Effects of additional organic micro-minerals and methionine on carcass composition, gait score, bone characteristics, and osteochondrosis in replacement gilts of different growth rate

Welfare of pigs on farm

This scientific opinion focuses on the welfare of pigs on farm, and is based on literature and expert opinion. All pig categories were assessed: gilts and dry sows, farrowing and lactating sows, suckling piglets, weaners, rearing pigs and boars. The most relevant husbandry systems used in Europe are described. For each system, highly relevant welfare consequences were identified, as well as related animal-based measures (ABMs), and hazards leading to the welfare consequences. Moreover, measures to prevent or correct the hazards and/or mitigate the welfare consequences are recommended. Recommendations are also provided on quantitative or qualitative criteria to answer specific questions on the welfare of pigs related to tail biting and related to the European Citizen's Initiative 'End the Cage Age'. For example, the AHAW Panel recommends how to mitigate group stress when dry sows and gilts are grouped immediately after weaning or in early pregnancy. Results of a comparative qualitative assessment suggested that long-stemmed or long-cut straw, hay or haylage is the most suitable material for nest-building. A period of time will be needed for staff and animals to adapt to housing lactating sows and their piglets in farrowing pens (as opposed to crates) before achieving stable welfare outcomes. The panel recommends a minimum available space to the lactating sow to ensure piglet welfare (measured by live-born piglet mortality). Among the main risk factors for tail biting are space allowance, types of flooring, air quality, health status and diet composition, while weaning age was not associated directly with tail biting in later life. The relationship between the availability of space and growth rate, lying behaviour and tail biting in rearing pigs is quantified and presented. Finally, the panel suggests a set of ABMs to use at slaughter for monitoring on-farm welfare of cull sows and rearing pigs.

Gilt rearing impacts on sow performance and longevity – a review

Lifetime performance and longevity are very important parameters of profitability in sow breeding. Opportunity to improve lifetime performance and longevity may be found in the rearing period and preparation of gilts for their future reproductive role. With the aim to prevent premature culling, it is possible to influence body condition, limb condition, mammary gland development, and proper function of the reproductive tract through nutrition, technology, and rearing strategies. Nutrition plays a very important role, as it can affect all the basic requirements for achieving satisfactory gilt performance. Selecting the most effective rearing strategy can be difficult because there are many factors affecting performance and longevity. The aim of this literature review is to provide up-to-date information on how sow longevity and performance can be influenced through choice of gilt rearing strategies and the important area of nutrition.

Effects of Exogenous 6-Phytase (EC 3.1.3.26) Supplementation on Performance, Calcium and Phosphorous Digestibility, and Bone Mineralisation and Density in Weaned Piglets

Simple Summary

Supplementation with a low dose (up to 500 FTU/kg feed) of a new 6-phytase, obtained by assembling gene sequences of various phytase-producing bacteria, increases phosphorous and calcium availability in phosphorus-limiting piglet diets. Therefore, this phytase can be used to reduce the use of unsustainable sources of inorganic phosphorous without compromising piglets’ performance and bone mineralization and density, and the higher phosphorous utilization will also reduce its excretion to the environment. This study also demonstrates that the effects of phytase on bone density can be evaluated using computed tomography, which may be useful for studies with live animals.

Abstract

Phosphorus (P) is an essential mineral for growing piglets, which is poorly accessible in vegetable feedstuffs as it is stored as phytates. Thus, phytase supplementation is essential to increase P availability. Two experiments were conducted to evaluate a novel 6-phytase (EC 3.1.3.26) in weaned pigs fed low-P diets. In each experiment, one hundred and twenty piglets were fed a positive control (PC; adequate in Ca and P), a negative control (NC; limiting in Ca and P), or NC supplemented with 125, 250, or 500 FTU/kg of phytase (NC125, NC250, and NC500, respectively). P content was lower in diets of Experiment 1 than diets of Experiment 2. In Experiment 1, piglets offered PC or phytase diets had higher growth and efficiency compared with NC diets. In Experiment 2, similar effects were obtained, but the effects were less significant. In both experiments, P and Ca ATTD and bone density were significantly increased with phytase supplementation. Moreover, PC and NC500 had higher P concentrations and lower alkaline phosphatase activity in plasma than NC. To conclude, supplementation with the new 6-phytase at doses up to 500 FTU/kg enhanced P utilization, growth performance, and bone density in piglets fed P-limiting diets.

Associations among individual gilt birth weight, litter birth weight phenotype, and the efficiency of replacement gilt production

Selection for larger litter size has increased the number of low individual birth weight (BWi) pigs and produced sows with a repeatable low average litter birth weight phenotype (BWP). Using an average of 3.6 litters records per sow, BWP was established in 644 nucleus-multiplication sows producing replacement gilts in a large commercial operation and classified as low (L-BWP, <1.18 kg, n = 85), medium (M-BWP, ≥1.18 to ≤1.35 kg, n = 250), or high (H-BWP, >1.35 kg, n = 309) on the basis of a BWi of 1.18 kg below which there was a high risk of early mortality and the average BWi (1.35 kg) for the population. In subsequent litters, potential replacement gilts born to these sows (n = 7,341) received a unique identification tag that allowed the impact of BWi, BWP, and their interactions on the efficiency of replacement gilt production to be evaluated. Negative effects of BWi on mortality until day 4 after birth were confirmed (P < 0.05) and cumulative losses to weaning, to day 70 of age, and to final pre-selection at 165 d of age were affected (P ≤ 0.05) by the interaction between BWP and BWi. Among the 2,035 gilts for which records for selection efficiency and production to fourth parity were available, a lower BWi decreased the probability of gilts reaching pubertal estrus (P < 0.05) after 21 and 28 d of boar stimulation starting at 180 d of age, with no effect of BWP. Overall, neither BWi, BWP, nor their interaction affected age at puberty. After breeding, only the main effect of BWP affected productivity and retention in the sow herd. In parities 1 and 2, percent stillborn was higher in litters born to gilts from H-BWP compared with L-BWP dams (P < 0.05), and in parity 2, total born and born alive were lower in sows derived from H-BWP compared with other BWPs. There were no differences in retention based on BWP classes until parity 2, after which retention tended (P ≤ 0.09) to be lower in sows derived from H-BWP compared with L-BWP dams. These results provide evidence that sow BWP is an important factor in the overall efficiency of replacement gilt management. This study also confirms that effective gilt selection and pre-breeding management protocols support excellent sow lifetime productivity and mitigate the risk of a high BWP in the litter of origin affecting retention in the breeding herd.

Effects of supplementing organic microminerals and methionine with or without limiting growth during the rearing phase of replacement gilts on lameness, growth, and body composition

Previous research suggested that lameness in growing pigs could be reduced using feeding strategies, such as limiting growth rate and supplementing trace minerals (TM) and (or) methionine (Met). The present study evaluates effects of 1) TM and Met and 2) limiting total lysine (Lys) during the rearing phase (90 d) of gilts (as a means to limit growth rate) on lameness, performance, and sow claw health and productivity (to first parity). Gilts (n = 240; 58.0 ± 11.1 kg body weight [BW]) were blocked, distributed into pens of 10 gilts, and pens were allocated to a 2 × 2 factorial arrangement. Factors were: 1) control or TM plus Met, which provided additional 10, 20, and 50 mg/kg of chelated copper, manganese, and zinc, respectively (0.1%, Aplomotec Plus, Tecnología & Vitaminas, S.L.; Alforja, Spain), and a 1.01 Met:Lys ratio and 2) standard Lys was formulated to meet growth requirements or low Lys to 19% below growth requirements. Feeding was provided through two phases, first between 119 and 163 d of age (phase I) and the second between 163 and 209 d of age (phase II). Diets had 2.43 and 2.31 Mcal net energy/kg for phases I and II, respectively, and were offered ad libitum. Low Lys did not affect feed intake but rather reduced average daily gain (ADG) by 6.35% and the final BW by 3.80% compared with standard Lys (P < 0.001). Low Lys reduced ADG (P < 0.001) and gain:feed (P = 0.012) during phase I but not during phase II. Lameness prevalence was 7.92% during rearing and increased with time (P < 0.001). Final BW (151 kg) and ADG (989 g) were similar (P > 0.05) whether gilts displayed lameness or not. Lameness was low in severity and not affected by dietary factors. However, TM- plus Met-fed gilts were 19.2 kg heavier (P = 0.016) than were control at lameness detection. On the sow farm, there was no evidence for differences in lameness or claw lesions among previous dietary treatments. In conclusion, lameness prevalence during the rearing phase was similar, independent of TM plus Met supplement, low Lys, or the interaction. Insufficient reduction of ADG and low severity in lameness may have limited the potential of dietary treatments. Moreover, a greater deficiency of Lys would be needed to achieve the degree of growth reduction previously reported to lessen lameness through feed restriction.