Secretion of insulin-like growth factors in milk and their effect on the neonate

Saccharomyces cerevisiae Yeast-Based Supplementation as a Galactagogue in Breastfeeding Women? A Review of Evidence from Animal and Human Studies

Perceived insufficient milk production (PIM) adversely affects breastfeeding duration. Women sometimes use galactagogues with the intent to increase breast milk production and support lactation. Saccharomyces cerevisiae yeast-based supplement (SCYS) is an inactive form of Saccharomyces cerevisiae yeast (SCY) either obtained from the fermentation process or grown on molasses. Anecdotal evidence suggests SCYS is a galactagogue. SCYS is promoted on the internet as a galactagogue in various forms and doses. Dietary supplementation with SCYS during gestation and lactation significantly increases milk yield in ruminants. No human study has evaluated efficacy of SCYS as a galactagogue. SCYS is rich in B vitamins, beta-glucan, mannan oligosaccharides and bioavailable chromium; these may impact breast milk production or composition, thus may alleviate PIM. The safety of taking SCYS during lactation is not well studied. Studies have reported contamination of SCYS with ochratoxin A (OTA) as well as minor side effects from SCYS. Studies are needed to evaluate the efficacy of SCYS on breast milk production and composition and to assess the safety of taking SCYS during lactation in humans.

Invited review: Metabolic challenges and adaptation during different functional stages of the mammary gland in dairy cows: Perspectives for sustainable milk production

Milk production of dairy cows has increased markedly during recent decades and continues to increase further. The evolutionarily conserved direction of nutrients to the mammary gland immediately after calving provided the basis for successful selective breeding toward higher performance. Considerable variation in adaptive responses toward energy and nutrient shortages exists; however, this variation in adaptability recently gained interest for identifying more metabolically robust dairy cows. Metabolic challenges during periods of high milk production considerably affect the immune system, reproductive performance, and product quality as well as animal welfare. Moreover, growing consumer concerns need to be taken into consideration because the public perception of industrialized dairy cow farming, the high dependency on feed sources suitable for human nutrition, and the apparently abundant use of antibiotics may affect the sales of dairy products. Breeding for high yield continues, but the metabolic challenges increasingly come close to the adaptational limits of meeting the mammary gland's requirements. The aim of the present review is to elucidate metabolic challenges and adaptational limitations at different functional stages of the mammary gland in dairy cows. From the challenges and adaptational limitations, we derive perspectives for sustainable milk production. Based on previous research, we highlight the importance of metabolic plasticity in adaptation mechanisms at different functional stages of the mammary gland. Metabolic adaptation and plasticity change among developing, nonlactating, remodeling, and lactational stages of the mammary gland. A higher metabolic plasticity in early-lactating dairy cows could be indicative of resilience, and a high performance level without an extraordinary occurrence of health disorders can be achieved.

Effect of the rearing system on financial returns from Murciano-Granadina breed goats

In dairy goats, the kid rearing system can have critical importance in financial returns. Commonly used criteria for the choice of rearing system are not always clear due to the high number of factors involved. The aim of this study was to quantify all those factors to facilitate decision making. So, the effect of two different kid rearing systems, mixed rearing system (MRS) and artificial rearing system (ARS), on milk yield, milk composition and somatic cell count (SCC), milk yield loss at weaning for MRS, kid growth and costs of the different traits on the financial returns in Murciano-Granadina breed goats was studied. Twenty-four goats per group were used. In the MRS, goats reared only one kid, which had free access to goat milk 24 h a day and were weaned at week 6 of lactation, whereas kids in the ARS were separated from their mothers at kidding, colostrum and artificially reared. In both systems, dams were machine-milked once a day throughout lactation and the records took place weekly. Potential milk yield was estimated according to the oxytocin method up to week 12 of lactation, and was similar for both rearing systems, although a 12.3% drop in potential milk yield at weaning was observed for MRS. During the first 6 weeks of lactation, marketable milk was lower for dams in MRS compared to those in ARS (72.1 v. 113.0 l), but similar for the rest of the experiment (101.5 v. 99.4 l, respectively). Marketable milk composition and SCC throughout the 12 weeks of lactation were unaffected by the rearing system. Artificial rearing system entailed an increment in production cost of 22.2€ per kid compared to the rearing by MRS. A similar economic return per goat and kid was obtained from ARS and MRS in this experiment, although, due to one herd's prolificacy of 1.8, the actual results would be 16.2€ per goat in favour of MRS. The real interest of this experiment may be the possibility of extrapolation to different flocks with diverse levels of milk production, prolificacy and prices and costs for incomes and outputs, to estimate the production system that increases returns. In conclusion, the results showed an increase in the cost of €22.2 per kid bred in the ARS, compared to the MRS, and a final return of 16.2€ per goat in favour of the mixed system.

Analysis of the IGF-system in milk from farm animals - Occurrence, regulation, and biomarker potential

IGFs and IGF-binding proteins (IGFBPs) are abundantly present in milk and in dairy products. Compared to the IGFs, the IGFBP have received less attention in milk, although truncated IGFBPs and IGFBP-glycosylation have been described in milk. Thereby, complex control of local IGF-effects can be assumed on the levels of IGFBPs, proteases, and protease inhibitors. The present review collects the current knowledge both on presence and regulation of IGFs and IGFBPs in milk particularly from dairy animal species. As a rule higher levels of IGF-I, IGF-II, and IGFBPs are measured around parturition if compared to later time-points of lactation. In all farm animal species included in this review, it is found that the relative abundancies of IGFBPs in milk and serum are similar, with IGFBP-3 and -2 characterized by higher concentrations if compared to IGFBP-4 or -5. The concentrations of IGFs and IGFBPs in milk or dairy products can be altered by hormones, dairy processing, or fermentation. Because milk can be used for non-invasive biomarker research, quality management, and health monitoring, we discuss novel directions of IGF-analysis and potential on-site biomarker research in milk.

Effects of age, nursing, and oral IGF1 supplementation on neonatal porcine cervical development

Nursing supports neonatal porcine uterine and testicular development, however, lactocrine effects on cervical development are undefined. Studies were conducted to determine the effects of i) age and the imposition of the lactocrine-null state from birth (postnatal day 0 (PND0)) by milk replacer feeding on cervical histology; ii) imposition of the lactocrine-null state for 2 days from birth on cervical cell proliferation, as reflected by proliferating cell nuclear antigen immunostaining; and iii) a single feeding of colostrum or milk replacer, administered at birth, with or without oral IGF1, on cervical cell proliferation and phosphorylated AKT (pAKT) and B-cell lymphoma 2 (BCL2) protein levels at 12 h postnatal. Cervical crypt depth and height of luminal epithelium (LE) increased with age by PND14, when both responses were reduced in replacer-fed gilts. Cell proliferation was reduced in LE at PND2, and in crypt epithelium and stroma by PND14 in replacer-fed gilts. Returning replacer-fed gilts to nursing on PND2 did not rescue the cervical phenotype by PND14. A single feeding of colostrum, but not milk replacer, was sufficient to support cervical cell proliferation at 12 h postnatal. IGF1 supplementation induced cell proliferation in replacer-fed gilts, and increased cervical pAKT and BCL2 levels in colostrum-fed gilts and replacer-fed gilts at 12 h postnatal. Results indicate that age and nursing support porcine cervical development, support is initiated at first ingestion of colostrum, IGF1 may be lactocrine-active, and identification of lactocrine-active factors can be accomplished by 12 h postnatal using this bioassay system.

The effect of 2 liquid feeds and 2 sources of protein in starter on performance and blood metabolites in Holstein neonatal calves

The aim of present study was to investigate the effect of 2 liquid feeds and 2 protein sources in starter on the performance and blood metabolite responses of Holstein neonatal calves from birth to 6 wk of age. Calves (20 males and 20 females) based on sex were randomly assigned to 4 treatments in a 2 × 2 × 2 factorial arrangement, including soybean meal (SBM) and meat and bone meal (MB) with either fermented colostrum (or fresh milk. Although sex and liquid feed had no significant effect on feed intake, calves consumed more feed intake on the diet containing SBM (15 ± 0.2 kg) than MB (13 ± 0.2 kg) during the experimental period; also, weight gain was affected by both liquid feed and starter. Liquid feed and starter had significant effects on calf body size, including pin width, hip width, withers height, hip height, and stomach size, but no significant effects were observed on calf body size between the sexes. Plasma glucose concentration was not affected by sex, liquid feed, or starter. Plasma urea nitrogen concentration decreased in the first 3 wk and then started to increase during the last 3 wk, but it was only affected by starter and calves receiving SBM (10.18 mg/dL) had a higher concentration of plasma urea nitrogen than calves receiving MB (9.6 mg/dL) at the end of the experiment. Plasma growth hormone and insulin-like growth factor I concentrations decreased in all treatment groups from d 0 to the end of the study. No significant effects were observed on plasma growth hormone and insulin-like growth factor I concentrations between the 2 sexes, but they were significantly affected by both liquid feed and starter. Results of the present study provide useful information to apply to Holstein neonatal calves during the first 6 wk of life when liquid feed and 2 sources of protein in starter are considered.

Preweaning milk replacer intake and effects on long-term productivity of dairy calves

The preweaning management of dairy calves over the last 30 yr has focused on mortality, early weaning, and rumen development. Recent studies suggest that nutrient intake from milk or milk replacer during the preweaning period alters the phenotypic expression for milk yield. The objective of this study was to investigate the relationship between nutrient intake from milk replacer and pre- and postweaning growth rate with lactation performance in the Cornell dairy herd and a commercial dairy farm. The analysis was conducted using traditional 305-d first-lactation milk yield and residual lactation yield estimates from a test-day model (TDM) to analyze the lactation records over multiple lactations. The overall objective of the calf nutrition program in both herds was to double the birth weight of calves by weaning through increased milk replacer and starter intake. First-lactation 305-d milk yield and residuals from the TDM were generated from 1,244 and 624 heifers from the Cornell herd and from the commercial farm, respectively. The TDM was used to generate lactation residuals after accounting for the effects of test day, calving season, days in milk, days pregnant, lactation number, and year. In addition, lactation residuals were generated for cattle with multiple lactations to determine if the effect of preweaning nutrition could be associated with lifetime milk yield. Factors such as preweaning average daily gain (ADG), energy intake from milk replacer as a multiple of maintenance, and other growth outcomes and management variables were regressed on TDM milk yield data. In the Cornell herd, preweaning ADG, ranged from 0.10 to 1.58 kg, and was significantly correlated with first-lactation yield; for every 1 kg of preweaning ADG, heifers, on average, produced 850 kg more milk during their first lactation and 235 kg more milk for every Mcal of metabolizable energy intake above maintenance. In the commercial herd, for every 1 kg of preweaning ADG, milk yield increased by 1,113 kg in the first lactation and further, every 1 kg of prepubertal ADG was associated with a 3,281 kg increase in first-lactation milk yield. Among the 2 herds, preweaning ADG accounted for 22% of the variation in first-lactation milk yield as analyzed with the TDM. These results indicate that increased growth rate before weaning results in some form of epigenetic programming that is yet to be understood, but has positive effects on lactation milk yield. This analysis identifies nutrition and management of the preweaned calf as major environmental factors influencing the expression of the genetic capacity of the animal for milk yield.

Nutrition in mammary gland health and lactation: Advances over eight Biology of Lactation in Farm Animals meetings1

Over the years, numerous studies have investigated the mechanisms controlling nutrient availability and metabolism in the mammary gland and how dietary interventions can influence these processes. The development of in vivo and in vitro systems made it possible to explore the trafficking and metabolic fate of nutrients and how these are influenced by hormones. To improve the quality and safety of milk products, attention has focused on improving animal health in general and mammary gland health in particular and also on enhancing the milk content of natural bioactive milk components that promote the health of human neonates and adults. In the past, attempts to probe the relationship among nutrition, animal health, and animal products were limited to administering single dietary components and investigating their biochemical and metabolic effects. Today, we have genomics, proteomics, and related technologies that allow us to pursue more holistic investigational strategies. These new technologies are providing new insights into interactions among nutrition, lactation, and product quality. The aim of this paper is to review advances in nutritional support of mammary gland function and health as presented in 14 yr of Biology of Lactation in Farm Animals (BOLFA) meetings.

Dietary fat during pregnancy and lactation increases milk fat and insulin-like growth factor I concentrations and improves neonatal growth rates in swine

Primiparous (n = 24) and multiparous (n = 24) sows were used to examine the effects of supplemental dietary fat and induction of parturition (d 112) on colostrum and milk composition and suckling piglet growth. Sows were assigned to one of eight treatments on d 90 of gestation that included variables such as parity (1 vs. >/=3), dietary fat (0 vs. 10%), and farrowing (natural vs. induction via lutalyse on d 112). Piglets suckling fat-supplemented dams grew up to 25% faster than control pigs nursing unsupplemented sows (250 vs. 200 g/d; P < 0.01). Improved growth was correlated with elevated milk fat and insulin-like growth factor (IGF) concentrations associated with fat supplementation. Dietary fat elevated milk fat concentration at 48 and 72 h postfarrowing by 21.6 and 22.6%, respectively (P < 0.05). Compared with nonfat-fed controls, multiparous sows fed 10% fat showed a more consistent rise in milk fat concentration, with 26% and 41% elevations for induced or naturally farrowing sows, respectively, vs. a 19% reduction or a 1% elevation in induced or naturally farrowing gilts (P < 0.01). The concentration of milk IGF-I tended to be lower in gilts than in multiparous sows (P < 0.2, 95.7 vs. 117.4 microg/L), and levels were particularly low in milk from induced gilts receiving no additional dietary fat (44.7 microg/L). However, fat supplementation elevated IGF-I to levels (110.6 microg/L) exceeding those measured in unsupplemented, naturally farrowing control sows and gilts (95.8 microg/L). In conclusion, supplemental dietary fat elevates milk fat in multiparous sows more than primiparous gilts regardless of farrowing treatment (induced vs. natural farrowing) and improves piglet growth throughout lactation irrespective of parity or farrowing treatment. The potential of supplemental dietary fat to reverse the reductions in milk IGF-I observed in first-parity females and in dams induced to farrow merits further investigation.

Determination of transforming growth factor-beta 1 (TGF-beta 1) and insulin-like growth factor (IGF-1) in bovine colostrum samples

The major growth factors in bovine colostrum are transforming growth factor-beta s (TGF-beta 1 and TGF-beta 2) and insulin-like growth factors (IGF-1 and IGF-2). Recently, TGF-beta 2 content of bovine colostrum was measured using a TGF-beta 2 specific ELISA (1) and now we have validated ELISAs for for bovine TGF-beta 1 and IGF-1. The concentrations of IGF-1 and TGF-beta 1 in the first milking after calving were 248-1850 ng/ml and 12.4-42.6 ng/ml, respectively, and they declined in correlation with total protein concentration to 27.0-101 ng/ml (IGF-1) and 0.80-3.49 ng/ml(TGF-beta 1) by the fifth milkings. The amount of TGF-beta 1 was on average 5.3 +/- 1.4% of that of TGF-beta 2 and there is a high correlation (r = 0.966) between the concentrations of these growth factors in the same samples. No free TGF-beta 1 form of could be detected.

Effects of bovine colostrum supplementation on serum IGF-I, IgG, hormone, and saliva IgA during training

The purpose of this study was to examine the effects of bovine colostrum supplementation (Bioenervi) on serum insulin-like growth factor I (IGF-I), immunoglobulin G, hormone, and amino acid and saliva immunoglobulin A concentrations during a strength and speed training period. Nine male sprinters and jumpers underwent three randomized experimental training treatments of 8 days separated by 13 days. The only difference in the treatments was the drink of 125 ml consumed per day. Posttraining increases were noticed for serum IGF-I in the 25-ml Bioenervi treatment (125 ml contained 25 ml Bioenervi) and especially in the 125-ml Bioenervi treatment (125 ml contained 125 ml Bioenervi) compared with the placebo (normal milk whey) treatment (P < 0.05). The change in IGF-I concentration during the 8-day periods correlated positively with the change in insulin concentration during the same periods with 25-ml Bioenervi treatment (r = 0.68; P = 0.045) and with 125-ml Bioenervi treatment (r = 0.69; P = 0.038). Serum immunoglobulin G, hormone, and amino acid and saliva immunoglobulin A responses were similar during the three treatments. It appears that a bovine colostrum supplement (Bioenervi) may increase serum IGF-I concentration in athletes during strength and speed training.

Insulin-like growth factors in milk and mammary gland

Milk contains insulin-like growth factor I and II (IGF-I and IGF-II) and four IGF binding proteins (IGFBP). Their concentrations are highest prepartum and early postpartum, coinciding with maximal proliferation of mammary cells and the time when the infant gut is the least developed. This has lead to the suggestion that IGFs may be important for the growth and development of the mammary gland and that IGFs in milk play a role in promoting development of the gastrointestinal tract of the newborn. IGF-I and, to a lesser extent, IGF-II can stimulate milk yield and blood flow in goats when infused directly into the mammary gland, suggesting they may also be important in supporting established lactation. Thus IGFs may have a dual function in the mammary gland, establishing and maintaining the maternal mammary system and, once secreted into milk, supporting gastrointestinal development in the newborn.