Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
Pop. Med. & Diag. Sci.
Non Technical Summary
Newborn calves are routinely separated from their dams within 24 h of birth. This approach has traditionally been thought to reduce separation stress of the cow-calf pair, as well as improve health of the calf. However, early cow-calf separation is scrutinized as an approach that may reduce animal welfare and well-being of cow and calf. Moreover, calf disease risk and mortality remain stagnant at unacceptably high levels. Our central hypothesis is that prolonged direct cow-calf social contact improves calf behavior, affective state, growth, immune response. We further anticipate that direct cow-calf contact changes the ability of the calf to establish a robust and diverse gastrointestinal and respiratory microbiome, meaning the entirety of the microbes of the gut and respiratory tract, and that this alters disease resistance. Regarding the postpartum cow, we hypothesize that early vs. delayed separation of the calf affects the behavior and well-being as well as udder health and milkability. We will address our hypotheses in four distinct objectives: the effects of early vs. delayed cow-calf separation on (1) cow and calf behavior and affective state, (2) calf health, growth and immune response, (3) the cow´s udder health, milkability and milk production, and (4) the calf gut and respiratory microbiome and the dam´s udder microbiome. Our goal is to provide scientific evidence to inform industry best practices based on all relevant outcomes measured in this multi-pronged collaborative approach. Our anticipated impact is that producers and their advisers will be enabled to evaluate current management practices on when to separate calves from cows are based on the best available data which will include our study results.
Animal Health Component
75%
Research Effort Categories
Basic
25%
Applied
75%
Developmental
(N/A)
Goals / Objectives
Our overarching goal of this international PARTNERSHIP is to use a multi-dimensional approach to evaluate effects of early vs. delayed separation on both cow and calf welfare and well-being. Because effects of prolonged cow-calf contact may be mediated by a combination of the social contact and the access to the dam´s milk during this period, we will also evaluate the contribution of transition milk feeding.Objective 1: Effects of early vs. delayed cow-calf separation on cow and calf behavior and affective state. We will evaluate the acute and long-term effects of delayed cow-calf separation on time budgets and activity, stress behaviors and physiological outcomes, as well as social interaction. Moreover, cow anhedonia and calf response to novelty are assessed.Objective 2: Effects of early vs. delayed cow-calf separation and transition milk feeding on calf health, growth and immune response. The adaptive and innate immune response of the calf will be tested in each of the four groups using in vivo measurements of passive immunity, mucosal and parenteral vaccine response as well as cytokine response to an inflammatory stimulus ex vivo. We are also recording effects on calf growth and disease events in the preweaning period, as well as long-term disease effects such as risk of infection with the Johne´s disease.Objective 3: Effects of early vs. delayed cow-calf separation with or without suckling on the dam´s udder health, milkability and production. We will evaluate intramammary infection risk in the different groups, as well differences in milkability and milk harvest for sale.Objective 4: Effects of early vs. delayed cow-calf separation on the calf gut and respiratory microbiomes and the dam´s udder microbiome. In this objective, we will measure the effects of treatment on the udder microbiome of the dam, as well as the establishment of microbial diversity within the gastrointestinal and upper respiratory tract of the calves.The immediate goal of our study is to contribute urgently needed evidence for industry best practice recommendations regarding cow-calf separation approaches. Our long-term goal is to improve the welfare and well-being of dairy cattle by refining current industry approaches, and to address critical consumer concerns in a scientifically sound and unbiased manner.
Project Methods
This study will evaluate the effect of early cow-calf separtion and transition milk feeding on the following four objectives- cow and calf behavior and affective state- calf health, growth, and immune response- udder health, milkability, and production- calf gut and respiratory micobome as well as dam milk microbiomeTo accomplish these objectives, we will enroll a total of 144 cow-calf pairs. Eligible cow-calf pairs will be enrolled immediately after parturition/birth when the initial assessment of eligibility is completed and will be performed following a randomized blocked design with parity (primiparous vs. multiparous dams) and calving date as blocking factors.The different experimental arms were constructed to isolate effects for each of the three main factors of interest: 1) the effect of unrestricted suckling vs. limiting suckling to 3 x/day, 2) the effects attributable to early vs. delayed separation from the dam, and 3) effects due to feeding transition milk vs. pooled mature milk. Within the group of cow-calf suckled pairs, we are comparing unrestricted (full-time access of calves to cows, URS, n=36) and restricted (access to the dam 3 x/day for 30 min 1 h after milking, RS, n=36) suckling. This will allow us to evaluate the practicability and effects of the restricted suckling management approach. Inclusion of a group that is fed the dam´s own transition milk for the duration of the treatment period (TM,n=36) will allow us to isolate effects that are due to consumption of this enriched milk. A control group of calves being fed pooled raw bulk-tank milk (PM,n=36) is included representing current industry practices.To minimize the confounding effect of transfer of passive immunity, all calves will receive colostrum in the maternity area as outlined above. For all treatment groups, cow-calf pairs will be moved to individual box stalls within 4 h of parturition/birth and after meeting all eligibility criteria. Calves are either housed with cows (allowing continuous or intermittent access to the cow stall from the calf creep area), or will be separated completely visually and physically from the dam by replacing the gate with a solid panel between calf creep area and cow stall (TM, PM). Housing cow-calf pairs in individual stalls will facilitate treatment allocation, allow undisturbed bonding, and prevent the suckling of other cows in a group housing situation Solid side panels prevent access to adjacent pairs. A separate service alley for cows and calves allows for ease of independent access, feeding, manure and bedding removal, as well as access to the parlor for cows. Each stall and pair will have assigned boots and washable aprons for each handler and stall compartment to abolish any cross-contamination between pairs and to secure integrity of sampling.Cows and their calves remain in the experimental allocations for 7 days. All calves are moved on day 7 to the calf barn for an individual observation period of one week before introduction to group housing. Dams will remain in the box stalls for an additional 24h before returning to the herd for behavior observation and collection of data on milkability, udder microbiome, and udder health.1) Behavioral outcomes will include measurements of time budget, stress behavior, social interaction, anhedonia and response to novelty. Physiological outcomes include measurements of heart rate and cortisol concentrations in feces following separation. As there will be several behavioral outcomes of interest, a multivariate mixed analysis of variance (MANOVA) will be considered to mitigate the effects of multiple testing.2) Calf health, growth, and immune response will include measureemtns of body weight, respiratory and fecal scores, rectal temperatures, determination of passive immune transfer, intranasal vaccine response, parenteral vaccine response, as well as in vitro T-cell response to BHV-1 stimulation and whole blood LPS stimulation. Repeated measures ANOVA or ANOVA will be used for outcomes that are observed over time or single time point, respectively. All models will include the random effect of calf and fixed effect of treatment, enrollment block, and calf birth body weight to adjust for potential confounding.3) Udder health of the dam, milkability and milk production will be measured by deterimation of milk flow with a portable electronic milk meter (Lactocorder) as well as by bacterial culture of quarter-level samples on day 1, day 8, and day 15 after parturition. Daily feed intake will be measured, and concentrations of BHB, NEFA, and glucose determiend on day 1,4,8, and 15 after calving. For the main outcome of interest, new IMI, multivariable logistic regression analysis will be performed with quarters classified as new IMI/no IMI. Groups URS+RS will be compared with TM+PM, however actual group assignment will be included in the model. Continuous outcomes such as milk production data, SCC, components, characteristics of milkability will be analyzed using multivariable repeated measures ANOVA4) The calf fecal and respiratory microbiome, as well as transfer from vaginal microbiome of the dam will be determiend using a subset of 15 animals in each group and samples on day 1,4,7, and 15 taken from the rectum and nasopharynx of the calf as well as from the vagina of the dam, using sterile swab methodology.The milk microbiome of the dam will be determined using sterile milk samples. The microbiome will be analyzed in vaginal, fecal, respiratory, and milk samples by sequencing amplicons of the V4 hypervariable region of the 16S rDNA gene. Data will be analyzed using the open-source software Qiime2 and Program R. Significance between and within group differences will be assessed using multivariate methods such as PERMANOVA, ANCOM, and ANOSIM. Similarities between microbial profiles will be assessed via principal component analysis of Aitchison distances, and shared taxa between niches will be described using UpSet plots.