Effects of weaning strategies on health, hematology, and productivity in Holstein dairy calves

Effects of preweaning calf daily gain and feed intake on first-lactation performance: A meta-analysis

This study aimed to investigate the effects of daily weight gain and feed intake of calves on first-lactation milk yield and composition using a meta-analysis. A total of 57 treatments from 18 studies were included in the study. Univariate and multivariate mixed models were constructed for calf ADG, liquid DMI (LDMI), starter DMI (SDMI), 305-d milk, milk fat, and protein yield data to gain insight into the effects of preweaning calf daily gain and feed intake on first-lactation performance. Univariate mixed models revealed ADG was significantly positively correlated with 305-d milk, milk fat, and protein yields during the first-lactation period. This indicates that ADG is a significant determinant of enhanced production performance during the first-lactation period. Furthermore, a significant quadratic correlation was observed between LDMI and 305-d milk, milk fat, and protein yields during the first-lactation period. The optimal performance during the first lactation was achieved when LDMI was maintained at 0.79 to 0.80 kg/d. In contrast, no significant association was observed between SDMI and production performance during the first-lactation period. Further multivariate mixed model analyses demonstrated that, when the effects of the 3 independent variables were considered collectively, only ADG exhibited a significant positive effect on 305-d milk yield and fat production during the first-lactation period. However, the modeling of milk protein yield revealed that ADG and LDMI exerted a significant influence, whereas the effect of SDMI remained insignificant. This study emphasized the significant effect of ADG and LDMI in optimizing the future lactation performance of calves, providing a crucial foundation for the development of scientific feeding management strategies.

Effect of weaning strategies on biosynthesis of oxylipids in Holstein dairy calves

The aim of this study was to determine the effect of the weaning calves at 2 ages (early vs. late) and 2 weaning paces (abrupt over 3 d vs. gradual over 14 d) on plasma oxylipids. Seventy-one dairy calves (38.8 ± 4.4 kg, BW ± SD), blocked by sex and BW at birth, were randomly assigned in a 2 × 2 factorial arrangement of treatments. The factors were weaning age (early: 6-7 wk vs. late: 8-9 wk) and weaning pace (abrupt: 3 weaning steps over 2 d vs. gradual: 7 weaning steps over 14 d), generating 4 treatment groups: early-abrupt, early-gradual, late-abrupt, and late-gradual. Blood samples were collected from the jugular vein 1 d preweaning, and one day postweaning. Oxylipids concentration was measured by liquid chromatography-tandem MS. Fatty acid profile (including nonesterified fatty acids) was also assessed. Weaning pace, age, pace × age, BW at birth, and sex were included as fixed effect and cohort was included as random effect in the model. Linoleic acid derivatives 13- oxooctadecadienoic (OxoODE) and 9-OxoODE had a greater concentration in calves abruptly weaned when compared with those for gradually weaned calves. Calves weaned gradually showed a greater concentration of 9-hydroxyoctadecadienoic (HODE), 13-HODE, 12,13-dihydroxyoctadecenoic (DiHOME), 9,10-DiHOME, all linoleic acid-derived compared with that for abruptly weaned calves. Anti-inflammatory oxylipid 17,18-dihydroxyeicosatrienoic, an eicosapentaenoic acid derivative, was greater in calves abruptly weaned compared with those gradually weaned. Overall, the pace of weaning affected the plasma concentration of oxylipids, demonstrating that weaning pace affects the oxylipids status involved in inflammation in dairy calves.

Invited review: The effect of weaning practices on dairy calf performance, behavior, and health-A systematic review

The aim of this systematic review was to summarize the literature assessing the effects of weaning practices on performance, behavior, and health of dairy calves. Only published, peer-reviewed articles written in English and specifically assessing the effects of weaning treatments on dairy calves were eligible for inclusion. Studies had to include 2 or more treatment groups that addressed at least one of 4 interventions: weaning age (i.e., when milk was fully removed), weaning duration (i.e., number of days from start of milk reduction to when milk was fully removed), weaning criteria (e.g., age vs. intake), or alternative weaning methods (e.g., water dilution). Outcome measures could include starter intake, growth (BW or ADG), behaviors (5 specific sucking behaviors; play behavior; lying behavior; vocalizations; unrewarded visits to an automated milk feeder), and health (mortality rate, diarrhea, and respiratory illness). We conducted 3 targeted searches using Web of Science and PubMed. The articles underwent a 2-step screening process, resulting in a final sample of 44 studies. The majority of studies investigated weaning age (n = 22), followed by weaning duration (n = 13), weaning criteria (n = 9), and other weaning methods such as dilution, linear versus step-down milk reduction, or meal-based approaches (n = 6). There was consensus for positive effects (or at least no negative effects) on overall growth of calves weaned at later ages, over longer durations, based on starter intake, or weaned using step-down or meal-based milk removal approaches. This is despite reduced starter intake in calves weaned at later ages; most studies found improved starter intake in calves weaned over longer durations. Weaning based on starter intake had superior growth and feed intakes compared with calves weaned at a fixed earlier age. Few studies assessed interactive effects of weaning method and milk allowance. However, weaning after 8 wk appears to support superior weight gain, provided preweaning milk allowances are adequate (above 6 L/d). Weaning can lead to hunger-related behaviors and reduced welfare, yet only half of the studies assessed the effects of weaning method on calf behavior. Weaning at later ages can reduce signs of hunger (based on unrewarded visits to the milk feeder), but it is unclear if weaning over longer durations or weaning by starter intake reduces or prolongs hunger. There was little consensus among the few studies that measured oral behaviors of calves. Positive welfare indicators, such as play behavior, were rarely measured, yet are crucial to understanding the emotional states of calves during this potentially stressful diet transition. Health was rarely the primary objective of the study, with low sample sizes to conduct statistical comparisons. Overall, there remains significant knowledge gaps in our understanding of how best to wean calves. A successful weaning program must minimize signs of hunger while promoting high growth and feed intakes, so we encourage future work to include behavioral indicators of hunger and positive welfare to evaluate how weaning methods are experienced by the calf.

Effects of weaning age and pace on blood metabolites, cortisol concentration, and mRNA abundance of inflammation-related genes in gastrointestinal, adipose, and liver tissue of Holstein dairy calves

The objective of this study was to evaluate the effects of weaning age and pace on blood metabolites, cortisol concentration, and mRNA abundance of inflammation-related genes in Holstein dairy calves. A total of 70 1-d-old calves (38.8 ± 4.4 kg BW ± SD), blocked by sex and birth BW, were randomly assigned to a 2 × 2 factorial arrangement of treatments. The first factor was weaning age, which was either early (6 wk) or late (8 wk). The second factor was weaning pace, which was either abrupt (4 steps down over 3 d; the initial milk replacer was 7.6 L, which was reduced by 1.9 L in each step-down) or gradual (7 steps down over 14 d; the initial milk replacer was 7.6 L, which was reduced by 1.09 L in each step-down), generating early-abrupt (EA), early-gradual (EG), late-abrupt (LA), and late-gradual (LG) treatments. All treatments had 10 female and 8 male calves, except EA that had 1 fewer male calf. Milk replacer (24% CP, 17% fat) was bottle fed, up to 1,200 g/d, twice daily (0600 h and 1800 h). The EA and EG treatment calves received 46.2 kg of milk replacer, and the LA and LG treatment calves received 63 kg of milk replacer. The study had 2 cohorts (2020, n = 40; 2021, n = 31), and each cohort included all treatments. Blood was collected from the jugular vein at 0900 h at 3 and 7 d of age, and a day before starting and a day after weaning completion. Male calves were humanely killed a day after weaning. Rumen, jejunum, large intestine, liver, omental adipose and perirenal adipose tissues were sampled to determine the mRNA abundance of inflammation-related genes. Weaning pace, age, pace × age, birth BW, and sex were included as fixed and cohort was included as random effects in the model. Blood metabolites and cortisol were analyzed as repeated measures, and sampling day, pace × sampling day, and age × sampling day were also included as additional fixed effects. Significance was noted at P ≤ 0.05 and tendencies when 0.05

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Key Words

• inflammation
• inflammatory markers
• preruminant calves
• weaning strategies

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MESH Headings

• Animals
• Cattle
• Weaning
• Hydrocortisone/blood
• Inflammation/veterinary
• Female
• Diet/veterinary
• Liver/metabolism
• RNA, Messenger/metabolism
• Male
• Adipose Tissue/metabolism

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Affiliation(s)

B C Agustinho Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844
A Wolfe Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
C Y Tsai Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844
L M Pereira Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844
D E Konetchy Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844
A H Laarman Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
P Rezamand Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844.

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