effect of higher incubation temperature on the post-hatch growth, possibly by influencing the mechanisms that regulate the hypertrophic growth of the muscle fibres
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