# Assessing Natural Weaning in Suckler Beef Cattle: A Single-Farm Retrospective Data Analysis of Calf-Raising Success and Colostrum Antibody Uptake in the Absence or Presence of a Yearling Calf

## TL;DR

This study shows that allowing beef calves to stay with their mothers until natural weaning doesn't harm the survival or health of the next calf.

## Contribution

The study is the first to show that natural weaning in beef cattle doesn't reduce calf survival or colostrum antibody uptake.

## Key findings

- Leaving calves with their dams until natural weaning does not reduce the survival of subsequent calves.
- Over 95% of calves survived to one year old regardless of yearling presence.
- Colostrum antibody uptake was not significantly lower in calves with a yearling sibling present.

## Abstract

Commercial suckler beef calves are commonly physically separated from their dams at four to ten months old, often causing stress and health issues in cows and calves. This retrospective study looked at a ‘natural weaning‘ approach where cows kept their calves and therefore had a yearling still with them when the next calf was born. It investigated for the first time whether the presence of a yearling calf would be negatively linked to the raising success of the dam’s next calf. To that end, it compared the survival rates of a cow’s new calf when her yearling calf was still present with when the yearling was absent because it had been separated from her at 8–9 months. The comparison was thus between ‘natural weaning’ and conventional separation. This study was conducted on a single large, extensive, organic suckler beef farm on chalk downland in the south of the UK as it gradually changed its management to natural weaning. In a complementary study on the same farm, blood samples of newborn calves with the yearling sibling present or absent were tested for total protein levels to check for colostrum antibody uptake. Main findings are that leaving calves with their dams, and not separating them at 8 months old, is not associated with reduced raising success or colostrum antibody uptake for the subsequent calf. Natural weaning thus has potential as a management strategy for extensively reared suckler beef calves on comparable grasslands.

Suckler beef cows and their calves are commonly separated when calves are between four and ten months old. This is earlier than would happen naturally and causes stress in dams and calves and reduces feed intake and immunocompetence, and thus introduces calf performance and health problems. To address these concerns, weaning by separation was gradually phased out on a single extensive suckler beef farm comprising nine separate breeding herds based on chalk downland in southern England. Over seven consecutive years, the farm’s breeding herds were converted to natural weaning, one to two herds per year. This meant yearling calves stayed with their dams until weaned off naturally and beyond the subsequent calving season. To examine the effects of yearlings being left with their dams, retrospective data were collected on the subsequent calves’ survival to one year old (‘raising success’). The dams had their previous calf either still present as a yearling (YP) when the new calf arrived or had had their previous calf removed at eight months old, so it was absent (YA). Data were retrospectively analysed on 1822 calves born to 663 dams in total over the seven years. Raising success overall was 96% for YP calves and 95% for YA. Chi-squared analysis of only one calf per cow (N = 663; YP = 382, YA = 281) confirmed that raising success was not negatively associated with yearling presence. A separate analysis compared farm data on serum total protein levels of 81 YP and 12 YA 1–10-day-old calves as measures of colostrum antibody uptake. Mann–Whitney U testing showed an insignificant trend towards higher antibody uptake in YA calves (p < 0.1). However, over 86% of calves in both groups had ‘excellent’ total protein values according to a standard classification used for dairy calves (>6.2 g/dL). The findings show for the first time and under conditions studied here that beef calves can be left with their dams without a negative effect on the survival of the subsequent calf. Concerns of sibling rivalry disturbing the bonding process and leading to competition for colostrum and milk were not confirmed. In conclusion, allowing cows to wean their calves naturally could potentially be a viable management option for similar beef suckler herds, including those used in habitat/soil restoration projects.