Growth performance and economic impact of Simmental fattening bulls fed dry or corn silage-based total mixed rations.

Bull-fattening diets in Europe and most developed countries around the world have traditionally been based on corn silage, starch-rich, and high-energy/ high-protein supplemental feeds. The impact of climate change on crop yields feed availability, and price volatility, requires new and adapted feeding strategies, including for fattening bulls. Therefore, the objective of this study was to compare the growth performance and economic impact of a representative, conventional corn silage-based (CONVL) total mixed ration, and a dry (DRY) total mixed ration (TMR) fed to Simmental bulls. For nine months (272 days), 24 bulls (215 ± 10 kg BW) were randomly assigned to one of two TMR feeding groups (n = 12 per group). The DRY-TMR was primarily characterised by the nutrient fibre source, exclusively based on straw and other by-products. The diets were formulated and balanced based on the Cornell Net Carbohydrate and Protein System. After 272 days of fattening, bulls were slaughtered. Feed intake, average daily gain (ADG)/DM intake (DMI) ratio, and nutrient intake were affected by treatment, time, and their interaction (P < 0.05). The treatment affected neither acid detergent lignin intake nor starch intake. Compared with CONVL bulls, animals fed DRY-TMR consumed more non-fibre carbohydrates and rumen undegradable neutral detergent fibre, showing lesser dry and fresh matter intake and less metabolisable energy and physically effective neutral detergent fibre intake. Despite differences in nutrient intake (P < 0.05), particle size distribution between the two diets and growth performance were not different (P = 0.45). Simmental bulls in both treatment groups reached target weight in a shorter time due to high ADG of 1.87 kg (DRY-TMR) and 1.84 kg (CONVL). Both treatments achieved a positive profit margin (598 ± 28 €/bull). While total income per bull and dressing percentage did not differ between treatments, the substantially higher feed costs (P < 0.01) of the DRY-TMR resulted in a higher (P = 0.04) income over feed cost in favour of the CONVL treatment group. Despite the higher feed cost of DRY compared with CONVL diets, the better ADG/DMI ratio (P < 0.01) of DRY-TMR contributed to lower absolute feed quantity requirements during the fattening period. Due to the positive profit margin and high ADG results, DRY-TMR solutions for fattening bulls based on straw and by-products can be considered a promising alternative feeding strategy.

Genetic aspects for the behaviour of lactating sows towards humans.

With the keeping of lactating sows in loose housing systems, ensuring work safety for stockpersons is gaining importance. Aim of the present study was to develop tests characterising the behaviour of lactating sows in farrowing environments with more freedom to move. The behaviour towards humans in different management procedures was examined. Emphasis was given to integrate tests into daily routines. The study was conducted in a nucleus herd with 771 purebred Landrace sows. Data were collected from October 2016 until December 2018. Sows were kept in individual indoor pens with movable farrowing crates in which the animals were restrained from 7 days antepartum (ap) to an average of 7 days postpartum (pp). The Dummy Arm Test (DAT; 1444 observations) was used to assess the sows' reaction towards a stockperson handling the piglets around day 4 pp (closed crates). With the Towel Test (TT; 2846 observations), the reaction of sows to a novel object and an unexpected situation was assessed. The Trough Cleaning Test (TCT; 2805 observations) described the sows' response to common procedures such as trough cleaning. TT and TCT were conducted on days 3 pp (closed crates) and 10 pp (open crates). Variance components of behavioural traits were estimated univariately with a linear animal model, and genetic correlations between traits were derived using a multivariate animal model in ASreml 3.0. Most sows showed no or only a slight reaction to human interactions without attempting to attack them. However, a strong defensive reaction of sows was recorded in 4.0% (TCT), 4.5% (TT), and 10.7% (DAT) of observations. This behaviour of sows was observed more frequently in the open than in the closed pen system. Estimates of heritabilities (h2 ± SE) were h2 = 0.17 ± 0.05 for behaviour of sows towards humans (DAT), h2 = 0.19 ± 0.04 for response of sows towards unexpected situations (TT), and h2 = 0.13 ± 0.04 for reactions of animals to TCT. Genetic correlations (rg ± SE) ranged from rg = 0.59 ± 0.37 between TT and TCT to rg = 0.77 ± 0.30 between TT and DAT. Our results show that the developed tests are suitable for assessing the behaviour of sows towards humans. Behavioural traits derived from these tests could be used as new phenotypes for the genetic selection of gentle and easy-to-handle sows. The genetic correlations of all tests studied were positive indicating related reaction patterns.