Ultrasonography to investigate the effect of supplementing whole milk with complex carbohydrates and specific amino acids on curd retention in the abomasum of dairy calves

Abstract

AIM: To determine whether the retention time of curd in the abomasum of calves was influenced by supplementing milk with a plant-derived carbohydrate and amino acid supplement, evaluated non-invasively using ultrasonography.

METHODS: Female dairy calves aged between 2–6 days of age were sourced from a commercial farm in March 2013. All calves were fed whole milk until weaning (4 L per day); 21 calves were supplemented with a probiotic until 18 days of age, and thereafter with a plant-derived complex carbohydrate and amino acid supplement until weaning, and 22 calves were just fed whole milk. Treatment groups were balanced for age, weight and breed. At 9–14, 24–29 and 52–57 days of age, the abomasum of each calf was examined using ultrasonography immediately before and after feeding, 1 and 2 hours after feeding, and then at 30 minute intervals until curd was no longer visible in the abomasum. Abomasal volume and curd size were recorded to assess retention time of curd in the abomasum.

RESULTS: At 9–14 days of age, mean retention time of curd in the abomasum was similar (4.6 hours) in both groups. At 24–29 days of age, when the supplemented calves had been receiving the supplement for approximately 10 days, mean curd retention time was longer by 1.4 (SE 0.28) hours in supplemented compared with unsupplemented calves (p<0.001). At 52–57 days of age, mean retention time was longer by 0.7 (SE 0.34) hours compared to unsupplemented calves (p=0.05).

CONCLUSION: Using ultrasonography, changes in abomasal content could be followed non-invasively over time and it was demonstrated that the plant-derived complex carbohydrate supplement increased the curd retention time in the abomasum. We speculate that the increased retention time enables an increased availability of nutrients following a more complete digestion of milk, thereby improving animal performance.

KEY WORDS:

• Ultrasonography
• curd
• retention time
• milk
• carbohydrate
• amino acid diet supplement
• dairy calves

Acknowledgements

The authors gratefully acknowledge: the financial support, supply of supplements and the automated feeder and technical support (Greg Pennell) from Bell-Booth Ltd; Wymond Symes (Catalyst Ltd) for his support throughout the development, planning and execution of the project; John Poole for allowing the use of his calves in this trial and for the supply of milk when a drought caused the research farm cows to dry-off earlier than expected; and the Tokanui Research Farm staff and science staff from AgResearch who have contributed significantly to the success of the project. The authors also express their gratitude to the AgResearch internal reviewers.

ORCIDK Singh http://orcid.org/0000-0003-0471-6121

Notes

1 J. Margerison, University of Nottingham, Nottingham, UK.