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Effect of age at weaning on the physiological stress response and temperament of two beef cattle breeds
- M. Blanco, I. Casasús, J. Palacio
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The study was conducted to evaluate the effect of age at weaning and breed on the stress response of calves to weaning and their temperament. At calving, 14 Parda de Montaña calves and 14 Pirenaica calves were randomly assigned to either early weaning (at 90 days) or traditional weaning (at 150 days) treatment. During nursing, calves were allowed to suckle their dams twice a day for 30 min. After weaning, calves were placed in an adjacent barn without access to their dams, where they remained for 7 days. On day 8 after weaning, they were transported to a feedlot where they received an intensive diet. Blood samples were taken 168 h before weaning (baseline) and 6, 24, 48 and 168 h after weaning for cortisol, fibrinogen and haematology analyses, and temperament was measured 90 and 180 days after weaning with the flight speed test. Cortisol concentration increased after weaning, irrespective of age at weaning. Early-weaned calves had a lower fibrinogen baseline and a greater increase in fibrinogen concentrations 48 h after weaning than traditionally weaned calves. Moreover, fibrinogen concentration returned to baseline values 168 h after weaning in traditionally weaned calves, whereas it remained high in early-weaned calves. Concerning breed effects, Pirenaica calves had higher cortisol concentration and fibrinogen increments after weaning than Parda de Montaña calves. Slight alterations occurred after weaning in haematology, but all parameters returned to baseline values 168 h after weaning, with no significant effects of age at weaning or breed. Despite the absence of clinical signs, early-weaned calves of both breeds suffered marginal anaemia, according to haemoglobin values. Regardless of age at weaning, Pirenaica calves had greater reactivity to human presence than Parda de Montaña calves, according to their higher flight speed values measured. Finally, early-weaned calves were lighter than traditionally weaned calves at weaning, but had similar weight gains in the feedlot. Consequently, they needed an additional 40 days to reach the target weight, irrespective of breed. Therefore, age at weaning had no major effects on the stress response to weaning or temperament, but early weaning increased the length of the feedlot period. On the other hand, Pirenaica calves were more reactive than Parda de Montaña calves to the stress of weaning and human presence.
Effects of pre-weaning concentrate feeding on calf performance, carcass and meat quality of autumn-born bull calves weaned at 90 or 150 days of age
- M. Blanco, D. Villalba, G. Ripoll, H. Sauerwein, I. Casasús
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A study was conducted to evaluate the effect of pre-weaning concentrate feeding in early-weaned (EW, day 90) or traditionally weaned (TW, day 150) autumn-born beef calves on growth, feed intake and feed efficiency, and carcass and meat quality. Twenty-eight male calves were either EW or TW, and offered a starter concentrate (S) or no additional feed (NS) during the pre-weaning period. Therefore, four management strategies were tested: EWS, EWNS, TWS and TWNS. Growth patterns were affected by management strategy. From day 90 to 150, TWNS calves presented a substantially lower average daily gain (ADG) than their counterparts, which had similar performance. During the finishing phase (from day 150 to slaughter at 450 kg live weight), EWS calves had the lowest ADG. Daily feed intake or efficiency in the finishing phase was unaffected by previous management. Serum IGF-I concentrations at day 90 and slaughter did not differ with management strategy, but early weaning and pre-weaning concentrate feeding increased IGF-I concentrations at day 150. Circulating leptin concentrations were unaffected by age at weaning and pre-weaning concentrate feeding, except for leptin concentrations at slaughter, which were higher in S calves than in NS calves. Total concentrate intake from birth to slaughter and the concomitant feed costs were higher for EWS and EWNS calves than for TWNS and TWS ones. However, cow feed costs were lower for cows whose calves had been early weaned. Concerning carcass quality, early weaning improved dressing percentage and increased fatness score, and particularly TWNS calves presented a poorer conformation. Meat quality was not affected by management strategy. Considering the economic performance, TWS, EWNS and EWS strategies yielded a similar economic margin, whereas TWNS would be the least advisable strategy when calves are fattened in the farm until slaughter.
Fibre and protein requirements of early weaned rabbits and the interaction with weaning age: effects on digestive health and growth performance
- A. Feugier, M. N. Smit, L. Fortun-Lamothe, T. Gidenne
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- Journal:
- Animal Science / Volume 82 / Issue 4 / August 2006
- Published online by Cambridge University Press:
- 09 March 2007, pp. 493-500
- Print publication:
- August 2006
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The aims of this work were first to evaluate nutritional requirements of early weaned kits (23 days of age), more especially fibre (experiment 1) and protein (experiment 2) needs. In experiment 1, 276 early weaned rabbits were offered from 23 to 50 days of age one of the three experimental diets containing increasing acid-detergent fibre level (160, 190 or 220 g/kg). Fibre was substituted by starch and fat to obtain three isoenergetic diets. In experiment 2, 306 early weaned rabbits were offered from 23 to 50 days of age one of the three experimental diets containing increasing crude protein (CP) level (150, 180 or 210 g/kg). Protein was substituted by starch and fat to obtain three isoenergetic diets. These studies revealed no effect of the dietary fibre level and the dietary CP level on health status. But from 23 to 36 days of age rabbits given diets containing a fibre level over 190 g/kg or a CP level under 180 g/kg showed the lowest growth rate as compared with other respective treatments. Secondly, this research aimed to evaluate the interaction between age at weaning (23 days or 35 days of age) and food (RD and RY diets) on digestive health and performances of young rabbits (experiment 3). RD diet was formulated to contain (per kg) 170 g starch, 160 g fibre and 180 g CP (according to the nutritional requirements of does) and RY diet was formulated to reach 110 g starch, 160 g fibre and 210 g CP (according to the results of experiments 1 and 2). 39 litters of nine pups per litter were assigned at 18 days of age to one of four experimental groups in a 2×2 factorial design: RD23 (no.=84 rabbits), RY23 (no. =85 rabbits), RD35 (no. =86 rabbits) and RY35 (no. =74 rabbits). Food intake and live weight were not influenced by feeding strategy. Between 23 and 35 days of age, mortality was higher in RY than in RD group (20·4 v. 6·8% respectively; P<0·05). During this period growth rate was proportionately 0·584 higher in conventionally weaned than in early weaned rabbits ( P<0·001). After 35 days of age, food intake and growth rate were proportionately 0·104 and 0·097 higher respectively in conventionally than in early weaned rabbits ( P<0·05). Consequently, live weight was higher in conventionally weaned rabbits at both 35 and 53 days of age (proportionately +0·113 and +0·267 respectively; P<0·001). Mortality rate between 23 and 35 days was 21 points higher ( P<0·001) in early weaned than in conventionally weaned pups and 43 points higher ( P<0·001) from 35 to 53 days of age. These data suggest that the removal of milk feeding by early weaning leads to detrimental effects on health and growth of the young, which were not compensated by a diet meeting better their nutritional needs.
Effect of weaning diet and weaning age on growth, body composition and caecal fermentation of young rabbits
- G. Xiccato, A. Trocino, A. Sartori, P. I. Queaque
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- Journal:
- Animal Science / Volume 77 / Issue 1 / August 2003
- Published online by Cambridge University Press:
- 18 August 2016, pp. 101-111
- Print publication:
- August 2003
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Two weaning diets (C and S) and three weaning ages (21, 25, and 28 days) were compared in a two factorial arrangement to evaluate their effect on growth performance, body composition and caecal fermentation activity of young rabbits. One hundred litters born the same day from multiparous does were used. Sixty litters were early weaned at 21, 25 and 28 days of age (20 litters per weaning age), put in collective cages (nine kits per cage) (W21, W25, and W28 litters) and offered the control diet C (crude protein (CP) : 175 g/kg dry matter (DM); ether extract : 20 g/kg DM; starch : 157 g/kg DM; acid-detergent lignin (ADL) : 60 g/kg DM; digestible energy (DE) : 11·08 MJ/kg DM) or the starter diet S (CP : 173 g/kg DM; ether extract : 41 g/kg DM; starch : 112 g/kg DM; ADL : 51 g/kg DM; DE : 11·31 MJ/kg DM). At 32 days of age, 180 early weaned rabbits (three rabbits from each of the 60 litters above) were selected : 60 animals were slaughtered; 120 animals were placed into individual cages and offered a fattening diet (CP : 166 g/kg DM; ether extract : 23 g/kg DM; starch : 177 g/kg DM; ADL : 49 g/kg DM; DE : 11·26 MJ/kg DM) from 32 to 56 days of age. At 56 days of age, another 60 representative rabbits were slaughtered. The administration of diet S to the early weaned rabbits increased litter weight at 32 days (6160 v. 6027 g; P <005) and gain to food ratio from weaning to 32 days (752 v 666 g/kg; P <0001) compared with diet C. Moreover, empty bodies (EB) of S rabbits were fatter (fat : 45 v. 41 g/kg; P = 001) and had greater energy content (5·92 v 5·71 MJ/kg; P <001). At 56 days of age, no residual effect of the diet was recorded. Weaning age affected growth performance, body composition and caecal fermentation at 32 days of age : EB weight (P <005) and EB protein concentration increased (from 164 to 168 g/kg, P <0·01) while caecal volatile fatty acid concentration decreased (from 71·7 to 53·8 mmol/l; P <0·01) when weaning age was increased from 21 to 28 days. At 56 days of age, no effect (P > 0·05) of weaning age was recorded on growth performance or caecal fermentation traits, but EB protein remained lower in the earliest weaned rabbits (P <0·05). In conclusion, feeding a high-fat low-starch diet to early weaned rabbits stimulated growth and body fat and energy retention of kits at 32 days of age with no effect on caecal fermentation. The early weaning successfully performed at 21 days of age strongly stimulated caecal fermentation but reduced body protein reserves.