Fat Milk Replacer Research Articles

Monitoring mammary gland development in preweaned dairy heifers using ultrasound imaging

Existing literature on the long-term effects of nutritional manipulation on milk production is incomplete and inconsistent as animals are typically culled before lactation. In addition, longitudinal studies are rarely conducted due to high costs and constraints related to tissue sampling; therefore, additional research is necessary to better understand the effect of early nutrition and growth on subsequent growth and milk production. Thirty Holstein heifer calves were pair-fed high (H; 22% crude protein and 15% fat) or low (L; 27% crude protein and 20% fat) milk replacers. Mammary gland ultrasound images and body weights were collected twice weekly, and blood samples weekly, for the first 8 weeks of life. Calves fed H had higher average daily gain (ADG) and mammary gland growth through 8 weeks of life. Calves from the H group also had larger fat pads at 8 weeks of age. Glucose and insulin concentrations were increased in H calves compared with L calves, whereas NEFA concentrations were not different between treatments. Our results suggest that ultrasound is a practical, noninvasive tool to monitor udder development preweaning, although additional research is necessary to improve image analysis techniques to analyze tissue composition. Our preliminary work provides data suggesting that the use of mammary gland ultrasound could provide a method of longitudinal analysis of the effects of preweaning nutrition on milk production.

Replacement of milk fat by rapeseed oil stabilised emulsion in commercial yogurt

The incorporation of lipid droplets and further characterization of matrices within dairy products may be possible using such adjacent particles as protein complexes/lipids. Among the range of varied emulsions and their functionalities, great attention has recently focused on the fabrication of high internal phase types. Feasibly, stable alternatives structured with health-beneficial lipids like those derived from plants could replace saturated fatty acids. As a fat replacement strategy, the fate of incorporated HIPE would require some adjustments either with storage stability and/or structural feat for the food matrix. Therefore, the replacement of milk fat by rapeseed oil stabilised emulsion in commercial yogurt was investigated. This involved 25%, 50% and 75% rapeseed oil respectively assigned as low (LIPE), medium (MIPE), and high internal phase emulsion (HIPE). Specifically, emulsions were examined by droplet size, encapsulation, pH, zeta potential, phase separation, and rheology. The fat free yogurt supplemented by HIPE were examined by droplet size, zeta potential, pH, color, sensory, texture and microbiological aspects against positive (regular milk fat) and negative (fat free) yogurt controls. Results showed increasing rapeseed oil contents would form smaller droplet-like emulsions. Within the yogurt matrix however, incorporating HIPE would seemingly reduce oil droplet size without much compromise to bacterial viability, sensory, or texture. Overall, this simple method of lipid alternation shows promise in dairy products.

Fat composition of milk replacer influences growth performance, feeding behavior, and plasma fatty acid profile in ad libitum–fed calves

Fat composition in milk replacers (MR) for calves differs from bovine milk fat in multiple ways. The aim of the study was to investigate the impact of different approaches of formulating fat in MR on growth, ad libitum intakes of MR and solid feeds, as well as blood metabolites in dairy calves. Upon 24 to 96 h after birth, 63 calves were acquired from dairy farms and incorporated into the study. Calves were blocked based on arrival day and randomly assigned within each block to one of 3 treatments differing in MR fat composition (n = 21 per group): VG was based on vegetable fats including 80% rapeseed and 20% coconut fats; AN was formulated with animal fats including 65% lard and 35% dairy cream; and MX with a mixture of 80% lard and 20% coconut fats. All 3 MR contained 30% fat, 24% crude protein, and 36% lactose and were formulated to have a fatty acid profile resembling that of milk fat. From arrival onward (3.1 ± 0.84 d of age; means ± standard deviation), calves were group housed and were offered an ad libitum supply of MR at 135 g/L (13.5% solids). Weaning was gradual and induced between wk 7 and 10, after which calves were fed only solid feeds. Starter feed, chopped straw, and water were offered ad libitum throughout the study. Calves were weighed, and blood was collected weekly until d 84 after arrival. Preweaning average daily gain was greater in calves fed AN (915 g/d) than other treatments (783 g/d), whereas no differences were detected in the weaning and postweaning phases. Preweaning MR intake was greater in calves fed AN than MX from wk 2 to 6 and was also higher in calves fed AN than VG in wk 5 and 6. Consistently, the number of rewarded visits during the ad libitum phase was greater in calves fed AN than MX, whereas VG showed no differences. This led to a higher preweaning total metabolizable energy intake in calves fed AN than in calves fed VG and MX. Serum cholesterol was higher, and serum albumin was lower in calves fed VG than other treatments. The proportion of high-density lipoprotein cholesterol in total plasma cholesterol was lower and that of low-density lipoprotein (LDL) cholesterol was higher in calves fed VG compared with other treatments. Overall, the fatty acid profile of plasma largely mirrored the MR fat composition during the preweaning period. Feeding AN enhanced MR intake and improved preweaning growth compared with other treatments. Feeding VG resulted in a marked increase in plasma cholesterol, particularly in the form of LDL cholesterol, which could be linked to an excessive intake of polyunsaturated fatty acids. These findings underscore the importance of formulating the fat content of MR to be similar to bovine milk fat.

PSIII-3 Effects of Milk Replacer Composition on Beef X Dairy Calf Growth and Muscle Fiber Cross-Sectional Area

Abstract Increased availability of female-sexed semen for the generation of replacement heifers within the dairy industry has expanded the opportunity for production of crossbred beef x dairy (BxD) calves. However, data evaluating feeding strategies for BxD calves are limited. The objective of this study was to determine the effects of two different milk replacers on muscle growth of BxD calves compared with dam-reared Angus calves. We hypothesized that both male and female BxD calves fed added fat and protein through milk replacer would have muscle fiber cross-sectional area (CSA) similar to that of purebred Angus calves. SimAngus x Holstein calves (n = 40) were assigned to one of two treatments: a) additional 32.0% crude protein (CP), 30% crude fat (CF) milk replacer (ADD, n = 10 males, 10 females), or b) control 22% CP, 20% CF milk replacer (CON, n = 10 males, 10 females). BxD calves were fed milk replacer 3 times daily from 0 to week 8 of age. BxD calves received starter grain and hay ad libitum at ±3 days of age. Twenty Angus calves (n=10 males, 10 females) were group housed in cow-calf pairs with ad libitum access to maternal milk. Calves were weighed within 24 h of birth. Longissimus muscle biopsies were performed on week 2 and 8. Samples were cryosectioned, stained with wheat germ agglutinin, and analyzed for muscle fiber CSA. Body weight and CSA were analyzed with PROC MIXED of SAS with animal as the subject and fixed effects of treatment, breed, age, sex, and their interactions. Repeated measures analysis was used for CSA. At birth, Angus calves were 24% lighter than BxD (P < 0.0001). Females were 8% lighter than males for both breeds (P ≤ 0.02). At week 2 of age, CSA of ADD BxD calves was 16% smaller than Angus or CON BxD calves (P ≤ 0.07). At week 8 of age, relative to CON, Angus calves had 22% larger CSA (P = 0.02) and ADD BxD calves had 17 % larger CSA (P = 0.07). There was no difference detected in CSA between Angus and ADD calves (P = 0.54). In conclusion, feeding milk replacer with additional CF and CP may increase muscle growth in BxD calves.

Encapsulating capacity of ultra-high-pressure homogenization (UHPH): Replacement of milk fat by vegetable oils using buttermilk as a functional ingredient in yogurt processing

This study investigated the characteristics of yogurts produced by substituting dairy fat with polyunsaturated fatty acids (PUFA)-rich oils encapsulated with buttermilk (BM) in spray-dried emulsions (SDE). Two homogenization methods, conventional (CH) and ultra-high-pressure homogenization (UHPH), were compared to obtain the emulsions for spray drying. Recombined milks (RMs) were formulated using two different concentrations (4 g/100 g and 6 g/100 g) of SDE, followed by fermentation. Yogurt characteristics were evaluated during cold storage using various parameters, including coagulation properties, texture and rheology, microstructure, physicochemical characteristics (color, pH, total acidity, and water holding capacity), oxidative stability, main fatty acid profile, microbial assessment, and sensory evaluation. During cold storage, several parameters significantly influenced the yogurt characteristics. The CH yogurts exhibited higher textural parameters (firmness and consistency) and viscoelastic parameters (G′ and G'') compared to the UHPH yogurts at the same SDE concentration. However, UHPH yogurts generally showed better water holding capacity (WHC) values. UHPH yogurts also demonstrated superior stability to oxidation and higher PUFA content. The observed differences between the CH and UHPH treatments can be attributed to the structuring of fat-protein-BM into colloidal particles based on the homogenization system employed in this study. Neither of the homogenization systems nor the SDE content impacted yogurt flavor.

Formulation, Characterization and Storage Stability of Prickly Pear (Opuntia ficus) Fruit and Milk Based Fermented Beverage

Background: Fermented milk based beverages are popular all over the world and cherished by people of all ages. Health conscious consumers nowadays desire for beverages with enhanced functionality. Prickly pear fruit crop having resilience to grow in arid and semi-arid lands, possess excellent antioxidant and natural food colorant potential. Present investigation was an attempt to combine prickly pear fruit with fermented milk. Methods: Effect of milk fat, pulp level and sugar replacement with low calorie sweetener was investigated on the sensory acceptability. Optimized prickly pear fruit and milk based beverages was evaluated for nutritional, colour, antioxidant properties and consumer acceptance. Stability of pear fruit and milk based beverage under refrigeration storage was analyzed. Result: Consumer acceptability test (n=100) of selected formulation indicated wide acceptability with overall liking score of 8.17±0.05 on a 9-point hedonic scale. Antioxidant potential of optimized prickly pear fruit and milk based beverage was significantly higher (648±6.11 TEAC/g) than the control samples (410.33±5.49 TEAC/g). Packed beverage in glass bottles remained acceptable up to 9th day.

Effects of milk fat substitution by canola oil on the properties of high-fat high-protein yoghurt

High-fat high-protein yoghurts [9% fat, 8.2% protein (w/w)] with substitution of milk fat by canola oil were produced. The effects of milk fat substitution (0–100%) and milk homogenisation pressure (10 or 35 MPa) on the texture, syneresis, and rheological properties were evaluated. The aroma profile after 0, 14, and 28 days of storage (5 °C) was also determined. Increasing the proportion of canola oil reduced the firmness and increased the syneresis of yoghurt, but had no effect on the elastic and viscous modulus at 1 Hz. Increasing milk homogenisation pressure increased yoghurt firmness, elastic and viscous modulus, and apparent viscosity because smaller droplets were better embedded into the yoghurt structure. The substitution of milk fat by canola oil and storage time affected the yoghurt aroma profile. Some impacts of milk fat replacement by canola oil could be overcome using a higher homogenisation pressure.

Effects of Coconut Oil and Palm Oil on Growth, Rumen Microbiota, and Fatty Acid Profile of Suckling Calves.

This study aimed to evaluate the effects of coconut oil and palm oil in milk replacer (MR) on the growth performance, blood lipids, rumen fermentation, rumen microbiota, and fatty acid profile of hepatic and muscle of suckling calves. Thirty-six Holstein male calves were randomly assigned to three treatments. Three milk replacers containing different fat sources were as follows: control group (CON, milk fat), coconut oil group (CCO, coconut oil powder as fat), and palm oil group (PLO, palm oil powder as fat). Calves were weighed and blood sampled at 14, 28, 42, and 56 days old, respectively, and the feed intake and fecal score were recorded daily. Fat sources in milk replacers had no effects on body weight, ADG, DMI, fecal score, or days of abnormal fecal in suckling calves among the three groups, while the PLO group tended to decrease starter intake compared with the other groups. Serum concentrations of TC, HDL-C, LDL-C, and VLDL-C in the CCO group increased compared with those of the CON group. Palm oil also decreased the serum GLU concentration of calves but had no effects on serum lipids compared with milk fat. Coconut oil or palm oil had no effects on rumen fermentation, rumen chyme enzyme activity, rumen bacterial community richness and diversity, and dominant phyla and genera when compared with milk fat. However, compared with the CON group, the CCO group increased the proportion of MCFAs and n-6 PUFAs, and decreased the proportion of UFAs and MUFAs in liver tissue, while the PLO group increased the proportion of PUFAs and decreased the proportion of n-3 PUFAs in liver tissue. In addition, compared with the CON group, the CCO group increased the proportion of MCFAs, and decreased the proportion of UFAs and n-3 PUFAs in longissimus dorsi, while the PLO group increased the proportion of PUFAs and decreased the proportion of n-3 PUFAs in longissimus dorsi. In conclusion, compared with milk fat, coconut oil or palm oil in MR had no effects on growth performance, rumen fermentation, and rumen microflora but significantly increased serum lipids concentration and changed some proportions of MCFAs and PUFAs in liver and longissimus dorsi in suckling calves. These results indicate that coconut oil or palm oil as the sole fat source for MRs has no adverse effect on calf rumen fermentation and rumen microbiota but has a detrimental effect on n-3 PUFAs deposition in the liver and longissimus dorsi muscle.

Ice cream supplemented with roasted and grilled corn powders: Physical properties, rheology, antioxidant activity, color, sensory evaluation, and production cost

The present study aimed to evaluate the effects of replacing milk fat with roasted and grilled corn powders on ice cream characteristics. The results revealed that the use of roasted and grilled corn powders (2, 4, and 6%) resulted in significant changes in the physical and rheological properties of ice cream mixtures. The different levels of corn powders caused an increase in the total phenolic compounds and antioxidant activity, while a diverse manner was observed with the progress in storage period. Furthermore, the melting resistance of ice cream treatments significantly increased coinciding with the increase in roasted or grilled corn powders addition levels. In addition, roasted corn powder based-ice cream treatments recorded higher sensory evaluation scores compared to other treatments. The production cost and profit of the produced ice cream were also evaluated, and treatments supplemented with corn powders exhibited lower production cost as compared to the control sample.

Effect of partial exchange of lactose with fat in milk replacer on performance and blood metabolites of Holstein calves

The objective of this study was to determine the effect of dietary energy source (fat vs. carbohydrate) in calf milk replacer (MR) on growth performance parameters and feed intake in rearing calves. In a randomized complete block design, 68 Holstein calves [40 females and 28 males; (mean ± SD) body weight (BW): 43.7 ± 1.43 kg] were assigned to 17 blocks of 4 calves based on birth date and parity of the dam. Within each block, calves were randomly assigned to 1 of 2 treatments: a high-lactose MR (HL; 17% fat; 44% lactose; n = 34), or a high-fat MR (HF; 23% fat; 37% lactose; n = 34). Lactose was exchanged for fat on a weight per weight basis, resulting in a 6% difference in metabolizable energy density per kilogram of MR. The feeding plan started with 6 L/d for 7 d, then 8 L/d for 35 d, 6 L/d for 7 d, and finally, 4 L/d for 7 d. Milk replacer allowances were offered in 2 meals per day at 140 g/L. Measurements included daily MR, starter and straw intakes, weekly BW, and blood metabolites, including nonesterified fatty acids (NEFA) and glucose, on wk 4, 6, 8, and 10. Increasing fat at the expense of lactose did not affect MR intake or solid feed intake during the preweaning and weaning periods. However, HF calves tended to consume more solid feed than HL calves during the postweaning period (2.63 ± 0.08 vs. 2.52 ± 0.08 kg/d). Additionally, average daily gain (HF = 0.78 ± 0.02, HL = 0.77 ± 0.02 kg/d) and final BW (HF = 98.8 ± 1.53, HL = 97.7 ± 1.57 kg) were not affected by MR composition. Nevertheless, NEFA concentration was higher in HF calves than in HL calves (0.21 ± 0.01 vs. 0.17 ± 0.01 mmol/L), and glucose concentration was higher in HF calves (6.52 ± 0.23 vs. 5.86 ± 0.23 mmol/L). Under the conditions of this study, HF calves consumed similar amounts of solid feed and grew comparably to the HL calves; however, the isonitrogenous replacement of lactose by fat had evident metabolic effects, such as increased blood NEFA and glucose concentrations.

Portable NIR spectrometer and chemometric tools for predicting quality attributes and adulteration levels in butteroil

Butteroil is valuable product appreciated for its sensory characteristics, economic importance, and social/cultural significance, as it has similarities in several regions of the world. Due to its high added value, this product is susceptible to adulteration by replacing authentic butteroil with other cheaper fats, or even by expired butteroil. Detection of butteroil adulteration demands chemical methods that are laborious and produce residues. Therefore, the aim of this study was to investigate the potential of a portable near-infrared (NIR) spectrometer for rapid detection of adulteration in butteroil produced in Brazil and prediction of quality attributes (acidity and peroxide index). DD-SIMCA and SVM-C classification models showed Accuracy >90%, for investigating adulteration in butter and discerning the type of adulterant. PLS and SVM-R regression models demonstrated excellent ability to predict the percentage of milk fat replacement by other fats (RPD >3.0) and can be applied to provide a quick estimate of acidity and peroxide values (RPD = 2.0–2.5). These results show that a portable NIR spectrometer is a reliable tool to identify adulteration and predict attributes in butteroil and could be used by producers and inspection agencies for quality control of butteroils at any stage of the supply chain.

Soybean Oil Bodies as a Milk Fat Substitute Improves Quality, Antioxidant and Digestive Properties of Yogurt.

In this experiment, the effect of replacing milk fat with soybean fat body (25%, 50%, 75%, 100%) on the quality, antioxidant capacity and in vitro digestive characteristics of yogurt was investigated while maintaining the total fat content of the yogurt unchanged. The results showed that increasing the substitution amount of soy fat body for milk fat had little effect on the pH and acidity of yogurt during the storage period, while the physicochemical properties, degree of protein gel network crosslinking, saturated fatty acid content, PV value and TBARS value of the yogurt significantly decreased (p < 0.05). Meanwhile, protein content, solids content, unsaturated fatty acid content, tocopherol content and water holding capacity significantly increased (p < 0.05). Flavor analysis revealed that yogurts with soybean oil bodies were significantly different when compared to those without soybean oil bodies (p < 0.05), and yogurt with 25% substitution had the highest sensory score. After in vitro digestion, the free fatty acid release, antioxidant capacity and protein digestibility of soybean oil body yogurt were significantly higher (p < 0.05). The SDS-PAGE results showed that the protein hydrolysis of the soybean oil body yogurt was faster. Therefore, the use of an appropriate amount of soybean oil bodies to replace milk fat is able to enhance the taste of yogurt and improve the quality of the yogurt.

Recent developments and prospects in the extraction, composition, stability, food applications, and in vitro digestion of plant oil bodies

AbstractOil bodies (OBs) are micron‐ or submicron‐sized sub‐organelles widely found in plants seeds and nuts. The structure of OBs is composed of a core of neutral lipids covered by a phospholipid‐protein layer, which ensures the stability of OBs under extreme environmental conditions and further protects core lipids as energy reserves. As naturally pre‐emulsified oil‐in‐water emulsions, OBs have been gradually applied to replace synthetically engineered oil droplets. In this paper, the recent research on the extraction, composition, stability, food applications, in vitro digestion, and future perspectives of plant OBs were reviewed. Recent studies have focused on the large‐scale extraction techniques and OBs surface protein identification and function. Electrostatic deposition and viscosity effect of polysaccharides significantly improve the stability of OBs emulsions. OBs have broad application prospects in replacing milk fat droplets, as fat replacers and delivery vehicles, and fabricating emulsion‐gels, oleogels or edible films. Notably, oleosins present a potential allergen risk. OBs are digested slowly, resulting in increased satiety and effectively helping to reduce calorie intake, but this can negatively affect the bioaccessibility of nutritional compounds in OBs. When OB as a delivery vehicle, its natural structure may be disrupted, whereas OBs‐based delivery system facilitates the bioaccessibility of hydrophobic active compounds.

The effect of fat replacement by whey protein microcoagulates on the physicochemical properties and microstructure of acid casein model processed cheese

Attempts to minimise fat content in popular food products have been made in the past. Research shows that microcoagulated forms of whey proteins can replace fat; they are capable of thickening the cheese mass and act as fat mimetics. This study investigated the effect of whey protein microcoagulates, as a fat replacer, on the textural, rheological properties, meltability, and microstructure of model processed cheese prepared using acid casein. Partial replacement of anhydrous milk fat with whey protein microcoagulates (3–8%) increased hardness and viscosity of model processed cheeses. Storage modulus (G′) was higher than the loss modulus (G″) during the whole experiment. The observed change in physicochemical properties, demonstrated by higher viscosity or ample meltability, suggests that whey protein microcoagulates can be utilised as a potential fat replacer in processed cheese.

Effects of feeding Saccharomyces cerevisiae fermentation products on the health and growth performance of Holstein dairy calves

It is essential to reduce antibiotic use in the livestock industry, which leads to a need for alternatives to antibiotics that reduce illness and promote growth in dairy calves. The objective of this study was to evaluate the effect of feeding dairy calves Saccharomyces cerevisiae fermentation products (SCFP) on average daily gain (ADG) and antibiotic use in dairy calves through 4 mo of age. Holstein bull calves (n = 60; 5 ± 3 d old) were blocked by body weight (BW) and serum total protein (STP) and assigned to 1 of 2 treatments. The control treatment (CON) fed a 24% crude protein (CP):17% fat milk replacer (MR), calf starter, grower #1, and grower #2 with no SCFP added. The SCFP treatment fed the same MR with 1 g/d of SCFP, calf starter with 0.8% (dry matter; DM) SCFP, grower #1 with 0.44% (DM) SCFP, and grower #2 with 0.275% (DM) SCFP. Calves were offered 2.84 L (12.5% solids) of MR twice daily (0630 and 1630 h) through d 51 and MR once daily (0630 h) from d 52 to 56, and were weaned on d 57. From d 1 to 56, calves also received ad libitum access to calf starter and water. On d 57, calves were switched to grower #1 and on d 84, calves were switched to grower #2, which contained a lower level of CP and a higher level of neutral detergent fiber (NDF). Individual calf BW, body condition score (BCS), hip height (HH), and hip width (HW) were measured biweekly from d 0 to 112. Feed intake was recorded daily, and feed efficiency (gain:feed) and ADG were calculated. Daily fecal and respiratory scores were recorded for each calf through d 56, and all medical interventions were recorded for the duration of the study and grouped based on illness. We found no effect of treatment on STP, BW, BCS, HH, or HW at d 0 or 56, nor effects on preweaning ADG and feed efficiency. No treatment effect was observed for BCS or HH at d 112; however, BW and HW were increased in SCFP calves at d 112. A treatment tendency was observed for postweaning ADG, with SCFP calves being larger than CON calves and SCFP calves having improved feed efficiency compared with CON calves after weaning. A treatment effect was observed for respiratory treatments postweaning, with SCFP calves being treated less frequently than CON calves. Our results suggest that feeding SCFP to calves improves postweaning growth and feed efficiency, and reduces postweaning respiratory disease interventions.

Improving Health Benefits, Nutritional Value and Quality Attributes of Low Fat Ice Milk Made from Camel ’s Milk And Defatted Chia Seeds Flour

Defatted chia seeds flour (DCSF) was prepared and its chemical composition and some functional properties were assessed. Nine chocolate ice milk batches were prepared to study the effect of replacing milk fat with DCSF. Control ice milk contained 4% fat, while the other 8 batches were prepared by replacing 25, 50, 75 and 100% of milk fat with DCSF either at the rate of 50 and 100% of substituted fat. Replacement of milk fat with the same amount of DCSF increased specific gravity, weight per gallon and viscosity, while decreased the freezing point of ice milk mixes. On the other hand substitution of milk fat with DCSF increased melting resistance, total protein, ash content and titratable acidity of ice milk treatments. This increase was more obvious by replacing with fat with the same amount of DCSF than those of ice milk treatments made by replacing milk fat with DCSF at the rate of 50% of substituted fat. Total solids, total protein and ash content and acidity of ice milk treatments did not change significantly during storage period. Replacing milk fat up to 50% with the same amount of DCSF increased the overrun and total scores of organoleptic properties, while increasing the rate of replacement above 50% reduced the overrun and scores of organoleptic properties. Ice milk treatment T22 that made with replacing 50% of milk fat with the same amount of DCSF gained the highest total score of organoleptic properties and was most acceptable ice milk treatment. Treatment T31 that made with replacing 75% of milk fat with 37.5% of DCSF exhibited higher total score than control ice milk. Therefore, it is possible to milk a good quality low fat ice milk by decreasing 50% of milk fat with 50% of DCSF and / or reducing 75% of milk fat with 37.5% of DCSF.

Effects of feeding Saccharomyces cerevisiae fermentation products on the health of Holstein dairy calves following a lipopolysaccharide challenge

Before weaning, dairy calves are at high risk for illness, especially respiratory and digestive diseases, which reduces average daily gain, age at first calving, and first-lactation milk production. Although these illnesses are commonly treated with antibiotics, efforts are being made to reduce antibiotic use, due to concerns about antibiotic-resistant bacteria. The objective was to evaluate the effects of Saccharomyces cerevisiae fermentation products (SCFP) on the immune status of calves, following a lipopolysaccharide (LPS) challenge administered just before weaning. Thirty Holstein bull calves were blocked based on initial body weight and then assigned to 1 of 2 study treatments. The control group (CON) was fed a 24% crude protein:17% fat milk replacer (MR) and calf starter with no SCFP added. The SCFP treatment was fed the same 24% crude protein:17% fat MR with 1 g/d of SmartCare (Diamond V) and calf starter with 0.8% NutriTek (Diamond V). SmartCare and NutriTek are both produced from anaerobic fermentation of S. cerevisiae. Calves were offered 2.84 L (12.5% solids) of MR twice daily at 0630 and 1630 h through d 51; from d 52 to 56, calves were fed MR once daily at 0630 h; and calves were weaned on d 57. Calves also received ad libitum access to a texturized calf starter and water. On d 50, a subset of calves (n = 20, 10 calves per treatment) were enrolled in an LPS challenge. At -1.5, -0.5, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, and 24 h relative to dosing with LPS, 20 mL of blood was collected, and rectal temperature and respiration rate were measured for each calf. Blood serum samples were analyzed for interleukin 6, TNF-α (tumor necrosis factor-α), interferon-gamma, haptoglobin, serum amyloid-A, fibrinogen, nonesterified fatty acid, cortisol, and glucose. This study observed increased concentrations of TNF-α at 1 h and 1.5 h and glucose at 0.5 h after dosing with LPS in SCFP calves compared with CON. Calves supplemented with SCFP also had an increase in respiration rate 0.5 h after dosing with LPS and reduced feed intake the day of the challenge compared with CON calves. These results suggest that dairy calves supplemented with SCFP exhibit an increased acute immune response, as observed by increased TNF-α, glucose, and respiration rate immediately after dosing with LPS, compared with CON calves.

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.

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.

Effect of porcine plasma on growth and health of Holstein calves

The objective of this trial was to compare the health and performance of calves provided high feeding rates of a whey-based all-milk-protein calf milk replacer (MR) with those fed an MR containing either 5% or 10% porcine plasma, which replaced, respectively, either 15% or 30% of the whey-based proteins in the MR formula. A total of 320 male Holstein calves weighing a mean (± SD) of 47.8 ± 4.1 kg were sourced from local dairy farms, auction facilities, and local order buyers. Calves arrived at the research facility in 4 batches of 80 animals each and were randomly assigned to 1 of 3 groups: (1) MR composed of whey-based milk proteins (control group); (2) whey replacement of 5% spray-dried porcine plasma (replacing 15% of protein); or (3) whey replacement of 10% spray-dried porcine plasma (replacing 30% of protein). Calves were housed in individual pens for the first 56 d of the experiment and offered, twice daily, a 26% crude protein (CP), 20% fat MR standardized using synthetic amino acids to 2.4% lysine, 0.8% methionine, and 1.6% threonine. Amounts of MR offered from wk 1 to 8 were 0.65, 0.78, 0.91, 1.04, 1.04, 0.78, 0.52, and 0.325 kg/d, respectively. Calves were also offered a 20% CP texturized calf starter from d 0 to 56 and then transitioned over 7 d (d 56–62) of a 50% calf starter and 50% corn and pellet ration with 2% straw to a corn and pellet ration with 2% straw (18.1% CP) for the remainder of the experiment (d 63–77). Calves were individually weighed upon arrival, weekly through d 56, and at d 77. Grain was fed ad libitum, and remaining grain was weighed weekly to determine weekly consumption. Remaining grain was discarded and was replaced with fresh grain that was weighed and recorded. All milk was offered individually via bucket twice daily, and refusals were recorded following milk feeding by weighing back the remaining unconsumed milk solution. Calves were health scored twice daily, and any medical treatments or mortality were recorded. Time to mortality and medical treatments were analyzed using survival analysis, health scoring data were analyzed using a generalized linear model, and growth was evaluated using a mixed repeated-measures linear regression model. No differences in mortality or incidence of diarrhea were noted between groups. Although there was a high incidence of respiratory disease (65%), no differences were found between groups. Over the entire experimental period, calves gained 67.0 ± 14.9 kg; however, no differences in growth among groups were noted, with the exception that, on d 77, BW was greater for calves in the control group (115.8 ± 15.5 kg) compared with those fed a MR with 5% porcine plasma (113.4 ± 17.8 kg). No differences were found between groups with respect to feed conversion. In this study, an MR composed of either 5% or 10% spray-dried porcine plasma performed comparably to a whey protein–based MR.