Breastfeeding: crucially important, but increasingly challenged in a market-driven world.

In this Series paper, we examine how mother and baby attributes at the individual level interact with breastfeeding determinants at other levels, how these interactions drive breastfeeding outcomes, and what policies and interventions are necessary to achieve optimal breastfeeding. About one in three neonates in low-income and middle-income countries receive prelacteal feeds, and only one in two neonates are put to the breast within the first hour of life. Prelacteal feeds are strongly associated with delayed initiation of breastfeeding. Self-reported insufficient milk continues to be one of the most common reasons for introducing commercial milk formula (CMF) and stopping breastfeeding. Parents and health professionals frequently misinterpret typical, unsettled baby behaviours as signs of milk insufficiency or inadequacy. In our market-driven world and in violation of the WHO International Code for Marketing of Breast-milk Substitutes, the CMF industry exploits concerns of parents about these behaviours with unfounded product claims and advertising messages. A synthesis of reviews between 2016 and 2021 and country-based case studies indicate that breastfeeding practices at a population level can be improved rapidly through multilevel and multicomponent interventions across the socioecological model and settings. Breastfeeding is not the sole responsibility of women and requires collective societal approaches that take gender inequities into consideration.

Marketing of commercial milk formula: a system to capture parents, communities, science, and policy.

Despite proven benefits, less than half of infants and young children globally are breastfed in accordance with the recommendations of WHO. In comparison, commercial milk formula (CMF) sales have increased to about US$55 billion annually, with more infants and young children receiving formula products than ever. This Series paper describes the CMF marketing playbook and its influence on families, health professionals, science, and policy processes, drawing on national survey data, company reports, case studies, methodical scoping reviews, and two multicountry research studies. We report how CMF sales are driven by multifaceted, well resourced marketing strategies that portray CMF products, with little or no supporting evidence, as solutions to common infant health and developmental challenges in ways that systematically undermine breastfeeding. Digital platforms substantially extend the reach and influence of marketing while circumventing the International Code of Marketing of Breast-milk Substitutes. Creating an enabling policy environment for breastfeeding that is free from commercial influence requires greater political commitment, financial investment, CMF industry transparency, and sustained advocacy. A framework convention on the commercial marketing of food products for infants and children is needed to end CMF marketing.

Working with companies that manufacture breastmilk substitutes: An EAACI position paper.

Breastmilk is the optimal source of nutrition for infants and should ideally be provided exclusively for the first 6 months of life, and alongside complementary food until 2 years of life. However, there are circumstances where a breastmilk substitute (BMS) may be required. This includes maternal and/or child conditions or personal preference. Whilst these circumstances should never be used as an opportunity to promote BMS, healthcare professionals (HCPs) need to have the knowledge of suitable alternatives and should always be guided by scientific and health motives when recommending a BMS. The Task Force 'Milk Formula Industry Sponsorship' from the European Academy of Allergy and Clinical Immunology (EAACI), provides with this publication recommendations for EAACI interactions with the BMS manufacturers and how this will be supervised.

The contribution of milk substitutes to the nutritional status of children with cow's milk allergy.

BACKGROUND: The impact of alternative milk substitutes on the nutritional status of children with cow's milk allergy (CMA), the prevailing cause of food allergies, is unresolved. METHODS: A cross-sectional study was performed in children older than 2 years with IgE-mediated CMA. Patients' clinical characteristics, anthropometric measurements, dietary intake (by 3-day food diary), and biochemical markers of nutritional status were assessed. RESULTS: One hundred two children with CMA (68.6% boys; median age, 3.7 years; 51% multiple food allergies) were evaluated. 44.1% of the children consumed plant-based beverages (PBB), 19.6% therapeutic formula and 36.3% did not consume any milk substitutes. In all age groups, dietary calcium, riboflavin, and vitamin D intake of those who did not use milk substitutes were lower than those who consumed formula or PBB (p < .01). Also in the 2-3 years old age group, dietary zinc (p = .011) and iron intake (p = .004) of the formula-fed group was higher. Formula-fed patients had higher levels of 25-OH vitamin D (µg/L) and serum vitamin B12 (ng/L) than PBB-fed patients (respectively; p < .001, p = .005) and those who did not consume any milk substitute (p < .001). Patients of all ages who did not utilize a milk substitute failed to obtain an adequate amount of dietary calcium. CONCLUSION: The use of milk substitutes positively affects dietary calcium, riboflavin, and vitamin D intake in CMA, but their contribution is variable. Those who do not use milk substitutes are at greater risk inadequate of dietary calcium intake. Personalized nutritional advice, given the clinical diversity and the impact of individual differences, is required.

Postprandial metabolism and gut permeability in calves fed milk replacer with different macronutrient profiles or a whole milk powder.

Significant differences exist in the composition of current milk replacers (MR) and bovine whole milk. This study investigated how the macronutrient profile of 3 different MR formulations containing varying amounts of fat, lactose, and protein, and a whole milk powder (WP), affect postprandial metabolism and gut permeability in male Holstein calves. Sixty-four calves (45.4 ± 4.19 kg [mean ± SD] and 1.8 ± 0.62 d of age) were blocked in order of arrival to the facility and within each block, calves were randomly assigned to 1 of 4 treatments. Treatments included a high-fat MR (HF: 25.0% dry matter [DM] fat, 22.5% protein, 38.6% lactose; n = 14), a high-lactose MR (HL: 44.6% lactose, 22.5% protein, 18.0% fat; n = 17), a high-protein MR (HP: 26.0% protein, 18.0% fat, 41.5% lactose; n = 17), and WP (26.0% fat, 24.5% protein, 38.0% lactose; n = 16). Calves were fed 3.0 L (135 g/L) 3 times daily at 0600, 1200, and 1800 h with a teat bucket. Milk intake was recorded daily for the first 28 d after arrival, and blood sampling and body weight measurements were performed at arrival and on d 7, 14, 21, and 27. Gut permeability was estimated from fractional urinary excretion of indigestible markers (Cr-EDTA, lactulose, and d-mannitol) administered as a single dose on d 21 instead of the morning milk meal. Digestibility was determined simultaneously from a total collection of feces over 24 h. Postprandial dynamics were measured on d 28 by sequential blood sampling over 7.5 h. Dry matter intake of MR over 28 d was slightly greater in calves fed HL and HP than in WP. Recovery of Cr-EDTA and d-mannitol over a 24-h urine collection was greater in calves fed WP and HP than HL calves. Apparent total-tract digestibility of crude ash, protein, and fat did not differ among treatments; however, DM digestibility was lower in calves fed WP than in other treatment groups. In addition, abomasal emptying, as indicated by the area under the curve (AUC) for acetaminophen, was slower in calves fed WP than in calves fed HF and HL. The AUC for postprandial plasma glucose was lower in calves fed HL than WP and HF and lower in calves fed HP than WP. The AUC for postprandial serum insulin was greater in calves fed HP than WP and HF, whereas calves fed HL did not differ from the other treatments. Postprandial triglycerides were greater in calves fed WP, and postprandial adiponectin was higher in calves fed HL than other treatments. The high content of lactose and protein in MR had a major effect on postprandial metabolism. This raises the possibility of optimizing MR formulations to maintain metabolic homeostasis and influence development.

A comparison of total cost estimates between exclusive breast-feeding and breast milk substitute usage in humanitarian contexts.

OBJECTIVE: Using a model-based analysis, we calculated the total costs associated with the exclusive breast-feeding (EBF) and breast milk substitute (BMS) usage for one infant for six months within select humanitarian contexts to (a) determine if there is a notable difference in costs and (b) use these results to inform future creation of data-informed humanitarian response standard operating procedures. DESIGN: The inputs and costing data were drawn from a mixture of local e-commerce vendors, peer-reviewed literature and personal communications with field-based humanitarian responders. To account for cost fluctuations, each input's costs along with low and high parameters are presented. All costs are presented in 2021 United States Dollars. SETTING: Humanitarian responses within Indonesia and Jordan. PARTICIPANTS: Not applicable. RESULTS: There was a notable difference in the total cost of care in both selected locations across the study arms (Indonesia: $542; Jordan: $892). CONCLUSIONS: Given the reality of limited funding for comprehensive humanitarian response around the world and the necessity of prioritising certain interventions, humanitarian response organisations should consider the notable cost difference between EBF and BMS usage (along with the proven health benefits of EBF). This difference should play a role in informing the future creation of standard operating procedures while also ensuring that all infants within a humanitarian crisis receive appropriate feeding.

Content analysis of on-package formula labelling in Great Britain: use of marketing messages on infant, follow-on, growing-up and specialist formula.

OBJECTIVE: To explore on-package formula messaging with reference to legislation and government-issued guidance in Great Britain (GB). DESIGN: Formula products were identified, pictures of all sides of packs collated and on-package text and images were coded. Compliance with both GB legislation and guidance issued by the Department of Health and Social Care (DHSC) was assessed. SETTING: All formula packs that were available for sale over the counter in GB between April and October 2020. PARTICIPANTS: Formula packs (n 71) including infant formula, follow-on formula, growing-up formula and specialist formula were identified, coded and analysed. RESULTS: In total, 41 % of formula packs included nutrition claims, and 18 % included health claims that may be considered non-permitted, according to DHSC guidance. Additionally, 72 % of products showed images considered 'non-permitted'. Breast Milk Substitute (BMS) legislation states infant and follow-on formula packs should be clearly distinguishable but does not provide criteria to assess similarity. Based on DHSC guidance, 72 % of infant and follow-on formula packs were categorised as showing a high degree of similarity. Marketing practices not covered by current legislation were widespread, such as 94 % of infant formula packs including advertisements for follow-on or growing-up formula. CONCLUSIONS: Text and images considered non-permitted according to DHSC guidance for implementing BMS legislation were widespread on formula products available in GB. As terms such as 'similarity' are not defined in BMS legislation, it was unclear if breaches had occurred. Findings support the WHO call for loopholes in domestic legislation to be closed as a matter of urgency.

Food values drive Chinese consumers' demand for meat and milk substitutes.

Increasing consumption of alternatives to animal-based food products can have significant implications for the sustainability of global food systems. We utilize consumers' food values to identify the drivers of demand for alternative meat and milk products in China, the world's largest consumer market. Using data from 3015 Chinese consumers, we find that public food values, such as environmental impacts and animal welfare, drive consumers' demand for alternative meat and milk. We estimate that approximately 35% of urban food shoppers constitute the potential market for these products. Plant-based meat alternatives to products with strong consumption dependence, such as pork, must compete on price, while alternatives to products with weak consumption dependence, like milk, are likely to earn market premiums. We estimate that modest consumption of alternative meat and milk products in these markets can improve food system sustainability by lowering China's animal production greenhouse gas emissions by 3.4% in addition to reducing animal slaughtering and potentially decreasing health risks associated with the consumption of animal-based food products.

Gastrointestinal permeability and inflammatory status of preweaning dairy calves in response to decreasing the ratio of n-6 to n-3 fatty acid in milk replacer.

The ratio of n-6 to n-3 fatty acid (FA) is between 2 and 10 times higher in milk replacer (MR) than in whole milk, which may promote inflammation and compromise the integrity of the intestinal epithelium. To evaluate how decreasing the n-6:n-3 FA ratio of MR affects gastrointestinal (GIT) permeability and inflammatory status, 30 dairy calves (2.8 ± 1.06 d of age; mean ± standard deviation) were randomly assigned to be fed an MR with an n-6:n-3 FA ratio of 40:1 (CON; 29.3% crude fat of DM; n = 15) or 6.5:1 (n-3; 29.1% crude fat of DM; n = 15). Calves were fed 7.0 L/d in 2 meals. Calves were weighed and fecal consistency was analyzed weekly. On d 22, calves were administered Cr-EDTA, lactulose, and d-mannitol to assess GIT permeability. Blood and total urine were sequentially collected for 6 and 24 h, respectively, and analyzed for marker content. Whole blood collected 4 h after the meal was subjected to an ex vivo lipopolysaccharide (LPS) challenge to evaluate cytokine secretion from blood cells. Calves were euthanized on d 25 for collection of intestinal tissue samples. Tissue samples were processed to assess FA composition by gas chromatography, histomorphology by bright-field microscopy, and gene expression of tight junction proteins, lipid metabolism enzymes, and immune molecules by real-time quantitative PCR. Data were analyzed using PROC GLIMMIX in SAS (version 9.4, SAS Institute Inc.). Growth performance and fecal consistency were unaffected. Calves fed MR with a lower ratio of n-6 to n-3 FA had 2-fold higher n-3 FA contents and 2-fold lower ratios of n-6 to n-3 FA in proximal jejunum and ileum tissues. Total urinary recovery (0-24 h relative to marker administration) and plasma concentrations of the markers were unaffected. Expression of TJP1 tended to be higher in proximal jejunum tissue and lower in ileum tissue of n-3 calves. The expression of TLR4 and TNFA tended to be higher and CD14 was higher in ileum tissue of n-3 calves. Plasma concentrations of interleukin-4 were decreased in response to the ex vivo LPS challenge in n-3 calves. Histomorphology and GIT permeability were largely unaffected by treatment. Furthermore, the inclusion of linseed and algae oil may promote inflammation, as suggested by greater concentrations of the acute-phase proteins haptoglobin and serum amyloid A postprandially, demonstrating that fat sources should be evaluated for their suitability for MR formulations. Understanding how MR composition affects dairy calf health may improve nutritional strategies on farm.

Gastrointestinal structure and function of preweaning dairy calves fed a whole milk powder or a milk replacer high in fat.

The composition of milk replacer (MR) for calves greatly differs from that of bovine whole milk, which may affect gastrointestinal development of young calves. In this light, the objective of the current study was to compare gastrointestinal tract structure and function in response to feeding liquid diets having a same macronutrient profile (e.g., fat, lactose, protein) in calves in the first month of life. Eighteen male Holstein calves (46.6 ± 5.12 kg; 1.4 ± 0.50 d of age at arrival; mean ± standard deviation) were housed individually. Upon arrival, calves were blocked based on age and arrival day, and, within a block, calves were randomly assigned to either a whole milk powder (WP; 26% fat, DM basis, n = 9) or a MR high in fat (25% fat, n = 9) fed 3.0 L 3 times daily (9 L total per day) at 135 g/L through teat buckets. On d 21, gut permeability was assessed with indigestible permeability markers [chromium (Cr)-EDTA, lactulose, and d-mannitol]. On d 32 after arrival, calves were slaughtered. The weight of the total forestomach without contents was greater in WP-fed calves. Furthermore, duodenum and ileum weights were similar between treatment groups, but jejunum and total small intestine weights were greater in WP-fed calves. The surface area of the duodenum and ileum did not differ between treatment groups, but the surface area of the proximal jejunum was greater in calves fed WP. Urinary lactulose and Cr-EDTA recoveries were greater in calves fed WP in the first 6 h post marker administration. Tight junction protein gene expression in the proximal jejunum or ileum did not differ between treatments. The free fatty acid and phospholipid fatty acid profiles in the proximal jejunum and ileum differed between treatments and generally reflected the fatty acid profile of each liquid diet. Feeding WP or MR altered gut permeability and fatty acid composition of the gastrointestinal tract and further investigation are needed to understand the biological relevance of the observed differences.

Feeding colostrum and transition milk facilitates digestive tract functionality recovery from feed restriction and fasting of dairy calves.

The objective of this study was to evaluate the digestive tract recovery and metabolism of feeding either bovine colostrum (BC), transition milk (TM), or milk replacer (MR) after an episode of feed restriction and fasting (FRF) in dairy calves. Thirty-five Holstein male calves (22 ± 4.8 d old) were involved in a 50-d study. After 3 d of feeding 2 L of rehydration solution twice daily and 19 h of fasting (d 1 of study), calves were randomly assigned to one of the 5 feeding treatments (n = 7): calves were offered either pooled BC during 4 (C4) or 10 (C10) days, pooled TM during 4 (TM4) or 10 (TM10) days, or MR for 10 d (CTRL) at the rate of 720 g/d DM content. Then, all calves were fed the same feeding program, gradually decreasing MR from 3 L twice daily to 2 L once daily at 12.5% DM until weaning (d 42), and concentrate feed, water, and straw were offered ad libitum until d 50. Citrulline, Cr-EDTA, ß-hydroxybutyrate (BHB), and nonesterified fatty acids (NEFA) in serum and complete blood count (CBC) were determined on d -3, 1, 2, 5, and 11 relative to FRF, except BHB and NEFA at d -3. Volatile fatty acids (VFA), lactoferrin (LTF), IgA, and microbiota (Firmicutes to Bacteroidetes ratio and Fecalis prausnitzii) were analyzed in feces on d 5 and 11 before the morning feeding. Health scores were recorded daily from d -3 to d 14 as well as d 23 and 30. Feed concentrate, MR, and straw intake were recorded daily, and body weight on d -3, 1, 2, 5, and 11 and weekly afterward. Calf performance, intake, serum Cr-EDTA, CBC, fecal LTF concentrations and microbiota parameters were similar among treatments throughout the study. Serum NEFA concentrations were greater in TM4, TM10 and C10 calves compared with the CTRL ones from d 2 to 11, and after the FRF, serum concentrations of BHB were lower in CTRL calves than in the other treatments, and on d 11, serum BHB concentrations in the long treatments (C10 and TM10) remained greater than those in the shorter ones (C4 and TM4) and CTRL. Serum citrulline concentrations were similar on d -3 and 1 in all treatments, but they were greater in C4, C10, TM4, and TM10 on d 2 and 5, and on d 11 they were only greater in C10 and TM10 than in CTRL calves. Fecal IgA concentrations tended to be greater in C10 than in CTRL, TM4, and TM10 calves, and in C4 and TM10 than in CTRL animals. Fecal propionate proportion was lesser in C10 than in CTRL, TM4, and TM10 calves, while butyrate was greater in C4 and C10 than in TM4 and CTRL calves. The proportion of non-normal fecal scores of C10 fed calves was greater than TM4 and TM10 calves. Results showed that TM and BC may help to recover intestinal functionality, provide gut immune protection, and increase liver fatty acid oxidation in calves after a FRF episode.

Regulating the marketing of foods for infants and young children: Lessons from assessment of gaps in monitoring and enforcement in Thailand.

Breast milk substitute (BMS) marketing harms breastfeeding and public health. To control BMS marketing, the Member States of the World Health Organization is called upon to adopt all provisions of the International Code of Marketing of Breastmilk Substitutes (the Code) into national law. In 2017, Thailand adopted many provisions of the Code through the Control of Marketing Promotion of Infant and Young Child Food Act B.E. 2560 (the Act), including the establishment of a compliance monitoring system and enforcement mechanisms. Nevertheless, recent research showed widespread violations. This study aims to assess gaps in the monitoring system and the Act's enforcement in its first three years of operation. This qualitative research study employed in-depth interviews between April and June 2020 with 34 key informants (KIs) from the Thai government, academia and civil society organisations. KIs identified gaps in six areas that could be mitigated to increase compliance with the Act. These gaps are unclear provisions on coverage of the Act; communications with retailers and the public; lack of strong direction and processes; inadequate budget allocations; skilled and confident human resources; and external factors which facilitate BMS marketing. Recommendations may be relevant for other countries and include revising and clarifying the Act, developing targeted communication strategies; providing clear monitoring direction including through setting key performance indicators related to the Act; and providing sufficient budget and training for authorised and support officers. Strengthening the health system and workplace support for breastfeeding and social marketing would also help address wider structural factors.

Marketing of commercial milk formula during COVID-19 in Indonesia.

Baby food marketing poses a substantial barrier to breastfeeding, which adversely affects mothers' and children's health. Over the last decade, the baby food industry has utilised various marketing tactics in Indonesia, including direct marketing to mothers and promoting products in public spaces and within the healthcare system. This study examined the marketing of commercial milk formula (CMF) and other breast-milk substitute products during the COVID-19 pandemic in Indonesia. Using a local, community-based reporting platform, information on publicly reported violations of the International Code of Marketing of Breast-milk Substitutes and subsequent World Health Assembly resolutions (the Code) was collected. It was found that a total of 889 reported cases of unethical marketing of such products were recorded primarily through social media from May 20 through December 31, 2021. Our results suggest that the COVID-19 pandemic has provided more opportunities for the baby food industry in Indonesia to attempt to circumvent the Code aggressively through online marketing strategies. These aggressive marketing activities include online advertisements, maternal child health and nutrition webinars, Instagram sessions with experts, and heavy engagement of health professionals and social media influencers. Moreover, product donations and assistance with COVID-19 vaccination services were commonly used to create a positive image of the baby food industry in violation of the Code. Therefore, there is an urgent need to regulate the online marketing of milk formula and all food and beverage products for children under the age of 3.

Violations of the International Code of Marketing of Breast-milk Substitutes: a multi-country analysis.

The marketing of formula milk as a substitute for breast milk continues to be ubiquitous and multifaceted despite passage by the World Health Assembly of the International Code of Marketing of Breast-milk Substitutes (the Code) in 1981. In this paper, we summarized reports of the Code violations from eight studies using the WHO/UNICEF NetCode protocol. Among 3,124 pregnant women and mothers with young children, in eight countries, 64% reported exposure to promotion of products covered under the Code in the previous 6 months, primarily from advertisements seen outside of health facilities (62%). Nearly 20% of mothers with an infant < 6 months reported that a health care provider had advised them to feed their child food or drink other than breast milk, and 21% of providers reported contact with a representative of a formula company in the previous 6 months to distribute promotional materials, samples, or free supplies (range 2%-53%). Of the 389 retail stores and pharmacies surveyed, promotions were observed in 63% (range 0-100%), and of 1,206 labels and inserts of products reviewed, nearly half included health and/or nutrition claims (range 0-100%). A strong, though non-significant, linear relationship between the composite violations score and quality of Code legislation was found; countries with the lowest percentage of violations had the strongest Code legislation. In Latin America, over 50% of health care providers reported no knowledge of the Code, and 50% reported no knowledge of national legislation. Our study highlights three key facts: 1) the marketing of BMS is ubiquitous and multifaceted, 2) the high variability of promotion across countries generally reflects the comprehensiveness of Code legislation, and 3) health care providers have poor knowledge of the Code and national legislation.

Simulation of feed restriction and fasting: Effects on animal recovery and gastrointestinal permeability in unweaned Angus-Holstein calves.

Feed restriction and fasting experienced during commercial production negatively affect unweaned calves' behavior and health status. Transportation and stays at assembly centers are the main factors generating these disorders. For this study, 20 unweaned Angus-Holstein bull calves [44.1 ± 2.04 kg of body weight (BW) and 14.7 ± 0.63 d of age (± standard error)] were used to evaluate the effects of feed restriction and fasting on performance, energy status [serum concentration of glucose, ß-hydroxybutyrate (BHB), and nonesterified fatty acids], and gastrointestinal permeability [serum concentration of citrulline, chromium (Cr)-EDTA, lactulose, and d-mannitol]. Calves were randomly assigned to 1 of 4 treatments that simulated the feed restrictions of an assembly center situation on one hand, and the fasting hours during transportation on the other. Treatments were as follows. Control (CT): from d -4 to -1, calves were fed 2.5 L of milk replacer (MR) twice daily; concentrate and straw were offered ad libitum. Mild (MD): calves were fed only MR (d -4 to -1) as described for CT, and on d -1 calves were subjected to a 9-h feed withdrawal. Moderate (MO): calves were fed only MR (d -4 to -1) as described for CT and on d -1 subjected to a 19-h feed withdrawal. Severe (SV): calves were fed only 2.5 L of a rehydrating solution twice daily (d -4 to -1) and on d -1 subjected to a 19-h feed withdrawal. From d 0 to d 42 (weaning) all calves were fed the same feeding program (MR, concentrate, and straw ad libitum). Results showed that BW was greater for the CT treatment compared with the others from d 0 to d 7, whereas BW of SV was lesser compared with the others from d -1 to d 7. No differences among treatments were observed at weaning. At d 2 concentrate intakes of MD, MO, and SV were lesser compared with CT. By d 4, concentrate intake of SV was similar to that for CT and greater than MD and MO. Similarly to BW, no differences in concentrate intake among treatments were observed at weaning on d 42 of the study. At d -1 for SV and d 0 in all restricted calves, serum glucose concentration was lesser compared with CT. At d -1 and 0, nonesterified fatty acids and BHB serum concentrations were greater in the SV calves compared with the other treatments. By d 2, serum concentrations of nonesterified fatty acids, BHB, and glucose were restored to CT levels. At d -1 serum citrulline concentration was lesser in SV and greater in MD calves. The CT calves had lower serum concentrations of Cr-EDTA (d -1 and d 0), lactulose (d 0), and d-mannitol (d 0) compared with the other restricted calves. Results showed that degree of dietary restriction, type of liquid diet (MR or rehydrating solution), and fasting hours (9 vs. 19 h) affected calves' BW, concentrate intake, and serum concentration of markers indicative of energy status and gastrointestinal permeability.

Effect of milk replacer feeding rate and frequency of preweaning dairy calves in the southeastern United States: Glucose metabolism.

The objective of this experiment was to examine the effect of milk replacer (MR) feeding rate (FR) and frequency (FF) on glucose metabolism before and after weaning during summer and winter in the subtropical climate of the southeastern United States. Holstein calves (n = 48/season) were enrolled at 8 d of age (DOA) in the summer (June to August, body weight = 40.6 ± 0.7 kg) and winter (November to January, body weight = 41.9 ± 0.8 kg). In each season, calves were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement including 2 FR [0.65 (low) or 0.76 kg of solids/d (high) of a 26% CP and 17% fat MR] and 2 FF [2× (0700 and 1600 h) or 3× (0700, 1600, and 2200 h)]. Calves were managed similarly and housed in polyethylene hutches bedded with sand. Milk replacer (12.5%) was fed based on treatments until 42 DOA when FR was reduced by half and offered 1×/d (0700 h) for 7 d. Plasma was collected weekly at 1400 h for analyses of glucose and insulin concentrations in all calves. Pre- and postprandial glucose and insulin concentrations of a subset of calves (n = 10/treatment per season) were measured on 20 DOA. A subset of calves (n = 8/treatment per season) was subjected to an intravenous glucose tolerance test (GTT) on 27 and 57 DOA and insulin challenge on 28 and 58 DOA at 1030 h. Average ambient temperature was 26.1 ± 2.2°C in summer and 12.9 ± 5.4°C in winter. During the preweaning period in both seasons, feeding high increased plasma glucose concentrations compared with low, and increasing FF reduced basal insulin concentrations. Compared with 2×, feeding 3× did not affect postprandial glucose but lowered insulin in the summer, whereas in the winter, increased glucose from 30 to 180 min but lowered insulin from 240 to 420 min after MR feeding. Following GTT before weaning in both seasons, 3× reduced insulin increment and area under the curve compared with 2× without affecting glucose disposal. After weaning, treatment did not affect glucose disposal or insulin responses after GTT during winter, but calves fed 3× had faster glucose disposal and stronger insulin responses than 2× during summer. In both summer and winter, preweaned calves fed 3× had greater decrement and area under the curve of plasma glucose after insulin challenge, suggesting enhanced peripheral tissue insulin response compared with 2×. This effect persisted after weaning only during summer. Increasing FR had no effect on metabolic responses in both seasons. In conclusion, increasing MR FF from 2 to 3 times per day reduced insulin secretion but enhanced insulin response on peripheral tissues of preweaned calves regardless of season.

Effects of milk replacer feeding rate and frequency of preweaning dairy calves in the southeastern United States: Performance, abomasal emptying, and nutrient digestibility.

To evaluate the effects of milk replacer (MR) feeding rate (FR) and frequency (FF) on performance, abomasal emptying, and nutrient digestibility in the southeastern United States, Holstein calves (n = 48/season) were enrolled at 8 d of age (DOA) during summer [June to August, body weight (BW; mean ± SD) = 40.71 ± 4.35 kg] and winter (November to January, BW = 42.03 ± 3.83 kg). Within season, calves were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement including 2 FR [0.65 (low) or 0.76 kg of solid per day (high) of a 26% crude protein and 17% fat MR], and 2 FF [2× (0700 and 1600 h) or 3× (0700, 1600, and 2200 h) daily]. Calves were housed in polyethylene hutches and managed similarly throughout the trial. Milk replacer (12.5% solids) was fed to calves based on their respective treatments until 42 DOA, when MR allowance was reduced by 50% and offered once a day (0700 h) for the following 7 d until weaning. Calves remained on trial until 63 DOA. Calf starter and water were offered ad libitum. Ambient temperature and relative humidity inside and outside hutches were measured hourly. Starter and MR intakes were recorded daily. Respiration rate and rectal temperature were recorded 3 times a week. Structural growth and BW were measured weekly. Acetaminophen (50 mg/kg of BW) mixed with MR was fed to a subset of calves (0700 h, n = 10/treatment per season) on 20 DOA. Plasma was collected at 15, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 420, and 480 min after feeding, to analyze acetaminophen. The acetaminophen concentration-time curve was modeled to the first derivative of Siegel's modified power exponential equation, and the time for plasma acetaminophen to reach maximum (Tmax) was calculated to evaluate abomasal emptying rate. During the pre- (14.9-17.9 DOA) and postweaning (51.0-54.0 DOA) periods, a subset (n = 8/treatment per season) of calves was used to determine the apparent digestibility of nutrients, using chromic oxide as the external marker. Feeding 3× reduced preweaning respiration rate during summer and reduced rectal temperature during winter. Increasing FR improved BW gain and structural growth. Feeding more times per day tended to improve growth during winter but not summer. We found no effect of treatment on nutrient digestibility. Increasing FR had no effect on Tmax during winter but tended to delay Tmax of plasma acetaminophen during summer. Regardless of season, increasing FF lowered Tmax of plasma acetaminophen. In conclusion, increasing FF accelerated abomasal emptying and might reduce heat load of preweaning dairy calves but improved growth only during winter. Increased MR allowance improved growth in both seasons but delayed abomasal emptying only under heat stress conditions.

Transition milk stimulates intestinal development of neonatal Holstein calves.

Colostrum stimulates gastrointestinal development. Similar to colostrum, transition milk (TM; the first few milkings after colostrum) contains elevated nutrient levels and bioactive components not found in milk replacer (MR), albeit at lower levels than the first colostrum. We hypothesized that feeding neonatal calves TM, compared with MR, for 4 d following colostrum at birth would further stimulate intestinal development. Holstein bull calves were fed 2.8 L of colostrum within 20 min of birth, allocated to 1 of 11 blocks based on birth date and body weight (BW), randomly assigned to MR (n = 12) or TM (n = 11) treatments within block, and fed treatments 3 times per day. Milk from milkings 2, 3, and 4 (TM) of cows milked 2 times daily was pooled by milking number and fed at 1.89 L per feeding; milking 2 was fed at feedings 2 through 5, milking 3 at feedings 6 through 8, and milking 4 at feedings 9 through 12. TM was not pasteurized and contained 17% solids, 5% fat, 7% protein, 4% lactose, and 20 g of IgG per liter on average, whereas MR (as fed) contained 15% solids, 4% protein, 3% fat, 6% carbohydrate, and no IgG. Refusals were similar, so calves fed TM consumed 1.0 Mcal of metabolizable energy per day more than those fed MR. On the morning of d 5, calves were injected i.v. with 5 mg of bromodeoxyuridine per kg of BW and slaughtered 130 min later; then, intestinal sections were excised. Feeding TM, instead of MR, doubled villus length, villus width, villus to crypt ratio, and mucosal length in all intestinal sections, increased submucosal thickness 70% in the proximal and mid jejunum, and tended to increase submucosal thickness in duodenum and ileum. Mucosal surface area was also increased in both the ileum and mid jejunum when feeding TM by 19 and 36%, respectively. Treatment did not alter crypt depth. Bromodeoxyuridine labeling was increased 50% by TM compared with MR in the cells along the epithelium of the crypts and within the villi of all sections, indicating that TM increased cell proliferation compared with MR. Calves fed TM gained more BW than calves fed MR and had improved cough, fecal, nose, and ear scores. We conclude that feeding TM for 4 d following an initial feeding of colostrum stimulates villus, mucosal, and submucosal development in all sections of the small intestine in the first few days of life and improves health and growth.

Macronutrient profile in milk replacer or a whole milk powder modulates growth performance, feeding behavior, and blood metabolites in ad libitum-fed calves.

Milk replacers (MR) for calves usually contain more lactose and less fat than bovine whole milk (WM). There are insufficient data to determine whether these MR formulations are optimal for calves fed at high planes of nutrition. Thus, the effect of 3 MR formulations and a WM powder were evaluated on growth, feeding behavior, and blood metabolites in 96 male Holstein calves fed ad libitum and with 45.5 ± 4.30 kg (mean ± standard deviation) BW at arrival. Calves were blocked based on arrival sequence, and randomly assigned within block to one of the 4 treatments (n = 24 calves/group): a high-fat MR (25.0% fat, dry matter basis; 22.5% protein, 38.6% lactose; 21.3 MJ/kg; HF), a high lactose MR (44.6% lactose, 22.5% protein, 18.0% fat; 19.7 MJ/kg; HL), a high protein MR (26.0% protein, 18.0% fat, 41.5% lactose; 20.0 MJ/kg; HP), and a WM powder (26.0% fat; 24.5% protein, 38.0% lactose; 21.6 MJ/kg; WP). In the first 2 wk after arrival, calves were individually housed and were fed 3.0 L of their respective liquid feed 3 times daily at 135 g/L. They were then moved to group housing and fed ad libitum until d 42 after arrival. Weaning was gradual and took place between d 43 and 70 after arrival; thereafter, calves were fed solids only. Concentrates, chopped straw, and water were available ad libitum throughout the study. Body weight was measured, and blood was collected at arrival and then weekly thereafter from wk 1 to 12. Weight gain and height were greater in HL than WP calves. In the preweaning phase, HL and HP-fed calves consumed more milk than WP, and HL-fed calves consumed more milk than HF calves. In wk 10, starter feed intakes were lower in HF calves than in the other groups. In the preweaning phase, ME intakes were the same for all treatments. This suggests that milk intakes were regulated by the energy density of the milk supplied. The percentage of calves requiring therapeutic interventions related to diarrhea was greater in WP-fed calves (29%) than HF and HL calves (4%), whereas HP (13%) did not differ with other groups. This was coupled with lower blood acid-base, blood gas, and blood sodium in WP than in MR-fed calves. Calves fed HF had greater serum nonesterified fatty acids compared with other groups, and greater serum amyloid A compared with WP and HL calves. Among the serum parameters, insulin-like growth factor-1 and lactate dehydrogenase correlated positively with ME intake and average daily gain. The high lactose and protein intakes in HL and HP calves led to greater insulin-like growth factor-1 concentrations than in WP-fed calves. Although growth differences were limited among MR groups, the metabolic profile largely differed and these differences require further investigation.