Producing highly productive dairy cows with good longevity starts with healthy, prosperous calves. Even though producers are usually aware of this, sickness and losses in calves are still major discussion topics. According to the Dairy Heifer Raiser overview from the USDA (2012), mortality in pre-weaning heifers was 4.2%. The biggest cause of pre-weaning mortality are digestive disorders and respiratory problems. Calf losses before weaning have a short-term economic impact, but they also influence the future genetic and earning potential of the production unit. Another economically relevant factor for successful dairy cow production is the achievement of good growth development in calves. In a study from Cornell University, Van Amburgh et al. (2009) showed that early life events appear to have long-term effects on performance. Soberon and Van Amburgh (2013) concluded that 100 g of additional pre-weaning daily weight gain could result in approximately 155 kg of additional milk yield during the animal's first lactation.
Key factors for calf development
Any factor that challenges the health or growth rate of calves should be prevented. Important measures that farmers can take which are associated with optimal calf development include:
- Ensuring an adequate supply of colostrum for new born calves
- Optimizing housing conditions
- Offering plentiful fresh water
- Supplying sufficient high quality milk or milk replacer and starter
In particular, the supply of water and starter feed are vitally important for adequate rumen development, which will subsequently lead to muscle and skeletal development and growth.
The importance of calf nutrition
Calves are young, non-ruminant animals that develop into ruminants over the course of only a few months. During this time, calves undergo tremendous change. Their first diet is composed of 100% liquid milk and transitions to being 100% solid feed (roughage and concentrates). This dramatic change in their nutrition represents a huge challenge for calves in terms of ensuring a sufficient level of feed intake. Calves are also susceptible to environmental stressors such as housing or grouping changes, which can influence feed intake and the digestion and utilization of feed, resulting in poor health and growth development.
During this challenging time, a feed additive that improves the palatability of the feed and supports the development of the gastrointestinal tract can be of great benefit. Specially selected phytogenic feed additives (PFAs) that have flavoring properties and support the optimal functioning of the intestinal tract can help ease calves through this critical period in their development. Digestarom® is a unique blend of herbs, extracts and essential oils that improves the palatability of feed, ensuring that calves reach and maintain optimal feed intake levels. Furthermore, Digestarom® also enhances digestibility, which is a pre-requisite for the efficient conversion of raw materials into growth performance, while also reducing intestinal stress. Improved digestibility of feed means there are less free nutrients available in the gut to nourish pathogenic bacteria. By adding Digestarom® to the diets of calves, the growth of pathogenic bacteria in the gut is limited, reducing the bacterial challenge faced by the calf. Moreover, Digestarom® directly supports the gastrointestinal tract through its anti-inflammatory and anti-oxidative properties.
Pool analysis of trials with Digestarom®
The positive effects of Digestarom® in calves have been observed in a number of field and scientific trials in pre-weaning and weaning calves (males and females). A pool analysis was conducted to evaluate improvements with Digestarom® based on the results of several trials. Parameters evaluated for the pool analysis were average daily weight gain (ADWG), average daily feed intake (ADFI) and feed conversion (FCR). Average daily weight gain was recorded in eleven trials, while ADFI and FCR were recorded in seven trials. Trials for the pool analysis were conducted in the United States and Europe. The performance of calves in the control groups were compared to calves receiving Digestarom® in milk/milk replacer or calf concentrates. Th e groups receiving milk replacer and/or feed supplemented with Digestarom® were compared to non-medicated milk replacer/feed or to medicated milk replacer/feed. Th e Control group in the illustrated results (Figures 1 and 2) combines the medicated and non-medicated milk replacer/feed. Th e majority (82%) of the trials were conducted with between 48 and 56 calves, while 18% of the trials were conducted with 100 or more calves. Nine of the eleven trials lasted 56 days, one trial lasted 42 days and the fi nal trial lasted 72 days.
Figure 1. Improvements (absolute numbers) of Digestarom® compared to Control calves in a pool-analysis [“n” represents the number of trials in which a parameter was recorded; the orange line represents the Control group of medicated and non-medicated calves].
Figure 2. Improvements (relative numbers) of Digestarom® compared to Control calves in a pool-analysis [“n” represents the number of trials in which a parameter was recorded; the orange line represents the Control group of medicated and non-medicated calves].
Consistency in performance improvements
Results of the pool analysis showed consistent improvements in ADWG, ADFI and FCR when Digestarom® was present (Figure 1 and Figure 2). Average daily weight gain improved by 75.2 g or 8.9% when the diet was supplemented with Digestarom®. Average daily feed intake improved by an average of 86.8 g or 5.3%, while fed-out feed was also utilized 4.1% more effi ciently (an improvement of 8.7 FCR points) in the presence of Digestarom®. The pool analysis results indicate that there is a direct positive economic benefit when Digestarom® is added to the diet, because of a more effi cient transformation of feed into growth performance. When the economic benefits of Digestarom® supplementation in young stock are combined with the conclusions drawn from a meta-regression by Soberon and van Amburgh (2013), Digestarom® supplementation could increase first lactation performance by an additional 116.6 kg (Figure 3).
Figure 3. Average performance improvement with Digestarom® suggests an additional 116.6 kg of milk in the first lactation.
To operate a successful dairy production business, and to realize the potential of calves, we need to focus on their health and growth rates. As well as a good management program, calves can benefi t from the supplementation of a selected phytogenic feed additive such as Digestarom® to ensure a smooth transition from liquid to solid feeding in the first three months of life. In numerous trials, Digestarom® improved feed intake and gut performance resulting in better weight gains.