Milk consumption and behavior of calves in automated calf feeders as early indicators of weaning liveweight

Modern intensive dairy farming relies on data to aid and prioritize management decisions made on farm. Decisions made early in an animal's life can have lasting effects on welfare, productivity, longevity, and profitability. Precision technology such as automated calf feeders (ACF) allow the customization of feeding programs, but despite this, weaning weights (WWT) vary substantially between calves. This observational study used a 3-yr dataset comprising 1,440 female Holstein Friesian calves at a single intensive commercial dairy farm (Dairy Australia feeding system 5; indoor, total mixed ration) using ACF to (1) determine the variability in WWT (as a proxy of animal performance) of calves within this system; (2) identify the contributing factors responsible for the variation in WWT; and (3) identify potential early management intervention points that could be indicative of the performance of calves at weaning within the system. Calves entered the ACF at 10 d of age with 12 calves per ACF; calves were weighed at birth and weaning using weigh scales. We discovered a large range of calf WWT (41-118 kg/head) at ~60 d of age despite the application of strict uniform management protocols. Our results from modeling showed that WWT was significantly and positively associated with birth weight (BWT), with low BWT calves (<36 kg) achieving an average of 70 kg weight at weaning. In contrast, heavier BWT (>36 kg) calves achieved an average of 82 kg at weaning. Based on calf feeder data, cumulative milk consumption and cumulative unrewarded visits to the feeder, as well as BWT, were identified as indicators of greater WWT as all these were highly significant terms in the model for WWT. Results suggest that quantifying consumption and number of visitations to the ACF at d 5 may allow farmers to identify, with time to intervene, calves underperforming within the feeder or system, therefore increasing their potential for growth. Additionally, this demonstrated that greater milk consumption (>30 kg) and interaction with the feeder up to d 5 in the feeder is more likely to yield a WWT >75 kg, identifying a potential point for management intervention for calves below consumption and interaction thresholds (e.g., by developing alarm systems based on consumption or visitation number).

Graduate Student Literature Review: Social and feeding behavior of group-housed dairy calves in automated milk feeding systems

Automated milk feeders (AMF) allow farmers to raise calves in groups while generating individual records on milk consumption, drinking speed, and frequency of visits. Calves raised in groups benefit from social interaction, which facilitates learning and adapting to novelty. However, calves in large groups (>12 calves/feeder) experience a higher risk of disease transmission and competition than those housed individually or in smaller groups. Therefore, if group size, grouping strategy, and disease detection are not optimal, the health and performance of calves can be compromised. The objectives of this narrative literature review, from publications available as of February 2023, are to (1) describe the use of AMF in group housing systems for calves and the associated feeding behavior variables they automatically collect, (2) linking feeding behavior collected from AMF to disease risk in calves, (3) describe research on social behavior in AMF systems, and (4) introduce social networks as a promising tool for the study of social behavior and disease transmission in group-housed AMF-fed calves. Existing research suggests that feeding behavior measures from AMF can assist in detecting bovine respiratory disease and enteric disease, which are common causes of morbidity and mortality for preweaning dairy heifers. Automated milk feeder records show reduced milk intake, drinking speed, or frequency of visits when calves are sick. However, discrepancies exist among published research about the sensitivity of feeding behavior measures as indicators of sickness, likely due to differences in feeding plans and disease-detection protocols. Therefore, considering the influence of milk allowance, group density, and individual variation on the analysis of AMF data is essential to derive meaningful information used to inform management decisions. Research using dynamic social networks derived from precision data show potential for the use of social network analysis to understand disease transmission and the effect of disease on social behavior of group-housed calves.

Welfare of calves

This Scientific Opinion addresses a European Commission request on the welfare of calves as part of the Farm to Fork strategy. EFSA was asked to provide a description of common husbandry systems and related welfare consequences, as well as measures to prevent or mitigate the hazards leading to them. In addition, recommendations on three specific issues were requested: welfare of calves reared for white veal (space, group housing, requirements of iron and fibre); risk of limited cow–calf contact; and animal‐based measures (ABMs) to monitor on‐farm welfare in slaughterhouses. The methodology developed by EFSA to address similar requests was followed. Fifteen highly relevant welfare consequences were identified, with respiratory disorders, inability to perform exploratory or foraging behaviour, gastroenteric disorders and group stress being the most frequent across husbandry systems. Recommendations to improve the welfare of calves include increasing space allowance, keeping calves in stable groups from an early age, ensuring good colostrum management and increasing the amounts of milk fed to dairy calves. In addition, calves should be provided with deformable lying surfaces, water via an open surface and long‐cut roughage in racks. Regarding specific recommendations for veal systems, calves should be kept in small groups (2–7 animals) within the first week of life, provided with ~ 20 m²/calf and fed on average 1 kg neutral detergent fibre (NDF) per day, preferably using long‐cut hay. Recommendations on cow–calf contact include keeping the calf with the dam for a minimum of 1 day post‐partum. Longer contact should progressively be implemented, but research is needed to guide this implementation in practice. The ABMs body condition, carcass condemnations, abomasal lesions, lung lesions, carcass colour and bursa swelling may be collected in slaughterhouses to monitor on‐farm welfare but should be complemented with behavioural ABMs collected on farm.

Feeding behaviors collected from automated milk feeders were associated with disease in group-housed dairy calves in the Upper Midwest United States

Automated milk feeders (AMF) are an attractive option for producers interested in adopting practices that offer greater behavioral freedom for calves and can potentially improve labor management. These feeders give farmers the opportunity to have a more flexible labor schedule and more efficiently feed group-housed calves. However, housing calves in group systems can pose challenges for monitoring calf health on an individual basis, potentially leading to increased morbidity and mortality. Feeding behavior recorded by AMF software could potentially be used as an indicator of disease. Therefore, the objective of this observational study was to investigate the association between feeding behaviors and disease in preweaning group-housed dairy calves fed with AMF. The study was conducted at a dairy farm located in the Upper Midwest United States and included a final data set of 599 Holstein heifer calves. The farm was visited on a weekly basis from May 2018, to May 2019, when calves were visually health scored and AMF data were collected. Calf health scores included calf attitude, ear position, ocular discharge, nasal discharge, hide dirtiness, cough score, and rectal temperatures. Generalized additive mixed models (GAMM) were used to identify associations between feeding behavior and disease. The final quasibinomial GAMM included the fixed (main and interactions) effects of feeding behavior at calf visit-level including milk intake (mL/d), drinking speed (mL/min), visit duration (min), rewarded (with milk being offered) and unrewarded (without milk) visits (number per day), and interval between visits (min), as well as the random effects of calf age in regard to their relationship with calf health status. Total milk intake (mL/d), drinking speed (mL/min), interval between visits (min) to the AMF, calf age (d), and rewarded visits were significantly associated with dairy calf health status. These results indicate that as total milk intake and drinking speed increased, the risk of calves being sick decreased. In contrast, as the interval between visits and age increased, the risk of calves being sick also increased. This study suggests that AMF data may be a useful screening tool for detecting disease in dairy calves. In addition, GAMM were shown to be a simple and flexible approach to modeling calf health status, as they can cope with non-normal data distribution of the response variable, capture nonlinear relationships between explanatory and response variables and accommodate random effects.

Welfare implications on management strategies for rearing dairy calves: A systematic review. Part 1-feeding management

Introduction

Calves are very susceptible to stress in the early stages of life, and it is necessary to ensure maximum welfare. Feeding management has been identified as a major risk factor for calf health and welfare at this stage. However, the management protocol for calf rearing and its impact on animal welfare is unclear. A systematic review of different management strategies for rearing dairy calves according to the three spheres of animal welfare was conducted using an electronic search strategy. In this review, management strategies were studied to identify scientific gaps, to know the welfare problems of these animals in order to prioritize actions and future research and to study the interpretive approach of this management from the three welfare spheres.

Methods

A protocol was used to analyze and extract information from the studies. Of the 1,783 publications screened, only 351 met the inclusion criteria for the management or welfare of calves' items.

Results

The publications identified in the search can be divided into two main groups feeding and socialization, based on the main topic of the publication. The main topics that emerged from the search in the feeding management group were milk replacer, colostrum, and weaning, divided into the three main areas of biological functioning and health, natural life and affective states or cognitive judgement.

Discussion

The main issues to be addressed were the different types of feed consumed by animals from birth to weaning and the weaning management. It has been found that the most researched issues are colostrum and solid starter feed management. Unresolved issues were highlighted, such as the lack of a clear protocol for the administration of milk replacers to reduce hunger and the best management of weaning to reduce stress.

A comparison of indoor and outdoor calf housing systems using automated and manual feeding methods and their effect on calf health, behaviour, growth and labour

Housing and feeding are integral to calf rearing, and must meet calf needs while remaining functional for the farmer. This study compared health, behavior, growth, and labor requirements of calves housed in groups indoors and fed via an automatic or manual milk feeding system compared to calves manually fed in individual or group hutches outdoors. Seventy-six (49 Holstein Friesian [HF] and 27 HF × Jersey) dairy heifer calves were balanced for birth weight (35.2 ± 4.95 kg), birth date (1 February ± 7.2 d) and breed. The experiment was a randomized block design with four treatments; 1) indoor group housing with automated feeding (IN_AUTO; 12 calves per pen), 2) indoor group housing with manual feeding (IN_MAN; 12 calves per pen), 3) outdoor group hutch with manual feeding (OUT_G_MAN; 8 calves per pen), and 4) outdoor individual hutch with manual feeding (OUT_I_MAN; 6 calves: 1 per pen). Calves in OUT_treatments moved outdoors at 18 d (± 5.9 d). Each treatment was replicated once. Milk allowance increased gradually from 6 to 8 L/day (15% reconstitution rate) with ad libitum fresh water, concentrates, and hay offered from 3 d old. Gradual weaning occurred at 8 wk old. Measurements were divided into period 1; before movement outdoors, and period 2; after movement outdoors. Health was similar among treatments, regardless of period, with the most frequent score being zero (i.e., healthy). Summarized, standing and lying were observed 24.3% and 29.8%, respectively, in OUT_I_MAN calves, compared to 8.0% and 49.1%, for the other systems, which were similar. No difference in bodyweight (BW) existed between treatments, except at weaning where BW was lower for OUT_I_MAN (67.4 ± 2.84 kg) compared to IN_MAN (74.2 ± 2.01 kg), and day 102 where OUT_I_MAN (94.1 ± 2.85 kg) were lighter than IN_AUTO (101.1 ± 2.10 kg) (P = 0.047). Total labor input was greatest for OUT_I_MAN (00:02:02 per calf per day; hh:mm:ss) and least for IN_AUTO (00:00:21 per calf per day) (P < 0.001). The labor for feeding (00:00:29 per calf per day), feeding inspection (00:00:10 per calf per day), and cleaning equipment (00:00:30 per calf per day) was greatest for OUT_I_MAN. All calves showed good health and growth patterns. Differences in behavior expressed by calves in the OUT_I_MAN, compared to other treatments may indicate compromised welfare. Thus, although outdoor group hutches do not negatively impact calves, indoor housing, particularly using automated feeders, can improve labor efficiency.

In seasonal calving dairy systems, cows calve in a period of approximately 12 wk. Demand for calf accommodation and labor is high during this time. Outdoor housing structures, such as robust plastic calf hutches, may offer an alternative to permanent indoor facilities. In this study, we compared indoor housing systems using automated and manual feeding methods and outdoor calf housing systems using manual feeding methods, to examine their effect on calf health, behavior, growth, and labor. Moving calves to their respective outdoor system commenced at approximately 18 d. This reflected a housing system with limited indoor availability, where older calves would be moved outdoors (allowing young calves to remain indoors). The most labor-efficient method of rearing was group housing calves indoors feeding via automatic feeder, followed by group housing indoors feeding via manual feeders, outdoor in group hutches, and outdoor in individual hutches with manual feeding. Calves in all systems showed health and growth patterns consistent with positive development. Calf behavior in the individual hutches outdoor may indicate compromised well-being, compared to all other systems. Thus, although outdoor group hutches do not negatively impact the calf, indoor housing, particularly when using automatic feeders, can provide improved labor efficiency.

Associations between Feeding Behaviors Collected from an Automated Milk Feeder and Neonatal Calf Diarrhea in Group Housed Dairy Calves: A Case-Control Study

Simple Summary

Precision technology devices are often integrated on dairies to monitor animal health. One precision technology used to manage calves is an automated milk feeder which can record feeding behaviors such as daily milk intake, drinking speed, and feeder visits. The objective of this study was to determine if calf feeding behaviors collected by an automated milk feeder, changed in the days surrounding diagnosis of neonatal calf diarrhea (NCD; e.g., −3 days to 5 days after diagnosis). Milk intake was lower for the greatest number of days surrounding diagnosis of NCD compared to control calves, but the sensitivity and specificity of detecting NCD using any individual behavior was low. However, parallel testing using cumulative feeding behaviors on the day of diagnosis of NCD increased the sensitivity for detecting disease. This study provides insights into the association of feeding behavior with calves destined for NCD using an automated milk feeder. We suggest feeding behaviors cannot replace visual diagnosis of NCD, but that feeding behaviors might serve as a screening tool for producers.

Abstract

The objective of this case-control study was to determine if feeding behavior data collected from an automated milk feeder (AMF) could be used to predict neonatal calf diarrhea (NCD) in the days surrounding diagnosis in pre-weaned group housed dairy calves. Data were collected from two research farms in Ontario between 2017 and 2020 where calves fed using an AMF were health scored daily and feeding behavior data (milk intake (mL/d), drinking speed (mL/min), number of rewarded or unrewarded visits) was collected. Calves with NCD were pair matched to healthy controls (31 pairs) by farm, gender, and age at case diagnosis to assess for differences in feeding behavior between case and control calves. Calves were first diagnosed with NCD on day 0, and a NCD case was defined as calves with a fecal score of ≥2 for 2 consecutive days, where control calves remained healthy. Repeated measure mixed linear regression models were used to determine if there were differences between case and control calves in their daily AMF feeding behavior data in the days surrounding diagnosis of NCD (−3 to +5 days). Calves with NCD consumed less milk on day 0, day 1, day 3, day 4 and day 5 following diagnosis compared to control calves. Calves with NCD also had fewer rewarded visits to the AMF on day −1, and day 0 compared to control calves. However, while there was a NCD status x day interaction for unrewarded visits, there was only a tendency for differences between NCD and control calves on day 0. In this study, feeding behaviors were not clinically useful to make diagnosis of NCD due to insufficient diagnostic ability. However, feeding behaviors are a useful screening tool for producers to identify calves requiring further attention.

Growth, health, and economics of dairy calves fed organic milk replacer or organic whole milk in an automated feeding system

•

Organic milk replacer was not available for organic dairy farmers until recently.

•

Calves had similar growth whether they were fed organic milk replacer or organic whole milk.

•

Milk feed cost was greater for calves fed organic milk replacer because of its higher cost.

•

Organic milk replacer may be used for convenience on organic dairy farms.

The objective of the study was to investigate the growth, health, behavior, and economics of dairy calves fed organic milk replacer (n = 41) or organic whole milk (n = 40) in an automatic feeding system. Calves were fed either organic milk replacer or whole milk (assigned to treatment in birth order) during 2 seasons from March to July 2018 and from September to December 2018 at the University of Minnesota West Central Research and Outreach Center in Morris, Minnesota. The treatment groups were (1) pasteurized whole milk fed at 13% total solids of organic milk (WM), or (2) milk replacer fed at 150.98 g of dry replacer powder per liter of water (MR). Milk replacer was fed at 14.65% total solids based on the manufacturer's recommendation. Calves were introduced to the automated feeder at 5 d and allowed to drink up to 8 L/d at the maximum allowance. At 50 d, the allowance was reduced by 0.2 L/d and calves were weaned at 56 d. Milk feeding behavior (feeding station visit behaviors and drinking speeds) were collected from the automatic feeding system and analyzed by feeding group. Body weights were recorded at birth and then weekly until weaning (56 d). Health scores of calves were recorded twice a week. Data were analyzed using PROC MIXED (SAS Institute Inc.). Independent variables for analyses were the fixed effects of breed group, season of birth, and treatment group, and the interaction of season and treatment group along with pen as a random effect. No differences were found between treatment groups for average daily gain, weaning weight, hip height, or heart girth. Milk feeding behavior varied between the 2 feeding treatment groups. The WM calves had shorter visits to the feeding station (2.44 vs. 3.01 min, respectively) compared with MR calves. Overall drinking speeds of the WM calves were higher (1,301 mL/min) than those of the MR calves (581 mL/min). The MR calves had higher fecal scores than WM calves. The average cost per kilogram of gain was lower for WM calves ($6.35/kg) compared with MR calves ($8.82/kg). The results of this study indicate health and economic advantages to feeding organic dairy heifer calves whole milk during the preweaning period.

Individual characteristics in early life relate to variability in weaning age, feeding behavior, and weight gain of dairy calves automatically weaned based on solid feed intake

Little is known about factors affecting individual variability in weaning age, feeding behavior, and growth of dairy calves. The objectives of this study were to (1) describe early-life individual characteristics of dairy calves and how these relate to weaning age, feeding behavior, and performance during the first 15 wk of age, and (2) to identify which of these individual characteristics predict weaning age of calves automatically weaned based on solid feed intake. Early-life characteristics of calves (n = 43) included scores for vitality at birth, drinking ability, learning ability to use the automated milk feeder in a group pen from d 1 of age, and personality traits assessed using exposure to a novel environment, a human, and an object at d 21 of age. Calves received 12 L/d of milk until d 30 when milk was reduced by 25% relative to the individual's previous 3-d intake average. Calves were weaned based on intake of solid feed (milk reduced by 25% at each of 2 intermediate solid feed intake targets, 225 and 675 g/d), and were weaned when they consumed 1,300 g/d of solid feed, resulting in variable weaning ages. A principal component analysis identified 5 factors that we labeled as low vitality, fearful, strong drinker, slow learner, and exploratory-active. Calves that were slow learners weaned at a later age, whereas fearful calves weaned earlier. No other early-life individual characteristics were associated with weaning age. Other characteristics (low vitality, strong drinkers, and exploratory-active) were associated with some measures of feeding behavior, feed intake, and growth, especially during the preweaning period. Measures of early solid feed intake (age to start eating and total preweaning intake) were best able to predict weaning age of calves. Individual early-life characteristics and measures of early solid feed intake can identify calves likely to do well or struggle during weaning.