Hillsborough Seminar Examined Sow Dietary Management

8 November 2012, at 11:48am

NORTHERN IRELAND, UK - Strategies to manage sow lactation feed intake to maximise litter performance and the ability to reduce feed costs through dietary factors were key points of discussion at a recent ‘Pig Seminar to Improve Sustainability’.

The seminar was organised by and held at the Agri-Food and Biosciences Institute (AFBI) Hillsborough, with lunch being sponsored by the Ulster Pork and Bacon Forum. Representatives from the pig industry in Northern Ireland and further afield received much information with regard to recent advances in pig research from scientists working at AFBI, Teagasc and Queen’s University Belfast.

Dr Elizabeth Magowan and Dr Elizabeth Ball (AFBI) presented findings from a recent PhD programme of research focusing on sow nutrition which was conducted by Dr Peter Cottney. The first paper presented the effect of oestrus number (heat number) when gilts are first served on their lifetime performance. The main finding from this study was that optimal lifetime performance was attained when gilts were served in their third standing oestrus.

The second paper presented in this area reported the results of studies investigating sow nutrition in late gestation and lactation on litter performance. With regard to nutrition in late gestation, the few studies that are reported in the literature using sows carrying large litters of low average birth weight found beneficial effects on litter birth weight when feed levels in late gestation were increased. However, the study undertaken at AFBI, also found that offering a high plane of nutrition in late gestation (over 42MJ digestible energy and 22g lysine per day from day 85 of gestation) reduced feed intake during lactation. With regard to the lactation diet, it was found that, offering sows a diet with an increased level of energy and amino acids can improve litter performance but effects are less pronounced when lactation feed intake is high. Overall, more research is required to understand the nutritional requirements of the modern, highly prolific sow.

Dr Peadar Lawlor (Teagasc) presented a paper which summarised results from a number of studies which manipulated the liquid feeding curves of sows with the aim of increasing lactation feed intake. The three approaches investigated included:

  • Increasing a commonly used liquid feeding curve by 15 per cent and 32 per cent;
  • Supplementing liquid feed with an additional allocation of dry feed; and
  • ad libitum dry feeding.

Of the liquid feeding curves examined, the standard feed curve increased by 15 per cent was found to be optimal, as it maximised both sow and litter performance and was associated with a low level of feed wastage. Supplementing a liquid feed curve with dry feed increased lactation feed intake and pre-weaning litter weight gain but did so at an unacceptable level of feed wastage. Ad libitum dry feeding resulted in a low level of feed wastage and reduced weight loss and back-fat depth loss in sows during lactation compared to the standard liquid feeding curve. Regression analysis showed that feed intake during week two of lactation was particularly important in predicting sow weight and back-fat depth change during lactation. An additional 1 MJ DE/day in intake during week two was associated with a reduced weight loss during lactation of 0.33 kg and reduced back-fat depth loss of 0.05 mm during lactation.

Dr Niamh O’Connell (QUB) reported the results from two studies that had been performed collaboratively between University College Dublin, Teagasc and Queens University Belfast. The studies focused on recording the prevalence of different welfare-related lesions in slaughter pigs, and the relationship between these lesions and carcass condemnations. The first study assessed tail biting injuries and carcass condemnations in a study population of over 35,000 pigs. This research was conducted across two abattoirs in Northern Ireland and 3 in the Republic of Ireland. There were significant differences between abattoirs and jurisdictions in the levels of tail injures and types of carcass condemnations. The second study, conducted in an abattoir in the Republic of Ireland, involved a detailed investigation into the prevalence of different welfare-related conditions, and also the link between these conditions and carcass condemnation. The research highlighted significant links between welfare lesions, such as bitten tails, and carcass condemnations, and suggested that the cost of carcass condemnations was €0.78 per pig to producers.

Mr Joe Black, a PhD student at QUB, under the supervision of Dr Angela Mousley and Dr Nikki Marks (QUB), presented results from his PhD study which investigated the prevalence and control of endoparasites on pig farms across Northern Ireland. His study found that many of the management strategies employed by pig producers in Northern Ireland are similar to those adopted in other intensive pig farming countries. Furthermore, management strategies employed are believed to contribute to a reduction in worm burden. These strategies include early weaning (28 days of age), low sow confinement, installation of slatted floored accommodation, the adoption of regular disinfection in conjunction with the ‘All in, All out’ approach, and the use of anthelmintic treatment. Ninety percent of pig producers adopted a prophylactic approach to worming where the sow herd was the most commonly treated. The evaluation of drug efficacy is not routine on Northern Ireland pig farms however nearly half of the producers surveyed had access to liverspot data obtained from abattoir. Overall this study provides a snapshot of the current situation with respect to parasite incidence and control in modern pig production units in Northern Ireland, which all strive for economic stability. The interplay between management regime and parasite incidence will ultimately influence policy optimisation.

Dr Elizabeth Ball (AFBI) reported the results from a large study investigating finishing pig performance and diet digestibility using feed in meal or pellet form which had a fine or coarse particle size profile. Pelleting improved feed conversion ratio mainly as a result of a reduction in feed wastage but also through improved nutrient digestibility and dietary digestible energy content. Offering diets with a fine particle size profile also improved feed conversion ratio and nutrient digestibility. The beneficial effects of pelleting and particle size were cumulative. The improvement in feed conversion ratio due to offering pellets compared with meal equated to 32.66 per finishing pig difference in profitability. Overall, a difference in profitability of 34.46 per finishing pig was observed when ‘fine pellets’ were offered compared with ‘coarse meal’ (assuming cost of feed was same for all diets). Finally, in order for the same profit to be gained from meal diets, the price differential between meal and pellets needed to be at least 322.42 per t (based on current diet costs).

The final paper was presented by Dr Elizabeth Magowan (AFBI) and it summarised results from a number of studies which aimed to make maximum use of the energy and protein in pig diets. The first series of studies in this paper compared pig performance when diets contained mainly cereals or co-products. The use of co-products reduced feed costs but compromised pig performance. However, the inclusion of oil to co-product based diets (1.9 – 3.8 per cent) improved pig performance and reduced the feed cost per kg of carcass gain to similar levels attained when cereal based diets were offered. With regard to optimizing the protein content of the diet it was concluded that the adoption of a two phase feeding regime for finisher pigs was not straightforward and a number of unknown factors required investigation before adoption could be advised. The cost per kg of live weight gain was found to be similar when a diet containing 0.95 per cent total lysine and 18 per cent crude protein (CP) was used compared with a two phase regime using a diet containing 0.95 per cent total lysine and 18 per cent CP reduced to a diet containing 0.8 per cent total lysine and 16.7 per cent CP. However, a separate study suggested that significant feed cost savings could be made by lowering the CP content of the diet, with no detrimental effect on pig performance from 40kg, to between 15.0 and 17.5 per cent providing that the diet contained ‘ideal protein’ and the level of total lysine did not fall below 0.95 per cent. With regard to taking pigs to heavy carcass weights the final study reported in this paper concluded that taking the slow growing pigs in a batch to heavy carcass weights (over 90 kg) was not profitable. This practice is likely only profitable for the fastest growing pigs in the batch.

The full papers of the studies summarised above were presented to attendees in a proceedings booklet. The publication of this booklet was funded through DARD’s Evidence and Innovation research programme (specifically project 11/1/08, Factors to improve the feed efficiency of pigs). Copies of the proceedings can be attained by contacting AFBI, Hillsborough (028 92682484 or [email protected]).

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