Minerals are supplemented routinely to dairy cows during the dry period to prevent metabolic issues postpartum. However, limited information exists on the impacts of mineral supplementation on colostrum carotenoids. This study aimed to determine the effects of prepartum supplementation with three micro-nutrients; inorganic selenium (INORG), organic selenium (ORG) or rumen-protected choline (RPC) on the carotenoid content of bovine colostrum and transition milk (TM) from pasture-based dairy cows. A total of 57 (12 primiparous and 45 multiparous) Holstein-Friesian (HF) and HF × Jersey (JEX) cows were supplemented daily for 49 ± 12.9 d before calving. Colostrum samples were collected from all cows immediately postpartum and TM one to five (TM1–TM5) were collected from a sub-set of 15 cows (five per treatment group) at each consecutive milking postpartum. Carotenoid concentration was determined using ultra-high performance liquid chromatography – diode array detection (UHPLC-DAD). With the use of transmittance, the colour index and colour parameters a*, b* and L* were used to determine colour variations over this period. Prepartum supplementation did not have a significant effect on colostrum β-carotene concentration or colour. Positive correlations between β-carotene and colour parameter b* (R2 = 0.671; P < 0.001) and β-carotene and colour index (R2 = 0.560; P < 0.001) were observed. Concentrations of β-carotene were highest in colostrum (1.34 μg/g) and decreased significantly with each milking postpartum (TM5 0.31 μg/g). Breed had a significant effect on colostrum colour with JEX animals producing a greater b* colostrum than HF animals (P = 0.030). Primiparous animals produced colostrum with the weakest colour compared to second or ≥third parity animals (P = 0.042). Despite statistical increases in the b* parameter in colostrum from JEX cows and multiparous cows, β-carotene concentrations did not significantly increase suggesting that other factors may influence colostrum colour. The b* parameter may be used as an indicator for estimating carotenoid concentrations in colostrum and TM, particularly when assessed via transmittance spectroscopy.

The practice of antenatal colostrum expression (ACE), or the extraction of colostrum from the breasts during pregnancy, has an interesting history and continues to evolve. This narrative review aims to describe how perception and practices of ACE have changed over time, summarise the evidence on ACE in maternal and infant care, and highlight areas for future research. The literature demonstrates that ACE is safe for low-risk women when done from around 36 weeks’ gestation. Women should be reassured that the skill of hand expressing is a valuable tool post-birth, regardless of whether they are able to collect colostrum antenatally or not. The collection and storage of colostrum in pregnancy can help avoid formula use in hospital, which may have follow on effects immune function and other areas. Ideally, colostrum collected during pregnancy would be kept safely frozen during the hospital stay and only defrosted and used during the stay if medically indicated, with parents supported through that process. Although ACE does not appear to improve long-term breastfeeding rates at present, it can increase confidence around breastfeeding. Further research in more diverse population groups, long-term breastfeeding and long-term health outcomes of using frozen antenatally expressed colostrum for babies (as compared to formula or fresh colostrum) would be valuable to gain a better understanding of the importance of ACE in maternity care.

The protein composition in goat milk undergoes changes throughout the different lactation periods, displaying distinct characteristics that are influenced by the dynamic nature of protein composition and concentration during the transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Saanen goats during the colostral phase and the first month of lactation, 110 milk samples from 11 healthy mammary halves of seven Saanen goats were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The biuret method determined total protein concentration, and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis. Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing throughout the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred 5 or 7 d postpartum.

Good colostrum management can confer protective immunity to newborn calves, making calves less susceptible to infectious disease, and fundamentally improving both their short- and long-term health, welfare and productivity. Industry recommendations commonly refer to ‘The Three ‘Q's’ of colostrum management: the need for calves to receive sufficient ‘Quantity’ of high ‘Quality’ colostrum ‘Quickly’ after birth; some also include ‘sQueaky clean’ and ‘Quantification of passive transfer’. However, research to date suggests that the failure of passive transfer of colostral antibodies is common on commercial dairy farms, contributing to sub-optimal calf health and mortality. This paper explores why this may be the case by investigating stakeholder perceptions of colostrum management and how these perceptions might affect the practice of ensuring adequate colostrum administration to newborn calves. Calf rearing and youngstock management practices on English dairy farms were investigated using 40 in-depth semi-structured interviews: 26 with dairy farmers and 14 with advisors (including veterinarians, feed and pharmaceutical company representatives). Interviews were audio-recorded, transcribed and thematically coded for analysis. ‘The Three ‘Q's’ were found to act as useful reminders about the goals of colostrum management, and a case can be made for further publicising the inclusion of ‘sQueaky clean’ and ‘Quantification of passive transfer’ as there remains a lack of focus on colostrum hygiene and measurement of successful antibody transfer. Knowledge of the ‘Q's’ did not guarantee implementation, and time and labour constraints alongside farmer misconceptions must be addressed when offering professional advice on improving calf health. Further research to encourage on-farm collection and analysis of monitoring data including rates of passive transfer is particularly needed. Advisors must not overlook the importance of colostrum management when assessing farm practices and ensure that they promote evidence-based recommendations if dairy calf morbidity and mortality is to be reduced.

Preservation of colostrum for neonatal dairy calves has seldom been seldom in recent years, much of the peer reviewed literature having been published in the 1970s and 1980s. First milking colostrum is high in bioactive immune enhancers such as immunoglobulins, lactoferrins, lysozymes and cytokines and is vital to confer passive immunity to newborn dairy calves to promote their health, welfare and future productivity. Bovine colostrum is advisedly restricted from the bulk milk supply for the first 8 milkings post calving due to high somatic cell counts and the risk of antimicrobial residues. As such, many producers refer to ‘colostrum’ as not only the first milking post calving, but also the aformentioned ‘transition’ milk. Colostrum is preserved in order to protect supply for feeding when production may be poor or where there is a glut of colostrum such as in seasonal calving systems. There are multiple reasons for newborn calves not to have access to their dam's colostrum, including multiple births, acute mastitis or maladapted maternal behaviour, especially in first lactation heifers. Shortages in colostrum may also be precipitated by purposeful discarding of colostrum from cows infected with Mycobacterium avium subsp paratuberculosis and Mycoplasma bovis. Broadly, colostrum may be preserved using low temperature (refrigeration or freezing) or chemical preservatives. The aim of this scoping review article was to identify options for preservation and gaps in research and to propose best practice for colostrum preservation.

Colostrum quality is of paramount importance in the management of optimal ruminant growth and infectious disease prevention in early life. Live yeast supplementation effect during the last month of gestation was evaluated on ewes’ colostrum composition. Two groups of ewes (n = 14) carrying twin lambs were constituted and twins were separated into groups (mothered or artificially fed) 12 h after birth. Nutrient, oligosaccharides (OS), IgG and lactoferrin concentrations were measured over 72 h after lambing, and bacterial community was described in colostrum collected at parturition (T0). Immune passive transfer was evaluated through IgG measurement in lamb serum. In both groups, colostral nutrient, OS concentrations and IgG concentrations in colostrum and lamb serum decreased over time (P < 0⋅01), except for lactose, which slightly increased (P < 0⋅001), and lactoferrin, which remained stable. Bacterial population was stable over time with high relative abundances of Aerococcaceae, Corynebacteriaceae, Moraxellaceae and Staphylococcaceae in T0 colostrum. No effect of supplementation was observed in nutrient and lactoferrin concentrations. In supplemented ewes, the level of colostral IgG was higher at T0 and a higher level of serum IgG was observed in lambs born from supplemented mothers and artificially fed, while no effect of supplementation was observed in the mothered lamb groups. Using a metabolomic approach, we showed that supplementation affected OS composition with significantly higher levels of colostral Neu-5Gc compounds up to 5 h after birth. No effect of supplementation was observed on bacterial composition. Our data suggest that live yeast supplementation offsets the negative impact of early separation and incomplete colostrum feeding in neonate lambs.

Failure of passive transfer (FPT) has health, welfare and economic implications for calves. Immunoglobulin G (IgG) concentration of 370 dairy calf serum samples from 38 Scottish dairy farms was measured via radial immunodiffusion (RID) to determine FPT prevalence. IgG concentration, total bacteria count (TBC) and total coliform count (TCC) of 252 colostrum samples were also measured. A questionnaire was completed at farm enrollment to investigate risk factors for FPT and poor colostrum quality at farm-level. Multivariable mixed effect logistic and linear regressions were carried out to determine significant risk factors for FPT and colostrum quality. Prevalence of FPT at calf level was determined to be 14.05%. Of 252 colostrum samples, 111 (44.05%) failed to meet Brix thresholds for colostrum quality. Of these 28 and 38 samples also exceeded TBC and TCC thresholds, respectively. Increased time between parturition and colostrum harvesting was numerically (non-significantly) associated with a colostrum Brix result <22%, and increased time spent in a bucket prior to feeding or storing was significantly associated with high TBC (≥100 000 cfu/ml and also ≥10 000 cfu/ml). High TBC values in colostrum were significantly associated with lower serum IgG concentrations. This study highlights associations between colostrum quality and FPT in dairy calves as well as potential risk factors for reduced colostrum quality; recommending some simple steps producers can take to maximise colostrum quality on farm.

This paper reveals the technological properties of lactic acid bacteria isolated from raw milk (colostrum and mature milk) of Wagyu cattle raised in Okayama Prefecture, Japan. Isolates were identified based on their physiological and biochemical characteristics as well as 16S rDNA sequence analysis. Streptococcus lutetiensis and Lactobacillus plantarum showed high acid and diacetyl-acetoin production in milk after 24 h of incubation at 40 and 30°C, respectively. These strains are thought to have potential for use as starter cultures and adjunct cultures for fermented dairy products.

The objective of this study was to evaluate the effect of feeding Bacillus altitudinis spores to sows and/or offspring on growth and health indicators. On day (D) 100 of gestation, twenty-four sows were selected and grouped as: control (CON), fed with a standard diet; and probiotic (PRO), fed the standard diet supplemented with B. altitudinis WIT588 spores from D100 of gestation until weaning. Offspring (n 144) from each of the two sow treatments were assigned to either a CON (no probiotic) or PRO (B. altitudinis-supplemented) treatment for 28 d post-weaning (pw), resulting in four treatment groups: (1) CON/CON, non-probiotic-supplemented sow/non-probiotic-supplemented piglet; (2) CON/PRO, non-probiotic-supplemented sow/probiotic-supplemented piglet; (3) PRO/CON, probiotic-supplemented sow/non-probiotic-supplemented piglet and (4) PRO/PRO, probiotic-supplemented sow/probiotic-supplemented piglet. B. altitudinis WIT588 was detected in the faeces of probiotic-supplemented sows and their piglets, and in the faeces and intestine of probiotic-supplemented piglets. Colostrum from PRO sows had higher total solids (P = 0·02), protein (P = 0·04) and true protein (P = 0·05), and lower lactose (P < 0·01) than colostrum from CON sows. Maternal treatment improved offspring feed conversion ratio at D0–14 pw (P < 0·001) and increased offspring body weight at D105 and D127 pw (P = 0·01), carcass weight (P = 0·05) and kill-out percentage (P < 0·01). It also increased small intestinal absorptive capacity and impacted the haematological profile of sows and progeny. There was little impact of pw treatment on any of the parameters measured. Overall, the lifetime growth benefits in the offspring of B. altitudinis-supplemented sows offer considerable economic advantages for pig producers in search of alternatives to in-feed antibiotics/zinc oxide.

The aim of the studies presented in this research communication was to compare species of origin (goat and sheep) and the effect of treatment (pasteurization at 56, 63 and 72 °C, skimming and curding) and refrigeration time on colostrum antimicrobial activity (AnAc). Two experiments were performed. In experiment 1, twenty-four first milking colostrum samples were obtained (12 goats, 12 sheep) and an aliquot of each sample was subjected to 6 different treatments, control (untreated), pasteurization at 56, 63 and 72 °C, skimming and curding. Colostrum AnAc was tested directly against E. coli using disks in a Petri dish and Enrofloxacin (antibiotic) and saline serum as positive and negative control, respectively. Species had no effect (P > 0.05) on colostrum AnAc, and neither did pasteurization at different temperatures or skimming. However, curding showed the lowest colostrum AnAc (P < 0.05) in both species. In the second experiment, four treatments were assayed, control, pasteurization at 56 and 63 °C and skimming. An aliquot of twelve goat colostrum samples were refrigerated after treatments for 10 d at 4 °C. Colostrum AnAc was measured at 0, 2, 4, 6, 8, and 10 d. A reduction in colostrum AnAc was observed due to refrigeration time. The results suggest that if farmers use frozen colostrum for neonates, the process of curding colostrum or refrigeration at 4 °C longer than 4 d is not recommended.

Maternal effects on development are profound. Together, genetic and epigenetic maternal effects define the developmental trajectory of progeny and, ultimately, offspring phenotype. Maternally provisioned environmental conditions and signals affect conceptus, fetoplacental and postnatal development from the time of conception until weaning. In the pig, reproductive tract development is completed postnatally. Porcine uterine growth and uterine endometrial development occur in an ovary-independent manner between birth (postnatal day = PND 0) and PND 60. Milk-borne bioactive factors (MbFs), exemplified by relaxin, communicated from lactating dam to nursing offspring via a lactocrine mechanism, represent an important source of extraovarian uterotrophic support in the neonatal pig. Lactocrine deficiency from birth affects both the neonatal porcine uterine developmental program and trajectory of uterine development, with lasting consequences for endometrial function and uterine capacity in adult female pigs. The potential lactocrine signaling window extends from birth until the time of weaning. However, it is likely that the maternal lactocrine programming window – that period when MbFs communicated to nursing offspring have the greatest potential to affect critical organizational events in the neonate – encompasses a comparatively short period of time within 48 h of birth. Lactocrine deficiency from birth was associated with altered patterns of endometrial gene expression in neonatally lactocrine-deficient adult gilts during a critical period for conceptus–endometrial interaction on pregnancy day 13, and with reduced litter size, estimated at 1.4 pigs per litter, with no effect of parity. Data were interpreted to indicate that reproductive performance of female pigs that do not receive sufficient colostrum from birth is permanently impaired. Observations to date suggest that lactocrine-dependent maternal effects program postnatal development of the porcine uterus, endometrial functionality and uterine capacity. In this context, reproductive management strategies and husbandry guidelines should be refined to ensure that such practices promote environmental conditions that will optimize uterine capacity and fecundity. This will entail careful consideration of factors affecting lactation, the quality and abundance of colostrum/milk, and practices that will afford neonatal pigs with the opportunity to nurse and consume adequate amounts of colostrum.

Colostrum plays an essential role in ensuring the survival, growth and health of piglets by providing energy, nutrients, immunoglobulins, growth factors and many other bioactive components and cells. Both colostrum yield and composition are highly variable among sows, yet mechanisms and factors that regulate colostrogenesis are not fully known. Unlike sow milk yield, sow colostrum yield is not highly determined by litter size and suckling intensity but is largely driven by sow-related factors. Colostrum synthesis is under hormonal control, with prolactin and progesterone concentrations prepartum having, respectively, positive and negative influences on colostrum yield. Less is known about the endocrine control of the end of colostrogenesis in swine, which is characterized by the closure of tight junctions in the mammary epithelium and the cessation of transfer of immunoglobulin G (IgG) into lacteal secretions. Recent studies indicate that exogenous hormones may influence colostrogenesis. Inducing parturition by injecting prostaglandin F2α on day 114 of gestation in combination with an oxytocin-like molecule reduced colostrum yield, and injection of prostaglandin F2α alone either reduced colostrum yield or had no effect. Injecting a supraphysiological dose of oxytocin to sows in the early postpartum period delayed the tightening of mammary tight junctions, thereby prolonging the colostral phase and increasing concentrations of IGF-I and IgG and IgA in early milk. The development of strategies to improve colostrum composition in swine through maternal feeding has been largely explored but very few attempts were made to increase colostrum yield. This is most likely because of the difficulty in measuring colostrum yield in swine. The fatty acid content of colostrum greatly depends on the amount of lipids provided in the sow diet during late gestation, whereas the fatty acid profile is largely influenced by the type of lipid being fed to the pregnant sow. Moreover, various ingredients that presumably have immuno-modulating effects (such as fish oil, prebiotics and probiotics) increased concentrations of IgG, IgA and/or IgM in sow colostrum when they were provided during the last weeks of gestation. Finally, there is some evidence that sow nutrition during late gestation may influence colostrum yield but this clearly warrants more research. This review emphasizes that although progress has been made in understanding the control of colostrogenesis in swine, and that strategies exist to manipulate fat and immunoglobulin contents of colostrum, ways to increase colostrum yield are still lacking.

Nursing piglets are entirely dependent, for their micronutrient provisions, upon in utero, colostrum and milk transfers from the dam. An adequate maternal transfer of micronutrients is all the more important during these periods which, in fact, lasts for approximately half the life cycle (conception to slaughter) of modern pigs. The present study aimed to set up a simple approach to assess the maternal perinatal transfer of vitamins and trace elements in sows. Prenatal transfer (R-u) was estimated as limited, passive or active using the ratio between pre-colostral serum concentrations of a given micronutrient in newborn piglets and corresponding pre-farrowing values in sows. Efficiency of the postnatal transfer (R-c) was estimated from the ratio between serum concentrations of post- and pre-colostral micronutrients in piglets. Data from literature (12 studies) were used for vitamins A, D, E, C, folic acid and B12, whereas vitamins B2, B3, B6 and B8 as well as Zn, Fe, Cu and Se were generated from a trial where blood sera from 20 sows, and their litter were collected during the perinatal period. In sow trial, statistical t tests were used to determine if ratios differed from 1. Prenatal transfer was active and in favour of piglets (R-u > 1, P < 0.03) for Zn and vitamins B6 and B8 (sow trial) as well as for vitamins C and B12 (literature data). This transfer was limited (R-u < 1, P < 0.01) for vitamin B2, Fe, Cu and Se (sow trial) and for vitamins A, E, D and folic acid (literature data) whereas it was passive for vitamin B3 (R-u = 1, P > 0.37). After birth, the early postnatal transfer through colostrum was active towards piglets for most micronutrients but vitamins B6 and B8 (R-c < 1, P < 0.01). Globally, the perinatal transfer (combination of R-u and R-c) was favourable to the neonatal piglets for most micronutrients except for vitamins A and D as well as Fe, Cu and Se whereas there is apparently a barrier for prenatal transfer which is not compensated by the colostrum provision to neonatal piglets. Then, post-colostral concentrations of these micronutrients in piglets remain below prenatal levels of their dam. Neonatal strategies of micronutrient provision are known for Fe (intramuscular injection) and Se (sow milk enrichment). Further studies are needed to assess the importance of the unfavourable perinatal transfer for Cu and vitamins A and D for piglet robustness later in life.

Sow productivity improvements continue to increase metabolic demands during lactation. During the peripartum period, energy requirements increase by 60%, and amino acid needs increase by 150%. As litter size has increased, research on peripartum sows has focused on increasing birth weight, shortening farrowing duration to reduce stillbirths and improving colostrum composition and yield. Dietary fibre can provide short-chain fatty acids to serve as an energy source for the uterus prior to farrowing; however, fat and glucose appear to be the main energy sources used by the uterus during farrowing. Colostrum immunoglobulin G concentration can be improved by increasing energy and amino acid availability prior to farrowing; however, the influence of nutrient intake on colostrum yield is unequivocal. As sows transition to the lactation period, nutrient requirements increase with milk production demands to support large, fast-growing litters. The adoption of automated feed delivery systems has increased feed supply and intake of lactating sows; however, sows still cannot consume enough feed to meet energy and amino acid requirements during lactation. Thus, sows typically catabolise body fat and protein to meet the needs for milk production. The addition of energy sources to lactation diets increases energy intake and energy output in milk, leading to a reduction in BW loss and an improvement in litter growth rate. The supply of dietary amino acids and CP close to the requirements improves milk protein output and reduces muscle protein mobilisation. The amino acid requirements of lactating sows are variable as a consequence of the dynamic body tissue mobilisation during lactation; however, lysine (Lys) is consistently the first-limiting amino acid. A regression equation using published data on Lys requirement of lactating sows predicted a requirement of 27 g/day of digestible Lys intake for each 1 kg of litter growth, and 13 g/day of Lys mobilisation from body protein reserves. Increases in dietary amino acids reduce protein catabolism, which historically leads to improvements in subsequent reproductive performance. Although the connection between lactation catabolism and subsequent reproduction remains a dogma, recent literature with high-producing sows is not as clear on this response. Many practical aspects of meeting the nutrient requirements of lactating sows have not changed. Sows with large litters should approach farrowing without excess fat reserves (e.g. <18 mm backfat thickness), be fed ad libitum from farrowing to weaning, be housed in a thermoneutral environment and have their skin wetted to remove excess heat when exposed to high temperatures.

The bovine whey consists of more than 200 different types of proteins, of which β-lactoglobulin, α-lactalbumin, serum albumin, immunoglobulins and lactoferrin predominate. However, their concentrations are not stable due to the existence of protein dynamics during a transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Jersey cows during a colostral phase and first month of lactation and an influence of the number of lactations, 268 milk samples from 135 Jersey cows were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The concentration of total proteins was determined by the biuret method and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis (12% SDS-PAGE). Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing over the course of the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred between 24 and 72 h postpartum. There was an influence of the number of lactations on the dynamics of whey proteins, indicating that multiparous cows had better immunological and nutritional quality when compared to primiparous cows.

The aim of this Research Communication was to contribute to the knowledge of milk sialic acid concentration of bovines with specific focus on India. Sialic acids (SA) are important constituents of mammalian milks. Buffaloes are the main milk producing species in India, therefore, our research focused on both cow and buffalo. Two Indian cattle (Bos indicus) breeds (Sahiwal, Tharparkar), one cross bred cattle – Karan Fries (Tharparkar × Holstein Friesian) and a buffalo breed (Murrah) were selected. Systematic comparisons of the total, free and bound form of SA and also its distribution over the course of lactation- colostrums and mature milk (120–140 d) was generated. Animal management, sample collection and methodology of SA estimation were identical for the different groups. Colostrum had the highest concentration of SA, which declined with the progress of lactation in all the groups. Majority of the SA existed in bound form. No significant (P < 0.05) difference was recorded in the total, bound or free SA across all the groups. However, differences were obvious in the total and bound SA level in the mature milk. Indian cattle, Sahiwal and Tharparkar were equivalent, but had higher concentration of total and bound SA than crossbred cattle. Milk of buffalo had SA equivalent to that of crossbred cattle. The mean (se) levels of total SA was 23.4 (0.8), 25.8 (2.4), 20.3 (0.6) and 20.2 (1.2) in Sahiwal, Tharparkar, cross bred and Murrah buffalo, respectively. The findings suggested that milk of indigenous cattle may be a potential source of SA, a bioactive compound with beneficial effect on human health and a potential functional ingredient in foods. Results add value to the currently declining indigenous cattle of India.

In pig husbandry, pregnant females are often exposed to stressful conditions, and their outcomes on maternal and offspring health have not been well evaluated. The present study aimed at testing whether improving the welfare of gestating sows could be associated with a better maternal health during gestation, changes in the composition of lacteal secretions and improvement in piglet survival. Two contrasted group-housing systems for gestating sows were used, that is, a French conventional system on slatted floor (C, 49 sows) and an enriched system using larger pens on deep straw (E, 57 sows). On the 105th days of gestation (DG105), sows were transferred into identical farrowing crates on slatted floor. Saliva was collected from all sows on DG35, DG105 and DG107. Blood samples were collected on DG105 from all sows and on the 1st day of lactation (DL1) from a subset of them (C, n=18; E, n=19). Colostrum and milk samples were collected from this subset of sows at farrowing (DL0) and DL4. Saliva concentration of cortisol was greater in C than in E sows at DG35 and DG105, and dropped to concentrations comparable to E sows after transfer into farrowing crates (DG107). On DG105, plasma concentrations of haptoglobin, immunoglobulins G (IgG) and A (IgA), blood lymphocyte counts and plasma antioxidant potential did not differ between groups (P > 0.10), whereas blood granulocyte count, and plasma hydroperoxide concentration were lower in E than in C sows (P < 0.05). Concentrations of IgG and IgA in colostrum and milk did not differ between the two groups. The number of cells did not differ in colostrum but was greater in milk from E than C sows (P < 0.05). Pre-weaning mortality rates were lower in E than C piglets (16.7% v. 25.8%, P < 0.001), and especially between 12 and 72 h postpartum (P < 0.001). Plasma concentration of IgG was similar in E and C piglets on DL4. In conclusion, differences in salivary cortisol, blood granulocyte count and oxidative stress markers between groups suggested improved welfare and reduced immune solicitation during late gestation in sows of the E compared with the C system. However, the better survival observed for neonates in the E environment could not be explained by variations in colostrum composition.

Colostrum-derived passive immunity is central to the health, performance and welfare of neonatal beef-suckler calves, and economics of beef-farming enterprises. Compared to dairy calves, mainly Holstein-Friesian, there is much less research carried out on passive immunity and associated factors in beef calves. Thus, this review aimed to summarise and interpret published information and highlight areas requiring further research. The transfer of immunoglobulin G1 (IgG1) from blood to mammary secretions is greater for beef × dairy cows compared to most beef breed types. Considerable between-animal variance is evident in first-milking colostrum yield and immunoglobulin concentration of beef-suckler cow breed types. First-milking colostrum immunoglobulin concentrations are similar for within-quarter fractions and for the front and rear quarters of the udder. First-milking colostrum yield is higher for beef × dairy cows than beef × beef and purebred beef breeds, and higher for multiparous than primiparous cows, but generally colostrum immunoglobulin concentration is relatively similar for each of the respective categories. Consequently, colostrum immunoglobulin mass (volume × concentration) production in beef cows seems to be primarily limited by colostrum volume. The effect of maternal nutrition during late gestation on colostrum yield is not well documented; however, most studies provide evidence that colostrum immunoglobulin concentration is not adversely affected by under-nutrition. Factors that impinge upon the duration between birth and first suckling, including dam parity, udder and teat anatomy and especially dystocia, negatively impact on calf passive immunity. Colostrum immunoglobulin mass ingested relative to birth weight post-parturition is the most important variable determining calf passive immunity. Research indicates that feeding the beef calf a colostrum volume equivalent to 5% of birth weight shortly after parturition, with subsequent suckling of the dam (or a second feed) 6 to 8 h later, ensures adequate passive immunity, equivalent to a well-managed suckling situation. Within beef-suckler cow genotypes, calf passive immunity is similar for many common beef breeds, but is generally higher for calves from beef × dairy cows. Compared to older cows, calves from younger cows, especially primiparous animals, have lower serum immunoglobulin concentrations. Most studies have shown no adverse impact of maternal dietary restriction on calf passive immunity. The prevalence of failure of passive transfer (FPT) in beef calves varies considerably across studies depending on the test used, and what cut-off value is assumed or how it is classified. The accuracy and precision of methodologies used to determine immunoglobulin concentrations is concerning; caution is required in interpreting laboratory results regarding defining colostrum ‘quality’ and calf passive immune ‘status’. Further research is warranted on colostrum-related factors limiting passive immunity of beef calves, and on the validation of laboratory test cut-off points for determining FPT, based on their relationships with key health and performance measures.

Artificial rearing of young animals represents a challenge in modern ruminant production systems. This work aims to evaluate the short- and long-term effects of the type of rearing on the animal’s health, growth, feed utilization and carcass performance. A total of 24 pregnant ewes carrying triplets were used. Within each triplet set, lambs were randomly allocated to one experimental treatment: natural rearing on the ewe (NN); ewe colostrum for 24 h followed by artificial rearing with milk replacer (NA) and 50 g of colostrum alternative supplementation followed by artificial rearing (AA). Milk replacer, ryegrass hay and creep feed were offered ad libitum, and each experimental group was kept in independent pens until weaning at 45 days of age. After weaning all lambs were placed together on the same pasture for fattening for 4 months. Blood samples were taken at 24 h after birth, at weaning and at the end of the fattening period (23 weeks). Results showed that no failure in the passive immune transfer was detected across treatments. Although artificially reared lambs at weaning had lower plasma levels of β-hydroxy-butyrate (−62%), high-density lipoproteins (−13%) and amylase (−25%), and higher levels of low-density lipoproteins (+38%) and alkaline phosphatase (+30%), these differences disappeared during the fattening period. Only the greater levels of calcium and the lower levels of haemoglobin and white blood cells detected at weaning in artificially reared lambs (+7.2%, −2.8% and −17.8%) persisted by the end of the fattening period (+4.3%, −3.3% and −9.5%, respectively). Minor diarrheal events from weeks 2 to 5 were recorded with artificial rearing, leading to lower growth rates during the 1st month. However, these artificially reared lambs caught up towards the end of the milk feeding period and reached similar weaning weights to NN lambs. During the fattening period NN lambs had a greater growth rate (+16%) possibly as a result of their greater early rumen development, which allowed a higher feed digestibility during the fattening period in comparison to NA lambs (+5.9%). As a result, NN lambs had heavier final BWs (+7.0%), but tended to have lower dressing percentage (−5.7%) than artificially reared lambs, thus no differences were noted in either carcass weight or in carcass conformation across treatments. In conclusion, the use of a colostrum alternative and milk replacer facilitated the successful rearing of lambs, reaching similar productive parameters; however, special care must be taken to maximize the rumen development before weaning.

Mammalian neonates undergo rapid transitions from a sterile uterine environment with a continuous intravenous supply of nutrients to a microbe-rich environment with intermittent ingesting of colostrum/milk via the gut. Currently, little is known about the colostrum-induced alterations of intestinal mucosal proteins in piglets with intra-uterine growth restriction (IUGR). In this study, we sought to investigate the innate differences and effects of colostrum on alterations in small-intestinal proteomes of IUGR piglets. Two IUGR (approximately 0·9 kg) and two normal-birth weight (NBW; approximately 1·3 kg) piglets were obtained from each of six sows at birth. One half (n 12; 6 IUGR v. 6 NBW) of the selected newborn piglets were killed to obtain jejunum samples, and the other half (n 12; 6 IUGR v. 6 NBW) of the newborn piglets were allowed to suckle colostrum from their own mothers for 24 h before jejunum sample collection. On the basis of proteomic analysis, we identified thirty-one differentially expressed proteins in the jejunal mucosa between IUGR and normal neonates before or after colostrum consumption. The intestinal proteins altered by colostrum feeding play important roles in the following: (1) increasing intestinal integrity, transport of nutrients, energy metabolism, protein synthesis, immune response and, therefore, cell proliferation; and (2) decreasing oxidative stress, and therefore cell apoptosis, in IUGR neonates. However, colostrum only partially ameliorated the inferior status of the jejunal mucosa in IUGR neonates. These findings provide the first evidence in intestinal protein alterations of IUGR neonates in response to colostrum ingestion, and thus render new insights into the mechanisms responsible for impaired growth in IUGR neonates and into new nutritional intervention strategies.