Associations of Grazing and Rumination Behaviours with Performance Parameters in Spring-Calving Dairy Cows in a Pasture-Based Grazing System.

This study investigated the relationship of the length of time spent grazing and ruminating with the performance parameters of spring-calved grazing dairy cows (n = 162) over the lactation period for three lactation seasons (n = 54 per season). The cows were Holstein Friesian (HFR), Jersey (JE), and a crossbreed of Holstein Friesian/Jersey (KiwiCross), with 18 cows from each breed. The cows were either in their 1st, 2nd, 3rd, or 4th lactation year, and had different breeding worth (BW) index values (103 < BW > 151). The cows were managed through a rotational grazing scheme with once-a-day milking in the morning at 05:00 h. The cows were mainly fed on grazed pastures consisting of perennial ryegrass (Lolium perenne), red clover (Trifolium pretense), and white clover (Trifolium repens), and received additional feeds on various days in the summer and autumn seasons. This study used an automated AfiCollar device to continuously record the grazing time and rumination time (min/h) of the individual cows throughout the lactation period (~270 days) for three consecutive years (Year-1, Year-2, and Year-3). The milk yield, milk fat, milk protein, milk solids, liveweight, and body condition score data of the individual animals for the study years were provided by the farm. PROC CORR was used in SAS to determine the correlation coefficients (r) between the behaviour and production parameters. A general linear model fitted with breed × lactation year, individual cows, seasons, feed within the season, grazing time, rumination time, as well as their interactions, was assessed to test the differences in milk yield, milk fat, milk protein, milk solids, liveweight, and body condition score. The type I sum of squares values were used to quantify the magnitude of variance explained by each of the study factors and their interactions in the study variables. Grazing time exhibited positive associations with MY (r = 0.34), MF (r = 0.43), MP (r = 0.22), MS (r = 0.39), LW (r = -0.47), and BCS (r = -0.24) throughout the study years. Rumination time was associated with MY (r = 0.64), MF (r = 0.57), MP (r = 0.52), and MS (r = 0.57) in all study years, while there were no effects of rumination time on LW (r = 0.26) and BCS (r = -0.26). Grazing time explained up to 0.32%, 0.49%, 0.17%, 0.31%, 0.2%, and 0.02%, and rumination time explained up to 0.39%, 6.73%, 4.63%, 6.53%, 0.44%, and 0.17% of the variance in MY, MF, MP, MS, LW, and BCS, respectively.

Increasing sustainability in pork production by using high inclusion levels of co-products distillers dried grains with solubles, wheat middling and canola meal doesn't affect pig growth performance and meat quality but reduces boar taint.

OBJECTIVE: The present study is to examine the effect of high inclusion of co-products in pig diets (referred to as an alternative diet) during the finishing stage on pig growth performance, meat quality and boar taint compounds. METHODS: Growing pigs were fed an alternative diet made with distillers dried grains with solubles (25%), canola meal (20%), and wheat middling (15%) or a control diet based on barley and soybean meal to investigate the impact of co-products on pig performance and meat quality. Sixteen female and sixteen entire male Duroc×(Large White×Landrace) pigs (22.6±2.07 kg, body weight±standard error) were equally allocated to the diets. RESULTS: Pigs fed the alternative diet had a lower feed intake; however, growth rate and feed conversion efficiency were unaffected by diet. A diet by sex interaction was found for gain:feed whereby males fed the alternative diet had the best feed conversion (p<0.01). Pork from pigs fed the alternative diet had lower a* and Chroma and protein % (p<0.05), while other meat quality characteristics were unaffected. The alternative diet reduced backfat skatole levels (p<0.001). CONCLUSION: A diet containing high inclusion levels of co-products can be fed to pigs during the finishing stage without detrimental effects on pig performance or meat quality and with the potential to enhance pork flavour. This finding suggests a solution to increase the sustainable development of pig production.

Variations in the 24 h temporal patterns and time budgets of grazing, rumination, and idling behaviors in grazing dairy cows in a New Zealand system.

This study investigated the variations in the temporal distributions and the lengths of times utilized for grazing, ruminating, and idling behaviors by grazing dairy cows over 24 h. Spring-calved lactating dairy cows (N = 54) from three breeds, Holstein-Friesian (HFR), Jersey (JE), and KiwiCross (KC) in different lactations (1st, 2nd, 3rd) and with different breeding worth index values (103 < BW > 151) were selected. The cows were managed through a rotational grazing scheme and milked once a day at 0500 hours. The cows grazed mainly pasture and consumed additional feeds (maize silage and turnips) in the summer and autumn seasons. AfiCollar was used to record grazing and rumination behaviors (min/h) in the individual cows throughout the lactation period (~270 d). The time neither utilized for grazing nor rumination was counted as idling behavior (min/h). A repeat measure design with PROC MIXED was performed in SAS considering the effects of breed, lactation, individual cow, the hour of the day, season, day within the season, and supplementary feed within the season to evaluate the difference in grazing, rumination, and idling behaviors. Hour of the day, season, day within season, and supplementary feed had significant effects on grazing, rumination, and idling behaviors. Regardless of the season and supplementary feed, cows spent most of the daytime grazing and most of the nighttime ruminating. Grazing activity remained consistently high throughout the day with two peaks around dawn and dusk and a short peak around midnight. Rumination activity remained high from the late evening until early morning. Grazing and ruminating patterns were similar between different breeds and lactations, however, JE cows grazed slightly longer than HFR and KC, and first-lactation cows grazed slightly longer than those in higher lactations. The onset and cessation of grazing activity by the cows were adjusted according to varying day lengths by season. Cows finished grazing earlier when they consumed additional supplements or silage along with pasture. Cows from different breed groups and lactations spent most of their 24 h grazing followed by ruminating and idling. Season and supplementary feed potentially affected the variations in behavior time budgets. These findings should support improving measures for grazing management to address pasture allocation and additional feed demands, and animal welfare in varying environmental and/or managemental conditions.

This study explored how grazing dairy cows pattern their essential such as including grazing, rumination, and idling, and how they distribute their time for those behaviors over 24 h. We used a group of spring-calved grazing dairy cows affiliated with different breeds, milking ages, and genetic merits and recorded their grazing and rumination behaviors for the whole milking period. An automated device, AfiCollar was used to continuously record minutes within an hour (min/h) utilized for grazing, rumination, and idling. The cows were mainly offered grass with some additional supplementary feeds on various days in summer and autumn and milked once a day at 0500 hours. Regardless of the breed, milking age, season, and supplementary feeds, grazing cows spent most of the daytime (from dawn to dusk) grazing and most of the nighttime ruminating, with a short grazing period around midnight. Cows adopted their grazing patterns according to varying day lengths during different seasons and finished grazing earlier when received supplementary feeds. Grazing cows allocated most of their time over 24 h for grazing followed by ruminating and idling. These findings could have implications to improve the measures for pasture management efficiency and additional feed demand, and animal welfare in varying environmental and/or managemental conditions.

Factors Affecting Grazing and Rumination Behaviours of Dairy Cows in a Pasture-Based System in New Zealand.

This study investigated the variation in daily time spent grazing and rumination in spring-calved grazing dairy cows (n = 162) of three breeds, Holstein-Friesian (HFR), Jersey (JE), and KiwiCross (KC) with different breeding worth index, and in different years of lactation (1st, 2nd, 3rd, 4th). The cows were managed through a rotational grazing system and milked once a day at 05:00 a.m. The cows grazed mainly pasture and received supplementary feeds depending on the season. Automated AfiCollar device continuously monitored and recorded grazing time and rumination time of the individual cows throughout the lactation period for three study years (Year-1, Year-2, Year-3) with 54 cows per year. A general linear mixed model fitted with breed × lactation year with days in milk (DIM), breeding worth (BW) index value, individual cow, season, and feed, and their interactions was performed in SAS. Variance partitioning was used to quantify the effect size of study factors and their interactions. Individual cows, DIM, and BW (except Year-3) had effects on grazing and rumination times throughout the study years. Grazing time and rumination time were different for different seasons due to varying supplementary feeds. Grazing time varied among breeds in Year-2 and Year-3, and among lactation years only in Year-1. Although rumination time differed among breeds in Year-3, it remained the same within different lactation years. Grazing time and rumination time had a negative relationship with each other, and their regression lines varied for different seasons. The total variance explained by the model in grazing time was 36-39%, mainly contributed by the individual cow (12-20%), season (5-12%), supplementary feed (2-6%), breed (1-5%), and lactation year (1-6%). The total variance explained in rumination was 40-41%, mainly contributed by the individual cow (16-24%), season (2-17%), supplementary feed (1-2%), breed (2-8%), and lactation year (~1%). These findings could contribute to improving the measures for feed resource management during different seasons over the lactation period for a mixed herd comprising JE, HFR and KC breeds in different years of lactation.

Animal Welfare Compromises Associated with Causes of Death in Neonatal Piglets.

This pilot study aimed to assess the welfare impacts of different causes of pre-weaning deaths in piglets. Piglets that died between 0-7 days after birth (n = 106) were collected from two commercial pig farms and subject to post-mortem examination to confirm their cause of death as well as any contributing factors. Using the Five Domains Model, the most likely affective experiences associated with the pathological findings were carefully inferred to better understand affective experience as it related to known causes of liveborn piglet mortality. The most common causes of liveborn piglet mortality were starvation (23%), crushing (23%) and non-viable (21%). Thirty one piglets had evidence of starvation, but it was only considered the primary cause of death in 15 piglets, as cofactors such as poor viability (n = 13) were also present in many piglets with evidence of starvation. All 15 piglets that were crushed died within 24 h after birth and most had evidence of thoracic and/or abdominal internal bleeding. This study found that common causes of liveborn piglet death were associated with compromises in Domains 1 (Nutrition/hydration), 3 (Health/function), and4 (Behavioural interactions), with the most likely resulting affective states described in Domain 5 (Mental state). This highlights the interaction between physical/functional and situation-related (behavioural) aspects that influence an animals' welfare status.

In Vitro Fermentation of Browsable Native Shrubs in New Zealand.

Information on the nutritive value and in vitro fermentation characteristics of native shrubs in New Zealand is scant. This is despite their potential as alternatives to exotic trees and shrubs for supplementary fodder, and their mitigation of greenhouse gases and soil erosion on hill-country sheep and beef farms. The objectives of this study were to measure the in vitro fermentation gas production, predict the parameters of the in vitro fermentation kinetics, and estimate the in vitro fermentation of volatile fatty acids (VFA), microbial biomass (MBM), and greenhouse gases of four native shrubs (Coprosma robusta, Griselinia littoralis, Hoheria populnea, and Pittosporum crassifolium) and an exotic fodder tree species, Salix schwerinii. The total in vitro gas production was higher (p < 0.05) for the natives than for the S. schwerinii. A prediction using the single-pool model resulted in biologically incorrect negative in vitro total gas production from the immediately soluble fraction of the native shrubs. However, the dual pool model better predicted the in vitro total gas production and was in alignment with the measured in vitro fermentation end products. The in vitro VFA and greenhouse gas production from the fermentation of leaf and stem material was higher (p < 0.05), and the MBM lower (p < 0.05), for the native shrubs compared to the S. schwerinii. The lower in vitro total gas production, VFA, and greenhouse gases production and higher MBM of the S. schwerinii may be explained by the presence of condensed tannins (CT), although this was not measured and requires further study. In conclusion, the results from this study suggest that when consumed by ruminant livestock, browsable native shrubs can provide adequate energy and microbial protein, and that greenhouse-gas production from these species is within the ranges reported for typical New Zealand pastures.

Reproduction of Black Soldier Fly (Diptera: Stratiomyidae) Under Different Adult Densities and Light Regimes.

The black soldier fly (BSF) Hermetia illucens (L.) (Diptera: Stratiomyidae) has been recognized as a promising insect species for sustainable management of organic waste and by-products. Indoor breeding of BSF with artificial lighting has been proved successful, but efforts are still needed to optimize BSF reproductive output. Increasing adult density seems an option to exploit space, whereas decreasing artificial lighting duration may reduce unnecessary power consumption. This study aimed at investigating the effects of adult density (10, 25, and 50 pairs per 30 × 30 × 30 cm cage; i.e., 370, 926, and 1,852 pairs/m3), light regime (8:16, 12:12, and 16:8 [L:D] h), and their possible interactions, on some BSF life history traits relevant to reproduction. The results show that the overall BSF reproductive output increased with increasing adult density but was not affected by light regimes per se. With the highest BSF adult density tested, an average of more than 20,000 neonate larvae were produced from a cage within 10 d. At this density, increasing photoperiod increased neonate production, but also decreased the number of neonates per watt used for artificial illumination. The temporal oviposition patterns, mean individual female reproductive output, mating success, egg hatching rate, and insect survival rate were not affected by adult density or light regime as simple effects. However, the interaction between adult density and light regime was significant for the first oviposition peak, mean individual female reproductive output, and insect survival rate. The possible mechanisms behind our results are discussed.

Growth and Body Composition of Artificially-Reared Lambs Exposed to Three Different Rearing Regimens.

This study was designed to investigate the influence of pellet fibre level, milk replacer composition and age at weaning on growth and body composition of lambs reared artificially. Romney ram lambs were randomly allocated to one of three rearing treatments; HFP57: commercial milk replacer to 57 days of age, and high fibre concentrate pellets; HFP42: commercial milk replacer with early weaning at 42 days of age, and high fibre concentrate pellets; LFP42: high protein milk replacer from 2-16 days of age followed by commercial milk replacer with early weaning at 42 days of age, and low fibre concentrate pellets. Lambs were slaughtered at 57 days of age. Overall average daily liveweight gain of lambs did not differ (p > 0.05) between treatments. Dressing out percentage, carcass weight, empty small intestine and omental fat were higher (p < 0.05) in HFP57 than in both HFP42 and LFP42 lambs. HFP42 and LFP42 lambs had heavier (p < 0.05) empty rumen weights. Whole body protein content was higher (p < 0.05) in HFP42 lambs compared to both HFP57 and LFP42 lambs. Fat content and daily fat deposition were greater (p < 0.05) in HFP57 lambs than HFP42 and LFP42 lambs. Weaning lambs at 42 days of age with provision of either low or high fibre concentrate pellets, resulted in similar growth rates, reduced whole body fat deposition and was a more cost-effective rearing regimen.

Rumen Development of Artificially-Reared Lambs Exposed to Three Different Rearing Regimens.

The objective of this study was to examine the effect of three different rearing regimens on rumen development in lambs reared artificially. Romney ram lambs were randomly allocated to one of three treatments: commercial milk replacer fed to 57 d of age and high fibre concentrate pellets (HFP57); commercial milk replacer, high fibre concentrate pellets, and early weaning from milk replacer at 42 d of age (HFP42); high protein milk replacer from 2-16 d of age followed by commercial milk replacer, low fibre concentrate pellets, and early weaning from milk replacer at 42 d of age (LFP42). Lambs were slaughtered at 57 d of age. Volatile fatty acid content in rumen fluid at slaughter was analysed and rumen tissue samples were collected for histological examination. The rumen n-butyric content was greater (p < 0.05) in both LFP42 and HFP42 treatment lambs compared to HFP57 lambs. The n-valeric content was greater (p < 0.05) in LFP42 lambs compared to both HFP57 and HFP42 treatment lambs. Thickness of the rumen dorsal wall determined by ultrasound scanning at 49 d was greater (p < 0.05) in both HFP42 and LFP42 lambs compared to HFP57 lambs. There was an interaction (p < 0.05) between treatment and site of rumen tissue sampling on papillae width, density, and rumen muscular layer thickness. Collectively, early weaning and the provision of a low fibre pellet leads to improved rumen function and physical development.

Validation of an Accelerometer Sensor-Based Collar for Monitoring Grazing and Rumination Behaviours in Grazing Dairy Cows.

This study evaluated the accuracy of a sensor-based device (AfiCollar) to automatically monitor and record grazing and rumination behaviours of grazing dairy cows on a real-time basis. Multiparous spring-calved dairy cows (n = 48) wearing the AfiCollar were selected for the visual observation of their grazing and rumination behaviours. The total observation period was 36 days, divided into four recording periods performed at different times of the year, using 12 cows in each period. Each recording period consisted of nine daily observation sessions (three days a week for three consecutive weeks). A continuous behaviour monitoring protocol was followed to visually observe four cows at a time for each daily observation session, from 9:00 a.m. to 5:00 p.m. Overall, 144 observations were collected and the data were presented as behaviour activity per daily observation session. The behaviours visually observed were also recorded through an automated AfiCollar device on a real-time basis over the observation period. Automatic recordings and visual observations were compared with each other using Pearson's correlation coefficient (r), Concordance correlation coefficient (CCC), and linear regression. Compared to visual observation (VO), AfiCollar (AC) showed slightly higher (10%) grazing time and lower (4%) rumination time. AC results and VO results had strong associations with each other for grazing time (r = 0.91, CCC = 0.71) and rumination time (r = 0.89, CCC = 0.80). Regression analysis showed a significant linear relationship between AC and VO for grazing time (R2 = 0.83, p < 0.05) and rumination time (R2 = 0.78, p < 0.05). The relative prediction error (RPE) values for grazing time and rumination time were 0.17 and 0.40, respectively. Overall, the results indicated that AfiCollar is a reliable device to accurately monitor and record grazing and rumination behaviours of grazing dairy cows, although, some minor improvements can be made in algorithm calibrations to further improve its accuracy.

The eggshell structure in apteryx; form, function, and adaptation.

Apteryx is a genus of flightless birds endemic to New Zealand known to lay very large eggs in proportion to body weight. The eggshell of Apteryx is unusually thin and less porous than allometrically expected possibly as a compensation for a very long incubation period. Past studies have been carried out on Apteryx australis, a species which once comprised all kiwi with brown plumage, now separated into three distinct species. These species use different habitats and live at different latitudes and altitudes, therefore generating a need to revise our knowledge of the attributes of their eggshells. In this study, we measured the physical characteristics and water conductance on eggshell fragments of these three species and Great-spotted Kiwi and relate them to the environmental conditions of their respective environments; we also measured the water vapor conductance of Brown Kiwi eggs of late stages of incubation. We found that several trade-offs exist between incubation behavior, environmental conditions, and eggshell structure. We found differences between species in eggshell water vapor conductance seemingly related to altitude; Brown Kiwi and Rowi generally inhabiting lower altitudes had the highest conductance and Tokoeka, generally living in montane environments, the lowest. This is achieved by an increased eggshell thickness rather than a pore area reduction. Finally, the water vapor conductance late in incubation was 58% higher than infertile unincubated eggs, suggesting a drastic increase in conductance throughout the long incubation period. Using the values previously reported, we calculated the embryonic eggshell thinning to be 32.5% at the equatorial region of the eggshell. We describe several new features, such as triangular mineral particles in the cuticle, reported for the extinct Trigonoolithus amoei, and confirmed the existence of plugged pores. We suggest that these structures provide microbial protection needed by a burrow nesting species with a long incubation period.

Personality and motivational predictors of well-being and coping during COVID-19: A reversal theory analysis.

This study used reversal theory to examine motivational predictors of well-being and coping during the COVID-19 pandemic in 2020. 149 UK based respondents completed an online survey including measures of demographics, well-being, coping, motivational style, and dominance. Well-being was predicted by optimism (positively), autic and mastery (negatively) dominances, by alloic sympathy, optimism and paratelic motivation styles (positively), and, negatively by arousal seeking, arousability and pessimism. Coping was positively predicted by optimism and negativism dominances and by negativist, paratelic and telic motivations, and, negatively by arousability and pessimism. Using motivational dominances, indirect support was identified for the link between psychodiversity and well-being, but not coping. Findings suggest that well-being and, to a lesser degree, coping could be enhanced by encouraging individuals to experience a range of motivations, possibly focusing on those identified here as significant predictors. Future research needs to determine the context specificity of these findings and explore psychodiversity, well-being and coping using both metamotivational states and composite profiles incorporating the full range of motivational constructs.

Selection by Lambs Grazing Plantain (Plantago lanceolata L.), Chicory (Cichorium intybus L.), White Clover (Trifolium repens L.), Red Clover (Trifolium pratense L.) and Perennial Ryegrass (Lolium perenne L.) across Seasons.

Plantain (Plantago lanceolata) and chicory (Cichorium intybus) are now widely used in combination with clover species to provide greater annual lamb live weight gains than perennial ryegrass and white clover pasture. Reported selective grazing of the species in herb-clover mixes could potentially detrimentally change the relative abundance of species and decrease lamb production. Lambs were offered three herbage treatments: Pasture (perennial ryegrass and white clover) mix, plantain (plantain, red clover and white clover) mix and a chicory (chicory, plantain, red clover and white clover) mix in each of four seasons for two years. The experiment was a randomized complete block design with three replicates with 18-30 lambs per treatment replicate depending on the season. Lambs were rotationally grazed and fed ad libitum. Selection by the lambs of individually tagged plants within the pasture treatments was observed for three days on two occasions per season. Red clover was the most selected species on day 1, but by day 3 there was no difference in the selection of the species (p < 0.05). Plantain and chicory in the plantain and chicory mixes were selected less on day 1 in autumn relative to the other seasons (p < 0.05). It was concluded that three days of grazing before moving lambs maintained the relative abundance of species in the herb-clover mixes.

Mating success of the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), under four artificial light sources.

Larvae of the black soldier fly (BSF) Hermetia illucens (L.) (Diptera: Stratiomyidae) are promising organisms to be used for organic waste bioconversion. Breeding BSF indoors has been suggested as a cost-effective approach for countries with long winters or low sunlight levels through the year. As the BSF mating is visually mediated, artificial illumination conditions are critical to a successful indoor breeding system. In this study, we tested four different types of artificial light sources for their effects on BSF mating success. They included: (1) a halogen lamp; (2) a combination of a white light-emitting diode (LED) lamp and a fluorescent ultra violet lamp; (3) a metal halide lamp, and (4) a specially designed light-emitting diode (BSFLED) lamp, whose design was based on the specific BSF adult visual spectral sensitivity. We determined the spectra of four artificial light sources, compared their spectral composition in relation to the BSF-visible spectrum, and compared their effects on the mating success of two different BSF colonies. BSFLED was the most energy efficient light source in spectral composition and led to the highest mating success in terms of the percentage of inseminated females and fertile clutches. Thus, BSFLED is the most suitable light source tested in our experiment for breeding BSF indoors. The colony effect and possible light flickering effect on BSF mating success were also detected. The implications of these findings are discussed.

Bioconversion of Three Organic Wastes by Black Soldier Fly (Diptera: Stratiomyidae) Larvae.

This study aimed to determine the suitability of several organic waste substrates to be processed by the larvae of the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) (BSFL) in a value-added bioconversion system. Three types of organic waste (brewer's waste, solid phase of pig manure, and semidigested grass) were tested and compared with a standard larval diet, broll (wheat middling). Larval survival and growth, chemical composition of the resulting prepupae, conversion ratios of nutrients and waste dry matter, and waste reduction rate were measured. Larval survival was high in all tested substrates. Compared with the larvae fed pig manure or semidigested grass, those fed standard diet or brewer's waste showed shorter development time, higher weight gain, and higher prepupal crude protein and crude fat content. BSFL also reduce more dry matter in the standard diet or in brewer's waste than in the other two substrates. On the other hand, larvae fed semidigested grass took 70 d to complete development and suffered fat loss. Thus, we suggest that brewer's waste is the most suitable substrate among the selected wastes for being processed by BSFL, whereas semidigested grass is an unsuitable substrate. We found that lignin had a significantly negative effect on larval growth, and emphasized the importance of applying lignin-digesting microorganisms to lignin-rich substrates being converted by BSFL. Moreover, a protein:fat:digestible carbohydrate ratio of 2:1:2 was hypothesized to benefit larval development.

Viral RNA load and histological changes in tissues following experimental infection with an arterivirus of possums (wobbly possum disease virus).

Tissues from Australian brushtail possums (Trichosurus vulpecula) that had been experimentally infected with wobbly possum disease (WPD) virus (WPDV) were examined to elucidate pathogenesis of WPDV infection. Mononuclear inflammatory cell infiltrates were present in livers, kidneys, salivary glands and brains of WPD-affected possums. Specific staining was detected by immunohistochemistry within macrophages in the livers and kidneys, and undefined cell types in the brains. The highest viral RNA load was found in macrophage-rich tissues. The detection of viral RNA in the salivary gland, serum, kidney, bladder and urine is compatible with transmission via close physical contact during encounters such as fighting or grooming, or by contact with an environment that has been contaminated with saliva or urine. Levels of viral RNA remained high in all tissues tested throughout the study, suggesting that on-going virus replication and evasion of the immune responses may be important in the pathogenesis of disease.

Timing of exogenous progesterone administration is critical for embryo development and uterine gene expression in an ovine model of maternal constraint.

Progesterone (P4) administration in early pregnancy enhances embryo growth in sheep but is associated with decreased embryo survival. This study examined the effects of exogenous P4 administered during specific time periods between pregnancy Day 0 and Day 6 to determine the critical time point for advancement of embryo growth without pregnancy loss and to examine Day 6 and Day 19 endometrial gene expression. Suffolk (S) embryos were transferred into Cheviot (C) ewes that received exogenous P4 (CP4) on Days 0-3 (CP40-3), Days 0-6 (CP40-6), Days 2-4 (CP42-4) or Days 3-6 (CP43-6). Additionally, S embryos were transferred to C and S ewes that did not receive P4 (CnP4 and SnP4). Day 19 embryos from CP4 ewes were longer (P<0.05) than those from CnP4 ewes. CP42-4 ewes had embryos of similar size to those of CP40-3 and CP40-6 ewes but had higher pregnancy rates. There was altered expression of genes associated with embryo implantation and histotroph production: diacylglycerol-O-acyltransferase (DGAT2), hepatocyte growth factor (HGF) and prostaglandin endoperoxide synthase 2 (PTSG2) on Day 6 and endometrial galectin 15 (LGALS15) and mucin glycoprotein 1 (MUC1) on Day 19. This suggests that specific timing of P4 administration is critical to the enhanced embryo growth and survival observed. These findings provide a platform for further investigation aimed at advancing embryo development and survival.

Evaluation of Iron Stores by Zinc Protoporphyrin Analysis in Blood Donors.

BACKGROUND: Zinc protoporphyrin (ZPP) testing has been studied previously as a substitute for ferritin (fer) testing of blood donors in determining iron stores. OBJECTIVE: To determine whether ZPP testing could be performed using specimens collected via the capillary (cap) finger-stick (FS) method, similar to predonation hemoglobin (HB) testing. Also, we evaluated the correlation among FS HB, venous (ven) ZZP, FS ZPP, and ven fer levels as predictors of iron depletion. METHODS: Blood donations from 328 study participants were evaluated using FS HB assay; we also performed ven ZPP, cap ZPP, and ven fer testing. We assessed the donors for subclinical iron deficiency (fer levels <26 ng/mL and ZPP levels >100 µmol/mol heme). RESULTS: Subclinical iron deficiency was present among first-time and repeat blood donors at all HB levels. Variation among test results (FS HB, ven fer, ven ZPP, and FS ZPP) was statistically significant (P <.001). CONCLUSION: Insufficient correlation existed regarding FS HB and ven fer test results to support use of ZPP to determine iron stores in blood donors.

Effect of exogenous progesterone on embryo size and ewe uterine gene expression in an ovine 'dam size' model of maternal constraint.

Progesterone (P4), acting via its receptor, regulates uterine function and histotroph production, which are crucial to embryo growth. This study aimed to examine exogenous P4 effects on embryo size and differential endometrial gene expression at Day 19 of gestation using a 'dam size' sheep model of maternal constraint. Purebred Suffolk (S, genotypically large) embryos were transferred into recipient groups of Cheviot (C, genotypically small) or Suffolk ewes that had, or had not, been pre-treated with P4 from Days 0 to 6 of pregnancy. At Day 19S embryos were collected from four experimental groups: P4 pretreated S ewes (SP4; n=5), untreated S ewes (SnP4; n=15), P4 pretreated C ewes (CP4; n=7) and untreated C ewes (CnP4; n=21). Day-19 embryos from CP4 ewes were larger (P<0.05) than those from CnP4 ewes and similar in size (P>0.05) to embryos from SnP4 and SP4 ewes. Expression of mucin 1 (MUC1) and prostaglandin-endoperoxide synthase 2 (PTGS2) was upregulated in uterine horns ipsilateral to the corpus luteum from CP4 ewes. Prostaglandin receptor (PGR), MUC1 and PTGS2 expression was upregulated, whilst cathepsin L (CTSL) and radical S-adenosyl methionine domain-containing 2 (RSAD2) expression was downregulated in the ipsilateral horn of SP4 ewes. This suggests that pretreating ewes with exogenous P4 may alleviate early pregnancy maternal constraint via mechanisms that alter uterine function. However, further research is required to investigate the timing of P4 administration and its impact on conception rates.

Pasture feeding conventional cows removes differences between organic and conventionally produced milk.

Perceptions of production methods for organic and conventional milk are changing, with consumers prepared to pay premium prices for milk from either certified organic or conventional grass-fed cows. Our study investigated whether chemical composition differed between milk produced by these two farming systems. Sampling was conducted on two farms sets, each comprised of one organic and one conventional farm. All farms applied year-round pasture grazing. Milk samples were collected throughout the milking season and analysed for free oligosaccharides, fatty acids, major casein and whey proteins, and milk fat volatiles. Fatty acids were influenced by breed and fertilizer application. Oligosaccharides differed between farming systems, with causes presently unknown, while farm set was the dominant influence factor on protein composition. Factors identified in this study influencing milk composition are not exclusive to either farming system, and pasture feeding conventional cows will remove differences previously reported for organic and conventionally produced milk.