DARD Management Notes: Beef and sheep

With calving imminent on many farms the breeding season is out of sight and mind, but February is an ideal time to purchase a stock bull if needed for the season. Buying a bull now allows plenty of time for the bull to adapt to new surroundings and diets before the breeding season. The majority of breed societies will have sales with a good selection of bulls to choose from.

Every farmer has their own opinion on the visual appearance of a bull. The bull also needs to have good feet, legs, functionality, growth, fleshing and be true to breed character. It is also important to consider Estimated Breeding Values (EBVs); to get a bull that ticks all the boxes is rare and more than likely will be very expensive so try to focus on the specific use of the bull. (See table)

In all instances bulls who go ‘against the grain’ or so called ‘curvebenders’ with both ease of calving and high growth rate traits should be sought.

Accuracy (%) is based on the amount of performance information available on the animal and its close relatives, particularly the number of progeny analysed. Accuracy is also based on the heritability of the trait and genetic relationships (correlations) with other recorded traits. Accuracy therefore indicates the ‘confidence level ‘of the EBV. The higher the accuracy value the lower the likelihood of change in the animal’s EBV as more information is analysed for that animal or its relatives. Even though an EBV with a low accuracy may change in the future, it is still the best estimate of an animal’s genetic merit for that trait.

SHEEP

Late pregnancy feeding

With six weeks pregnancy remaining 70-75 per cent of foetal growth has still to take place. The effect of rumen restriction and constrained intake is well documented in sheep and therefore it is not a time for low quality feedstuffs. Any feed plan should start with forage analysis as variations can be great. The difference in recommended additional feeding between recently tested first cut silage and second cut silage was over 300 grams per head per day, proving the importance of forage analysis. The quality of forage can also vary greatly from one year to another.

The ME level of a concentrate should be 12.5 MJ per kilogramme dry matter at minimum. Lower energy content is not appropriate as higher feed rates will be needed which may compromise forage intake. ME levels are rarely declared on a feed label so it is important to check this with the supplier. Protein is declared and a level of 18 per cent crude protein is desirable. The breakdown of effective rumen degradable and digestible undegradable protein (DUP) may not be on the label either but this needs consideration. It is important to supply DUP in late pregnancy as microbial protein alone will not meet the ewe’s demands, especially in ewes carrying multiple lambs. Hipro soya is the best source of DUP supplying 130 g per kilogramme. Rapeseed meal, peas and beans also supply DUP but at lower levels than soya. Most suppliers include a protein source supplying DUP in pregnant ewe meal.