The objective of this study was to determine the effect of growth rate on muscle fibre characteri... more The objective of this study was to determine the effect of growth rate on muscle fibre characteristics, concentration of nucleic acids (RNA and DNA) as indicators of muscle protein synthesis capacity and activity of the calpain system at time of slaughter in m. longissimus lumborum (LL) and m. supraspinatus (SS) from calves, in order to elucidate the effect of growth rate on muscle protein turn-over at time of slaughter. Twenty-four Friesian heifer calves were allocated to two different feeding regimens that allowed for a moderate/moderate (MM) or high/high (HH) growth rate from 5 days of age to 90 kg body weight (BW) (period I) and from 90 kg BW to slaughter at 250 kg BW (period II), respectively. The growth rates in the two periods and the weight of LL and SS at slaughter were recorded. Within 30 min after exsanguination, samples were removed from LL and SS, snap-frozen, and later analysed for muscle fibre type frequency and cross-sectional area, DNA and RNA concentration and the ...
Abstract Forage based low-input dairy systems include a certain risk of a temporary undersupply w... more Abstract Forage based low-input dairy systems include a certain risk of a temporary undersupply with nutrients and energy. Therefore the aim of the present study was to investigate the productive, reproductive and metabolic response of two different dairy cow types to a reduction of concentrate supplementation in an Alpine low-input milk production system. The cow types compared were conventional Austrian Brown Swiss (BS) and a specific strain of Holstein Friesian (HFL). The latter was primarily selected for lifetime performance and fitness under low-input conditions and is therefore considered by farmers as being better suited for low-input production systems. Both genotypes were assigned to one of two concentrate supplementation levels, receiving 618 kg (Con) or 279 kg (Low) of concentrates per lactation. During two years data were collected for 21 lactations from 13 BS cows and 29 lactations from 20 HFL cows. No significant interactions between cow type and dietary treatment were found for most traits investigated. However, there was a tendency (Pcow type×diet=0.096) for energy-corrected-milk (ECM) yield to be reduced at the Low compared with the Con concentrate level in BS but not in HFL during the first 7 weeks of lactation. Over the entire lactation, BS was significantly heavier than HFL (590 vs. 535 kg), but no significant differences between cow types were observed for ECM yield, the development of body condition score and back fat thickness or reproductive performance. The reduction of concentrate supplementation decreased energy balance (−10%; Pdiet=0.002) in both cow types, but HFL seemed to be able to support milk production primarily by increasing mobilisation of body fat reserves in early lactation. In contrast BS tended to reduce ECM yield, sustain blood glucose, and increase plasma urea and non-esteryfied fatty acids levels. However, measured over the entire lactation loss of body tissue and reproductive performance were relatively insensitive to dietary treatment. The results indicate that BS was probably not able to express its full genetic potential for milk production in any of the dietary treatments and that for both genotypes the nutritional challenge did not exceed the range of metabolic adaptions although the adaptation pattern was somewhat cow type specific.
The objective of this study was to determine the effect of growth rate on muscle fibre characteri... more The objective of this study was to determine the effect of growth rate on muscle fibre characteristics, concentration of nucleic acids (RNA and DNA) as indicators of muscle protein synthesis capacity and activity of the calpain system at time of slaughter in m. longissimus lumborum (LL) and m. supraspinatus (SS) from calves, in order to elucidate the effect of growth rate on muscle protein turn-over at time of slaughter. Twenty-four Friesian heifer calves were allocated to two different feeding regimens that allowed for a moderate/moderate (MM) or high/high (HH) growth rate from 5 days of age to 90 kg body weight (BW) (period I) and from 90 kg BW to slaughter at 250 kg BW (period II), respectively. The growth rates in the two periods and the weight of LL and SS at slaughter were recorded. Within 30 min after exsanguination, samples were removed from LL and SS, snap-frozen, and later analysed for muscle fibre type frequency and cross-sectional area, DNA and RNA concentration and the activity of the calpain system. High growth rate (i.e. 895 g/day and 1204 g/day in periods I and II, respectively), compared with moderate growth rate (678 g/day and 770 g/day in periods I and II, respectively) had a marked effect on muscle weight and muscle characteristics. High compared with moderate growth rate resulted in hypertrophic growth of type I, IIA and IIB fibres in LL and of type IIA and type IIB fibres in SS, but had no effect on the muscle fibre type frequency in either of the muscles. High growth rate increased total DNA and RNA content and the RNA: DNA ratio in LL, indicating a greater potential for protein synthesis in this muscle, whereas the effect of growth rate was smaller in SS. The activity of µ-calpain, m-calpain and calpastatin was higher in the red SS muscle compared with the whiter LL muscle. However, these enzyme activities were not affected by growth rate, and thus, did not indicate a higher myofibrillar proteolysis in vivo in calves exhibiting high growth rate compared with moderate growth rate. Overall the results showed that different types of muscles react differently to high versus moderate growth rate. High growth rate induced muscle hypertrophy and increased protein synthesis capacity especially in LL and less in SS, but the activities of the enzymes in the calpain system did not show any concomitant increase in muscle protein degradation that would be in favour of improved meat tenderness.
The objective was to investigate the effect of the β-adrenergic agonist, cimaterol, on gain, comp... more The objective was to investigate the effect of the β-adrenergic agonist, cimaterol, on gain, composition and meat quality of primerib (M. longissimus dorsi) from Friesian young bulls slaughtered at different developmental stages. Twelve pairs of monozygotic twins were allocated to three liveweight (LW) groups (162, 299 and 407 kg, respectively). Within each pair, one animal was given 0·056 mg cimaterol per kg LW for 90 days, while the other served as a control. Cimaterol treatment increased the estimated gain and the weight of primerib by 55 and 20%, respectively (both P < 0·001), and lean and protein content of the longissimus dorsi muscle by 26 and 25%, respectively (both P < 0·001), and concomitantly reduced fat content of primerib by 16% (P < 0·01) and intramuscular fat in longissimus dorsi by 36% (P < 0·001). Cimaterol treatment reduced total collagen content (P < 0·02), but not collagen solubility (P > 0·55). Meat colour was slightly lighter (lightness, P < 0·06), but pH(24) and pH(final) was not affected by cimaterol. Cimaterol increased Volodkevich shear force values (P < 0·001). In general, the effect of cimaterol on meat quality characteristics was evident in all three LW groups, and LW only affected percent fat in primerib, intramuscular fat content in longissimus dorsi, meat colour and absolute contents of protein, fat and bone.
The present study was conducted to determine the effect of growth rate of calves on the activity ... more The present study was conducted to determine the effect of growth rate of calves on the activity of the calpain system post mortem, post mortem desmin degradation, myofibrillar fragmentation index and meat tenderness of m. longissimus lumborum (LL) and m. supraspinatus (SS). Twenty-four Friesian heifer calves were allocated to two treatment groups: MM and HH. The MM calves were given food to achieve a moderate growth rate (678 g/day from 5 days of age to 90 kg body weight (BW) (period I) and 770 g/day from 90 kg BW to slaughter at 250 kg BW (period II)) and the HH calves were given food to achieve a high growth rate (period I: 895 g/day and period II: 1204 g/day). The myofibril fragmentation index (MFI), desmin degradation and the activity of µ-calpain, m-calpain and calpastatin were measured in LL and SS at slaughter, and 1 and 7 days post mortem. Shear force was measured in LL and SS after 1 and 7 days of ageing and a sensory panel evaluated the eating quality of the loin aged 7 d...
The mitogenic activity of milk from different stages of lactation was studied in primary cultures... more The mitogenic activity of milk from different stages of lactation was studied in primary cultures of undifferentiated bovine mammary epithelial cells. The mitogenic activity, measured as DNA synthesis, was 3–4-fold higher in colostrum than in basal medium. The mitogenic activity declined rapidly after calving, and in mid and late lactation the effect was inhibitory, not stimulatory. The content of IGF-I in milk varied with stage of lactation declining from more than 300 ng per ml in colostrum to 1–2 ng per ml in mid lactation and increasing to 20 ng per ml in late lactation. The difference in mitogenic activities between colostrum and mature milk was closely related to the difference in IGF-I content. The changes in IGF-I, however, cannot account for the inhibitory effect of mid and late lactation milk and the difference in the mitogenic effect of colostrum and BPMS (bovine prepartum milk-like secretion). The amounts of IGF binding proteins (24, 28, 34 and 41–44 kDa) in milk followed the same pattern as IGF-I with high content in early lactation and low content in mid lactation. The discrepancies between mitogenic activity and IGF-I content may in some, but not all, cases be related to the content of binding proteins.
... In the Nordic countries, the AAT-PBV-system (Hvelplund & Madsen, 1990) has been widely ... more ... In the Nordic countries, the AAT-PBV-system (Hvelplund & Madsen, 1990) has been widely adapted in ... feedstuffs in a dairy cow's ration to optimise milk production and reduce N-losses to ... The first-limiting AA is dependent on: 1) AA-composition of the feed, 2) the degradation ...
The objective of this study was to determine the effect of the beta-adrenergic agonist cimaterol ... more The objective of this study was to determine the effect of the beta-adrenergic agonist cimaterol (CIM) on fiber characteristics, capillary supply, and metabolic enzyme activities in muscles of young Friesian bulls. Four pairs of monozygotic twins in each of three live weight groups (WG) were used (initial average live weight [LW]: 162, 299, and 407 kg, respectively). Within each pair, one twin was fed .06 mg of CIM.kg LW-1.d-1 for 90 d. The other twin served as control (C). Needle biopsies were obtained from the longissimus (LM) and semitendinosus (ST) muscles at d 82 to 84 of treatment, and muscle fibers were identified as slow-twitch (Type I) or fast-twitch (Type IIA or Type IIB) by the myosin ATPase stain. In LM, the proportion of Type I (C: 24.0%, CIM: 20.4%; P < .07) and Type IIA fibers (C: 24.2%, CIM: 8.6%; P < .001) decreased, whereas the proportion of Type IIB fibers increased (C: 51.7%, CIM: 71.1%; P < .001). Cimaterol increased the cross-sectional area of Type I (...
The objective of this study was to determine the effect of growth rate on muscle fibre characteri... more The objective of this study was to determine the effect of growth rate on muscle fibre characteristics, concentration of nucleic acids (RNA and DNA) as indicators of muscle protein synthesis capacity and activity of the calpain system at time of slaughter in m. longissimus lumborum (LL) and m. supraspinatus (SS) from calves, in order to elucidate the effect of growth rate on muscle protein turn-over at time of slaughter. Twenty-four Friesian heifer calves were allocated to two different feeding regimens that allowed for a moderate/moderate (MM) or high/high (HH) growth rate from 5 days of age to 90 kg body weight (BW) (period I) and from 90 kg BW to slaughter at 250 kg BW (period II), respectively. The growth rates in the two periods and the weight of LL and SS at slaughter were recorded. Within 30 min after exsanguination, samples were removed from LL and SS, snap-frozen, and later analysed for muscle fibre type frequency and cross-sectional area, DNA and RNA concentration and the ...
Abstract Forage based low-input dairy systems include a certain risk of a temporary undersupply w... more Abstract Forage based low-input dairy systems include a certain risk of a temporary undersupply with nutrients and energy. Therefore the aim of the present study was to investigate the productive, reproductive and metabolic response of two different dairy cow types to a reduction of concentrate supplementation in an Alpine low-input milk production system. The cow types compared were conventional Austrian Brown Swiss (BS) and a specific strain of Holstein Friesian (HFL). The latter was primarily selected for lifetime performance and fitness under low-input conditions and is therefore considered by farmers as being better suited for low-input production systems. Both genotypes were assigned to one of two concentrate supplementation levels, receiving 618 kg (Con) or 279 kg (Low) of concentrates per lactation. During two years data were collected for 21 lactations from 13 BS cows and 29 lactations from 20 HFL cows. No significant interactions between cow type and dietary treatment were found for most traits investigated. However, there was a tendency (Pcow type×diet=0.096) for energy-corrected-milk (ECM) yield to be reduced at the Low compared with the Con concentrate level in BS but not in HFL during the first 7 weeks of lactation. Over the entire lactation, BS was significantly heavier than HFL (590 vs. 535 kg), but no significant differences between cow types were observed for ECM yield, the development of body condition score and back fat thickness or reproductive performance. The reduction of concentrate supplementation decreased energy balance (−10%; Pdiet=0.002) in both cow types, but HFL seemed to be able to support milk production primarily by increasing mobilisation of body fat reserves in early lactation. In contrast BS tended to reduce ECM yield, sustain blood glucose, and increase plasma urea and non-esteryfied fatty acids levels. However, measured over the entire lactation loss of body tissue and reproductive performance were relatively insensitive to dietary treatment. The results indicate that BS was probably not able to express its full genetic potential for milk production in any of the dietary treatments and that for both genotypes the nutritional challenge did not exceed the range of metabolic adaptions although the adaptation pattern was somewhat cow type specific.
The objective of this study was to determine the effect of growth rate on muscle fibre characteri... more The objective of this study was to determine the effect of growth rate on muscle fibre characteristics, concentration of nucleic acids (RNA and DNA) as indicators of muscle protein synthesis capacity and activity of the calpain system at time of slaughter in m. longissimus lumborum (LL) and m. supraspinatus (SS) from calves, in order to elucidate the effect of growth rate on muscle protein turn-over at time of slaughter. Twenty-four Friesian heifer calves were allocated to two different feeding regimens that allowed for a moderate/moderate (MM) or high/high (HH) growth rate from 5 days of age to 90 kg body weight (BW) (period I) and from 90 kg BW to slaughter at 250 kg BW (period II), respectively. The growth rates in the two periods and the weight of LL and SS at slaughter were recorded. Within 30 min after exsanguination, samples were removed from LL and SS, snap-frozen, and later analysed for muscle fibre type frequency and cross-sectional area, DNA and RNA concentration and the activity of the calpain system. High growth rate (i.e. 895 g/day and 1204 g/day in periods I and II, respectively), compared with moderate growth rate (678 g/day and 770 g/day in periods I and II, respectively) had a marked effect on muscle weight and muscle characteristics. High compared with moderate growth rate resulted in hypertrophic growth of type I, IIA and IIB fibres in LL and of type IIA and type IIB fibres in SS, but had no effect on the muscle fibre type frequency in either of the muscles. High growth rate increased total DNA and RNA content and the RNA: DNA ratio in LL, indicating a greater potential for protein synthesis in this muscle, whereas the effect of growth rate was smaller in SS. The activity of µ-calpain, m-calpain and calpastatin was higher in the red SS muscle compared with the whiter LL muscle. However, these enzyme activities were not affected by growth rate, and thus, did not indicate a higher myofibrillar proteolysis in vivo in calves exhibiting high growth rate compared with moderate growth rate. Overall the results showed that different types of muscles react differently to high versus moderate growth rate. High growth rate induced muscle hypertrophy and increased protein synthesis capacity especially in LL and less in SS, but the activities of the enzymes in the calpain system did not show any concomitant increase in muscle protein degradation that would be in favour of improved meat tenderness.
The objective was to investigate the effect of the β-adrenergic agonist, cimaterol, on gain, comp... more The objective was to investigate the effect of the β-adrenergic agonist, cimaterol, on gain, composition and meat quality of primerib (M. longissimus dorsi) from Friesian young bulls slaughtered at different developmental stages. Twelve pairs of monozygotic twins were allocated to three liveweight (LW) groups (162, 299 and 407 kg, respectively). Within each pair, one animal was given 0·056 mg cimaterol per kg LW for 90 days, while the other served as a control. Cimaterol treatment increased the estimated gain and the weight of primerib by 55 and 20%, respectively (both P &amp;amp;lt; 0·001), and lean and protein content of the longissimus dorsi muscle by 26 and 25%, respectively (both P &amp;amp;lt; 0·001), and concomitantly reduced fat content of primerib by 16% (P &amp;amp;lt; 0·01) and intramuscular fat in longissimus dorsi by 36% (P &amp;amp;lt; 0·001). Cimaterol treatment reduced total collagen content (P &amp;amp;lt; 0·02), but not collagen solubility (P &amp;amp;gt; 0·55). Meat colour was slightly lighter (lightness, P &amp;amp;lt; 0·06), but pH(24) and pH(final) was not affected by cimaterol. Cimaterol increased Volodkevich shear force values (P &amp;amp;lt; 0·001). In general, the effect of cimaterol on meat quality characteristics was evident in all three LW groups, and LW only affected percent fat in primerib, intramuscular fat content in longissimus dorsi, meat colour and absolute contents of protein, fat and bone.
The present study was conducted to determine the effect of growth rate of calves on the activity ... more The present study was conducted to determine the effect of growth rate of calves on the activity of the calpain system post mortem, post mortem desmin degradation, myofibrillar fragmentation index and meat tenderness of m. longissimus lumborum (LL) and m. supraspinatus (SS). Twenty-four Friesian heifer calves were allocated to two treatment groups: MM and HH. The MM calves were given food to achieve a moderate growth rate (678 g/day from 5 days of age to 90 kg body weight (BW) (period I) and 770 g/day from 90 kg BW to slaughter at 250 kg BW (period II)) and the HH calves were given food to achieve a high growth rate (period I: 895 g/day and period II: 1204 g/day). The myofibril fragmentation index (MFI), desmin degradation and the activity of µ-calpain, m-calpain and calpastatin were measured in LL and SS at slaughter, and 1 and 7 days post mortem. Shear force was measured in LL and SS after 1 and 7 days of ageing and a sensory panel evaluated the eating quality of the loin aged 7 d...
The mitogenic activity of milk from different stages of lactation was studied in primary cultures... more The mitogenic activity of milk from different stages of lactation was studied in primary cultures of undifferentiated bovine mammary epithelial cells. The mitogenic activity, measured as DNA synthesis, was 3–4-fold higher in colostrum than in basal medium. The mitogenic activity declined rapidly after calving, and in mid and late lactation the effect was inhibitory, not stimulatory. The content of IGF-I in milk varied with stage of lactation declining from more than 300 ng per ml in colostrum to 1–2 ng per ml in mid lactation and increasing to 20 ng per ml in late lactation. The difference in mitogenic activities between colostrum and mature milk was closely related to the difference in IGF-I content. The changes in IGF-I, however, cannot account for the inhibitory effect of mid and late lactation milk and the difference in the mitogenic effect of colostrum and BPMS (bovine prepartum milk-like secretion). The amounts of IGF binding proteins (24, 28, 34 and 41–44 kDa) in milk followed the same pattern as IGF-I with high content in early lactation and low content in mid lactation. The discrepancies between mitogenic activity and IGF-I content may in some, but not all, cases be related to the content of binding proteins.
... In the Nordic countries, the AAT-PBV-system (Hvelplund & Madsen, 1990) has been widely ... more ... In the Nordic countries, the AAT-PBV-system (Hvelplund & Madsen, 1990) has been widely adapted in ... feedstuffs in a dairy cow's ration to optimise milk production and reduce N-losses to ... The first-limiting AA is dependent on: 1) AA-composition of the feed, 2) the degradation ...
The objective of this study was to determine the effect of the beta-adrenergic agonist cimaterol ... more The objective of this study was to determine the effect of the beta-adrenergic agonist cimaterol (CIM) on fiber characteristics, capillary supply, and metabolic enzyme activities in muscles of young Friesian bulls. Four pairs of monozygotic twins in each of three live weight groups (WG) were used (initial average live weight [LW]: 162, 299, and 407 kg, respectively). Within each pair, one twin was fed .06 mg of CIM.kg LW-1.d-1 for 90 d. The other twin served as control (C). Needle biopsies were obtained from the longissimus (LM) and semitendinosus (ST) muscles at d 82 to 84 of treatment, and muscle fibers were identified as slow-twitch (Type I) or fast-twitch (Type IIA or Type IIB) by the myosin ATPase stain. In LM, the proportion of Type I (C: 24.0%, CIM: 20.4%; P < .07) and Type IIA fibers (C: 24.2%, CIM: 8.6%; P < .001) decreased, whereas the proportion of Type IIB fibers increased (C: 51.7%, CIM: 71.1%; P < .001). Cimaterol increased the cross-sectional area of Type I (...
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Papers by Mogens Vestergaard