The aim of this study was to assess the effect of castration and slaughter age on the volatile pr... more The aim of this study was to assess the effect of castration and slaughter age on the volatile profile of cooked meat from Scottish Blackface (SB) and Texel × Scottish Blackface (T×SB) lambs. M. longissimus thoracis et lumborum was sampled at slaughter and subjected to volatile analysis by SPME-GC-MS. Rams had higher relative proportions, expressed as relative abundance (RA), in lipid oxidation products while castrates had higher RA in pyrazines and benzenoid compounds. There was no consistent age effect on the RA of volatiles, although rams in November and January had a different volatile profile to castrates. There were higher proportions of free branched-chain fatty acids in muscle from SB compared to T×SB lambs. Overall, the results showed that production factors affected the volatile profile of cooked lamb meat which may explain differences in lamb flavor.
Background This study investigated the factors relating to pasture chemical and fatty acid (FA) c... more Background This study investigated the factors relating to pasture chemical and fatty acid (FA) composition that influence the milk fat percentage of spring calving, grazing dairy cows. The relationship between milk fat percentage and FA composition of the milk in these herds was also investigated. Milk protein percentage, milk casein percentage and cheddar cheese yield were increased in milk from HMF herds. Cows from LMF herds did not have negatively altered milk processability including rennet coagulation time (RCT), pH and ethanol stability. Crude protein, NDF, ADF, ether extract and total FA content of pasture was not different between LMF and HMF herds. Milk fat concentration of conjugated linoleic acid (CLA) t10, c12 was not different between HMF and LMF herds. Pre-grazing herbage mass and pasture content of crude protein, neutral detergent fibre (NDF) and total FA were similar between HMF and LMF herds. Pasture offered to LMF herds had a higher concentration of monounsaturated fatty acids (MUFA). A strong negative relationship (r = -0.40) was evident between milk fat percentage and pasture crude protein content for MMF herds (3.31-3.94% milk fat). This research reports improved milk protein percentage, milk casein percentage and cheddar cheese yield from HMF herds compared to LMF herds. Milk processability was not impacted by low milk fat percentage. Pasture NDF and total fatty acid content was similar in HMF herds and LMF herds. Milk fat percentage had a strong negative association (r = -0.40) with pasture crude protein content in MMF herds . Correlation values between pasture chemical and FA composition and milk fat percentage in LMF herds and HMF herds were low, indicating that diet is not the only causative factor for variation in milk fat of grazing dairy cows. Comparison of milk fatty acid composition from herds with and without milk fat depression suggests that there may be other fatty acids apart from CLA t10, c12 that contribute to the inhibition of milk fat synthesis during milk fat depression in grazing herds.
The breeding of sport horses to compete in the Olympic disciplines of show jumping, eventing, and... more The breeding of sport horses to compete in the Olympic disciplines of show jumping, eventing, and dressage is fast becoming a global industry with the increased use of reproductive technologies, including artificial insemination and embryo transfer. Reproductive technologies have facilitated the dissemination of genetics from elite horses across multiple countries and breeds as breeders are no longer limited by location. Due to this increased level of crossbreeding, there is an increased need for estimated breeding values (EBVs) for sport horse performance that can be compared across breeds and countries. However, the implementation of across-breed or across-country genetic evaluations has been limited by the differences in each studbook's individual breeding programs and genetic evaluations. Consequently, the aim of this review was to compare the genetic evaluations for show jumping of sport horse studbooks worldwide. The top sport horse studbooks in the world according to the World Breeding Federation for Sport Horses Studbook Rankings 2019 were contacted by email to request information on their current breeding programs and genetic evaluations. Twenty-six of the 51 studbooks contacted replied to this request but only 18 of these studbooks conducted their own genetic evaluations or were part of a larger genetic evaluation in their country of origin. The other eight studbooks were not involved in genetic evaluations at present but expressed an interest in the implementation of such in the future. Overall, many differences were identified among the genetic evaluations of each studbook or each country. The definition of show jumping performance differed within each evaluation and the methods and models utilized also differed. Despite some stallions and mares being registered in multiple studbooks or having progeny in multiple studbooks, these differences make comparison of EBVs across studbooks difficult. Further transparency and collaboration of sport horse studbooks with organizations such as Interstallion, will be essential to facilitate any future implementation of international genetic evaluations for show jumping performance.
The breeding of sport horses to compete in the Olympic disciplines of show jumping, eventing, and... more The breeding of sport horses to compete in the Olympic disciplines of show jumping, eventing, and dressage is fast becoming a global industry with the increased use of reproductive technologies, including artificial insemination and embryo transfer. Reproductive technologies have facilitated the dissemination of genetics from elite horses across multiple countries and breeds as breeders are no longer limited by location. Due to this increased level of crossbreeding, there is an increased need for estimated breeding values (EBVs) for sport horse performance that can be compared across breeds and countries. However, the implementation of across-breed or across-country genetic evaluations has been limited by the differences in each studbook’s individual breeding programs and genetic evaluations. Consequently, the aim of this review was to compare the genetic evaluations for show jumping of sport horse studbooks worldwide. The top sport horse studbooks in the world according to the Worl...
Background This study investigated the factors relating to pasture chemical and fatty acid (FA) c... more Background This study investigated the factors relating to pasture chemical and fatty acid (FA) composition that influence the milk fat percentage of spring calving, grazing dairy cows. The relationship between milk fat percentage and FA composition of the milk in these herds was also investigated. Results Milk protein percentage, milk casein percentage and cheddar cheese yield were increased in milk from HMF herds. Cows from LMF herds did not have negatively altered milk processability including rennet coagulation time (RCT), pH and ethanol stability. Crude protein, NDF, ADF, ether extract and total FA content of pasture was not different between LMF and HMF herds. Milk fat concentration of conjugated linoleic acid (CLA) t10, c12 was not different between HMF and LMF herds. Pre-grazing herbage mass and pasture content of crude protein, neutral detergent fibre (NDF) and total FA were similar between HMF and LMF herds. Pasture offered to LMF herds had a higher concentration of monoun...
Additional file 3: Table S3. of The prevalence, temporal and spatial trends in bulk tank equivalent milk fat depression in Irish milk recorded herds
The number of herds milk recording for each county by month between 2004 and 2014. (DOCX 19 kb)
Additional file 2: Table S2. of The prevalence, temporal and spatial trends in bulk tank equivalent milk fat depression in Irish milk recorded herds
The number of herds milk recording per month between 2004-2014. (DOCX 16 kb)
Additional file 1: Table S1. of The prevalence, temporal and spatial trends in bulk tank equivalent milk fat depression in Irish milk recorded herds
The herd mean, median and mode of test day milk production records between 2004 and 2014. (DOCX 1... more The herd mean, median and mode of test day milk production records between 2004 and 2014. (DOCX 13 kb)
Whilst older cows can be some of the most profitable producers on the farm, as well as helping to... more Whilst older cows can be some of the most profitable producers on the farm, as well as helping to reduce the environmental impact of dairy production and improving consumer perception of dairy farming, they can also be more prone to early lactation metabolic challenges and at higher risk of culling or death in early lactation. Research into nutritional supplementation strategies specifically to support older, at-risk herd members has not, to the author's knowledge, been carried out and leaves a dearth of knowledge as to how best to support the successful transition of this valuable cohort of cows from gestation into peak lactation. The objective of this study was to evaluate the effect of supplementation with a combined calcium, magnesium and antioxidant bolus (Cow Start) on key early lactation health and performance indicators in a cohort of older, higher yielding dairy cows that may be expected to be at greater risk of developing key post-partum metabolic disorders. High yielding multiparous (n=38) cows averaging 4.7 lactations at calving were enrolled in this study and randomly assigned to either a control (CON, n=19) group or a Cow Start oral bolus supplemented (CSC, n=19) group. The CON group experienced a clinical milk fever (Blood Ca <1.5 mM) incidence rate of 15.7% compared to 0% for the CSC group. Cows in the CSC group recorded a treatment effect of a significantly (P<0.01) higher blood calcium status compared to CON. Energy Corrected Milk volumes showed a statistical trend of an increase (P < 0.10) from day 5 until day 60 of lactation for the CSC group (+1.8 kg/day) when compared to CON, also milk fat kg (P < 0.05) and combined fat and protein kg yields (P < 0.10) were increased in the CSC group when compared to the CON group. Results of this study suggest that supplementation of older at-risk cows with a combined calcium, magnesium and antioxidant (Cow Start) oral bolus can reduce the incidence rate of clinical milk fever and exposure to sub-clinical milk fever, whilst also improving blood calcium status and increasing milk production parameters in early lactation when compared to CON.
BackgroundBovine mastitis, an inflammatory disease of the mammary gland, is classified as subclin... more BackgroundBovine mastitis, an inflammatory disease of the mammary gland, is classified as subclinical or clinical. Circulating neutrophils are recruited to the udder to combat infection. We compared the transcriptomic profiles in circulating leukocytes between healthy cows and those with naturally occurring subclinical or clinical mastitis.Methods and ResultsHolstein Friesian dairy cows from six farms in EU countries were recruited. Based on milk somatic cell count and clinical records, cows were classified as healthy (n = 144), subclinically (n = 48) or clinically mastitic (n = 22). Circulating leukocyte RNA was sequenced with Illumina NextSeq single end reads (30 M). Differentially expressed genes (DEGs) between the groups were identified using a DESeq2 package, followed by GO enrichment analysis. Both subclinical and clinical mastitis caused significant changes in the leukocyte transcriptome, with more intensive changes attributed to clinical mastitis. We detected 491 DEGs betwee...
Improving nitrogen use efficiency (NUE) at both the individual cow and the herd level has become ... more Improving nitrogen use efficiency (NUE) at both the individual cow and the herd level has become a key target in dairy production systems, for both environmental and economic reasons. Cost-effective and large-scale phenotyping methods are required to improve NUE through genetic selection and by feeding and management strategies. The aim of this study was to evaluate the possibility of using mid-infrared (MIR) spectra of milk to predict individual dairy cow NUE during early lactation. Data were collected from 129 Holstein cows, from calving until 50 d in milk, in 3 research herds (Denmark, Ireland, and the UK). In 2 of the herds, diets were designed to challenge cows metabolically, whereas a diet reflecting local management practices was offered in the third herd. Nitrogen intake (kg/d) and nitrogen excreted in milk (kg/d) were calculated daily. Nitrogen use efficiency was calculated as the ratio between nitrogen in milk and nitrogen intake, and expressed as a percentage. Individual daily values for NUE ranged from 9.7 to 81.7%, with an average of 36.9% and standard deviation of 10.4%. Milk MIR spectra were recorded twice weekly and were standardized into a common format to avoid bias between apparatus or sampling periods. Regression models predicting NUE using milk MIR spectra were developed on 1,034 observations using partial least squares or support vector machines regression methods. The models were then evaluated through (1) a cross-validation using 10 subsets, (2) a cow validation excluding 25% of the cows to be used as a validation set, and (3) a diet validation excluding each of the diets one by one to be used as validation sets. The best statistical performances were obtained when using the support vector machines method. Inclusion of milk yield and lactation number as predictors, in combination with the spectra, also improved the calibration. In cross-validation, the best model predicted NUE with a coefficient of determination of cross-validation of 0.74 and a relative error of 14%, which is suitable to discriminate between low-and high-NUE cows. When performing the cow validation, the relative error remained at 14%, and during the diet validation the relative error ranged from 12 to 34%. In the diet validation, the models showed a lack of robustness, demonstrating difficulties in predicting NUE for diets and for samples that were not represented in the calibration data set. Hence, a need exists to inte-
The objective of this study was to evaluate both the safety, and efficacy of supplementation at c... more The objective of this study was to evaluate both the safety, and efficacy of supplementation at calving with a combined oral calcium and anti-oxidant bolus on post-partum metabolic status, fresh cow energy status, vaginal mucous score and early lactation milk production performance. Multiparous (n=103) cows from 3 dairy herds in Ireland were enrolled in this study and randomly assigned to either a control (CON, n=51) group or an oral bolus supplemented (BOL, n=52) group. CON cows received no oral boluses. BOL cows received 2 oral boluses, at 0 and 18 hours (hrs) after calving. Cows were fed a standard dry cow diet of second cut grass silage with supplemental pre-calving minerals, and fewer than 2.3% of all fresh cows (n=899) in these herds were treated for clinical milk fever (below target incidence level). Trial-eligible cows treated with IV calcium at calving were excluded from the trial. No adverse events associated with bolus safety were observed. The bolus was adminstered with ease and was well-tolerated by all animals. Calving and early lactation disease events were recorded. Metabolic status was evaluated by using milk ketone (beta hydroxybutyrate (BHBA)) testing at day 14 and day 21 postpartum. Cows in the BOL group recorded significantly lower milk BHBA levels (0.46mg/dl) compared to CON cows (0.67mg/dl), (p<0.0001). Milk yield, Milk Fat % and kg, Milk Protein % and kg, combined milk components (milk fat and milk protein kg) and somatic cell counts (SCC) were recorded but no significant differences were observed. Results of this study indicate that the bolus is safe to use in post-partum dairy cows. Furthermore, cows responded favourably to treatment with the bolus with regard to improved metabolic status in the critical post-partum period. Results of this study suggest that supplementing dairy cows with oral boluses can have beneficial effects, even in dairy herds with a below-average incidence of hypocalcaemia.
Protein is an expensive component of the dairy cow diet, and overfeeding protein can have adverse... more Protein is an expensive component of the dairy cow diet, and overfeeding protein can have adverse economic and environmental impacts. Our objective was to maintain milk production and components while decreasing dietary crude protein (CP) through use of a heat-treated, rumen-resistant sugar amino acid complex (SAAC) as the Schiff base, as an addition to low-protein diets. Dietary treatments included a negative control [NC, 146 g of CP/kg of dry matter (DM)], a positive control (PC, 163 g of CP/kg of DM), and the NC supplemented with SAAC in lieu of some barley grain (SAAD, 151 g of CP/kg of DM). Diets were fed to 30 multiparous Holstein-Friesian dairy cows for the first 50 d postpartum. Dry matter intake (DMI) was determined daily. Milk yield and content of fat, protein, lactose, and casein were recorded weekly from wk 2 to 7 of lactation. The fixed effects of treatment, week, treatment × week, month of calving, and BCS at calving, and a random effect of cow, were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). The SAAD treatment had greater energycorrected milk yield than did NC. The PC treatment had greater DMI than did NC, and SAAD tended to have greater DMI than did NC. We found significant treatment effects for fat percentage and yield. The NC and SAAD treatments had higher fat percentages than did PC, and SAAD had a higher fat yield than did the NC and PC treatments. Treatment effects were found for casein yield and percentage. We discovered a treatment effect for protein percentage and yield. The PC treatment had higher protein percentage than did NC and SAAD. The PC treatment had a higher protein yield than did NC, and analysis revealed no difference in protein yield between PC and SAAD. The SAAD treatment had higher total milk solids than did the NC treatment. Lactose yield tended to be higher in PC than in NC, and no differences were found between PC and NC and SAAD treatments. The PC treatment had a higher casein percentage than did NC and SAAD; however, the SAAD and PC treatments had higher casein yields than did NC. The PC treatment had a higher casein: fat ratio than did the NC and SAAD treatments. The NC and SAAD treatments had higher Cheddar cheese yields than did PC. We found no treatment × week interactions for any parameter. Supplementing low-protein dairy cow diets with a heat-treated, rumenresistant SAAC caused beneficial effects by improving milk components and increasing cheese yield to levels similar to those found when feeding expensive and environmentally damaging high-protein diets.
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