Breeding and genetics
Optimised parent selection and minimum inbreeding mating in small aquaculture breeding schemes: a simulation study
- F. S. Hely, P. R. Amer, S. P. Walker, J. E. Symonds
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- Published online by Cambridge University Press:
- 06 July 2012, pp. 1-10
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The effectiveness of low cost breeding scheme designs for small aquaculture breeding programmes were assessed for their ability to achieve genetic gain while managing inbreeding using stochastic simulation. Individuals with trait data were simulated over 15 generations with selection on a single trait. Combinations of selection methods, mating strategies and genetic evaluation options were evaluated with and without the presence of common environmental effects. An Optimal Parent Selection (OPS) method using semi-definite programming was compared with a truncation selection (TS) method. OPS constrains the rate of inbreeding while maximising genetic gain. For either selection method, mating pairs were assigned from the selected parents by either random mating (RM) or Minimum Inbreeding Mating (MIM), which used integer programming to determine mating pairs. Offspring were simulated for each mating pair with equal numbers of offspring per pair and these offspring were the candidates for selection of parents of the next generation. Inbreeding and genetic gain for each generation were averaged over 25 replicates. Combined OPS and MIM led to a similar level of genetic gain to TS and RM, but inbreeding levels were around 75% lower than TS and RM after 15 generations. Results demonstrate that it would be possible to manage inbreeding over 15 generations within small breeding programmes comprised of 30 to 40 males and 30 to 40 females with the use of OPS and MIM. Selection on breeding values computed using Best Linear Unbiased Prediction (BLUP) with all individuals genotyped to obtain pedigree information resulted in an 11% increase in genetic merit and a 90% increase in the average inbreeding coefficient of progeny after 15 generations compared with selection on raw phenotype. Genetic evaluation strategies using BLUP wherein elite individuals by raw phenotype are genotyped to obtain parentage along with a range of different samples of remaining individuals did not increase genetic progress in comparison to selection on raw phenotype. When common environmental effects on full-sib families were simulated, performance of small breeding scheme designs was little affected. This was because the majority of selection must anyway be applied within family due to inbreeding constraints.
Correlations of unfavorable movement characteristics in warmblood foals and mares with routinely assessed conformation and performance traits
- A.-C. Becker, K. F. Stock, O. Distl
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- 06 July 2012, pp. 11-21
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New movement traits reflecting unfavorable movement characteristics were defined on the basis of detailed movement evaluations (DME) of warmblood foals and mares performed in connection with regular breeding events of the Oldenburg horse breeding societies in 2009 and 2010. DME information was available for 3374 foals and 2844 mares and used for correlation analyses with conformation information on 1987 mares from studbook inspections (SBI) in 2009 and performance information on 2758 mares from mare performance tests (MPT) in 2000 to 2008. Analyses of variance revealed few significant differences between scores for SBI and MPT traits in mares without and with indications of imbalance (IMB) in general or specific findings like irregular tail tone or posture (TTP). SBI scores for general impression and development were significantly lower and MPT scores for trot under rider tended to be higher in IMB-positive mares. Genetic parameters were estimated in linear animal models with residual maximum likelihood. Additive genetic correlations and Pearson correlation coefficients between univariately predicted breeding values indicated unfavorable genetic correlations of IMB and TTP with dressage-related conformation and performance traits. For SBI and MPT traits, we found similarities between the correlation patterns for DME traits in foals and mares. The results implied that breeding of dressage horses may benefit from revision of current movement evaluation and consideration of specific movement characteristics.
Economic values of body weight, reproduction and parasite resistance traits for a Creole goat breeding goal
- M. Gunia, N. Mandonnet, R. Arquet, G. Alexandre, J-L. Gourdine, M. Naves, V. Angeon, F. Phocas
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- Published online by Cambridge University Press:
- 09 July 2012, pp. 22-33
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A specific breeding goal definition was developed for Creole goats in Guadeloupe. This local breed is used for meat production. To ensure a balanced selection outcome, the breeding objective included two production traits, live weight (BW11) and dressing percentage (DP) at 11 months (the mating or selling age), one reproduction trait, fertility (FER), and two traits to assess animal response to parasite infection: packed cell volume (PCV), a resilience trait, and faecal worm eggs count (FEC), a resistance trait. A deterministic bio-economic model was developed to calculate the economic values based on the description of the profit of a Guadeloupean goat farm. The farm income came from the sale of animals for meat or as reproducers. The main costs were feeding and treatments against gastro-intestinal parasites. The economic values were 7.69€ per kg for BW11, 1.38€ per % for FER, 3.53€ per % for DP and 3 × 10−4€ per % for PCV. The economic value for FEC was derived by comparing the expected profit and average FEC in a normal situation and in an extreme situation where parasites had developed resistance to anthelmintics. This method yielded a maximum weighting for FEC, which was −18.85€ per log(eggs per gram). Alternative scenarios were tested to assess the robustness of the economic values to variations in the economic and environmental context. The economic values of PCV and DP were the most stable. Issues involved in paving the way for selective breeding on resistance or resilience to parasites are discussed.
Genetic parameters for production, health, fertility and longevity traits in dairy cows
- T. Pritchard, M. Coffey, R. Mrode, E. Wall
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- 16 July 2012, pp. 34-46
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Milk production, fertility, longevity and health records, were extracted from databases of two milk recording organisations in the United Kingdom for the first three lactations of the Holstein–Friesian breed. These included data related to health events (mastitis and lameness), voluntarily recorded on a proportion of farms. The data were analysed to calculate disease incidence levels and to estimate genetic parameters for health traits and their relationships with production and other functional traits. The resulting dataset consisted of 124 793 lactations from 75 137 animals of 1586 sires, recorded in 2434 herds. Incidence of health events increased with parity. The overall incidence of mastitis (MAS) and lameness (LAM), defined as binary traits, were 17% and 16%, respectively. Heritability estimates for MAS and LAM were 0.04 and 0.02, respectively, obtained from repeatability linear sire models. Heritability estimates of mastitis and lameness as count traits were slightly higher, 0.05 and 0.03, respectively. Genetic correlations were obtained by bivariate analyses of all pair-wise combinations between milk 305-day yield (MY), protein 305-day yield (PY), fat 305-day yield (FY), lactation average loge transformed lactation average somatic cell count (SCS), calving interval (CI), days to first service (DFS), non-return at 56 days (NR56), number of inseminations (NINS), mastitis (MAS), number of mastitis episodes (NMAS), lameness (LAM), number of lameness episodes (NLAM) and lifespan score (LS). As expected, MAS was correlated most strongly with SCS (0.69), which supports the use of SCS as an indicator trait for mastitis. Genetic correlations between MAS and yield and fertility traits were of similar magnitude ranging from 0.27 to 0.33. Genetic correlations between MAS with LAM and LS were 0.38 and −0.59, respectively. Not all genetic correlations between LAM and other traits were significant because of fewer numbers of lameness records. LAM had significant genetic correlations with MY (0.38), PY (0.28), CI (0.35), NINS (0.38) and LS (−0.53). The heritability estimates of mastitis and lameness were low; therefore, genetic gain through direct selection alone would be slow, yet still positive and cumulative. Direct selection against mastitis and lameness as additional traits should reduce incidence of both diseases, and simultaneously improve fertility and longevity. However, both health traits had antagonistic relationships with production traits, thus genetic gain in production would be slower.
Nutrition
Bioavailability of zinc sources and their interaction with phytates in broilers and piglets
- P. Schlegel, D. Sauvant, C. Jondreville
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- 18 May 2012, pp. 47-59
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Zinc (Zn) is essential for swine and poultry and native Zn concentrations in feedstuffs are too low to meet their Zn requirement. Dietary Zn bioavailability is affected by phytate, phytase and Zn supplemented in organic form is considered as more bioavailable than inorganic sources. A meta-analysis using GLM procedures was processed using broiler and piglet databases to investigate, within the physiological response of Zn, (1) the bioavailability of inorganic and organic Zn sources (Analysis I); (2) the bioavailability of native and inorganic Zn dependent from dietary phytates, vegetal and supplemental phytase activity (Analysis II). Analysis I: the bioavailability of organic Zn relative to inorganic Zn sources ranged, depending on the variable, from 85 to 117 never different from 100 (P > 0.05). The coefficients of determination of the regressions were 0.91 in broilers and above 0.89 in piglets. Analysis II: in broilers, bone Zn was explained by supplemental Zn (linear and quadratic, P < 0.001) and by supplemental phytase (linear, P < 0.001). In piglets, the interaction between dietary Zn and phytates/phytases was investigated by means of a new variable combining dietary phytic phosphorus (PP) and phytase activity. This new variable represents the remaining dietary PP after its hydrolysis in the digestive tract, mainly due to phytase and is called non-hydrolyzed phytic phosphorus (PPNH). Bone Zn was increased with native Zn (P < 0.001), but to a lower extent in high PP or low phytase diets (ZNN × PPNH, P < 0.001). In contrast, the increase in bone zinc in response to supplemental Zn (P < 0.001) was not modulated by PPNH (P > 0.05). The coefficients of determination of the regressions were 0.92 in broilers and above 0.92 in piglets. The results from the two meta-analyses suggest that (1) broilers and piglets use supplemented Zn, independent from Zn source; (2) broiler use native Zn and the use is slightly enhanced with supplemental phytase; (3) however, piglets are limited in the use of native Zn because of the antagonism of non-hydrolyzed dietary phytate. This explains the higher efficacy of phytase in improving Zn availability in this specie.
Effect of dietary iodine on thyroid hormones and energy blood metabolites in lactating goats
- A. Nudda, G. Battacone, G. Bomboi, B. Floris, M. Decandia, G. Pulina
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- 24 May 2012, pp. 60-65
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Aim of this work was to evaluate if long-term dietary supplementation of potassium iodide (KI) to dairy goats can influence metabolic and hormonal parameters. Thirty Sarda crossbred dairy goats were divided into three groups, which were orally administered 0 (control group; CON), 0.45 (low iodine group; LI) or 0.90 (high iodine group; HI) mg of KI/day, respectively. The daily dose of KI (76.5% of iodine) was administered as salt dissolved in water for 8 weeks. Plasma contents of nonesterified fatty acids (NEFA), urea, glucose, insulin, free triiodothyronine (FT3) and thyroxine (FT4) were determined weekly. Iodine supplementation increased significantly the FT3 hormone (P = 0.007) and FT3/FT4 ratio (P = 0.001) and tended to influence the FT4 hormone (P = 0.059). An iodine level × week of sampling interaction for NEFA (P = 0.013) evidenced a temporary concentration increase in supplemented groups. The ‘Revised Quantitative Insulin Sensitivity Check Index’ increased with KI supplementation (P ⩽ 0.01). Blood urea nitrogen (BUN) and insulin were lowered (P ⩽ 0.01) by iodine supplementation (groups LI and HI; P ⩽ 0.01). The glucose concentration evidenced an iodine level × week of sampling interaction (P = 0.025) due to an unexpected and temporary increase of its concentration in the CON group. Glucose concentration was decreased by KI supplementation only in LI group (P < 0.05). In conclusion, the daily supplementation of low doses of KI can improve insulin sensitivity and decrease BUN in dairy goats.
Effects of feeding finisher pigs with chicory or lupine feed for one week or two weeks before slaughter with respect to levels of Bifidobacteria and Campylobacter
- A. N. Jensen, L. L. Hansen, D. L. Baggesen, L. Mølbak
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- 02 July 2012, pp. 66-74
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This study aimed to assess whether inclusion of chicory or lupine (prebiotics) in the diet of pre-slaughter pigs for just 1 or 2 weeks could change the composition of their intestinal microbiota, stimulate the growth of bifidobacteria and help to lower the amount of thermoplilic Campylobacter spp. (mainly Campylobacter jejuni and Campylobacter coli), which are a major cause of food-borne infections in humans. A total of 48 pigs that had an initial live weight of 90 kg were fed with either a lupine (organic concentrate with 25% blue lupine seeds), chicory (organic concentrate with 10% dried chicory roots) or control (100% organic concentrate) diet for 1 week (24 pigs) or 2 weeks (24 pigs) before slaughter. The Campylobacter spp. level in rectal faecal samples after 0, 1 and 2 weeks of feeding and in the luminal content from ileum, caecum and colon at slaughter was determined by direct plating on modified charcoal-cefoperazone-deoxycholate agar plates. DNA extracted from the luminal content of distal ileum and caecum was used for terminal restriction fragment length polymorphism (T-RFLP) analysis of the composition of intestinal microbiota and for measuring the amount of bifidobacterial and total bacterial DNA by quantitative real-time PCR (qPCR). Campylobacter spp. were excreted by all pigs and present in the luminal content from distal ileum to midway colon with particularly high numbers in the caecum, but the excretion was reduced by 10-fold in pigs fed lupines for 1 week as compared with control- and chicory-fed pigs (mean log10 2.9 v. 4.1 CFU/g; P < 0.05). The qPCR analysis showed that feeding with lupines resulted in higher levels of bifidobacteria in caecum as compared with the other diets (P < 0.05). T-RFLP analysis showed that four of the most abundant bacteria with terminal restriction fragment values >5% relative to the intensity of total abundance differed between the feed treatments (P < 0.05). Therefore, this study showed that even a short-term alternative feeding strategy with prebiotics in the diet of pre-slaughter pigs elicited changes in the composition of the intestinal microbiota, where lupine increased the level of bifidobacteria in caecum and reduced the Campylobacter spp. excretion level after 1 week.
Effects of protein sources on concentrations of hydrogen sulphide in the rumen headspace gas of dairy cows
- A. J. M. Fonseca, A. R. J. Cabrita, L. A. O. Pinho, E. J. Kim, R. J. Dewhurst
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- 15 May 2012, pp. 75-81
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Two Latin square design experiments investigated the relationship between hydrogen sulphide concentration in the rumen headspace gas of dairy cows and the early stages of protein degradation in the rumen. In Expt 1, three protein sources differing in rumen N (nitrogen) degradability (maize gluten feed (MGF); sunflower meal (SFM); and soyabean meal (SBM)) were used, whereas in Expt 2 four different batches of the same feed (MGF) differing in colour (CIE L*, a*, b* (CIELAB) scale) were used. After allowing the concentration of hydrogen sulphide in rumen gas to decline close to zero, a fixed amount of protein sources was offered to cows and the concentrations of hydrogen sulphide were recorded in rumen headspace gas at 30-min intervals. In Expt 1, the concentration of hydrogen sulphide showed considerable variation between protein sources, with MGF having the highest concentration followed by SFM and SBM resulting in very low concentrations. The N wash losses (zero time measurements with nylon bags) ranked the feeds in the same way, from MGF (highest; 61%) to SBM (lowest; 26%). There were marked differences in the degradation of cystine and methionine between protein sources, although the degradation of cystine was always higher than for methionine. MGF (Expt 2) led to increased concentrations of hydrogen sulphide, with peak concentrations achieved between 1 and 2 h after feeding. The concentrations of hydrogen sulphide were higher for MGF1, intermediate for MGF2 and lower for MGF3 and MGF4, agreeing with colour scale. Differences in the early stages of dietary sulphur degradation corresponded with differences in hydrogen sulphide concentrations in rumen gas. The results suggest that hydrogen sulphide concentrations in the rumen headspace gas could be useful to evaluate nutritional parameters not measured by the in sacco technique, contributing to a better understanding of the response of dairy cows to different protein supplements.
Mixing sainfoin and lucerne to improve the feed value of legumes fed to sheep by the effect of condensed tannins
- J. Aufrère, M. Dudilieu, D. Andueza, C. Poncet, R. Baumont
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- 29 May 2012, pp. 82-92
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The aim of this study was to investigate whether the use of sainfoin-based condensed tannins (CT) enhances feed value when given with tannin-free legumes (lucerne) to sheep. The experiments were conducted with fresh sainfoin and lucerne harvested at two stages (vegetative stage as compared with early flowering) in the first growth cycle. Fresh sainfoin and lucerne forages were combined in ratios of 100 : 0, 75 : 25, 25 : 75 and 0 : 100 (denoted S100, S75, S25 and S0, respectively). Voluntary intake, organic matter digestibility (OMD) and nitrogen (N) retention were measured in sheep fed the different sainfoin and lucerne mixtures. Loss of dry matter (DM) and N from polyester bags suspended in the rumen, abomasum and small intestine (SI) was also measured using rumen-fistulated sheep and intestinally fistulated sheep. The CT content in sainfoin (S100) decreased with increasing percentage of lucerne in the mixture (mean value from 58 g/kg DM for S100 to 18 g/kg DM for S25) and with growth stage (S100: 64 to 52 g/kg DM). OMD did not differ between different sainfoin/lucerne mixture ratios. Sainfoin and lucerne had an associative effect (significant quadratic contrast) on voluntary intake, N intake, total-tract N digestibility, N in faeces and urine (g/g N intake) and N retained (g/g N intake). Compared with lucerne mixtures (S0 and S25), high-sainfoin-content mixtures (S100 and S75) increased the in situ estimates of forage N escaping from the rumen (from 0.162, 0.188 for S0 and S25 to 0.257, 0.287 for S75 and S100) but decreased forage N intestinal digestibility (from 0.496, 0.446 for S0 and S25 to 0.469, 0.335 for S75 and S100). The amount of forage N disappearing from the bags in the SI (per g forage N) was the highest for high-sainfoin mixtures (from 0.082, 0.108 for S100 and S75 to 0.056, 0.058 for S25 and S0, P < 0.001). Rumen juice total N (tN) and ammonia N (NH3-N) values were the lowest in the high-sainfoin diet (mean tN 0.166 mg/g in S100 as compared with 0.514 mg/g in S0; mean NH3-N 0.104 mg/g in S100 as compared with 0.333 mg/g in S0, P < 0.001).
Effect of cull potatoes in the diet for finishing Belgian Blue double-muscled cows
- L. O. Fiems, J. L. De Boever, J. M. Vanacker, D. L. De Brabander
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- 15 May 2012, pp. 93-100
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The use of culled potatoes was investigated in Belgian Blue double-muscled finishing cows, confined in tie stalls. The control diet (Treatment 1) consisted of concentrate and maize silage (50/50 on a dry matter (DM) basis). Potatoes either replaced 60% maize silage (Treatment 2) or 60% concentrate (Treatment 3). Diets were formulated to be isocaloric and isonitrogenous. They were fed ad libitum. Approximately 18 kg potatoes were fed daily in Treatments 2 and 3. Daily gain was not significantly altered; it decreased from 1.09 kg (Treatment 1) to 1.04 kg (Treatment 2) or increased to 1.20 kg (Treatment 3), although potatoes stimulated DM intake by 5% to 8% (P < 0.05). Feed conversion was unaffected in comparison with the control diet, when expressed in terms of DM, but energy efficiency (MJ/kg live weight gain) was substantially lower for Treatment 2 compared with Treatment 1 (89.9 v. 79.0; P = 0.046). Carcass weight, grading and composition were not affected by treatments, but potatoes increased dressing percentage (P = 0.009). Treatment had no significant effect on meat quality parameters. However, potatoes (Treatments 2 and 3) tended to decrease moisture content (P = 0.090) and tended to increase drip loss (P = 0.059) compared with Treatment 1. Because of a better animal performance and a lower feed cost, it is most appropriate to use potatoes as a replacement for concentrate. Feeding large amounts of potatoes besides concentrate may have an adverse effect on the fibrousness of the diet, resulting in a tendency (−5%) for a reduced daily gain and a lower energy efficiency (P < 0.05).
Physiology and functional biology of systems
Potential role of sirtuins in livestock production
- Y. Ghinis-Hozumi, A. Antaramian, F. Villarroya, E. Piña, O. Mora
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- 08 June 2012, pp. 101-108
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Sirtuins are NAD+-dependent histone and protein deacetylases, which have been studied during the last decade with a focus on their role in lifespan extension and age-related diseases under normal and calorie-restricted or pathological conditions. However, sirtuins also have the ability to regulate energy homeostasis as they can sense the metabolic state of the cell through the NAD+/NADH ratio; hence, changes in the diet can modify the expression of these enzymes. Dietary manipulations are a common practice currently being used in livestock production with favorable results, probably due in part to the enhanced activity of sirtuins. Nevertheless, sirtuin expression in livestock species has not been a research target. For these reasons, the goal of this review is to awaken interest in these enzymes for future detailed characterization in livestock species by presenting a general introduction to what sirtuins are, how they work and what is known about their role in livestock.
Expression of leptin and its receptor genes in the ovarian follicles of cycling and early pregnant pigs
- N. Smolinska, T. Kaminski, G. Siawrys, J. Przala
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- 29 June 2012, pp. 109-117
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Leptin is a polypeptide hormone produced primarily by adipocytes. It has been implicated in the regulation of satiety and energy homeostasis. Leptin has been suggested to play a role in reproduction based on its involvement in the regulation of the hypothalamic–pituitary–gonadal axis via endocrine, paracrine and/or autocrine pathways. The aim of the present study was to localize the cellular distribution of leptin and the long isoform of leptin receptor (OB-Rb) genes in porcine ovarian antral follicles and to compare the expression levels of leptin and OB-Rb mRNAs in porcine granulosa cells (GC), theca interna (TIC) and theca externa (TEC) cells during the luteal phase of the estrous cycle and in early pregnancy. The expression of leptin and OB-Rb genes was detected in GC, TIC and TEC. Significantly higher levels of leptin gene expression in GC were observed during the mid- and late-luteal phases of the cycle than on days 30 to 32 of pregnancy. On days 14 to 16 of pregnancy, leptin mRNA expression was higher than that on days 14 to 16 of the cycle. The expression of the OB-Rb gene in GC and TEC increased during pregnancy in comparison with the analyzed luteal phases of the cycle. Our results validate the hypothesis that locally produced leptin plays a role in the regulation of porcine reproduction at the ovarian level and exerts a direct effect on porcine follicles. The differences in OB-Rb gene expression in porcine GC and theca cells also suggest that their sensitivity to leptin varies in the ovaries of pregnant and cyclic pigs.
Evaluation of blood and milk oxidative status during early postpartum of dairy cows
- A. Rizzo, E. Ceci, M. Pantaleo, M. Mutinati, M. Spedicato, G. Minoia, R. L. Sciorsci
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- 08 June 2012, pp. 118-123
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In dairy cows, the intensity of metabolic activity, associated with the negative energy balance (NEBAL), is responsible for an increased production of reactive oxygen species (ROS) and, subsequently, for the development of the condition of oxidative stress, which may overwhelm the antioxidant potential of the bovine maternal organism, making it prone to the development of many puerperal dysfunctions, as well as to an alteration of colostrum and milk quality. Given these premises, the aims of this study are to evaluate serum and milk concentrations of ROS and lipoperoxides, vitamins A and E, on the 10th, 12th, 14th and 16th day postpartum of dairy cows, a particularly critical period during which the NEBAL reaches its nadir, and to compare the trends of these parameters in two different bovine breeds. The study was performed in pluriparous Italian Friesian and Brown dairy cows. On the 10th day postpartum, all cows underwent a clinical examination to exclude the presence of alterations; furthermore, on the same day, a milk sample was collected from each cow, in order to perform the somatic cell count (SCC; (CE) N. 853/2004) and to establish which of them had an SCC ⩽400 000/ml or >400 000/ml. In this study, among the 110 cows that were initially selected, the evaluation of these parameters allowed the inclusion of 80 animals, which were divided into four groups of 20 subjects each: Group F and F1: Italian Friesian healthy cows, with SCC ⩽400 000/ml and >400 000/ml, respectively; Group B and B1: Italian Brown healthy cows, with SCC ⩽400 000/ml and >400 000/ml, respectively. On the 10th, 12th, 14th and 16th day postpartum, peripheral blood and milk samples were collected. The results obtained show that in group B1 there were higher concentrations of ROS and milk antioxidants compared with Friesian group cows. This datum let us suppose that even in the presence of higher ROS concentrations the antioxidant status found in group B1 seems to be able to counteract the oxidative damage, which is more likely to develop in these cows.
The decrease in milk yield during once daily milking is due to regulation of synthetic activity rather than apoptosis of mammary epithelial cells in goats
- H. Ben Chedly, P. Lacasse, P-G. Marnet, M. Boutinaud
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- 02 July 2012, pp. 124-133
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Once daily milking (ODM) is a management practice that can improve working conditions and reduce production costs in dairy farming compared with twice daily milking (TDM). However, ODM is associated with a decrease in milk yield. Previous research indicated that disruption of tight junctions in the mammary gland may be one of the regulatory factors involved in the milk yield decrease observed during ODM. The aim of this study was to investigate the involvement of mammary epithelium disruption in the regulation of the activity and dynamics of mammary epithelial cells (MEC) during 5 weeks of ODM in goats. Twelve alpine goats (producing 3.67 ± 0.64 kg/day and 47 ± 1.6 days in milk) were assigned to two groups that were milked once or twice a day during 5 weeks and then switched back to TDM. Mammary biopsies were collected before and on days 2 and 16 of both ODM and TDM switchback periods. Milk purified epithelial cells were collected before and on days 1, 7, 21 and 28 during ODM as well on days 1 and 7 of the TDM switchback period. The mRNA levels of genes involved in the regulation of synthetic activity and apoptosis were analysed by RT-PCR in milk MEC and mammary biopsies. ODM decreased yields of milk (−23%), lactose (−23%) and casein (−16%). Lactose synthesis was regulated at the transcriptional level by downregulation of α-lactalbumin mRNA levels in both biopsy samples (−30%) and milk MEC (−74%). TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling) staining of mammary gland biopsies did not show any increase in cell apoptosis after 2 and 16 days of ODM (0.8% and 1%, respectively) despite upregulation of Bax mRNA levels in milk MEC. This suggests that the decrease in milk yield observed during ODM is attributable to a decrease in synthetic activity rather than to induction of MEC cell death. ODM induced the disruption of tight junctions in the mammary gland only on the first day of the treatment as indicated by increased blood lactose concentration. This indicates that the decrease in MEC activity observed over the 5 weeks of ODM was not due to disruption of the mammary gland tight junctions. There was no carryover effect of 5 weeks of ODM on milk production. Therefore, it appears that the decrease in milk yield that occurs during ODM in goats is due to regulation of synthetic activity rather than to apoptosis of MEC.
Pyrethroids cypermethrin, deltamethrin and fenvalerate have different effects on in vitro maturation of pig oocytes at different stages of growth
- J. Petr, E. Chmelíková, T. Žalmanová, L. Tůmová, K. Kheilová, V. Kučerová-Chrpová, F. Jílek
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- 12 June 2012, pp. 134-142
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Pesticides can significantly harm reproduction in animals and people. Pyrethroids are often used as insecticides, and their toxicity for mammals is considered to be low. However, cypermethrin, deltamethrin and fenvalerate – as potent specific inhibitors of protein phosphatase calcineurin – can influence the meiosis of mammalian oocytes. The objective of this study was to evaluate the effects of these pyrethroids on the in vitro maturation of pig oocytes at different levels of meiotic competence. Under the tested concentrations, cypermethrin, deltamethrin and fenvalerate neither had a significant effect on the viability of oocytes nor did they induce significant degeneration of oocytes. However, these pyrethroids significantly affected meiotic maturation. The effects depended on the stage of meiotic competence of the oocytes. Maturation of growing pig oocytes with partial meiotic competence was induced. On the other hand, in fully grown pig oocytes with full meiotic competence, maturation in vitro was delayed. The specificity of these effects was further supported by the same effect of non-pyrethroidal inhibitors of calcineurin – cyclosporin A or hymenistatin I – on the maturation of oocytes with different levels of meiotic competence. However, pyrethroids, which do not inhibit calcineurin – allethrin or permethrin – had no effect on pig oocyte maturation. We demonstrated a significant effect of pyrethroids on the maturation of mammalian oocytes under in vitro conditions. This indicates that exposure to these substances could affect the fertility of people or animals.
Behaviour, welfare and health
Stress responses to comparative handling procedures in sheep
- M. Yardimci, E. H. Sahin, I. S. Cetingul, I. Bayram, R. Aslan, E. Sengor
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- Published online by Cambridge University Press:
- 10 July 2012, pp. 143-150
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The objective of this study was to compare some husbandry procedures on the base of physiological stress parameters and evaluate the welfare status in sheep. Forty ewes were used as the study material. Measurements were taken during several routine husbandry procedures such as milking, shearing, weighing, loading and hoof care. Data regarding time spent for each application, as well as heart and respiratory rates were recorded during the applications. Blood samples were taken 15 min before and after each application and malondialdehyde (MDA), glutathione-peroxidase (GSH-Px), cortisol T3 and T4 parameters were measured. In addition, changes in the same parameters between pre- and post-application periods were evaluated. According to the results, machine milking caused less stress than hand milking. No significant difference was seen between shearing methods for hand shearer or clipper; however, both applications caused stress in animals. The results for weighing methods of animals demonstrated significant differences in cortisol, T3 and T4 values in favor of traditional method. Cortisol, T3 and T4 levels were significantly higher in manual loading compared with loading by ramp. Regarding hoof care, all the examined parameters differed in favor of modern method. On the other hand, significant differences were determined between the stress parameters regarding pre- and post-applications. All values differed for hand milking while no significant difference was observed in MDA and T3 values in machine milking group. Parameters in weighing groups changed significantly. For loading process, GSH, cortisol, T3 and T4 values differed in both treatment groups. With regard to hoof care, parameters except T4 in laying group differed significantly. An increase occurred in minute-based measurements of heart and respiratory rates parallel to physiological data. The number of the respiratory rates during the applications differed except for the shearing process. All the parameters displayed significant differences between groups in terms of heart rates. Time spent for each application also differed between groups. Time saved for milking, shearing, weighing, loading and hoof care was 3.23 min, 4.37 min, 1.71 min, 7.85 s and 1.55 min, respectively. These results appear to provide a tangible advantage of using new husbandry methods to the breeders. It was concluded that using new methods in sheep husbandry procedures provided advantages in terms of saving time and reducing labor, as well as improved conditions for welfare of animals. In addition, it facilitated the routine works and flock husbandry.
Effects of dietary fish meal and soybean meal on the ovine innate and acquired immune response during pregnancy and lactation
- J. A. Stryker, R. Fisher, Q. You, M. M. Or-Rashid, H. J. Boermans, M. Quinton, B. W. McBride, N. A. Karrow
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- Published online by Cambridge University Press:
- 06 July 2012, pp. 151-159
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In recent years, livestock producers have been supplementing animal diets with fish meal (FM) to produce value-added products for health conscious consumers. As components of FM have unique neuroendocrine–immunomodulatory properties, we hypothesize that livestock producers may be influencing the overall health of their animals by supplementing diets with FM. In this study, 40 pregnant ewes were supplemented with rumen protected (RP) soybean meal (SBM: control diet) or RP FM, commencing gestation day 100 (gd100), in order to evaluate the impact of FM supplementation on the innate and acquired immune response and neuroendocrine response of sheep during pregnancy and lactation. On gd135, half the ewes from each diet (n = 10 FM, n = 10 SBM) were challenged iv with lipopolysaccharide (LPS) to simulate a systemic bacterial infection and the febrile, respiratory and neuroendocrine responses were monitored over time; the other half (n = 10 FM, n = 10 SBM) of the ewes received a saline injection as control. On lactation day 20 (ld20), all ewes (n = 20 FM, n = 20 SBM) were sensitized with hen egg white lysozyme (HEWL) and the serum haptoglobin (Hp) response was measured over time. The cutaneous hypersensitivity response (CHR) to HEWL challenge was measured on ld30 (n = 20 FM, n = 20 SBM), and blood samples were collected over time to measure the primary and secondary immunoglobulin G (IgG) response to HEWL. There was an attenuated trend in the LPS-induced febrile response by the FM treatment when compared with the SBM treatment (P = 0.06), as was also true for the respiratory response (P = 0.07), but significant differences in neuroendocrine function (serum cortisol and plasma ACTH) were not observed between treatments. Basal Hp levels were significantly lower in the FM supplemented ewes when compared with the SBM supplemented ewes (P < 0.01), and the Hp response to HEWL sensitization differed significantly over time between treatments (P < 0.01). The CHR to HEWL was also significantly attenuated in the FM treatment compared with the SBM (P < 0.01); however, treatment differences in the primary and secondary IgG responses to HEWL were not observed. These results indicate that FM supplementation differentially affects the innate and acquired immune responses in pregnant and lactating sheep compared with a typical SBM diet of commercial flocks. The long-term implications of this immunomodulation warrant further investigation.
Daily grazing time as a risk factor for alterations at the hock joint integument in dairy cows
- E. Burow, P. T. Thomsen, T. Rousing, J. T. Sørensen
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- Published online by Cambridge University Press:
- 06 July 2012, pp. 160-166
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Structural changes lead to increasing sizes of dairy herds and a reduction in grazing use. Thus, cows spend more time in the barn and become more exposed to the barn environment. The cubicle surface can result in damages of the cows’ hock joint integument. Pasture is generally seen as a beneficial environment for cows. We hypothesized that a higher number of daily grazing hours reduce the probability of hock joint alterations in dairy cows from large herds. In total, 3148 lactating cows from 36 grazing and 20 zero-grazing dairy herds, with an average herd size of 173 cows, were assessed individually on one randomly selected body side for alterations in hock integument (score 0 for no alterations or hairless areas <2 cm, 1 for at least one hairless area of ⩾2 cm, 2 for lesion or swelling). The cows were further assessed for lameness and cleanliness. Information on breed, parity and days in milk per cow was extracted from a national database. Cubicle surface was evaluated for each herd. Daily grazing hours 30 days before herd visits were recorded by the stockmen and later categorized as follows: zero hours (zero-grazing), few hours (3 to 9) and many hours (>9 to 21). The effects of daily grazing hours and other potential cow and herd-level risk factors were evaluated for their impact on hock integument alterations using a logistic analysis with a multi-level model structure. The probability for hock integument alterations such as hair loss, lesions or swellings decreased with increasing amount of grazing hours (odds of 3 to 9 h 2.2 times and odds of >9 to 21 h 4.8 times lower than of zero-grazing). The probability for only lesions or swellings decreased with >9 to 21 grazing hours (odds 2.1 times) but not with 3 to 9 h (odds 1.0 times) compared with zero-grazing. Lameness, hard cubicle surface and Danish Holstein v. other breeds showed an increasing effect on the probability for integument alterations. Increase in days in milk only showed an increasing effect on the probability for lesions and swellings. We concluded that a long daily stay on pasture is most beneficial for the hock joint integument of a dairy cow.
Measures to improve dairy cow foot health: consequences for farmer income and dairy cow welfare
- M. R. N. Bruijnis, H. Hogeveen, E. N. Stassen
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- Published online by Cambridge University Press:
- 10 July 2012, pp. 167-175
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Dairy farming in western countries with cubicle housing is an efficient way of dairy farming. Though, a disadvantage is the high prevalence and incidence of foot disorders (clinical and subclinical), which cause high economic losses and also seriously impair the welfare of dairy cattle. To point out the importance of reducing the amount and severity of foot disorders, advice to farmers should include information about the scale of the problem and the consequences in terms of economics and animal welfare. To provide support in making decisions on implementing intervention measures, insight into costs and benefits of different measures should be available. The objective of this study, therefore, is to provide more insight into the costs and benefits, for farmer and cow, of different intervention measures to improve dairy cow foot health. Intervention measures were modeled when they were applicable on a dairy farm with cubicle housing and when sufficient information was available in literature. Net costs were calculated as the difference between the costs of the measure and the economic benefits resulting from the measure. Welfare benefits were calculated as well. Cost-effective measures are: improving lying surface (mattress and bedding, €7 and €1/cow per year, respectively), reducing stocking density (break even) and performing additional foot trimming (€1/cow per year). Simultaneously, these measures have a relative high welfare benefit. Labor costs play an important role in the cost-effectiveness of labor-intensive measures. More insight into cost-effectiveness and welfare benefits of intervention measures can help to prioritize when choosing between intervention measures.
Optimal barn characteristics for high-yielding Holstein cows as derived by a new heat-stress model
- E. Shoshani, A. Hetzroni
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- Published online by Cambridge University Press:
- 24 May 2012, pp. 176-182
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Meticulous planning is required to minimize heat-stress conditions in barns. The objective of this study was to determine optimum barn characteristics for high-yielding dairy cows under Israeli (Mediterranean) summer ambient conditions, by using a new stress model that takes ambient temperature, relative humidity and wind velocity into account. During the summers of 2004 and 2005, three meteorological stations were alternately installed in 39 barns: two stations inside the barn at the prevailing downwind direction, and a third station outside the upwind end of the barn. Ambient temperature, relative humidity, wind speed and direction were measured and recorded every 10 min for 3 to 5 consecutive days at each barn in turn. The data were collected at different geographical and climatic conditions. Therefore, the data collected by an outside station were used as covariates. A heat-stress model was used to determine the threshold temperature (THRT) at which a cow begins to increase its respiratory rate; THRT was the response variable in the statistical model. The THRT model takes in account assumed values of a cow's physiological characteristics: daily milk yield of 45 kg, containing 3.5% fat, and 3 mm fur depth. The independent variables were: orientation, barn type, roof slope, roof ridge, marginal height, roof type (fixed or sliding) and barn width. Results showed that the optimal barn for high-yielding cows is the loose-housing type, oriented with its long axis perpendicular to the prevailing wind direction. Advantageous to the design would be an open ridge or pagoda with marginal height of over 4.7 m for north-south orientation and over 5 m for east-west orientation, roof slope over 11%, and barn width between 43 and 51 m for north-south orientation but lower than 42 m for east-west orientation. A sliding roof was also found to be an excellent solution when outside yards are banned by environmental regulations.