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Molecular characterization, polymorphism and association study of lysozyme gene with milk production and somatic cell trait in Bos indicus × Bos taurus cattle
- M. Salehin, A. K. Ghosh, P. K. Mallick, T. K. Bhattacharya
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 623-631
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Lysozyme, an anti-bacterial enzyme, is mostly found in the body fluids, various tissues and secretions of animals and humans, and confers immunity against a wide range of bacterial species. The present study was carried out to elucidate the gene sequence of this enzyme in Indian Sahiwal × Holstein Friesian crossbred cattle and to explore the polymorphism of the gene as well as their association with milk production and somatic cell traits. The total length of lysozyme cDNA was found to be of 447 bp. The similarity with Bos taurus, human, pig, monkey, gorilla, mice, rat, chicken, dog and sheep was estimated as 99.1%, 85%, 81.0%, 85.2%, 84.3%, 77.9%, 77.9%, 41.4%, 40.5% and 24.6%, respectively. Polymorphism study of two fragments, extended exon1 including promoter, exon1 and partial intron1 (268 bp), and extended exon2 including partial intron1 and 2, and exon2 region (287 bp) of milk lysozyme gene was carried out by employing single-stranded conformation polymorphism (SSCP). In the extended exon1 fragment, three alleles namely A, B and C with frequencies of 0.59, 0.28 and 0.12 were observed while in the exon extended fragment, three different alleles – P, Q and R with respective frequencies of 0.61, 0.38 and 0.01 – were determined in Indian Sahiwal × Holstein Friesian cross. A total of eight haplotypes were found in this population where the most predominant one was h1 (0.52). Genotypes of exon1 extended fragment showed significant association with total milk yield, daily milk yield, peak yield and somatic cell score at P < 0.05 while that of exon2 extended fragment had significant correlation with only total lactational milk yield. Haplotype combinations also revealed significant association with total milk production where h1h1 homozygous showed highest yield during first lactation.
A genome scan for loci affecting adipocyte size and number in abdominal fat in a White Duroc × Erhualian F2 resource population
- L. T. Liu, J. Ren, L. Li, W. B. Li, B. Yang, W. C. Zhu, B. L. Guo, J. W. Ma, L. S. Huang
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 632-636
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Adipocyte size and number are correlated with fat deposition, which is of major concern to human health and pork producers. To identify quantitative trait loci (QTL) for adipocyte size and number in pigs, a total of 341 F2 animals at 240 days in a White Duroc × Erhualian cross were measured for the area, perimeters, volume and number of adipocyte in abdominal fat. A genome scan was performed on these animals and their parents and grandparents with 183 microsatellite markers spanning the pig genome. Five chromosomal regions showed effects on the traits measured, predominantly on adipocyte size, on pig chromosome (SSC) 1, 4, 7 and 9. Neither of these QTL has been reported before this study. The QTL for adipocyte size detected in this study perfectly correspond to the previously reported QTL for fatness traits on SSC1, 4 and 7. The most significant association was evidenced at 58 cM on SSC7. At the locus, the favorable allele decreasing adipocyte size was unusually originated from the obese Erhualian breed. Only a suggestive QTL was detected for adipocyte number on SSC9. The results shed new lights on the understanding of the genetic basis of fatness traits in pigs.
Differences in productive robustness in rabbits selected for reproductive longevity or litter size
- P. Theilgaard, M. Baselga, E. Blas, N. C. Friggens, C. Cervera, J. J. Pascual
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 637-646
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The aim of this work was to evaluate the ability of a line selected for reproductive longevity (LP) to confront productive challenges compared to a line selected during 31 generations for litter size at weaning (V). A total of 133 reproductive rabbit does were used (72 and 61 from LP and V lines, respectively). Within each line, three groups with different levels of productive effort were planned: PP9, inseminated at day 4 after the first partum and with nine kits during the second partum, and inseminated after first weaning (30 days) and with nine (PW9) or five kits (PW5) during the second partum. The reproductive performance, body condition (perirrenal fat thickness (PFT)) and lipolytic response were controlled. LP does showed greater mean live weight (LW; +128 g; P < 0.05), PFT (+0.47 mm; P < 0.05) and estimated body energy (EBE; +0.29 MJ/kg; P < 0.01) than V does at second partum. However, LP does that mated at first post partum did not significantly differ in EBE relative to V does at second partum. During the first week of lactation, dry matter (DM) intake was similar for both lines (94 and 95 g DM/kg LW0.75 day for V and LP does, respectively). There was a significant difference in milk yield between both lines during the first week when litter size was nine (60 v. 54 g of milk/kg LW0.75 day for LP and V does, respectively; P < 0.01), but no difference when litter size was five. Consequently, when litter size was nine, LP does showed a lower recovery of PFT (0.6 mm less; P < 0.05) than V does during the first 10 days of lactation. However, when litter size was five, LP does showed a higher LW (+210 g; P < 0.05) than V does at 10 days of lactation and a similar recovery of PFT. During the last 3 weeks of the lactation, LP does showed a higher feed intake (+6 g DM/kg LW0.75 day; P < 0.05) and milk yield (+27 g/day; P < 0.001) than V does when litter size was nine, resulting in no significant differences in LW at 30 days of lactation. However, when litter size was five, both lines showed similar feed intake and milk yield, maintaining their differences in LW at 30 days of lactation (+206 g for LP does; P < 0.05). These results show that the rabbit line selected for reproductive longevity is more robust with respect to coping with productive challenges, than a line selected for reproductive intensity.
Genetic parameters for pathogen-specific mastitis resistance in Danish Holstein Cattle
- L. P. Sørensen, P. Madsen, T. Mark, M. S. Lund
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- 01 May 2009, pp. 647-656
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The objective of this study was to estimate heritabilities for and genetic correlations among different pathogen-specific mastitis traits. The traits were unspecific mastitis, which is all mastitis treatments regardless of the causative pathogen as well as mastitis caused by Streptococcus dysgalactiae, Escherichia coli, coagulase-negative staphylococci (CNS), Staphylococcus aureus and Streptococcus uberis. Also groups of pathogens were investigated, Gram-negative v. Gram-positive and contagious v. environmental pathogens. Data from 168 158 Danish Holstein cows calving first time between 1998 and 2006 were used in the analyses. Variances and covariances were estimated using uni- and bivariate threshold models via Gibbs sampling. Posterior means of heritabilities of pathogen-specific mastitis were lower than the heritability of unspecific mastitis, ranging from 0.035 to 0.076 for S. aureus and S. uberis, respectively. The heritabilities of groups of pathogen ranged from 0.053 to 0.087. Genetic correlations among the pathogen-specific mastitis traits ranged from 0.45 to 0.77. These estimates tended to be lowest for bacteria eliciting very different immune responses, which can be considered as the overall pleiotropic effect of genes affecting resistance to a specific pathogen, and highest for bacteria sharing characteristics regarding immune response. The genetic correlations between the groups of pathogens were high, 0.73 and 0.83. Results showed that the pathogen-specific traits used in this study should be considered as different traits. Genetic evaluation for pathogen-specific mastitis resistance may be beneficial despite lower heritabilities than unspecific mastitis because a pathogen-specific mastitis trait is a direct measure of an udder infection, and because the cost of a mastitis case caused by different pathogens has been shown to differ greatly. Sampling bias may be present because there were not pathogen information on all mastitis treatments and because some farms do not record pathogen information. Therefore, improved recording of pathogen information and mastitis treatments in general is critical for a successful genetic evaluation of udder health. Also, economic values have to be specified for each pathogen-specific trait separately.
Effect of plane of nutrition of 1- and 2-year-old ewes in early and mid-pregnancy on ewe reproduction and offspring performance up to weaning
- C. Muñoz, A. F. Carson, M. A. McCoy, L. E. R. Dawson, N. E. O’Connell, A. W. Gordon
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 657-669
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The objective of the present study was to determine the effect of plane of nutrition in early pregnancy (EP) and mid-pregnancy (MP), on the productive performance of 1- and 2-year-old ewes and their offspring. Over 2 successive years, between days 0 and 39 after synchronized mating (EP), 1- (n = 117) and 2- (n = 52) year-old ewes were allowed 60% (low, L-EP), 100% (medium, M-EP) or 200% (high, H-EP) of requirements for maintenance (M). Between days 40 and 90 (MP), 1-year-old ewes were allowed 140% (M-MP) or 200% (H-MP), while 2-year-old ewes were allowed 80% (M-MP) or 140% (H-MP) of their M requirement. After day 90, all ewes were fed to meet requirements for late pregnancy. Increasing the plane of nutrition between days 0 and 39 resulted in increases in live weight (LW) (P < 0.001) and body condition score (BCS) (P < 0.001) during the EP period (H-EP > M-EP > L-EP), differences that in 1-year-old ewes were sustained to lambing (P < 0.05). On day 42 of gestation H-EP ewes had lower plasma progesterone concentrations than L-EP or M-EP ewes in 1- (P < 0.01) and 2- (P < 0.001) year olds. This was concomitant with diet H-EP tending to reduce the number of lambs born per ewe in both age groups (P = 0.06 and 0.07, respectively). Foetuses from 1-year-old L-EP ewes had smaller cranial (P < 0.01) and abdominal (P < 0.05) diameters at day 53 of gestation, with H-EP lambs tending to be heaviest at birth (P = 0.07). Similar findings were recorded for 2-year-old ewes. One-year-old ewes offered diet L-EP presented negative maternal behaviours more frequently (P < 0.05), while the incidence of lamb mortality at 6 weeks tended to be greater for L-EP lambs (P = 0.07). In MP, 1-year-old ewes offered diet M-MP were associated with foetuses with bigger abdominal diameters at day 78 (P < 0.05). However, there were no differences in lamb weight or size at term (P > 0.05). These ewes exhibited more positive maternal behaviours (e.g. increased grooming frequency and duration; P < 0.05) than ewes offered diet H-MP, and their offspring were more successful in suckling (P < 0.05). Results suggest that in young ewes, a temporary nutrient restriction in EP resulted in increased prolificacy. However, ewes and their offspring were lighter at birth and ewe maternal behaviour was poorer, resulting in increased lamb mortality. In MP, a medium plane of nutrition offered to 1-year-old ewes led to improved maternal and offspring behaviour.
Effect of fermented liquid diet prepared with Lactobacillus plantarum LQ80 on the immune response in weaning pigs
- K. Mizumachi, R. Aoki, H. Ohmori, M. Saeki, T. Kawashima
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 670-676
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Probiotics such as lactic acid bacteria directly influence the host’s health and have beneficial effects such as decreasing the number of enteric pathogens, regulating intestinal immune responses and preventing diseases. Among domestic animals, probiotics have been expected to be an alternative to antibiotics added in the diet; and fermented liquid diet (FLD) containing probiotics has great potential as a diet for reducing the use of antibiotics. In this study, we evaluated the immunomodulatory effects of FLD, prepared using Lactobacillus plantarum LQ80 (LQ80), on the immune response of weaning pigs. Ten weaning piglets were divided into two groups and were fed the FLD (n = 5) or a non-fermented liquid diet (NFLD) (n = 5) for 28 days. At the end of the experiment, the total immunoglobulin M (IgM) and immunoglobulin G (IgG) levels in the sera of the FLD-fed piglets were significantly higher than those of the NFLD-fed piglets (P < 0.05). In contrast, the total immunoglobulin A (IgA) levels in the feces and saliva were not significantly affected by FLD feeding. However, the mean fecal IgA levels of FLD-fed piglets at day 28 were higher than those at 14 and 21 days (P < 0.05). Blood cells from the FLD-fed piglets showed a low level of interferon-γ secretion and mitogen-induced proliferation compared to that of the NFLD-fed piglets. Furthermore, the levels of interluekin-8 and tumor necrosis factor-α, which are proinflammatory cytokines, in the blood cells of the FLD-fed piglets were lower than those of the NFLD-fed piglets (P < 0.05). In conclusion, the FLD used in this study could alter the immune responses of weaning piglets by stimulation of the systemic or mucosal antibody response, without unnecessary inflammatory reactions. This indicates, that the FLD feed prepared with the use of LQ80 may be a candidate feed, with regard to enhancing immune responses and preventing diseases in weaning piglets.
Bioavailability of threonine and tryptophan in peanut meal for starter pigs using slope-ratio assay
- O. Adeola
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 677-684
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The objective of the two studies was to determine the bioavailability of threonine (thr) and tryptophan (trp) in peanut meal, relative to l-thr and l-trp, for starter pigs using the slope-ratio bioassay. Basal diets (BDs) contained surfeit amounts of all amino acids for 10 to 20 kg pigs, except for thr (Experiment 1) or trp (Experiment 2). In the first study, four reference diets were formulated by supplementing the BD with 0, 0.4, 0.8 or 1.2 g of l-thr/kg at the expense of cornstarch; two test diets were formulated by replacing cornstarch in the BD with peanut meal at 32 or 64 g/kg of diet to supply 0.4 or 0.8 g thr/kg, respectively. Four reference diets consisting of the BD supplemented with 0, 0.15, 0.3 or 0.45 g of l-trp/kg at the expense of cornstarch and two test diets in which cornstarch in the BD was replaced with peanut meal at 30 or 60 g/kg of diet to supply 0.14 or 0.28 g trp/kg, respectively were used in the second study. Body weight gain responded in a linear way to supplemental l-thr or thr from peanut meal (P < 0.001). There was a linear response (P < 0.001) to thr supplementation from l-thr or peanut meal in gain-to-feed ratio. The addition of trp to the BD linearly increased (P < 0.05) body weight gain, feed intake and gain-to-feed ratio regardless of the trp source. Common-intercept, multiple linear regression in slope-ratio methodology using weight gain or gain-to-feed ratio as dependent variables and supplemental thr intake as independent variable gave relative bioavailability estimates of 71.9% or 75.7%, respectively. Corresponding values for trp were 92% and 75.7%. The fiducial limits for none of the relative bioavailability estimates included 100%. The data from these studies suggest that the bioavailabilities of thr and trp in peanut meal are less than those of l-thr and l-trp, and that the bioavailabilities of thr and trp in peanut meal are 72% to 76% and 76% to 92%, respectively.
Improvement of insulin response in the streptozotocin model of insulin-dependent diabetes mellitus. Insulin response with and without a long-acting insulin treatment
- L. Nordquist, M. Sjöquist
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 685-689
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Streptozotocin-induced diabetes mellitus (STZ-DM) in rats is a model of type 1 diabetes, which is commonly used to study diabetes, but differs from human diabetic pathophysiology in its insulin resistance. An STZ-DM rat can be administered five times the dose of insulin compared to that of a diabetic patient. Thus, attaining normoglycaemia in STZ-DM rats with insulin injections is complicated, and it involves an obvious risk of overdosing before getting a response. This study was designed to investigate whether suboptimal treatment with long-acting insulin restores insulin sensitivity in the STZ-DM rat, and thus an approach to more closely mimic the human condition. Male Sprague-Dawley rats were made diabetic by means of a single intravenous injection of STZ (55 mg/kg body weight (BW)), resulting in an increase in blood glucose (BG) from 6.5 ± 0.2 to 22.5 ± 1.0 mmol/l (P ⩽ 0.05) within 24 h. After treating the STZ-DM rats with vehicle for 14 days, BG was 26.1 ± 1.1 mmol/l, and the response to a single injection of fast-acting insulin (Humalog, 5 IE/kg BW) was a 23% reduction in BG. Thereafter, the rats were treated daily with a suboptimal dose of long-acting insulin for a total of 7 days (Insulatard, 5 IE/kg per day), which resulted in a BG level of 19.4 ± 2.7. The response to fast-acting insulin after the suboptimal treatment was a 61% reduction in BG. Thereafter, the animals were vehicle-treated for another 7 days, which resulted in a response to fast-acting insulin similar to the initial values (−34%). Furthermore, the group treated with suboptimal doses of long-acting insulin had a longer duration of the reduction in BG (150 min, as opposed to 90 min in the vehicle-treated groups). We conclude that the development of a decreased insulin response occurs rapidly within the first 2 weeks after the onset of diabetes in STZ-DM rats. This leads to a brief and significantly reduced decrease in BG when fast-acting insulin is administered. The insulin response is increased by treatment with suboptimal doses of long-acting insulin, but rapidly decreases again when treatment is withdrawn. Regular administration of suboptimal insulin doses may provide an approach to eliminate the effects of a lowered insulin response.
Can audio–visual or visual stimuli from a prospective mate stimulate a reproductive neuroendocrine response in sheep?
- P. A. R. Hawken, T. Esmaili, V. Scanlan, D. Blache, G. B. Martin
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- 01 May 2009, pp. 690-696
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Stimuli from a prospective mate increase the secretion of luteinising hormone (LH) in sheep. This ‘male effect’ in ewes and ‘female effect’ effect in rams is predominantly mediated by olfactory signals, though it is thought that non-olfactory signals play synergistic or substitutive roles. In this study, we tested whether exposure to visual or audio–visual stimuli from a prospective mate would stimulate an increase in LH secretion in ewes (Experiment 1) and rams (Experiment 2). In Experiment 1, groups of eight Merino ewes were exposed to one of three stimuli midway through a frequent blood-sampling regimen: full ram contact, still images of rams, a video of ewes and rams mating. Control ewes (n = 8) were completely isolated from rams. Exposure to still images of rams appeared to stimulate an increase in mean LH concentrations (P < 0.05) and tended to increase LH pulse frequency (P < 0.1), but the response was significantly smaller than that observed in ewes exposed to rams (P < 0.01). Audio–visual stimuli had no effect on any parameters of LH secretion (P > 0.1). In Experiment 2, Merino rams were allocated to either an Exposure (n = 7) or a Control (n = 7) group. Exposure rams underwent two exposure periods midway through a frequent blood-sampling regimen; exposure to still images of ewes and audio recorded during mating of ewes and rams (audio–visual exposure); exposure to oestrous ewes (ewe exposure). Control rams were sampled at the same frequency but remained isolated from ewe stimuli. Exposure of rams to the audio–visual stimuli did not affect any parameters of LH secretion (P > 0.1). In contrast, exposure to oestrous ewes increased LH pulse frequency (P < 0.05) and advanced the onset of the next LH pulse (P < 0.05). In conclusion, visual signals appear to be involved in eliciting the neuroendocrine response of ewes to rams and are of greater importance to this phenomenon in ewes (male effect) than rams (female effect). However, overall the visual and audio–visual signals used in this study were far less effective than stimulus animals, suggesting that these stimuli are less important than olfactory signals, or a combination of olfactory and audio–visual signals.
No effect of the plant growth regulator, chlormequat, on boar fertility
- M. T. Sørensen, M. E. Poulsen, H. Leffers, G. Vajta, U. Halekoh
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- 01 May 2009, pp. 697-702
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Chlormequat is a commonly used plant growth regulator in agriculture. Defined levels of chlormequat residue are allowed in food and an acceptable daily intake is defined for humans. However, there are results in the literature suggesting that a daily intake below the acceptable level for human is detrimental for mammalian reproduction. In the present experiment we investigated the effect of chlormequat at levels up to that acceptable for humans on reproduction in male pigs. Chlormequat (also known as chlorocholine chloride (CCC)) was mixed into the diet and given to the experimental animals at three levels (three treatment groups), i.e. 0 mg CCC/kg BW per day (Control), 0.025 mg CCC/kg BW per day and 0.05 mg CCC/kg BW per day. Eight mother sows per treatment group were used in the experiment. From the day of insemination, the mother sows received the experimental diets. The piglets were weaned at 4 weeks of age and two boar littermates continued on the same treatment as the dam until maturity and delivery of semen for in vitro fertilization (IVF) and in vivo fertilization. Semen volume, sperm concentration and fraction of live sperms were not (P ⩾ 0.46) detrimentally affected by chlormequat intake. The fraction of oocytes developing to more than the one-cell stage at day 5 after IVF was not (P = 0.88) detrimentally affected by chlormequat intake. Chlormequat intake did not detrimentally affect the fraction of gilts being pregnant after one insemination (P = 0.65) or the number of embryos in the pregnant gilts (P = 0.36). Serum chlormequat concentration was 0.9 μg/kg in the 0.025 mg CCC/kg BW per day group and 1.8 μg/kg in the 0.05 mg CCC/kg BW per day group, but was below the detection limit in control animals. In conclusion, the plant growth regulator chlormequat could not be proven to be detrimental to the selected reproduction traits in male pigs. This is in contrast to existing results from the male mouse.
In vitro primary satellite cell growth and differentiation within litters of pigs
- P. M. Nissen, N. Oksbjerg
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 703-709
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Postnatal muscle growth is dependent on satellite cell (SC) proliferation, differentiation and fusion to increase the DNA content of existing muscle fibres and thereby the capacity to synthesize protein. The purpose of the present study was to examine the ability of isolated SCs from low, medium and high weaning weight litter mates of pigs to proliferate and differentiate, and to affect protein synthesis and degradation after fusion into myotubes. At 6 weeks of age, SCs from the lowest weight (LW), medium weight (MW) and highest weight (HW) female pigs within eight litters were isolated. Thereby, eight cultures of SCs were established for each of the three weight groups within litter, representing three groups of SCs from pigs exhibiting differences in postnatal muscle growth performance. Proliferation was estimated as the number of viable cells at different time points after seeding. SC differentiation was evaluated by measuring the activity of the muscle-specific enzyme, creatine phosphokinase, and protein synthesis and degradation were measured by incorporation and release of 3H-tyrosine, respectively. A tendency towards a difference in proliferation between SC cultures was found (P = 0.09). This was evident as the number of viable cells at day 3 was lower in cultures from LW pigs than from HW (P < 0.05) and MW (P < 0.01) pigs. Differentiation was significantly different between cultures (P < 0.05). There was a significant difference between LW and MW cultures at 72 h (P < 0.05), and a tendency towards a difference between LW and HW cultures at 45 h (P = 0.07). Protein synthesis per μg protein or per μg DNA did not differ among SC cultures from LW, MW and HW pigs. Neither did protein degradation rate differ significantly among SC cultures from LW, MW and HW pigs. Overall, the results show that SCs from LW pigs seem to proliferate and differentiate at a slower rate than SCs from MW and HW pigs. The results found in this study show no difference in the ability of SCs to affect protein synthesis or degradation between SCs from litter mates exhibiting different growth rates in vivo.
Udder quarter milk composition at different levels of somatic cell count in cow composite milk
- L. Forsbäck, H. Lindmark-Månsson, A. Andrén, M. Åkerstedt, K. Svennersten-Sjaunja
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 710-717
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Automatic milking systems have made possible the separation of high- and low-quality milk at the udder quarter level during the milking process. The aim of this study was to investigate the composition and yield of milk from individual udder quarters to determine whether deteriorated milk composition occurs in udders that are assumed to be healthy and whether quarters with high-quality milk are found in udders with high milk somatic cell count (SCC). Milk samples were collected on one occasion from 90 cows at udder quarter level and cow composite level. The milk was analyzed for content of total protein, whey protein, casein, fat, lactose, citric acid and SCC; milk yield was registered. The cows were divided into three groups depending on the SCC of their composite milk. Cows in group 1, cow composite SCC < 100 000 cells/ml, were assumed to have healthy udders. However, instances of increased SCC and decreased milk quality were discovered in one or more udder quarters of approximately 30% of the group. Cows in group 2, cow composite SCC of 100 000 to 300 000 cells/ml, and group 3, cow composite SCC > 300 000 cells/ml, were assumed to have affected udders. However, the majority of these cows had one or more udder quarters in which increased SCC and deteriorated milk quality were not detected. Calculations of bulk-tank milk values, when separation of milk from affected udder quarters was performed, indicate that SCC changes to a much greater degree compared to the other milk components. These results show that milk from affected udder quarters suffers compositional changes, but calculations of simulated separation indicate that the compositional changes in bulk-tank milk are small. The effect of separation of milk from individual udder quarters on bulk-tank milk needs to be further studied.
Effect of level of eicosapentaenoic acid on the transcriptional regulation of Δ-9 desaturase using a novel in vitro bovine intramuscular adipocyte cell culture model
- S. M. Waters, D. A. Kenny, A. P. Killeen, S. A. Spellman, A. Fitzgerald, A. A. Hennessy, A. C. Hynes
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 718-727
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Ruminant fat is often perceived as having a negative impact on human health; however, the composition of the fat is under complex biochemical control and can be improved through strategic manipulation of the animal’s diet. There were two major objectives of this study, namely (i) to develop and validate a primary bovine intramuscular adipocyte cell line and (ii) to examine the effect of eicosapentaenoic acid (EPA) on the transcriptional regulation of Δ-9 desaturasein vitro using the novel cell line. Intramuscular adipose tissue was obtained from the Musculus longissimus thoracis of a beef heifer. Mature adipocytes were isolated and cultured, and subsequently harvested and evaluated for lipid accumulation and the expression of genes regulating key functional adipocyte protein markers at passages 10, 20 and 30. Isolated cells were shown to accumulate lipid in culture over time. Fatty acid analysis by gas chromatography was carried out at passage 30. Thirteen fatty acids ranging from tetradecanoic acid (C14:0) to the polyunsaturated fatty acid, docosahexaenoic acid (C22:6), were easily detected and measured. High-quality total RNA was isolated from adipocytes and the expression of peroxisome proliferator-activated receptor-γ, fatty acid synthase, fatty acid-binding protein-4, adipocyte lipid-binding protein, CD36, Δ-9 desaturase, sterol regulatory element-binding protein (SREBP), microsomal triglyceride transfer protein and leptin genes were identified by reverse transcriptase-PCR and sequence analysis. Expression of the negative control, liver-specific hepatocyte nuclear factor-1alpha, was not detected. Adipocytes were subsequently incubated in medium containing 0, 50 or 100 μM EPA for 24 h. Increasing the EPA concentration of the culture media led to a linear increase in adipocyte EPA concentration (P < 0.01). Expression of Δ-9 desaturase mRNA was decreased five- and seven-fold, respectively, following 50 and 100 μM EPA incubation compared to the control. Gene expression of SREBP-1c was decreased by 6- and 18-fold in cells supplemented with 50 and 100 μM EPA, respectively, compared to the control. Regression analysis showed a negative linear relationship between EPA concentration and the gene expression of both Δ-9 desaturase (P < 0.001) and SREBP-1c (P < 0.001), while a significant positive relationship was observed between Δ-9 desaturase and SREBP-1c gene expression (P < 0.001). This is the first report demonstrating that EPA treatment of bovine intramuscular adipocyte cells decreased gene expression of both Δ-9 desaturase and SREBP-1cin vitro. The bovine adipocyte cell line developed here is an important resource for future studies facilitating less-expensive, rapid screening of research hypotheses and circumventing the limitations associated with the use of experimental animals including cost, inter-animal variation, pre-experimental management and ethics.
Origin and assessment of bruises in beef cattle at slaughter
- A. C. Strappini, J. H. M. Metz, C. B. Gallo, B. Kemp
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- 01 May 2009, pp. 728-736
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Studies of bruises, as detected on carcasses at the slaughterhouse, may provide useful information about the traumatic situations the animals endure during the pre-slaughter period. In this paper, we review scientific data on the prevalence, risk factors and estimation of the age of bruises in beef cattle. Risk factors such as animal characteristics, transport conditions, stocking density, livestock auction and handling of the animals are discussed. Investigation of the age of bruises could provide information on when in the meat chain bruises occur and, could help to pinpoint where preventive measures should be taken, from the stage of collecting the animals on the farm until slaughter. We review the methods available to assess the age of the bruises; data on human forensic research are also included. The feasibility to identify traumatic episodes during the pre-slaughter period, in order to improve animal welfare is discussed.
The relationship between the stockperson’s personality and attitudes and the productivity of dairy cows
- D. Hanna, I. A. Sneddon, V. E. Beattie
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- 01 May 2009, pp. 737-743
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This study investigated the relationships amongst personality traits and attitudes of 311 dairy stockpeople and the milk yield they obtained. A questionnaire pack consisting of a big-five measure of personality (which includes the traits of extraversion, agreeableness, conscientiousness, emotional stability and intellect), a four-factor attitude questionnaire and associated demographic and production questions was posted out to Northern Ireland dairy farmers. Pearson correlations were used to assess the relationship between personality and attitudes and partial correlations were calculated between milk yield and these psychometric measures. The personality traits of agreeableness and conscientiousness were most strongly correlated to positive attitudes towards working with dairy cows. None of the stockpeople’s personality traits were significantly correlated with the milk yield they obtained. Three of the attitude scales, however, were significantly correlated with milk yield; milk yield was related to higher levels of empathy and job satisfaction and lower levels of negative beliefs. These findings, along with previous research, suggest stockperson attitudes may be important in relation to dairy cow welfare and production.
Microbial pollution of water by livestock: approaches to risk assessment and mitigation
- A. J. A. Vinten, J. Potts, L. Avery, N. J. C. Strachan
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 744-752
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In this study, we investigate the extent to which the incidence of Escherichia coli O157:H7 can be predicted in human faeces, from human intake and infection via water contaminated by livestock and carrying this zoonotic pathogen in North-East (NE) and South-West (SW) regions of Scotland. In SW Scotland, there is a risk of coastal recreational waters failing EU standards for faecal indicator organisms, and this is assumed to be the main potential waterborne route of infection. In NE Scotland, the main waterborne route is assumed to be the many private drinking water supplies; these are mainly derived from shallow groundwater and surveys show that there is potential for significant levels of microbial contamination from livestock. The risk to human health from these sources has been assessed using a combination of process models, epidemiological risk-assessment methods and survey data. A key assumption in the calculations is the amount of mixing of pathogenic and non-pathogenic E. coli between animal faecal sources and contaminated water intake by humans. Using the probability distributions of the E. coli O157 content of individual faecal pat material (which would imply no mixing between source and human intake), based on three recent surveys of animal faeces in Scotland, led to predicted annual risks of infection slightly higher than observed human infection incidence. Using the geometric mean to represent partial mixing (which theoretically may over- or underestimate incidence with a concave dose–response curve) gave infection rates similar to those observed for two of the three faecal surveys. Using the arithmetic mean led to over-prediction of risk. This is to be expected if the true dose–response curve is (such as the Beta-Poisson curve used here) concave. Other factors that may lead to over-prediction of incidence are discussed, including under-reporting, loss of infectivity as a result of environmental exposure, immunity and the appropriateness of the Beta-Poisson curve. It is concluded that better epidemiological data for calibration of the dose–response curve, better knowledge of the degree of mixing and understanding of immunity are key requirements for progress in process model-based predictions of infection rate. The paper also explores the potential of improved farm and catchment scale management to deliver cost-effective mitigation of pollution of bathing and drinking water by livestock zoonoses.
Is intensification of reproduction rhythm sustainable in an organic sheep production system? A 4-year interdisciplinary study
- M. Benoit, H. Tournadre, J. P. Dulphy, G. Laignel, S. Prache, J. Cabaret
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 753-763
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A 4-year interdisciplinary study was performed to compare two organically managed sheep production systems, using 118 ewes and 24 ha each. The systems differed in the ewes’ reproduction rhythm: one lambing per ewe per year (1L/1Y), with the aim of balancing feed self-sufficiency and lamb marketing periods v. three lambings over 2 years (3L/2Y), with the aim of maximising ewes’ productivity. The sustainability was evaluated through ewes’ reproductive performance, lamb growth rate, carcass characteristics and quality, animal health, forage and feed self-sufficiency, soil mineral balance and gross margin. General animal health was assessed by recording ewe and lamb mortality and putative cause of death. Nematode digestive-tract strongyles parasitism was studied using faecal egg counts and necropsies. Carcass quality was assessed by recording carcass weight, conformation and fatness, and colour and firmness of subcutaneous fat. Thirty-three percent of 3L/2Y ewes lambed twice a year against 4% of 1L/1Y. Mean ewe productivity was 161.3% and 151.0% in 3L/2Y and 1L/1Y, respectively, and it was more variable between years in 3L/2Y. Average concentrate feed consumption and the corresponding cost per ewe were higher in 3L/2Y than in 1L/1Y (156 v. 121 kg, and €49.5 v. €39.3, respectively). Finally, average gross margin was lower in 3L/2Y than in 1L/1Y (€59 v. €65 per ewe, respectively). Even in year 2002, when ewe productivity was highest in 3L/2Y (193%), gross margin was not different between systems (€90 v. €86 per ewe in 3L/2Y and 1L/1Y, respectively), because of higher concentrate costs in 3L/2Y. The 3L/2Y animals presented a lower health status, with a higher lamb mortality (P < 0.05) and a higher digestive-tract strongyles and coccidia parasitism level (P < 0.05). Lamb carcass conformation, fatness and fat colour were not different between systems, but carcass weight and subcutaneous dorsal fat firmness were lower in 3L/2Y lambs than in 1L/1Y lambs (P < 0.05 and < 0.001, respectively). Intensification in an organically managed sheep system, through an increased reproduction rhythm, thus did not lead to better economic results and proved riskier, more variable and more difficult to manage, and so less sustainable. The less intensive system (1L/1Y) was both highly efficient from the animal standpoint and highly feed self-sufficient. The technical and economic results of this system were better than those of organic private farms in the same area and matched those of non-organic farms.
Does the chicken genotype ‘Géline de Touraine’ have specific carcass and meat characteristics?
- E. Baéza, P. Chartrin, E. Le Bihan-Duval, M. Lessire, J. Besnard, C. Berri
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- Published online by Cambridge University Press:
- 01 May 2009, pp. 764-771
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The aim of this study was to determine the specific characteristics of carcass and meat from an old French chicken breed, the ‘Géline de Touraine’ (GT), characterised by a very slow-growing rate and usually slaughtered at 120 days of age. For this purpose, we compared the GT with an experimental crossbreed (EC) exhibiting the same growth rate, and with a ‘Label rouge’ (LR) genotype usually slaughtered at 84 days of age. A total of 250 males and 250 females per genotype were reared by separating sexes and genotypes. The growth performances were recorded. At 84 days of age, 80 birds per sex and per genotype were slaughtered. The frequency of clawing and pecking injuries on the carcass was noted. We also measured the skin colour and the thickness of wing membrane. The relative percentages of carcass, breast, thigh + drumstick, abdominal fat, testis or ovary to body weight were determined. On breast and thigh muscles the ultimate pH (pHu) and colour were measured. The juice loss after 3 days’ storage at +4°C and after cooking at 85°C, and the shear force value of Warner–Bratzler were only measured on breast muscles. At 120 days of age, we repeated the same measurements but only on EC and GT genotypes in order to compare birds at the same age or at the respective slaughter age for each production. Whatever the slaughter age, the body weight of males was always higher than that of the females but the carcass yield was similar for both sexes. The females had higher breast yield and carcass fatness but lower thigh + drumstick yield than the males. The yellowness of skin and meat was higher for the females than for the males while the contrary was observed for the redness of the meat. The breast meat of the females also had higher cooking loss than that of the males. GT and EC birds exhibited a higher occurrence of carcass defects and a higher pHu in meat than LR birds. The GT chickens were characterised by a lower breast yield, a higher fattiness and an earlier sexual maturity than the other genotypes, which could confer typical sensorial attributes to their meat. Finally, the EC chickens exhibited a skin and a meat more coloured than the other genotypes, particularly for yellowness, a character which could be under genetic control.
Front Cover (OFC, IFC) and matter
ANM volume 3 issue 5 Cover and Front matter
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- 01 May 2009, pp. f1-f4
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Back Cover (OBC, IBC) and matter
ANM volume 3 issue 5 Cover and Back matter
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- Published online by Cambridge University Press:
- 01 May 2009, pp. b1-b3
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