Calving difficulties (dystocia) contributes heavily to production losses in suckler herds. The obvious losses are due to calves or cows that die at or soon after calving. Studies from the USA have shown have that calves which experience difficult births are 4 times more likely to be born dead or die within the 1st 24 hours of birth compared to those born without difficulty.

Less noticeable losses that are due to calving difficulties include delayed return to heat, poorer conception rates and subsequent higher barren rates and extended calving patterns. Labour and vet and med cost also escalate the more problems you have. While occasional calving problems are almost unavoidable, minimising dystocia by careful management and selection of genetics will obviously improve calf survival rates and the profitability of your herd.

Many factors influence the incidence of dystocia, but broadly they can be spit into two groups.

• Calf Birth Weight
• Breed and genetics of Sire
• Position and presentation in the uterus

• Cow’s Pelvic Area
• Age and Breed of Cow
• Nutrition and Condition

Genetics – Estimated Breeding Values

Genetic solutions are not straight forward as the heritable of calving ease is fairly low as it is influenced by management, feeding and season of calving, hence it can be hard to predict in an individual animal. It can be improved by comparing information from different sources. These sources include the animals own records for calving ease, its contemporaries in the same herd, those of relatives in other herds and also the animals and relatives genetic merit for other recorded traits (e.g. birth weights, 200 day weight, 400 day weight, gestation length, muscle score and muscle depth.) This will improve the accuracy of the animals calving ease EBV and birth weight EBV which then can be used as tools in reducing the incidence of dystocia along with other physical performance traits to maximise the productivity of your herd.

Recommendations for Reducing Dystocia

• Mate bulling heifers and small cows to bulls that will sire small calves.
• Consider the breed, estimated birth weight variation, actual birth weight, calving ease and physical structure of the bull.
• Aim to calve heifers down at 85% of their expected mature weight.
• Monitor body condition score and target spring calving cows to be in BCS 2-2.5 at calving, autumn calving cows to be in BCS 3.
• Don’t try to limit feed prior to calving. It will reduce birth weights, but as it will limit cow nutrition it can actually increase calving problems as underfed cows will struggle to progress through a normal calving despite having a lighter calf. Additional as underfed cows will take longer to return to heat this practice is not recommended.
• Consider measuring pelvic area in replacement heifers and culling those that are too small if your herd has had problems. Target pelvic area sizes will vary from one breed to the next. As a rule of thumb heifers of medium sized breeds should have pelvises of at least 160 cm² at breeding, larger breeds 180 cm² or more.
• Don’t retain daughters of cows that have a record of calving difficulties.
• Aim to calve heifers 21-30 days prior to the planned start of calving for cows. It will allow more observation of heifers and allow them an extra period to resume cycling prior to bulling.
• Feeding the herd later in the day will encourage more cows to calve in daylight.
• Keep a record of calving ease for calves you observe born. If this changes over time consider reasons for this.
• When assisting cows at calving. Provide adequate time for a cow or heifer to calve prior to interfering. Don’t rush in.
• House assisted calves for a few days post calving. Studies have shown that this improves their chance of survival than if left outdoors in the immediate period post calving. If housing is limited these should be top priorities.