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

Abstract

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 exploratoryactive) 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.

Use of a food neophobia test to characterize personality traits of dairy calves

“…Individual behavioural responses to different novel or challenging situations were assessed using three traditional tests (open field, novel human, and a novel object tests 15 ), and a novel food (food neophobia) test. In line with our previous work 5,25 , and other studies in dairy calves 26,38 , we anticipated these tests to identify boldness and exploratory personality traits. These tests were carried out individually in a test pen that was identical to the home pen except that access to the feeding equipment was prevented using plywood.…”

“…latency to approach novel food) and exploratory (e.g. time spent inspecting and eating the novel food) personality traits that have previously been identified in other novelty tests in dairy calves 5,25,26 . Indeed, a novel food test has been employed in a number of other species as a means of measuring these personality traits (fish: 27,28 ; birds: [29][30][31] primates: 32,33 ).…”

Effects of milk replacer meal size on feed intake, growth performance, and blood metabolites and hormones of calves fed milk replacer with or without butyrate ad libitum: A cluster-analytic approach

“…Several studies have shown interindividual variability in milk intake among dairy calves before and after weaning (Rosenberger et al, 2017;Dennis et al, 2018), which likely contributes to the interindividual variability in weight gains (e.g., 0.1-1.6 kg/d; Soberon et al, 2012) or weaning age (Neave et al, 2019) observed across studies. Also, interindividual variability was reported in feeding behavior such as drinking speed and the number of rewarded and unrewarded visits to the milk feeder among preweaning calves (de Passillé and Rushen, 2012;Korst et al, 2017;Gerbert et al, 2018).…”

Artificial Grooming during Early Life could Boost the Activity and Human Affinity of Holstein Female Calves

“…Usually, calves start consuming small amounts of solid feed around 14 days of age [19]. Neave et al [30,31] observed a large variation in the age (range from 4 to 41 days of age in the study in 2018; range from 18 to 75 days of age in the study in 2019) when calves first found and began to consume starter. Some of our experimental calves started to consume the starter diet as early as 6 days of age, and the artificial grooming group tended to have a higher proportion of starter-diet-consuming calves.…”

“…There is evidence that calves that were more exploratorily active began to consume starter at an earlier age, showed greater starter dry matter intake, and had higher overall average daily weight gain [30]. There is also a positive association between the level of exploratory activity and preweaning of calves [31]. Therefore, it seems likely that artificial grooming treatment might accelerate the solid food intake of calves by increasing their activity level.…”